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Definition of HAI and Criteria
For Specific Types of Infections

CDC/NHSN Surveillance Definition of Healthcare-Associated Infection
and Criteria for Specific Types of Infections in the Acute Care Setting
This chapter contains the CDC/NHSN surveillance definition of healthcare-associated
infection (HAI) and criteria for all specific types of HAI. These criteria include those for the
“Big Four” infection types (surgical site infection [SSI], pneumonia [PNEU], bloodstream
infection [BSI] and urinary tract infection [UTI]), outlined in earlier chapters of this manual,
as well as criteria for other types of HAI. Of particular importance, this chapter provides
further required criteria for the specific event types that constitute organ/space SSIs (e.g.,
mediastinitis [MED] that may follow a coronary artery bypass graft, intra-abdominal abscess
[IAB] after colon surgery). Additionally, it is necessary to refer to the criteria in this chapter
when determining whether a positive blood culture represents a primary BSI or is secondary
to a different type of HAI. A BSI that is identified as secondary to another site of infection
must meet one of the criteria of HAI detailed in this chapter. Secondary BSIs are not reported
as separate events in NHSN, nor can nor should they be associated with a central line.
NOTE: Some CDC/NHSN definitions and criteria have been updated since the article
contained in this chapter was published. In such cases, the updates to any
criteria which are no longer valid have been listed and the changes summarized
in the table below.
Section

Update

Document/Article
Page

1. UTI-Urinary Tract
Changed as of 1/1/2009. See
310
Infection:
Appendix, pages 17-27 through 17• SUTI- Symptomatic
30.
urinary tract infection
1) SUTI- criteria dependent on
• ASB- Asymptomatic
current, recent or no presence of
bacteriuria
indwelling urinary catheter and
age of patient.
2) ASB- removed as specific
infection type.
3) Specific infection type Asymptomatic bacteremic
urinary tract infection (ABUTI)
created.
2. Table 1. CDC/NHSN
major and specific types
of healthcare-associated
infections

June, 2011

1) ABUTI- Asymptomatic
bacteremic urinary tract
infection added as specific
infection type.
2) ASB- Asymptomatic

17-1

311

Section

Update

Document/Article
Page

bacteriuria removed as specific
infection type.
3. OUTI- Other infections
of the urinary tract
(kidney, ureter, bladder,
urethra, or tissue
surrounding the
retroperitoneal or
perinephric space):
• 3 d &e
• 4d&e
• Reporting instruction
4. BSI-Bloodstream
Infection: LCBILaboratory-confirmed
bloodstream infection
• Criterion #2
• Criterion #3

June, 2011

Removed (d) physician diagnosis of
specific infections and (e) physician’s
institution of appropriate therapy from
the criteria for OUTI for any age
patient.

312

Criterion 2 and 3: Change
314
terminology “common skin
contaminant” to “common
commensal”; exclude
Corynebacterium diphtheria from
Corynebacterium spp.;
Removed:
• “4. There are several issues to
consider when determining
sameness of organisms”
• Table 2. (Examples of how to
interpret the sameness of two
skin contaminant isolates by
comparing antimicrobial
susceptibilities)
• 4 b. If common skin
contaminant organisms from
the cultures are speciated but
no antibiograms are done or
they are done for only 1 of the
isolates, it is assumed that the
organisms are the same.
• 4 c. If the common skin
contaminants from the
cultures have antibiograms
that are different for 2 or more
antimicrobial agents, it is
assumed that the organisms
are not the same (see

17-2

Section

Update

examples in Table 3).
4 d. For the purpose of NHSN
antibiogram reporting, the category
interpretation of intermediate (I)
should not be used to distinguish
whether 2 organisms are the same.
Added:
Only genus and species identification
should be utilized to determine the
sameness of organisms. No additional
comparative methods should be used
(e.g., morphology or antibiograms)
because laboratory testing capabilities
and protocols may vary between
facilities. This will reduce reporting
variability, solely due to laboratory
practice, between facilities reporting
LCBIs meeting criterion 2. Report the
organism to the genus/species level
only once, and if antibiogram data are
available, report the results from the
most resistant panel.
Criterion 3 (for patient < 1 year of
age): Fever (>38°C, core) replaces
fever (>38°C, rectal).
Hypothermia(<36°C, core) replaces
hypothermia(<37°C, rectal).
REPORTING INSTRUCTIONS:
• Report organisms cultured from
blood as BSI – LCBI when no
other site of infection is evident.
• When there is a positive blood
culture and clinical signs or
symptoms of localized infection at
a vascular access site, but no other
infection can be found, the
infection is considered a primary
BSI.
• Purulent phlebitis confirmed with
a positive semiquantitative culture
of a catheter tip, but with either

June, 2011

17-3

Document/Article
Page

Section

Update

Document/Article
Page

negative or no blood culture is
considered a CVS-VASC, not a
BSI nor an SST-SKIN or ST
infection.
Occasionally a patient with both
peripheral and central IV lines
develops a primary bloodstream
infection (LCBI) that can clearly be
attributed to the peripheral line (e.g.,
pus at the insertion site and matching
pathogen from pus and blood). In this
situation, enter “Central Line = No” in
the NHSN application. You should,
however, include the patient’s central
line days in the summary denominator
count.
Removed CSEP as a CDC/NHSN
316
infection type as of 1/1/2010.
6. Skin and Soft Tissue
Added Instruction: Even if there are
324-325
Infection:
clinical signs or symptoms of
• Reporting
localized infection at a vascular access
instructions
site, but no other infection can be
found, the infection is considered a
primary BSI.
—Please review the identified sections for more details.—
5. CSEP- Clinical Sepsis-

June, 2011

17-4

CDC/NHSN surveillance definition
of health care–associated infection
and criteria for specific types of
infections in the acute care setting
Teresa C. Horan, MPH, Mary Andrus, RN, BA, CIC, and Margaret A. Dudeck, MPH
Atlanta, Georgia

BACKGROUND
Since 1988, the Centers for Disease Control and
Prevention (CDC) has published 2 articles in which nosocomial infection and criteria for specific types of nosocomial infection for surveillance purposes for use in
acute care settings have been defined.1,2 This document
replaces those articles, which are now considered obsolete, and uses the generic term ‘‘health care–associated
infection’’ or ‘‘HAI’’ instead of ‘‘nosocomial.’’ This document reflects the elimination of criterion 1 of clinical
sepsis (effective in National Healthcare Safety Network
[NHSN] facilities since January 2005) and criteria for laboratory–confirmed bloodstream infection (LCBI). Specifically for LCBI, criterion 2c and 3c, and 2b and 3b,
were removed effective in NHSN facilities since January
2005 and January 2008, respectively. The definition of
‘‘implant,’’ which is part of the surgical site infection
(SSI) criteria, has been slightly modified. No other infection criteria have been added, removed, or changed.
There are also notes throughout this document that
reflect changes in the use of surveillance criteria since
the implementation of NHSN. For example, the

From the National Healthcare Safety Network, Division of Healthcare
Quality Promotion, Centers for Disease Control and Prevention,
Atlanta, GA.
Address correspondence to Teresa C. Horan, MPH, Division of Healthcare Quality Promotion, Centers for Disease Control and Prevention,
Mailstop A24, 1600 Clifton Road, NE, Atlanta, GA 30333. E-mail:

population for which clinical sepsis is used has been restricted to patients #1 year old. Another example is that
incisional SSI descriptions have been expanded to specify whether an SSI affects the primary or a secondary incision following operative procedures in which more
than 1 incision is made. For additional information about
how these criteria are used for NHSN surveillance, refer
to the NHSN Manual: Patient Safety Component Protocol
available at the NHSN Web site (www.cdc.gov/ncidod/
dhqp/nhsn.html). Whenever revisions occur, they will
be published and made available at the NHSN Web site.

CDC/NHSN SURVEILLANCE DEFINITION OF
HEALTH CARE–ASSOCIATED INFECTION
For the purposes of NHSN surveillance in the acute
care setting, the CDC defines an HAI as a localized or
systemic condition resulting from an adverse reaction
to the presence of an infectious agent(s) or its toxin(s).
There must be no evidence that the infection was present or incubating at the time of admission to the acute
care setting.
HAIs may be caused by infectious agents from
endogenous or exogenous sources.
d

[email protected].

Am J Infect Control 2008;36:309-32.
0196-6553/$34.00
Copyright ª 2008 by the Association for Professionals in Infection
Control and Epidemiology, Inc.

Other important
following:
d

doi:10.1016/j.ajic.2008.03.002

Endogenous sources are body sites, such as the skin,
nose, mouth, gastrointestinal (GI) tract, or vagina
that are normally inhabited by microorganisms.
Exogenous sources are those external to the patient, such as patient care personnel, visitors, patient care equipment, medical devices, or the
health care environment.
considerations

include

the

Clinical evidence may be derived from direct observation of the infection site (eg, a wound) or
309

310

Vol. 36 No. 5

review of information in the patient chart or other
clinical records.
For certain types of infection, a physician or surgeon diagnosis of infection derived from direct observation during a surgical operation, endoscopic
examination, or other diagnostic studies or from
clinical judgment is an acceptable criterion for an
HAI, unless there is compelling evidence to the
contrary. For example, one of the criteria for SSI
is ‘‘surgeon or attending physician diagnosis.’’ Unless stated explicitly, physician diagnosis alone is
not an acceptable criterion for any specific type
of HAI.
Infections occurring in infants that result from
passage through the birth canal are considered
HAIs.
The following infections are not considered health
care associated:
s Infections associated with complications or extensions of infections already present on admission, unless a change in pathogen or
symptoms strongly suggests the acquisition of
a new infection;
s infections in infants that have been acquired
transplacentally (eg, herpes simplex, toxoplasmosis, rubella, cytomegalovirus, or syphilis)
and become evident #48 hours after birth; and
s reactivation of a latent infection (eg, herpes zoster [shingles], herpes simplex, syphilis, or
tuberculosis).
The following conditions are not infections:
s Colonization, which means the presence of microorganisms on skin, on mucous membranes,
in open wounds, or in excretions or secretions
but are not causing adverse clinical signs or
symptoms; and
s inflammation that results from tissue response
to injury or stimulation by noninfectious
agents, such as chemicals.

CRITERIA FOR SPECIFIC TYPES OF INFECTION
Once an infection is deemed to be health care associated according to the definition shown above, the specific type of infection should be determined based on
the criteria detailed below. These have been grouped
into 13 major type categories to facilitate data analysis.
For example, there are 3 specific types of urinary tract
infections (symptomatic urinary tract infection, asymptomatic bacteriuria, and other infections of the urinary
tract) that are grouped under the major type of Urinary
Tract Infection. The specific and major types of infection used in NHSN and their abbreviated codes are listed
in Table 1, and the criteria for each of the specific types
of infection follow it.

Horan, Andrus, and Dudeck

USE OF THESE CRITERIA FOR PUBLICLY
REPORTED HAI DATA
Not all infections or infection criteria may be appropriate for use in public reporting of HAIs. Guidance on
what infections and infection criteria are recommended is available from other sources (eg, HICPAC [http:
//www.cdc.gov/ncidod/dhqp/hicpac_pubs.html]; National
Quality Forum [http://www.qualityforum.org/]; professional organizations).

UTI-URINARY TRACT INFECTION
SUTI-Symptomatic urinary tract infection
A symptomatic urinary tract infection must meet
at least 1 of the following criteria:
1. Patient has at least 1 of the following signs or
symptoms with no other recognized cause: fever
(.388C), urgency, frequency, dysuria, or suprapubic tenderness
and
patient has a positive urine culture, that is, $105
microorganisms per cc of urine with no more
than 2 species of microorganisms.
2. Patient has at least 2 of the following signs or symptoms with no other recognized cause: fever
(.388C), urgency, frequency, dysuria, or suprapubic tenderness
and
at least 1 of the following
a. positive dipstick for leukocyte esterase and/
or nitrate
b. pyuria (urine specimen with $10 white
blood cell [WBC]/mm3 or $3 WBC/highpower field of unspun urine)
c. organisms seen on Gram’s stain of unspun
urine
d. at least 2 urine cultures with repeated
isolation of the same uropathogen (gramnegative bacteria or Staphylococcus saprophyticus) with $102 colonies/mL in nonvoided specimens
e. #105 colonies/mL of a single uropathogen
(gram-negative bacteria or S saprophyticus)
in a patient being treated with an effective
antimicrobial agent for a urinary tract
infection
f. physician diagnosis of a urinary tract
infection
g. physician institutes appropriate therapy for
a urinary tract infection.
3. Patient #1 year of age has at least 1 of the following signs or symptoms with no other recognized cause: fever (.388C rectal), hypothermia

Horan, Andrus, and Dudeck

June 2008

Table 1. CDC/NHSN major and specific types of health
care–associated infections
UTI

SSI

Urinary tract infection
SUTI
Symptomatic urinary
tract infection
ASB
Asymptomatic bacteriuria
OUTI
Other infections
of the urinary tract
Surgical site infection
SIP
Superficial incisional
primary SSI
SIS
Superficial incisional
secondary SSI
DIP
Deep incisional
primary SSI
DIS
Deep incisional
secondary SSI
Organ/space
Organ/space SSI. Indicate
specific type:
d

BONE

LUNG

BRST

MED

CARD

MEN

DISC

ORAL

EAR

OREP

EMET

OUTI

ENDO

EYE

SINU

GIT

IAB

VASC

VCUF

JNT

BSI

Bloodstream infection
LCBI
Laboratory-confirmed
bloodstream infection
CSEP
Clinical sepsis

PNEU

Pneumonia
PNU1
PNU2
PNU3

Table 1. Continued
EENT

Eye, ear, nose, throat, or mouth infection
CONJ
Conjunctivitis
EYE
Eye, other
than conjunctivitis
EAR
Ear, mastoid
ORAL
Oral cavity
(mouth, tongue, or gums)
SINU
Sinusitis
UR
Upper respiratory
tract, pharyngitis,
laryngitis, epiglottitis

Gastrointestinal system infection
GE
Gastroenteritis
GIT
Gastrointestinal (GI) tract
HEP
Hepatitis
IAB
Intraabdominal, not specified
elsewhere
NEC
Necrotizing enterocolitis

LRI

Lower respiratory tract infection, other
than pneumonia
BRON
Bronchitis, tracheobronchitis,
tracheitis, without
evidence of pneumonia
LUNG
Other infections
of the lower
respiratory tract

REPR

Reproductive tract infection
EMET
Endometritis
EPIS
Episiotomy
VCUF
Vaginal cuff
OREP
Other infections
of the male
or female reproductive
tract

SST

Skin and soft tissue infection
SKIN
Skin
ST
Soft tissue
DECU
Decubitus ulcer
BURN
Burn
BRST
Breast abscess
or mastitis
UMB
Omphalitis
PUST
Pustulosis
CIRC
Newborn circumcision

SYS

Systemic Infection
DI

Clinically defined pneumonia
Pneumonia with
specific laboratory findings
Pneumonia in
immunocompromised
patient

Bone and joint infection
BONE
Osteomyelitis
JNT
Joint or bursa
DISC
Disc space

CNS

Central nervous system
IC
Intracranial infection
MEN
Meningitis or ventriculitis
SA
Spinal abscess
without meningitis

CVS

Cardiovascular system infection
VASC
Arterial or venous infection
ENDO
Endocarditis
CARD
Myocarditis or pericarditis
MED
Mediastinitis
Continued

311

Disseminated infection

(,378C rectal), apnea, bradycardia, dysuria, lethargy, or vomiting
and
patient has a positive urine culture, that is, $105
microorganisms per cc of urine with no more
than two species of microorganisms.
4. Patient #1 year of age has at least 1 of the following signs or symptoms with no other recognized
cause: fever (.388C), hypothermia (,378C), apnea, bradycardia, dysuria, lethargy, or vomiting

312

and
at least 1 of the following:
a. positive dipstick for leukocyte esterase and/
or nitrate
b. pyuria (urine specimen with $10 WBC/mm3
or $3 WBC/high-power field of unspun
urine)
c. organisms seen on Gram’s stain of unspun
urine
d. at least 2 urine cultures with repeated
isolation of the same uropathogen (gramnegative bacteria or S saprophyticus)
with $102 colonies/mL in nonvoided
specimens
e. #105 colonies/mL of a single uropathogen
(gram-negative bacteria or S saprophyticus)
in a patient being treated with an effective
antimicrobial agent for a urinary tract
infection
f. physician diagnosis of a urinary tract
infection
g. physician institutes appropriate therapy for
a urinary tract infection.

ASB-Asymptomatic bacteriuria
An asymptomatic bacteriuria must meet at least 1 of
the following criteria:
1. Patient has had an indwelling urinary catheter
within 7 days before the culture
and
patient has a positive urine culture, that is, $105
microorganisms per cc of urine with no more
than 2 species of microorganisms
and
patient has no fever (.388C), urgency, frequency,
dysuria, or suprapubic tenderness.
2. Patient has not had an indwelling urinary catheter within 7 days before the first positive culture
and
patient has had at least 2 positive urine cultures,
that is, $105 microorganisms per cc of urine
with repeated isolation of the same microorganism and no more than 2 species of
microorganisms
and
patient has no fever (.388C), urgency, frequency,
dysuria, or suprapubic tenderness.

Comments
d

Horan, Andrus, and Dudeck

Vol. 36 No. 5

A positive culture of a urinary catheter tip is not an
acceptable laboratory test to diagnose a urinary
tract infection.

Urine cultures must be obtained using appropriate
technique, such as clean catch collection or
catheterization.
In infants, a urine culture should be obtained by
bladder catheterization or suprapubic aspiration;
a positive urine culture from a bag specimen is unreliable and should be confirmed by a specimen
aseptically obtained by catheterization or suprapubic aspiration.

OUTI-Other infections of the urinary tract
(kidney, ureter, bladder, urethra, or tissue
surrounding the retroperitoneal or perinephric
space)
Other infections of the urinary tract must meet at
least 1 of the following criteria:
1. Patient has organisms isolated from culture of
fluid (other than urine) or tissue from affected site.
2. Patient has an abscess or other evidence of infection seen on direct examination, during a surgical
operation, or during a histopathologic
examination.
3. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever
(.388C), localized pain, or localized tenderness at
the involved site
and
at least 1 of the following:
a. purulent drainage from affected site
b. organisms cultured from blood that are
compatible with suspected site of infection
c. radiographic evidence of infection (eg, abnormal ultrasound, computerized tomography [CT] scan, magnetic resonance imaging
[MRI], or radiolabel scan [gallium, technetium], etc)
d. physician diagnosis of infection of the
kidney, ureter, bladder, urethra, or tissues
surrounding the retroperitoneal or perinephric space
e. physician institutes appropriate therapy for
an infection of the kidney, ureter, bladder,
urethra, or tissues surrounding the retroperitoneal or perinephric space.
4. Patient #1 year of age has at least 1 of the following signs or symptoms with no other recognized
cause: fever (.388C rectal), hypothermia (,378C
rectal), apnea, bradycardia, lethargy, or vomiting
and
at least 1 of the following:
a. purulent drainage from affected site
b. organisms cultured from blood that are
compatible with suspected site of infection

Horan, Andrus, and Dudeck

c. radiographic evidence of infection (eg, abnormal ultrasound, CT scan, MRI, or radiolabel scan [gallium, technetium])
d. physician diagnosis of infection of the kidney, ureter, bladder, urethra, or tissues surrounding
the
retroperitoneal
or
perinephric space
e. physician institutes appropriate therapy for
an infection of the kidney, ureter, bladder,
urethra, or tissues surrounding the retroperitoneal or perinephric space.

June 2008

Reporting instructions
d

d
d

Reporting instruction
d

Report infections following circumcision in newborns as CIRC.

SSI-SURGICAL SITE INFECTION
SIP/SIS-Superficial incisional surgical site
infection
A superficial incisional SSI (SIP or SIS) must meet the
following criterion:
Infection occurs within 30 days after the operative
procedure
and
involves only skin and subcutaneous tissue of the
incision
and
patient has at least 1 of the following:
a. purulent drainage from the superficial incision
b. organisms isolated from an aseptically obtained
culture of fluid or tissue from the superficial
incision
c. at least 1 of the following signs or symptoms of
infection: pain or tenderness, localized swelling,
redness, or heat, and superficial incision is deliberately opened by surgeon and is culture positive
or not cultured. A culture-negative finding does
not meet this criterion.
d. diagnosis of superficial incisional SSI by the surgeon or attending physician.
There are 2 specific types of superficial incisional SSI:
d Superficial incisional primary (SIP): a superficial incisional SSI that is identified in the primary incision in a patient who has had an operation with
1 or more incisions (eg, C-section incision or chest
incision for coronary artery bypass graft with a donor site [CBGB]).
d Superficial incisional secondary (SIS): a superficial
incisional SSI that is identified in the secondary incision in a patient who has had an operation with
more than 1 incision (eg, donor site [leg] incision
for CBGB).

313

Do not report a stitch abscess (minimal inflammation and discharge confined to the points of suture
penetration) as an infection.
Do not report a localized stab wound infection as
SSI, instead report as skin (SKIN), or soft tissue
(ST), infection, depending on its depth.
Report infection of the circumcision site in newborns as CIRC. Circumcision is not an NHSN operative procedure.
Report infected burn wound as BURN.
If the incisional site infection involves or extends
into the fascial and muscle layers, report as a
deep incisional SSI.
Classify infection that involves both superficial
and deep incision sites as deep incisional SSI.

DIP/DIS-Deep incisional surgical site infection
A deep incisional SSI (DIP or DIS) must meet the following criterion:
Infection occurs within 30 days after the operative
procedure if no implant1 is left in place or within
1 year if implant is in place and the infection appears
to be related to the operative procedure
and
involves deep soft tissues (eg, fascial and muscle layers)
of the incision
and
patient has at least 1 of the following:
a. purulent drainage from the deep incision but not
from the organ/space component of the surgical
site
b. a deep incision spontaneously dehisces or is deliberately opened by a surgeon and is culture-positive or not cultured when the patient has at least
1 of the following signs or symptoms: fever
(.388C), or localized pain or tenderness. A culture-negative finding does not meet this criterion.
c. an abscess or other evidence of infection involving
the deep incision is found on direct examination,
during reoperation, or by histopathologic or radiologic examination
d. diagnosis of a deep incisional SSI by a surgeon or
attending physician.
There are 2 specific types of deep incisional SSI:
d

Deep incisional primary (DIP): a deep incisional SSI
that is identified in a primary incision in a patient

1
A nonhuman-derived object, material, or tissue (eg, prosthetic heart
valve, nonhuman vascular graft, mechanical heart, or hip prosthesis)
that is permanently placed in a patient during an operative procedure
and is not routinely manipulated for diagnostic or therapeutic purposes.

314

Horan, Andrus, and Dudeck

Vol. 36 No. 5

who has had an operation with one or more incisions (eg, C-section incision or chest incision for
CBGB); and
Deep incisional secondary (DIS): a deep incisional
SSI that is identified in the secondary incision in
a patient who has had an operation with more
than 1 incision (eg, donor site [leg] incision for
CBGB).

Reporting instruction
d

Classify infection that involves both superficial
and deep incision sites as deep incisional SSI.

Organ/space-Organ/space surgical site infection
An organ/space SSI involves any part of the body,
excluding the skin incision, fascia, or muscle layers,
that is opened or manipulated during the operative
procedure. Specific sites are assigned to organ/space
SSI to identify further the location of the infection.
Listed below in reporting instructions are the specific
sites that must be used to differentiate organ/space
SSI. An example is appendectomy with subsequent
subdiaphragmatic abscess, which would be reported
as an organ/space SSI at the intraabdominal specific
site (SSI-IAB).
An organ/space SSI must meet the following criterion:
Infection occurs within 30 days after the operative
procedure if no implant1 is left in place or within
1 year if implant is in place and the infection appears
to be related to the operative procedure
and
infection involves any part of the body, excluding the
skin incision, fascia, or muscle layers, that is opened
or manipulated during the operative procedure
and
patient has at least 1 of the following:
a. purulent drainage from a drain that is placed
through a stab wound into the organ/space
b. organisms isolated from an aseptically obtained
culture of fluid or tissue in the organ/space
c. an abscess or other evidence of infection involving the organ/space that is found on direct examination, during reoperation, or by histopathologic
or radiologic examination
d. diagnosis of an organ/space SSI by a surgeon or
attending physician.

Reporting instructions
d

Specific sites of organ/space SSI (see also criteria
for these sites)
s BONE
s BRST

s CARD
s DISC
s EAR
s EMET
s ENDO
s EYE
s GIT
s IAB
s IC
s JNT

s LUNG
s MED

s MEN
s ORAL
s OREP
s OUTI
s SA
s SINU
s UR
s VASC
s VCUF

Occasionally an organ/space infection drains
through the incision. Such infection generally
does not involve reoperation and is considered a
complication of the incision; therefore, classify it
as a deep incisional SSI.

BSI-BLOODSTREAM INFECTION
LCBI-Laboratory-confirmed bloodstream
infection
LCBI criteria 1 and 2 may be used for patients of any
age, including patients #1 year of age.
LCBI must meet at least 1 of the following criteria:
1. Patient has a recognized pathogen cultured from
1 or more blood cultures
and
organism cultured from blood is not related to an
infection at another site. (See Notes 1 and 2.)
2. Patient has at least 1 of the following signs or
symptoms: fever (.388C), chills, or hypotension
and
signs and symptoms and positive laboratory results are not related to an infection at another site
and
common skin contaminant (ie, diphtheroids
[Corynebacterium spp], Bacillus [not B anthracis]
spp, Propionibacterium spp, coagulase-negative
staphylococci [including S epidermidis], viridans
group streptococci, Aerococcus spp, Micrococcus
spp) is cultured from 2 or more blood cultures
drawn on separate occasions. (See Notes 3
and 4.)
3. Patient #1 year of age has at least 1 of the following signs or symptoms: fever (.388C, rectal), hypothermia (,378C, rectal), apnea, or bradycardia
and
signs and symptoms and positive laboratory results are not related to an infection at another site
and
common skin contaminant (ie, diphtheroids [Corynebacterium spp], Bacillus [not B
anthracis] spp, Propionibacterium spp, coagulasenegative staphylococci [including S epidermidis],
viridans group streptococci, Aerococcus spp, Micrococcus spp) is cultured from 2 or more blood

Horan, Andrus, and Dudeck

cultures drawn on separate occasions. (See Notes
3 and 4.)

Notes
1. In criterion 1, the phrase ‘‘1 or more blood cultures’’ means that at least 1 bottle from a blood
draw is reported by the laboratory as having
grown organisms (ie, is a positive blood culture).
2. In criterion 1, the term ‘‘recognized pathogen’’
does not include organisms considered common
skin contaminants (see criteria 2 and 3 for a list of
common skin contaminants). A few of the recognized pathogens are S aureus, Enterococcus spp, E
coli, Pseudomonas spp, Klebsiella spp, Candida
spp, and others.
3. In criteria 2 and 3, the phrase ‘‘2 or more blood cultures drawn on separate occasions’’ means (1) that
blood from at least 2 blood draws were collected
within 2 days of each other (eg, blood draws on
Monday and Tuesday or Monday and Wednesday
would be acceptable for blood cultures drawn on
separate occasions, but blood draws on Monday
and Thursday would be too far apart in time to
meet this criterion) and (2) that at least 1 bottle
from each blood draw is reported by the laboratory as having grown the same common skin contaminant organism (ie, is a positive blood culture).
(See Note 4 for determining sameness of
organisms.)
a. For example, an adult patient has blood
drawn at 8 AM and again at 8:15 AM of the
same day. Blood from each blood draw is inoculated into 2 bottles and incubated (4 bottles total). If 1 bottle from each blood draw
set is positive for coagulase-negative staphylococci, this part of the criterion is met.
b. For example, a neonate has blood drawn
for culture on Tuesday and again on Saturday, and both grow the same common
skin contaminant. Because the time between these blood cultures exceeds the
2-day period for blood draws stipulated
in criteria 2 and 3, this part of the criteria
is not met.
c. A blood culture may consist of a single bottle for a pediatric blood draw because of volume constraints. Therefore, to meet this
part of the criterion, each bottle from 2 or
more draws would have to be culture positive for the same skin contaminant.
4. There are several issues to consider when determining sameness of organisms.
a. If the common skin contaminant is identified to the species level from 1 culture,

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315

Table 2. Examples of ‘‘sameness’’ by organism speciation
Culture

Companion Culture

Report as.

S epidermidis

Coagulase-negative
staphylococci
B cereus
Strep viridans

S epidermidis

Bacillus spp (not anthracis)
S salivarius

B cereus
S salivarius

Table 3. Examples of ‘‘sameness’’ by organism
antibiogram
Organism Name

Isolate A

Isolate B

Interpret as.

S epidermidis
S epidermidis

All drugs S
OX R
CEFAZ R
PENG R
CIPRO S
All drugs S

All drugs S
OX S
CEFAZ S
PENG S
CIPRO R
All drugs S
except
ERYTH R

Same
Different

Corynebacterium spp
Strep viridans

Different
Same

S, sensitive; R, resistant.

and a companion culture is identified with
only a descriptive name (ie, to the genus
level), then it is assumed that the organisms
are the same. The speciated organism
should be reported as the infecting pathogen (see examples in Table 2).
b. If common skin contaminant organisms
from the cultures are speciated but no antibiograms are done or they are done for only
1 of the isolates, it is assumed that the organisms are the same.
c. If the common skin contaminants from the
cultures have antibiograms that are different for 2 or more antimicrobial agents, it is
assumed that the organisms are not the
same (see examples in Table 3).
d. For the purpose of NHSN antibiogram reporting, the category interpretation of intermediate (I) should not be used to distinguish
whether 2 organisms are the same.

Specimen collection considerations
Ideally, blood specimens for culture should be obtained from 2 to 4 blood draws from separate venipuncture sites (eg, right and left antecubital veins),
not through a vascular catheter. These blood draws
should be performed simultaneously or over a short
period of time (ie, within a few hours).3,4 If your facility
does not currently obtain specimens using this technique, you may still report BSIs using the criteria and
notes above, but you should work with appropriate
personnel to facilitate better specimen collection practices for blood cultures.

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Reporting instructions
d

Purulent phlebitis confirmed with a positive semiquantitative culture of a catheter tip, but with either negative or no blood culture is considered a
CVS-VASC, not a BSI.
Report organisms cultured from blood as BSI–LCBI
when no other site of infection is evident.

CSEP-CLINICAL SEPSIS
CSEP may be used only to report primary BSI in neonates and infants. It is not used to report BSI in adults
and children.
Clinical sepsis must meet the following criterion:
Patient #1 year of age has at least 1 of the following
clinical signs or symptoms with no other recognized
cause: fever (.388C rectal), hypothermia (,378C rectal), apnea, or bradycardia
and
blood culture not done or no organisms detected in
blood
and
no apparent infection at another site
and
physician institutes treatment for sepsis.

Reporting instruction
d

Report culture-positive infections of the bloodstream as BSI-LCBI.

PNEU-PNEUMONIA
See Appendix.

BJ–BONE AND JOINT INFECTION

c. radiographic evidence of infection (eg, abnormal findings on x-ray, CT scan, MRI, radiolabel scan [gallium, technetium, etc]).

Reporting instruction
d

Report mediastinitis following cardiac surgery
that is accompanied by osteomyelitis as SSI-MED
rather than SSI-BONE.

JNT-Joint or bursa
Joint or bursa infections must meet at least 1 of the
following criteria:
1. Patient has organisms cultured from joint fluid or
synovial biopsy.
2. Patient has evidence of joint or bursa infection
seen during a surgical operation or histopathologic examination.
3. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: joint
pain, swelling, tenderness, heat, evidence of effusion or limitation of motion
and
at least 1 of the following:
a. organisms and white blood cells seen on
Gram’s stain of joint fluid
b. positive antigen test on blood, urine, or joint
fluid
c. cellular profile and chemistries of joint fluid
compatible with infection and not explained by an underlying rheumatologic
disorder
d. radiographic evidence of infection (eg, abnormal findings on x-ray, CT scan, MRI, radiolabel scan [gallium, technetium, etc]).

BONE-Osteomyelitis
Osteomyelitis must meet at least 1 of the following
criteria:
1. Patient has organisms cultured from bone.
2. Patient has evidence of osteomyelitis on direct
examination of the bone during a surgical operation or histopathologic examination.
3. Patient has at least 2 of the following signs
or symptoms with no other recognized cause:
fever (.388C), localized swelling, tenderness,
heat, or drainage at suspected site of bone
infection
and
at least 1 of the following:
a. organisms cultured from blood
b. positive blood antigen test (eg, H influenzae,
S pneumoniae)

DISC-Disc space infection
Vertebral disc space infection must meet at least 1 of
the following criteria:
1. Patient has organisms cultured from vertebral
disc space tissue obtained during a surgical operation or needle aspiration.
2. Patient has evidence of vertebral disc space infection seen during a surgical operation or histopathologic examination.
3. Patient has fever (.388C) with no other recognized cause or pain at the involved vertebral
disc space
and
radiographic evidence of infection, (eg, abnormal
findings on x-ray, CT scan, MRI, radiolabel scan
[gallium, technetium, etc]).

Horan, Andrus, and Dudeck

June 2008

4. Patient has fever (.388C) with no other recognized cause and pain at the involved vertebral
disc space
and
positive antigen test on blood or urine (eg, H influenzae, S pneumoniae, N meningitidis, or Group B
Streptococcus).

b. positive antigen test on blood or urine
c. radiographic evidence of infection, (eg, abnormal findings on ultrasound, CT scan,
MRI, radionuclide brain scan, or arteriogram)
d. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for
pathogen
and
if diagnosis is made antemortem, physician institutes appropriate antimicrobial therapy.

CNS-CENTRAL NERVOUS SYSTEM INFECTION
IC-Intracranial infection (brain abscess,
subdural or epidural infection,
encephalitis)
Intracranial infection must meet at least 1 of the following criteria:
1. Patient has organisms cultured from brain tissue
or dura.
2. Patient has an abscess or evidence of intracranial
infection seen during a surgical operation or histopathologic examination.
3. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: headache, dizziness, fever (.388C), localizing neurologic signs, changing level of consciousness, or
confusion
and
at least 1 of the following:
a. organisms seen on microscopic examination of brain or abscess tissue obtained by
needle aspiration or by biopsy during a surgical operation or autopsy
b. positive antigen test on blood or urine
c. radiographic evidence of infection, (eg, abnormal findings on ultrasound, CT scan,
MRI, radionuclide brain scan, or arteriogram)
d. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for pathogen
and
if diagnosis is made antemortem, physician institutes appropriate antimicrobial therapy.
4. Patient #1 year of age has at least 2 of the following signs or symptoms with no other recognized
cause: fever (.388C rectal), hypothermia (,378C
rectal), apnea, bradycardia, localizing neurologic
signs, or changing level of consciousness
and
at least 1 of the following:
a. organisms seen on microscopic examination of brain or abscess tissue obtained by
needle aspiration or by biopsy during a surgical operation or autopsy

317

Reporting instruction
d

If meningitis and a brain abscess are present together, report the infection as IC.

MEN-Meningitis or ventriculitis
Meningitis or ventriculitis must meet at least 1 of the
following criteria:
1. Patient has organisms cultured from cerebrospinal fluid (CSF).
2. Patient has at least 1 of the following signs or
symptoms with no other recognized cause: fever
(.388C), headache, stiff neck, meningeal signs,
cranial nerve signs, or irritability
and
at least 1 of the following:
a. increased white cells, elevated protein, and/
or decreased glucose in CSF
b. organisms seen on Gram’s stain of CSF
c. organisms cultured from blood
d. positive antigen test of CSF, blood, or urine
e. diagnostic single antibody titer (IgM) or 4-fold
increase in paired sera (IgG) for pathogen
and
if diagnosis is made antemortem, physician institutes appropriate antimicrobial therapy.
3. Patient #1 year of age has at least 1 of the
following signs or symptoms with no other recognized cause: fever (.388C rectal), hypothermia (,378C rectal), apnea, bradycardia, stiff
neck, meningeal signs, cranial nerve signs, or
irritability
and
at least 1 of the following:
a. positive CSF examination with increased
white cells, elevated protein, and/or decreased glucose
b. positive Gram’s stain of CSF
c. organisms cultured from blood
d. positive antigen test of CSF, blood, or urine
e. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for
pathogen

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Vol. 36 No. 5

and
if diagnosis is made antemortem, physician institutes appropriate antimicrobial therapy.
2.

Reporting instructions
d

d
d

Report meningitis in the newborn as health careassociated unless there is compelling evidence
indicating the meningitis was acquired
transplacentally.
Report CSF shunt infection as SSI-MEN if it occurs
#1 year of placement; if later or after manipulation/access of the shunt, report as CNS-MEN.
Report meningoencephalitis as MEN.
Report spinal abscess with meningitis as MEN.

SA-Spinal abscess without meningitis
An abscess of the spinal epidural or subdural space,
without involvement of the cerebrospinal fluid or adjacent bone structures, must meet at least 1 of the following criteria:
1. Patient has organisms cultured from abscess in
the spinal epidural or subdural space.
2. Patient has an abscess in the spinal epidural or
subdural space seen during a surgical operation
or at autopsy or evidence of an abscess seen during a histopathologic examination.
3. Patient has at least 1 of the following signs or
symptoms with no other recognized cause: fever
(.388C), back pain, focal tenderness, radiculitis,
paraparesis, or paraplegia
and
at least 1 of the following:
a. organisms cultured from blood
b. radiographic evidence of a spinal abscess
(eg, abnormal findings on myelography, ultrasound, CT scan, MRI, or other scans [gallium, technetium, etc]).
and
if diagnosis is made antemortem, physician institutes appropriate antimicrobial therapy.

Reporting instruction
d

Report spinal abscess with meningitis as MEN.

CVS-CARDIOVASCULAR SYSTEM INFECTION
VASC-Arterial or venous infection
Arterial or venous infection must meet at least 1 of
the following criteria:
1. Patient has organisms cultured from arteries or
veins removed during a surgical operation

and
blood culture not done or no organisms cultured
from blood.
Patient has evidence of arterial or venous infection seen during a surgical operation or histopathologic examination.
Patient has at least 1 of the following signs or
symptoms with no other recognized cause: fever
(.388C), pain, erythema, or heat at involved vascular site
and
more than 15 colonies cultured from intravascular cannula tip using semiquantitative culture
method
and
blood culture not done or no organisms cultured
from blood.
Patient has purulent drainage at involved vascular site
and
blood culture not done or no organisms cultured
from blood.
Patient #1 year of age has at least 1 of the following signs or symptoms with no other recognized
cause: fever (.388C rectal), hypothermia (,378C
rectal), apnea, bradycardia, lethargy, or pain, erythema, or heat at involved vascular site
and
more than 15 colonies cultured from intravascular cannula tip using semiquantitative culture
method
and
blood culture not done or no organisms cultured
from blood.

Reporting instructions
d

Report infections of an arteriovenous graft, shunt,
or fistula or intravascular cannulation site without
organisms cultured from blood as CVS-VASC.
Report intravascular infections with organisms
cultured from the blood as BSI-LCBI.

ENDO-Endocarditis
Endocarditis of a natural or prosthetic heart valve
must meet at least 1 of the following criteria:
1. Patient has organisms cultured from valve or
vegetation.
2. Patient has 2 or more of the following signs or
symptoms with no other recognized cause: fever
(.388C), new or changing murmur, embolic phenomena, skin manifestations (ie, petechiae, splinter hemorrhages, painful subcutaneous nodules),

Horan, Andrus, and Dudeck

congestive heart failure, or cardiac conduction
abnormality
and
at least 1 of the following:
a. organisms cultured from 2 or more blood
cultures
b. organisms seen on Gram’s stain of valve
when culture is negative or not done
c. valvular vegetation seen during a surgical
operation or autopsy
d. positive antigen test on blood or urine (eg, H
influenzae, S pneumoniae, N meningitidis, or
Group B Streptococcus)
e. evidence of new vegetation seen on
echocardiogram
and
if diagnosis is made antemortem, physician institutes appropriate antimicrobial therapy.
3. Patient #1 year of age has 2 or more of the following signs or symptoms with no other recognized
cause: fever (.388C rectal), hypothermia (,378C
rectal), apnea, bradycardia, new or changing murmur, embolic phenomena, skin manifestations
(ie, petechiae, splinter hemorrhages, painful subcutaneous nodules), congestive heart failure, or
cardiac conduction abnormality
and
at least 1 of the following:
a. organisms cultured from 2 or more blood
cultures
b. organisms seen on Gram’s stain of valve
when culture is negative or not done
c. valvular vegetation seen during a surgical
operation or autopsy
d. positive antigen test on blood or urine (eg, H
influenzae, S pneumoniae, N meningitidis, or
Group B Streptococcus)
e. evidence of new vegetation seen on
echocardiogram
and
if diagnosis is made antemortem, physician institutes appropriate antimicrobial therapy.

CARD-Myocarditis or pericarditis
Myocarditis or pericarditis must meet at least 1 of
the following criteria:
1. Patient has organisms cultured from pericardial
tissue or fluid obtained by needle aspiration or
during a surgical operation.
2. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever
(.388C), chest pain, paradoxical pulse, or increased heart size

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319

and
at least 1 of the following:
a. abnormal EKG consistent with myocarditis
or pericarditis
b. positive antigen test on blood (eg, H influenzae, S pneumoniae)
c. evidence of myocarditis or pericarditis on
histologic examination of heart tissue
d. 4-fold rise in type-specific antibody with or
without isolation of virus from pharynx or
feces
e. pericardial effusion identified by echocardiogram, CT scan, MRI, or angiography.
3. Patient #1 year of age has at least 2 of the following signs or symptoms with no other recognized
cause: fever (.388C rectal), hypothermia (,378C
rectal), apnea, bradycardia, paradoxical pulse, or
increased heart size
and
at least 1 of the following:
a. abnormal EKG consistent with myocarditis
or pericarditis
b. positive antigen test on blood (eg, H influenzae, S pneumoniae)
c. histologic examination of heart tissue shows
evidence of myocarditis or pericarditis
d. 4-fold rise in type-specific antibody with or
without isolation of virus from pharynx or
feces
e. pericardial effusion identified by echocardiogram, CT scan, MRI, or angiography.

Comment
d

Most cases of postcardiac surgery or postmyocardial infarction pericarditis are not infectious.

MED-Mediastinitis
Mediastinitis must meet at least 1 of the following
criteria:
1. Patient has organisms cultured from mediastinal
tissue or fluid obtained during a surgical operation or needle aspiration.
2. Patient has evidence of mediastinitis seen during a
surgical operation or histopathologic examination.
3. Patient has at least 1 of the following signs or
symptoms with no other recognized cause: fever
(.388C), chest pain, or sternal instability
and
at least 1 of the following:
a. purulent discharge from mediastinal area
b. organisms cultured from blood or discharge
from mediastinal area

320

c. mediastinal widening on x-ray.
4. Patient #1 year of age has at least 1 of the following signs or symptoms with no other recognized
cause: fever (.388C rectal), hypothermia (,378C
rectal), apnea, bradycardia, or sternal instability
and
at least 1 of the following:
a. purulent discharge from mediastinal area
b. organisms cultured from blood or discharge
from mediastinal area
c. mediastinal widening on x-ray.

Reporting instruction
d

Horan, Andrus, and Dudeck

Vol. 36 No. 5

Report mediastinitis following cardiac surgery
that is accompanied by osteomyelitis as SSI-MED
rather than SSI-BONE.

EYE-Eye, other than conjunctivitis
An infection of the eye, other than conjunctivitis,
must meet at least 1 of the following criteria:
1. Patient has organisms cultured from anterior or
posterior chamber or vitreous fluid.
2. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: eye
pain, visual disturbance, or hypopyon
and
at least 1 of the following:
a. physician diagnosis of an eye infection
b. positive antigen test on blood (eg, H influenzae, S pneumoniae)
c. organisms cultured from blood.

EAR-Ear mastoid
EENT-EYE, EAR, NOSE, THROAT, OR MOUTH
INFECTION
CONJ-Conjunctivitis
Conjunctivitis must meet at least 1 of the following
criteria:
1. Patient has pathogens cultured from purulent exudate obtained from the conjunctiva or contiguous tissues, such as eyelid, cornea, meibomian
glands, or lacrimal glands.
2. Patient has pain or redness of conjunctiva or
around eye
and
at least 1 of the following:
a. WBCs and organisms seen on Gram’s stain
of exudate
b. purulent exudate
c. positive antigen test (eg, ELISA or IF for Chlamydia trachomatis, herpes simplex virus,
adenovirus) on exudate or conjunctival
scraping
d. multinucleated giant cells seen on microscopic examination of conjunctival exudate
or scrapings
e. positive viral culture
f. diagnostic single antibody titer (IgM) or 4-fold
increase in paired sera (IgG) for pathogen.

Reporting instructions
d
d

Report other infections of the eye as EYE.
Do not report chemical conjunctivitis caused by
silver nitrate (AgNO3) as a health care–associated
infection.
Do not report conjunctivitis that occurs as a part of
a more widely disseminated viral illness (such as
measles, chickenpox, or a URI).

Ear and mastoid infections must meet at least 1 of
the following criteria:
Otitis externa must meet at least 1 of the following
criteria:
1. Patient has pathogens cultured from purulent
drainage from ear canal.
2. Patient has at least 1 of the following signs or
symptoms with no other recognized cause: fever
(.388C), pain, redness, or drainage from ear
canal
and
organisms seen on Gram’s stain of purulent
drainage.
Otitis media must meet at least 1 of the following
criteria:
1. Patient has organisms cultured from fluid from
middle ear obtained by tympanocentesis or at
surgical operation.
2. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever
(.388C), pain in the eardrum, inflammation, retraction or decreased mobility of eardrum, or
fluid behind eardrum.
Otitis interna must meet at least 1 of the following
criteria:
1. Patient has organisms cultured from fluid from
inner ear obtained at surgical operation.
2. Patient has a physician diagnosis of inner ear
infection.
Mastoiditis must meet at least 1 of the following
criteria:
1. Patient has organisms cultured from purulent
drainage from mastoid.

Horan, Andrus, and Dudeck

2. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever
(.388C), pain, tenderness, erythema, headache,
or facial paralysis
and
at least 1 of the following:
a. organisms seen on Gram’s stain of purulent
material from mastoid
b. positive antigen test on blood.

ORAL-Oral cavity (mouth, tongue, or gums)
Oral cavity infections must meet at least 1 of the following criteria:
1. Patient has organisms cultured from purulent
material from tissues of oral cavity.
2. Patient has an abscess or other evidence of oral
cavity infection seen on direct examination, during a surgical operation, or during a histopathologic examination.
3. Patient has at least 1 of the following signs or
symptoms with no other recognized cause: abscess, ulceration, or raised white patches on inflamed mucosa, or plaques on oral mucosa
and
at least 1 of the following:
a. organisms seen on Gram’s stain
b. positive KOH (potassium hydroxide) stain
c. multinucleated giant cells seen on microscopic examination of mucosal scrapings
d. positive antigen test on oral secretions
e. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for
pathogen
f. physician diagnosis of infection and treatment with topical or oral antifungal therapy.

Reporting instruction
d

Report health care–associated primary herpes
simplex infections of the oral cavity as ORAL; recurrent herpes infections are not health care–
associated.

SINU-Sinusitis
Sinusitis must meet at least 1 of the following
criteria:
1. Patient has organisms cultured from purulent
material obtained from sinus cavity.
2. Patient has at least 1 of the following signs or
symptoms with no other recognized cause: fever
(.388C), pain or tenderness over the involved sinus, headache, purulent exudate, or nasal
obstruction

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321

and
at least 1 of the following:
a. positive transillumination
b. positive radiographic examination (including CT scan).

UR-Upper respiratory tract, pharyngitis,
laryngitis, epiglottitis
Upper respiratory tract infections must meet at least
1 of the following criteria:
1. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever
(.388C), erythema of pharynx, sore throat,
cough, hoarseness, or purulent exudate in throat
and
at least 1 of the following:
a. organisms cultured from the specific site
b. organisms cultured from blood
c. positive antigen test on blood or respiratory
secretions
d. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for
pathogen
e. physician diagnosis of an upper respiratory
infection.
2. Patient has an abscess seen on direct examination, during a surgical operation, or during a histopathologic examination.
3. Patient #1 year of age has at least 2 of the following signs or symptoms with no other recognized
cause: fever (.388C rectal), hypothermia (,378C
rectal), apnea, bradycardia, nasal discharge, or
purulent exudate in throat
and
at least 1 of the following:
a. organisms cultured from the specific site
b. organisms cultured from blood
c. positive antigen test on blood or respiratory
secretions
d. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for
pathogen
e. physician diagnosis of an upper respiratory
infection.

GI-GASTROINTESTINAL SYSTEM INFECTION
GE-Gastroenteritis
Gastroenteritis must meet at least 1 of the following
criteria:
1. Patient has an acute onset of diarrhea (liquid
stools for more than 12 hours) with or without

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Vol. 36 No. 5

vomiting or fever (.388C) and no likely noninfectious cause (eg, diagnostic tests, therapeutic regimen other than antimicrobial agents, acute
exacerbation of a chronic condition, or psychologic stress).
2. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: nausea, vomiting, abdominal pain, fever (.388C), or
headache
and
at least 1 of the following:
a. an enteric pathogen is cultured from stool
or rectal swab
b. an enteric pathogen is detected by routine
or electron microscopy
c. an enteric pathogen is detected by antigen
or antibody assay on blood or feces
d. evidence of an enteric pathogen is detected
by cytopathic changes in tissue culture
(toxin assay)
e. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for
pathogen.

GIT-Gastrointestinal tract (esophagus, stomach,
small and large bowel, and rectum) excluding
gastroenteritis and appendicitis
Gastrointestinal tract infections, excluding gastroenteritis and appendicitis, must meet at least 1 of the following criteria:
1. Patient has an abscess or other evidence of infection seen during a surgical operation or histopathologic examination.
2. Patient has at least 2 of the following signs or
symptoms with no other recognized cause and
compatible with infection of the organ or tissue
involved: fever (.388C), nausea, vomiting, abdominal pain, or tenderness
and
at least 1 of the following:
a. organisms cultured from drainage or tissue
obtained during a surgical operation or endoscopy or from a surgically placed drain
b. organisms seen on Gram’s or KOH stain or
multinucleated giant cells seen on microscopic examination of drainage or tissue obtained during a surgical operation or
endoscopy or from a surgically placed drain
c. organisms cultured from blood
d. evidence of pathologic findings on radiographic examination
e. evidence of pathologic findings on endoscopic examination (eg, Candida esophagitis
or proctitis).

HEP-Hepatitis
Hepatitis must meet the following criterion:
Patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever
(.388C), anorexia, nausea, vomiting, abdominal pain,
jaundice, or history of transfusion within the previous
3 months
and
at least 1 of the following:
a. positive antigen or antibody test for hepatitis
A, hepatitis B, hepatitis C, or delta hepatitis
b. abnormal liver function tests (eg, elevated ALT/
AST, bilirubin)
c. cytomegalovirus (CMV) detected in urine or oropharyngeal secretions.

Reporting instructions
d

Do not report hepatitis or jaundice of noninfectious origin (alpha-1 antitrypsin deficiency, etc).
Do not report hepatitis or jaundice that results
from exposure to hepatotoxins (alcoholic or acetaminophen-induced hepatitis, etc).
Do not report hepatitis or jaundice that results
from biliary obstruction (cholecystitis).

IAB-Intraabdominal, not specified elsewhere
including gallbladder, bile ducts, liver
(excluding viral hepatitis), spleen, pancreas,
peritoneum, subphrenic or subdiaphragmatic
space, or other intraabdominal tissue or area
not specified elsewhere
Intraabdominal infections must meet at least 1 of the
following criteria:
1. Patient has organisms cultured from purulent
material from intraabdominal space obtained
during a surgical operation or needle aspiration.
2. Patient has abscess or other evidence of intraabdominal infection seen during a surgical operation or histopathologic examination.
3. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever
(.388C), nausea, vomiting, abdominal pain, or
jaundice
and
at least 1 of the following:
a. organisms cultured from drainage from surgically placed drain (eg, closed suction
drainage system, open drain, T-tube drain)
b. organisms seen on Gram’s stain of drainage
or tissue obtained during surgical operation
or needle aspiration

Horan, Andrus, and Dudeck

June 2008

c. organisms cultured from blood and radiographic evidence of infection (eg, abnormal
findings on ultrasound, CT scan, MRI, or radiolabel scans [gallium, technetium, etc] or
on abdominal x-ray).

(.388C rectal), cough, new or increased sputum
production, rhonchi, wheezing, respiratory distress, apnea, or bradycardia
and
at least 1 of the following:
a. organisms cultured from material obtained
by deep tracheal aspirate or bronchoscopy
b. positive antigen test on respiratory
secretions
c. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for
pathogen.

Reporting instruction
d

Do not report pancreatitis (an inflammatory syndrome characterized by abdominal pain, nausea,
and vomiting associated with high serum levels
of pancreatic enzymes) unless it is determined to
be infectious in origin.

NEC-Necrotizing enterocolitis
Necrotizing enterocolitis in infants must meet the
following criterion:
Infant has at least 2 of the following signs or symptoms with no other recognized cause: vomiting, abdominal distention, or prefeeding residuals
and
persistent microscopic or gross blood in stools
and
at least 1 of the following abdominal radiographic
abnormalities:
a. pneumoperitoneum
b. pneumatosis intestinalis
c. unchanging ‘‘rigid’’ loops of small bowel.

LRI-LOWER RESPIRATORY TRACT INFECTION,
OTHER THAN PNEUMONIA
BRON-Bronchitis, tracheobronchitis,
bronchiolitis, tracheitis, without evidence of
pneumonia
Tracheobronchial infections must meet at least 1 of
the following criteria:
1. Patient has no clinical or radiographic evidence of
pneumonia
and
patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever
(.388C), cough, new or increased sputum production, rhonchi, wheezing
and
at least 1 of the following:
a. positive culture obtained by deep tracheal
aspirate or bronchoscopy
b. positive antigen test on respiratory
secretions.
2. Patient #1 year of age has no clinical or radiographic evidence of pneumonia
and
patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever

323

Reporting instruction
d

Do not report chronic bronchitis in a patient with
chronic lung disease as an infection unless there is
evidence of an acute secondary infection, manifested by change in organism.

LUNG-Other infections of the lower respiratory
tract
Other infections of the lower respiratory tract must
meet at least 1 of the following criteria:
1. Patient has organisms seen on smear or cultured from lung tissue or fluid, including pleural
fluid.
2. Patient has a lung abscess or empyema seen during a surgical operation or histopathologic
examination.
3. Patient has an abscess cavity seen on radiographic examination of lung.

Reporting instructions
d

Report concurrent lower respiratory tract infection and pneumonia with the same organism(s)
as PNEU.
Report lung abscess or empyema without pneumonia as LUNG.

REPR-REPRODUCTIVE TRACT INFECTION
EMET-Endometritis
Endometritis must meet at least 1 of the following
criteria:
1. Patient has organisms cultured from fluid or tissue from endometrium obtained during surgical
operation, by needle aspiration, or by brush
biopsy.
2. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: fever

324

(.388C), abdominal pain, uterine tenderness, or
purulent drainage from uterus.

Reporting instruction
d

Horan, Andrus, and Dudeck

Vol. 36 No. 5

Report postpartum endometritis as a health care–
associated infection unless the amniotic fluid is
infected at the time of admission or the patient
was admitted 48 hours after rupture of the
membrane.

3. Patient has 2 of the following signs or symptoms
with no other recognized cause: fever (.388C),
nausea, vomiting, pain, tenderness, or dysuria
and
at least 1 of the following:
a. organisms cultured from blood
b. physician diagnosis.

Reporting instructions
d
d

Report endometritis as EMET.
Report vaginal cuff infections as VCUF.

EPIS-Episiotomy
Episiotomy infections must meet at least 1 of the following criteria:
1. Postvaginal delivery patient has purulent drainage from the episiotomy.
2. Postvaginal delivery patient has an episiotomy
abscess.

Comment
d

Episiotomy is not considered an operative procedure in NHSN.

VCUF-Vaginal cuff
Vaginal cuff infections must meet at least 1 of the
following criteria:
1. Posthysterectomy patient has purulent drainage
from the vaginal cuff.
2. Posthysterectomy patient has an abscess at the
vaginal cuff.
3. Posthysterectomy patient has pathogens cultured
from fluid or tissue obtained from the vaginal
cuff.

Reporting instruction
d

Report vaginal cuff infections as SSI-VCUF.

OREP-Other infections of the male or female
reproductive tract (epididymis, testes, prostate,
vagina, ovaries, uterus, or other deep pelvic
tissues, excluding endometritis or vaginal cuff
infections)
Other infections of the male or female reproductive
tract must meet at least 1 of the following criteria:
1. Patient has organisms cultured from tissue or
fluid from affected site.
2. Patient has an abscess or other evidence of infection of affected site seen during a surgical operation or histopathologic examination.

SST-SKIN AND SOFT TISSUE INFECTION
SKIN-Skin
Skin infections must meet at least 1 of the following
criteria:
1. Patient has purulent drainage, pustules, vesicles,
or boils.
2. Patient has at least 2 of the following signs or
symptoms with no other recognized cause: pain
or tenderness, localized swelling, redness, or
heat
and
at least 1 of the following:
a. organisms cultured from aspirate or drainage from affected site; if organisms are
normal skin flora (ie, diphtheroids [Corynebacterium spp], Bacillus [not B anthracis]
spp, Propionibacterium spp, coagulase-negative staphylococci [including S epidermidis],
viridans
group
streptococci,
Aerococcus spp, Micrococcus spp), they
must be a pure culture
b. organisms cultured from blood
c. positive antigen test performed on infected
tissue or blood (eg, herpes simplex, varicella
zoster, H influenzae, N meningitidis)
d. multinucleated giant cells seen on microscopic examination of affected tissue
e. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for
pathogen.

Reporting instructions
d
d

d
d
d
d

Report omphalitis in infants as UMB.
Report infections of the circumcision site in newborns as CIRC.
Report pustules in infants as PUST.
Report infected decubitus ulcers as DECU.
Report infected burns as BURN.
Report breast abscesses or mastitis as BRST.

Horan, Andrus, and Dudeck

ST-Soft tissue (necrotizing fascitis, infectious
gangrene, necrotizing cellulitis, infectious
myositis, lymphadenitis, or lymphangitis)
Soft tissue infections must meet at least 1 of the following criteria:
1. Patient has organisms cultured from tissue or
drainage from affected site.
2. Patient has purulent drainage at affected site.
3. Patient has an abscess or other evidence of infection seen during a surgical operation or histopathologic examination.
4. Patient has at least 2 of the following signs or
symptoms at the affected site with no other recognized cause: localized pain or tenderness, redness, swelling, or heat
and
at least 1 of the following:
a. organisms cultured from blood
b. positive antigen test performed on blood or
urine (eg, H influenzae, S pneumoniae, N
meningitidis, Group B Streptococcus, Candida spp)
c. diagnostic single antibody titer (IgM) or 4fold increase in paired sera (IgG) for
pathogen.

Reporting instructions
d
d

Report infected decubitus ulcers as DECU.
Report infection of deep pelvic tissues as OREP.

DECU-Decubitus ulcer, including both
superficial and deep infections
Decubitus ulcer infections must meet the following
criterion:
Patient has at least 2 of the following signs or symptoms with no other recognized cause: redness, tenderness, or swelling of decubitus wound edges
and
at least 1 of the following:
a. organisms cultured from properly collected fluid
or tissue (see Comments)
b. organisms cultured from blood.

Comments
d

Purulent drainage alone is not sufficient evidence
of an infection.
Organisms cultured from the surface of a decubitus ulcer are not sufficient evidence that the ulcer is infected. A properly collected specimen
from a decubitus ulcer involves needle aspiration of fluid or biopsy of tissue from the ulcer
margin.

June 2008

325

BURN-Burn
Burn infections must meet at least 1 of the following
criteria:
1. Patient has a change in burn wound appearance
or character, such as rapid eschar separation, or
dark brown, black, or violaceous discoloration
of the eschar, or edema at wound margin
and
histologic examination of burn biopsy shows invasion of organisms into adjacent viable tissue.
2. Patient has a change in burn wound appearance or character, such as rapid eschar separation, or dark brown, black, or violaceous
discoloration of the eschar, or edema at wound
margin
and
at least 1 of the following:
a. organisms cultured from blood in the absence of other identifiable infection
b. isolation of herpes simplex virus, histologic
identification of inclusions by light or electron microscopy, or visualization of viral
particles by electron microscopy in biopsies
or lesion scrapings.
3. Patient with a burn has at least 2 of the following
signs or symptoms with no other recognized
cause: fever (.388C) or hypothermia (,368C), hypotension, oliguria (,20 cc/hr), hyperglycemia at
previously tolerated level of dietary carbohydrate,
or mental confusion
and
at least 1 of the following:
a. histologic examination of burn biopsy
shows invasion of organisms into adjacent
viable tissue
b. organisms cultured from blood
c. isolation of herpes simplex virus, histologic
identification of inclusions by light or electron microscopy, or visualization of viral
particles by electron microscopy in biopsies
or lesion scrapings.

Comments
d

Purulence alone at the burn wound site is not adequate for the diagnosis of burn infection; such
purulence may reflect incomplete wound care.
Fever alone in a burn patient is not adequate for
the diagnosis of a burn infection because fever
may be the result of tissue trauma or the patient
may have an infection at another site.
Surgeons in Regional Burn Centers who take care
of burn patients exclusively may require Criterion
1 for diagnosis of burn infection.

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d

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Vol. 36 No. 5

Hospitals with Regional Burn Centers may further
divide burn infections into the following: burn
wound site, burn graft site, burn donor site, burn
donor site-cadaver; NHSN, however, will code all
of these as BURN.

BRST-Breast abscess or mastitis

2. Infant has 1 or more pustules
and
physician institutes appropriate antimicrobial
therapy.

Reporting instructions
d

A breast abscess or mastitis must meet at least 1 of
the following criteria:
1. Patient has a positive culture of affected breast
tissue or fluid obtained by incision and drainage
or needle aspiration.
2. Patient has a breast abscess or other evidence of
infection seen during a surgical operation or histopathologic examination.
3. Patient has fever (.388C) and local inflammation
of the breast
and
physician diagnosis of breast abscess.

Comment
d

Breast abscesses occur most frequently after childbirth. Those that occur within 7 days after childbirth should be considered health care associated.

UMB-Oomphalitis
Omphalitis in a newborn (#30 days old) must meet
at least 1 of the following criteria:
1. Patient has erythema and/or serous drainage
from umbilicus
and
at least 1 of the following:
a. organisms cultured from drainage or needle
aspirate
b. organisms cultured from blood.
2. Patient has both erythema and purulence at the
umbilicus.

Reporting instructions
d

Report infection of the umbilical artery or vein related to umbilical catheterization as VASC if there
is no accompanying blood culture or a blood culture is negative.
Report as health care associated if infection occurs
in a newborn within 7 days of hospital discharge.

PUST-Infant pustulosis
Pustulosis in an infant (#1 year old) must meet at
least 1 of the following criteria:
1. Infant has 1 or more pustules
and
physician diagnosis of skin infection.

Do not report erythema toxicum and noninfectious causes of pustulosis.
Report as health care associated if pustulosis occurs in an infant within 7 days of hospital
discharge.

CIRC-Newborn circumcision
Circumcision infection in a newborn (#30 days old)
must meet at least 1 of the following criteria:
1. Newborn has purulent drainage from circumcision site.
2. Newborn has at least 1 of the following signs or
symptoms with no other recognized cause at circumcision site: erythema, swelling, or tenderness
and
pathogen cultured from circumcision site.
3. Newborn has at least 1 of the following signs or
symptoms with no other recognized cause at circumcision site: erythema, swelling, or tenderness
and
skin contaminant (ie, diphtheroids [Corynebacterium spp], Bacillus [not B anthracis] spp, Propionibacterium spp, coagulase-negative staphylococci
[including S epidermidis], viridans group streptococci, Aerococcus spp, Micrococcus spp) is cultured from circumcision site
and
physician diagnosis of infection or physician institutes appropriate therapy.

SYS-SYSTEMIC INFECTION
DI-Disseminated infection
Disseminated infection is infection involving multiple organs or systems, without an apparent single site
of infection, usually of viral origin, and with signs or
symptoms with no other recognized cause and compatible with infectious involvement of multiple organs or
systems.

Reporting instructions
d

Use this code for viral infections involving multiple organ systems (eg, measles, mumps, rubella,
varicella, erythema infectiosum). These infections
often can be identified by clinical criteria alone.
Do not use this code for health care–associated

Horan, Andrus, and Dudeck

d
d
d

June 2008

infections with multiple metastatic sites, such as
with bacterial endocarditis; only the primary site
of these infections should be reported.
Do not report fever of unknown origin (FUO) as DI.
Report neonatal ‘‘sepsis’’ as CSEP.
Report viral exanthems or rash illness as DI.

References
1. Garner JS, Jarvis WR, Emori TG, Horan TC, Hughes JM. CDC definitions for nosocomial infections, 1988. Am J Infect Control 1988;16:
128-40.
2. Horan TC, Gaynes RP. Surveillance of nosocomial infections. In: Mayhall
CG, editor. Hospital epidemiology and infection control. 3rd ed. Philadelphia: Lippincott Williams & Wilkins; 2004. p. 1659-702.
3. Clinical and Laboratory Standards Institute (CLSI). Principles and procedures for blood cultures; approved guideline. CLSI document M47A (ISBN 1-56238-641-7). Clinical and Laboratory Standards Institute,
940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898
USA, 2007.
4. Baron EJ, Weinstein MP, Dunne WM Jr, Yagupsky P, Welch DF, Wilson
DM. Blood Cultures IV. Washington, DC: ASM Press; 2005.

APPENDIX. PNEU-PNEUMONIA
There are 3 specific types of pneumonia: clinically
defined pneumonia (PNU1), pneumonia with specific
laboratory findings (PNU2), and pneumonia in immunocompromised patients (PNU3). Listed below are general comments applicable to all specific types of
pneumonia, along with abbreviations used in the algorithms (Tables 4-7) and reporting instructions. Table 8
shows threshold values for cultured specimens used
in the surveillance diagnosis of pneumonia. Figures
1 and 2 are flow diagrams for the pneumonia algorithms that may be used as data collection tools.

General comments
1. Physician diagnosis of pneumonia alone is not an
acceptable criterion for health care–associated
pneumonia.
2. Although specific criteria are included for infants
and children, pediatric patients may meet any of
the other pneumonia specific site criteria.
3. Ventilator-associated pneumonia (ie, pneumonia
in persons who had a device to assist or control
respiration continuously through a tracheostomy
or by endotracheal intubation within the 48-hour
period before the onset of infection, inclusive of
the weaning period) should be so designated
when reporting data.
4. When assessing a patient for presence of pneumonia, it is important to distinguish between
changes in clinical status due to other conditions
such as myocardial infarction, pulmonary embolism, respiratory distress syndrome, atelectasis,
malignancy, chronic obstructive pulmonary

327

disease, hyaline membrane disease, bronchopulmonary dysplasia, etc. Also, care must be taken
when assessing intubated patients to distinguish
between tracheal colonization, upper respiratory
tract infections (eg, tracheobronchitis), and early
onset pneumonia. Finally, it should be recognized
that it may be difficult to determine health care–
associated pneumonia in the elderly, infants, and
immunocompromised patients because such
conditions may mask typical signs or symptoms
associated with pneumonia. Alternate specific
criteria for the elderly, infants and immunocompromised patients have been included in this definition of health care–associated pneumonia.
Health care–associated pneumonia can be characterized by its onset: early or late. Early onset
pneumonia occurs during the first 4 days of hospitalization and is often caused by Moraxella
catarrhalis, H influenzae, and S pneumoniae.
Causative agents of late onset pneumonia are
frequently gram negative bacilli or S aureus,
including methicillin-resistant S aureus. Viruses
(eg, influenza A and B or respiratory syncytial virus) can cause early and late onset nosocomial
pneumonia, whereas yeasts, fungi, legionellae,
and Pneumocystis carinii are usually pathogens
of late onset pneumonia.
Pneumonia due to gross aspiration (for example,
in the setting of intubation in the emergency
room or operating room) is considered health
care associated if it meets any specific criteria
and was not clearly present or incubating at the
time of admission to the hospital.
Multiple episodes of health care–associated
pneumonia may occur in critically ill patients
with lengthy hospital stays. When determining
whether to report multiple episodes of health
care–associated pneumonia in a single patient,
look for evidence of resolution of the initial infection. The addition of or change in pathogen alone
is not indicative of a new episode of pneumonia.
The combination of new signs and symptoms
and radiographic evidence or other diagnostic
testing is required.
Positive Gram stain for bacteria and positive
KOH (potassium hydroxide) mount for elastin
fibers and/or fungal hyphae from appropriately
collected sputum specimens are important
clues that point toward the etiology of the infection. However, sputum samples are frequently contaminated with airway colonizers
and therefore must be interpreted cautiously.
In particular, Candida is commonly seen on
stain, but infrequently causes healthcare-associated pneumonia.

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Horan, Andrus, and Dudeck

Fig 1. Pneumonia flow diagram.

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June 2008

329

Fig 2. Pneumonia flow diagram alternate criteria for infants and children.

Abbreviations
BAL–bronchoalveolar lavage
EIA–enzyme immunoassay
FAMA–fluorescent-antibody staining of
membrane antigen
IFA–immunofluorescent antibody
LRT–lower respiratory tract
PCR–polymerase chain reaction
PMN–polymorphonuclear leukocyte
RIA–radioimmunoassay

Reporting instructions
d

There is a hierarchy of specific categories within
the major type pneumonia (PNEU). Even if a

patient meets criteria for more than 1 specific
site, report only 1:
s If a patient meets criteria for both PNU1 and
PNU2, report PNU2.
s If a patient meets criteria for both PNU2 and
PNU3, report PNU3.
s If a patient meets criteria for both PNU1 and
PNU3, report PNU3.
Report concurrent lower respiratory tract infection (eg, abscess or empyema) and pneumonia
with the same organism(s) as pneumonia.
Lung abscess or empyema without pneumonia are
classified as LUNG.
Bronchitis, tracheitis, tracheobronchitis, or bronchiolitis without pneumonia are classified as
BRON.

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Vol. 36 No. 5

Table 4. Algorithms for clinically defined pneumonia (PNU1)
Radiology
Two or more serial chest radiographs
with at least 1 of the following1,2:
d New or progressive and persistent
infiltrate
d Consolidation
d Cavitation
d Pneumatoceles, in infants #1 year old
NOTE: In patients without underlying
pulmonary or cardiac disease (eg, respiratory
distress syndrome, bronchopulmonary dysplasia,
pulmonary edema, or chronic obstructive
pulmonary disease), 1 definitive chest radiograph
is acceptable.1

Signs/Symptoms

FOR ANY PATIENT, at least 1 of the following:
d Fever (.388C or .100.48F) with no other recognized cause
3
3
d Leukopenia (,4000 WBC/mm ) or leukocytosis ($12,000 WBC/mm )
d For adults $70 years old, altered mental status with no other recognized
cause
and
at least 2 of the following:
3
4
d New onset of purulent sputum or change in character of sputum or
increased respiratory secretions or increased suctioning requirements
5
d New onset or worsening cough, or dyspnea, or tachypnea
6
d Rales or bronchial breath sounds
7
d Worsening gas exchange (eg, O2 desaturations [eg, PaO2/FiO2 #240],
increased oxygen requirements, or increased ventilator demand)

ALTERNATE CRITERIA, for infants #1 year old:
Worsening gas exchange (eg, O2 desaturations, increased oxygen requirements, or
increased ventilator demand)
and
at least 3 of the following:
d Temperature instability with no other recognized cause
3
3
d Leukopenia (,4000 WBC/mm ) or leukocytosis ($15,000 WBC/mm ) and
left shift ($10% band forms)
3
4
d New onset of purulent sputum or change in character of sputum, or
increased respiratory secretions or increased suctioning requirements
5
d Apnea, tachypnea, nasal flaring with retraction of chest wall or grunting
6
d Wheezing, rales, or rhonchi
d Cough
d Bradycardia (,100 beats/min) or tachycardia (.170 beats/min)
ALTERNATE CRITERIA, for child .1 year old or #12 years old, at least 3 of the
following:
d Fever (.38.48C or .101.18F) or hypothermia (,36.58C or ,97.78F) with
no other recognized cause
3
3
d Leukopenia (,4000 WBC/mm ) or leukocytosis ($15,000 WBC/mm )
3
4
d New onset of purulent sputum or change in character of sputum or
increased respiratory secretions or increased suctioning requirements
5
d New onset or worsening cough or dyspnea, apnea, or tachypnea
6
d Rales or bronchial breath sounds
d Worsening gas exchange (eg, O2 desaturations [eg, pulse oximetry ,94%],
increased oxygen requirements, or increased ventilator demand)
Footnotes to Algorithms:
1. Occasionally, in nonventilated patients, the diagnosis of health care–associated pneumonia may be quite clear on the basis of symptoms, signs, and a single definitive
chest radiograph. However, in patients with pulmonary or cardiac disease (for example, interstitial lung disease or congestive heart failure), the diagnosis of
pneumonia may be particularly difficult. Other noninfectious conditions (for example, pulmonary edema from decompensated congestive heart failure) may simulate
the presentation of pneumonia. In these more difficult cases, serial chest radiographs must be examined to help separate infectious from noninfectious pulmonary
processes. To help confirm difficult cases, it may be useful to review radiographs on the day of diagnosis, 3 days prior to the diagnosis and on days 2 and 7 after the
diagnosis. Pneumonia may have rapid onset and progression, but does not resolve quickly. Radiographic changes of pneumonia persist for several weeks. As a result,
rapid radiographic resolution suggests that the patient does not have pneumonia but rather a noninfectious process such as atelectasis or congestive heart failure.
2. Note that there are many ways of describing the radiographic appearance of pneumonia. Examples include, but are not limited to, ‘‘air-space disease,’’ ‘‘focal opacification,’’
‘‘patchy areas of increased density.’’ Although perhaps not specifically delineated as pneumonia by the radiologist, in the appropriate clinical setting these alternative descriptive
wordings should be seriously considered as potentially positive findings.
3. Purulent sputum is defined as secretions from the lungs, bronchi, or trachea that contain $25 neutrophils and #10 squamous epithelial cells per low power field (x100). If your
laboratory reports these data qualitatively (eg, ‘‘many WBCs’’ or ‘‘few squames’’), be sure their descriptors match this definition of purulent sputum. This laboratory
confirmation is required because written clinical descriptions of purulence are highly variable.
4. A single notation of either purulent sputum or change in character of the sputum is not meaningful; repeated notations over a 24-hour period would be more indicative of the
onset of an infectious process. Change in character of sputum refers to the color, consistency, odor, and quantity.

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331

Table 5. Algorithms for pneumonia with common bacterial or filamentous fungal pathogens and specific laboratory findings
(PNU2)
Radiology
Two or more serial chest radiographs with
at least 1 of the following1,2:
d New or progressive and persistent
infiltrate
d Consolidation
d Cavitation
d Pneumatoceles, in infants #1 year old
NOTE: In patients without underlying pulmonary
or cardiac disease (eg, respiratory distress
syndrome, bronchopulmonary dysplasia,
pulmonary edema, or chronic obstructive
pulmonary disease), 1 definitive chest
radiograph is acceptable.1

Signs/Symptoms

Laboratory

At least 1 of the following:
d Fever (.388C or .100.48F) with no other
recognized cause
3
d Leukopenia (,4000 WBC/mm ) or
leukocytosis ($12,000 WBC/mm3)
d For adults $70 years old, altered mental
status with no other recognized cause
and
at least 1 of the following:
3
d New onset of purulent sputum or change
in character of sputum4 or increased
respiratory secretions or increased
suctioning requirements
d New onset or worsening cough or dyspnea
or tachypnea5
6
d Rales or bronchial breath sounds
d Worsening gas exchange (eg, O2
desaturations [eg, PaO2/FiO2 #240]7,
increased oxygen requirements, or
increased ventilator demand)

At least 1 of the following:
8
d Positive growth in blood culture not
related to another source of infection
d Positive growth in culture of pleural fluid
9
d Positive quantitative culture from
minimally contaminated LRT specimen (eg,
BAL or protected specimen brushing)
d $5% BAL-obtained cells contain
intracellular bacteria on direct microscopic
exam (eg, Gram stain)
d Histopathologic exam shows at least 1 of
the following evidences of pneumonia:
d Abscess formation or foci of consolidation
with intense PMN accumulation in
bronchioles and alveoli
9
d Positive quantitative culture of lung
parenchyma
d Evidence of lung parenchyma invasion by
fungal hyphae or pseudohyphae

Table 6. Algorithms for pneumonia with viral, Legionella, Chlamydia, Mycoplasma, and other uncommon pathogens and
specific laboratory findings (PNU2)
Radiology
Two or more serial chest radiographs with at
least 1 of the following1,2:
d New or progressive and persistent
infiltrate
d Consolidation
d Cavitation
d Pneumatoceles, in infants #1 year old
NOTE: In patients without underlying pulmonary
or cardiac disease (eg, respiratory distress
syndrome, bronchopulmonary dysplasia,
pulmonary edema, or chronic obstructive
pulmonary disease), 1 definitive chest
radiograph is acceptable.1

Signs/Symptoms

Laboratory

At least 1 of the following:
d Fever (.388C or .100.48F) with no other
recognized cause
3
d Leukopenia (,4000 WBC/mm ) or
leukocytosis ($12,000 WBC/mm3)
d For adults $70 years old, altered mental
status with no other recognized cause
and
at least 1 of the following:
3
d New onset of purulent sputum or change
in character of sputum4 or increased
respiratory secretions or increased
suctioning requirements
d New onset or worsening cough or
dyspnea or tachypnea5
6
d Rales or bronchial breath sounds
d Worsening gas exchange (eg, O2
desaturations [eg, PaO2/FiO2 #240],7
increased oxygen requirements, or
increased ventilator demand)

At least 1 of the following10-12:
d Positive culture of virus or Chlamydia from
respiratory secretions
d Positive detection of viral antigen or
antibody from respiratory secretions (eg,
EIA, FAMA, shell vial assay, PCR)
d Four-fold rise in paired sera (IgG) for
pathogen (eg, influenza viruses, Chlamydia)
d Positive PCR for Chlamydia or Mycoplasma
d Positive micro-IF test for Chlamydia
d Positive culture or visualization by microIF of Legionella spp, from respiratory
secretions or tissue
d Detection of Legionella pneumophila
serogroup 1 antigens in urine by RIA or
EIA
d Four-fold rise in L pneumophila serogroup
1 antibody titer to $1:128 in paired acute
and convalescent sera by indirect IFA

5. In adults, tachypnea is defined as respiration rate .25 breaths per minute. Tachypnea is defined as .75 breaths per minute in premature infants born at ,37 weeks gestation and
until the 40th week; .60 breaths per minute in infants ,2 months old; .50 breaths per minute in infants 2 to 12 months old; and .30 breaths per minute in children .1 year old.
6. Rales may be described as ‘‘crackles.’’
7. This measure of arterial oxygenation is defined as the ratio of the arterial tension (PaO2) to the inspiratory fraction of oxygen (FiO2).
8. Care must be taken to determine the etiology of pneumonia in a patient with positive blood cultures and radiographic evidence of pneumonia, especially if the patient has invasive
devices in place such as intravascular lines or an indwelling urinary catheter. In general, in an immunocompetent patient, blood cultures positive for coagulase-negative
staphylococci, common skin contaminants, and yeasts will not be the etiologic agent of the pneumonia.
9. Refer to threshold values for cultured specimens (Table 8). An endotracheal aspirate is not a minimally contaminated specimen. Therefore, an endotracheal aspirate does not
meet the laboratory criteria.
10. Once laboratory-confirmed due to pneumonia because of respiratory syncytial virus (RSV), adenovirus, or influenza virus have been identified in a hospital, clinician’s
presumptive diagnosis of these pathogens in subsequent cases with similar clinical signs and symptoms is an acceptable criterion for presence of health care–associated infection.

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Table 7. Algorithms for pneumonia in immunocompromised patients (PNU3)
Radiology
Two or more serial chest radiographs with at
least 1 of the following1,2:
d New or progressive and persistent
infiltrate
d Consolidation
d Cavitation
d Pneumatoceles, in infants #1 year old
NOTE: In patients without underlying
pulmonary or cardiac disease (eg,
respiratory distress syndrome,
bronchopulmonary dysplasia, pulmonary
edema, or chronic obstructive pulmonary
disease), 1 definitive chest radiograph is
acceptable.1

Signs/Symptoms

Laboratory

Patient who is immunocompromised13 has at
least 1 of the following:
d Fever (.388C or .100.48F) with no
other recognized cause
d For adults $70 years old, altered
mental status with no other
recognized cause
3
d New onset of purulent sputum or
change in character of sputum4 or
increased respiratory secretions or
increased suctioning requirements
d New onset or worsening cough or
dyspnea or tachypnea5
6
d Rales or bronchial breath sounds
d Worsening gas exchange (eg, O2
desaturations [eg, PaO2/FiO2 #240],7
increased oxygen requirements, or
increased ventilator demand)
d Hemoptysis
d Pleuritic chest pain

At least 1 of the following:
d Matching positive blood and sputum
cultures with Candida spp14,15
d Evidence of fungi or Pneumocystis carinii
from minimally contaminated LRT
specimen (eg, BAL or protected
specimen brushing) from 1 of the
following:
s Direct microscopic exam
s Positive culture of fungi
d Any of the laboratory criteria defined
under PNU2

11. Scant or watery sputum is commonly seen in adults with pneumonia due to viruses and Mycoplasma although sometimes the sputum may be mucopurulent. In infants, pneumonia
due to RSV or influenza yields copious sputum. Patients, except premature infants, with viral or Mycoplasmal pneumonia may exhibit few signs or symptoms, even when significant
infiltrates are present on radiographic exam.
12. Few bacteria may be seen on stains of respiratory secretions from patients with pneumonia due to Legionella spp, mycoplasma, or viruses.
13. Immunocompromised patients include those with neutropenia (absolute neutrophil count ,500/mm3), leukemia, lymphoma, HIV with CD4 count ,200, or splenectomy; those
who are early posttransplantation, are on cytotoxic chemotherapy, or are on high-dose steroids (e.g., .40mg of prednisone or its equivalent [.160mg hydrocortisone, .32mg
methylprednisolone, .6mg dexamethasone, .200mg cortisone] daily for .2weeks).
14. Blood and sputum specimens must be collected within 48 hours of each other.
15. Semiquantitative or nonquantitative cultures of sputum obtained by deep cough, induction, aspiration, or lavage are acceptable. If quantitative culture results are available, refer
to algorithms that include such specific laboratory findings.

Table 8. Threshold values for cultured specimens used in
the diagnosis of pneumonia
Specimen collection/technique
Lung parenchyma*
Bronchoscopically obtained specimens
Bronchoalveolar lavage
Protected BAL
Protected specimen brushing
Nonbronchoscopically obtained (blind) specimens
Bronchoalveolar lavage
Protected BAL

Values
$104 cfu/g tissue
$104 cfu/mL
$104 cfu/mL
$104 cfu/mL
$104 cfu/mL
$104 cfu/mL

cfu, colony-forming units.
*Open-lung biopsy specimens and immediate post-mortem specimens obtained by
transthoracic or transbronchial biopsy.

Appendix: Urinary Tract Infection (UTI)
Criterion

Urinary Tract Infection (UTI)
Symptomatic Urinary Tract Infection (SUTI)
Must meet at least 1 of the following criteria
Patient had an indwelling urinary catheter in place at the time of specimen collection
and
at least 1 of the following signs or symptoms with no other recognized cause:
fever (>38°C), suprapubic tenderness, or costovertebral angle pain or tenderness
and
a positive urine culture of ≥105 colony-forming units (CFU)/ml with no more than 2 species of
microorganisms.
----------------------------------------------------OR---------------------------------------------------------------

Patient had indwelling urinary catheter removed within the 48 hours prior to specimen collection
and
at least 1 of the following signs or symptoms with no other recognized cause:
fever (>38°C), urgency, frequency, dysuria, suprapubic tenderness, or costovertebral angle pain
or tenderness
and
a positive urine culture of ≥105 colony-forming units (CFU)/ml with no more than 2 species of
microorganisms.
Patient did not have an indwelling urinary catheter in place at the time of specimen collection
nor within 48 hours prior to specimen collection
and
has at least 1 of the following signs or symptoms with no other recognized cause: fever (>38°C) in
a patient that is ≤65 years of age, urgency, frequency, dysuria, suprapubic tenderness, or
costovertebral angle pain or tenderness
and
a positive urine culture of ≥105 CFU/ml with no more than 2 species of microorganisms.
Patient had an indwelling urinary catheter in place at the time of specimen collection
and
at least 1 of the following signs or symptoms with no other recognized cause:
fever (>38°C), suprapubic tenderness, or costovertebral angle pain or tenderness
and
a positive urinalysis demonstrated by at least 1 of the following findings:
a. positive dipstick for leukocyte esterase and/or nitrite
b. pyuria (urine specimen with ≥10 white blood cells [WBC]/mm3 of unspun urine or ≥3
WBC/high power field of spun urine)
c. microorganisms seen on Gram stain of unspun urine
and
a positive urine culture of ≥103 and <105 CFU/ml with no more than 2 species of microorganisms.
----------------------------------------------------OR--------------------------------------------------------------Patient had indwelling urinary catheter removed within the 48 hours prior to specimen collection
and
at least 1 of the following signs or symptoms with no other recognized cause:

June, 2011

17-29

Criterion

Urinary Tract Infection (UTI)
fever (>38°C), urgency, frequency, dysuria, suprapubic tenderness, or costovertebral angle pain
or tenderness
and
a positive urinalysis demonstrated by at least 1 of the following findings:
a. positive dipstick for leukocyte esterase and/or nitrite
b. pyuria (urine specimen with ≥10 white blood cells [WBC]/mm3 of unspun urine or ≥3
WBC/high power field of spun urine)
c. microorganisms seen on Gram stain of unspun urine
and
a positive urine culture of ≥103 and <105 CFU/ml with no more than 2 species of microorganisms.
Patient did not have an indwelling urinary catheter in place at the time of specimen collection
nor within 48 hours prior to specimen collection
and
has at least 1 of the following signs or symptoms with no other recognized cause: fever (>38°C) in
a patient that is ≤65 years of age, urgency, frequency, dysuria, suprapubic tenderness, or
costovertebral angle pain or tenderness
and
a positive urinalysis demonstrated by at least 1 of the following findings:
a. positive dipstick for leukocyte esterase and/or nitrite
b. pyuria (urine specimen with ≥10 WBC/mm3 of unspun urine or ≥3 WBC/high power field
of spun urine)
c. microorganisms seen on Gram stain of unspun urine
and
a positive urine culture of ≥103 and <105 CFU/ml with no more than 2 species of
microorganisms.
Patient ≤1 year of age with or without an indwelling urinary catheter has at least 1 of the
following signs or symptoms with no other recognized cause: fever (>38°C core), hypothermia
(<36°C core), apnea, bradycardia, dysuria, lethargy, or vomiting
and
a positive urine culture of ≥105 CFU/ml with no more than 2 species of microorganisms.
Patient ≤1 year of age with or without an indwelling urinary catheter has at least 1 of the
following signs or symptoms with no other recognized cause: fever (>38°C core), hypothermia
(<36°C core), apnea, bradycardia, dysuria, lethargy, or vomiting
and
a positive urinalysis demonstrated by at least one of the following findings:
a. positive dipstick for leukocyte esterase and/or nitrite
b. pyuria (urine specimen with ≥10 WBC/mm3 of unspun urine or ≥3 WBC/high power field
of spun urine)
c. microorganisms seen on Gram’s stain of unspun urine
and
a positive urine culture of between ≥103 and <105 CFU/ml with no more than two species of
microorganisms.

Criterion

Asymptomatic Bacteremic Urinary Tract Infection (ABUTI)

Patient with or without an indwelling urinary catheter has no signs or symptoms (i.e., for any age
patient, no fever (>38°C), urgency, frequency, dysuria, suprapubic tenderness, or costovertebral
angle pain or tenderness, OR for a patient ≤1 year of age, no fever (>38°C core), hypothermia
(<36°C core), apnea, bradycardia, dysuria, lethargy, or vomiting)
June, 2011

17-30

Criterion

Comments

Criterion

1
2
3

June, 2011

Urinary Tract Infection (UTI)
and
a positive urine culture of >105 CFU/ml with no more than 2 species of uropathogen
microorganisms*
and
a positive blood culture with at least 1 matching uropathogen microorganism to the urine
culture, or at least 2 matching blood cultures drawn on separate occasions if the
matching pathogen is a common skin contaminant.
* For ABUTI, report only isolate(s) in both blood and urine specimens.
* Uropathogen microorganisms are: Gram-negative bacilli, Staphylococcus spp., yeasts, betahemolytic Streptococcus spp., Enterococcus spp., G. vaginalis, Aerococcus urinae,and
Corynebacterium (urease positive).
• Urinary catheter tips should not be cultured and are not acceptable for the diagnosis of a
urinary tract infection.
• Urine cultures must be obtained using appropriate technique, such as clean catch collection
or catheterization. Specimens from indwelling catheters should be aspirated through the
disinfected sampling ports.
• In infants, urine cultures should be obtained by bladder catheterization or suprapubic
aspiration; positive urine cultures from bag specimens are unreliable and should be
confirmed by specimens aseptically obtained by catheterization or suprapubic aspiration.
• Urine specimens for culture should be processed as soon as possible, preferably within 1 to 2
hours. If urine specimens cannot be processed within 30 minutes of collection, they should
be refrigerated, or inoculated into primary isolation medium before transport, or
transported in an appropriate urine preservative. Refrigerated specimens should be cultured
within 24 hours.
• Urine specimen labels should indicate whether or not the patient is symptomatic.
• Report secondary bloodstream infection = “Yes” for all cases of Asymptomatic Bacteremic
Urinary Tract Infection (ABUTI).
• Report only pathogens in both blood and urine specimens for ABUTI.
• Report Corynebacterium (urease positive) as either Corynebacterium species unspecified
(COS) or, as C. urealyticum (CORUR) if so speciated.
Other Urinary Tract Infection (OUTI) (kidney, ureter, bladder, urethra, or tissue surrounding
the retroperineal or perinephric space)
Other infections of the urinary tract must meet at least 1 of the following criteria:
Patient has microorganisms isolated from culture of fluid (other than urine) or tissue from
affected site.
Patient has an abscess or other evidence of infection seen on direct examination, during a
surgical operation, or during a histopathologic examination.
Patient has at least 2 of the following signs or symptoms with no other recognized cause: fever
(>38°C), localized pain, or localized tenderness at the involved site
and
at least 1 of the following:
a. purulent drainage from affected site
b. microorganisms cultured from blood that are compatible with suspected site of
infection
c. radiographic evidence of infection (e.g., abnormal ultrasound, CT scan, magnetic
resonance imaging [MRI], or radiolabel scan [gallium, technetium]).
17-31

Criterion
4

Comment

June, 2011

Urinary Tract Infection (UTI)
Patient < 1 year of age has at least 1 of the following signs or symptoms with no other recognized
cause: fever (>38°C core), hypothermia (<36°C core), apnea, bradycardia, lethargy, or vomiting
and
at least 1 of the following:
a. purulent drainage from affected site
b. microorganisms cultured from blood that are compatible with suspected site of
infection
c. radiographic evidence of infection, (e.g., abnormal ultrasound, CT scan, magnetic
resonance imaging [MRI], or radiolabel scan [gallium, technetium]).
• Report infections following circumcision in newborns as SST-CIRC.

17-32

File Type	application/pdf
File Title	CDC/NHSN Surveillance Definition of Healthcare-Associated Infection
Author	CDC/OID/NCEZID/DHQP
File Modified	2011-05-27
File Created	2011-05-24