Att G13_LTCF MDRO CDI

NHSN Long-term Care Facility Component
MDRO & CDI

Laboratory-identified Multidrug-Resistant Organism (MDRO) & Clostridium
difficile Infection (CDI) Events for Long-term Care Facilities (LTCFs)
Background: Clostridium difficile infections (CDI), methicillin-resistant Staphylococcus aureus
(MRSA), vancomycin-resistant Enterococcus spp. (VRE), and certain multidrug-resistant gramnegative bacilli (e.g. carbapenem-resistant Enterobacteriaceae) have increased in prevalence in
U.S. healthcare settings over the last three decades, and have important implications for residents
of long-term care facilities (LTCF). Studies have demonstrated a large proportion of residents are
at risk for carrying or acquiring these multidrug-resistant organisms (MDRO) in LTCF. MDRO
infections are associated with increased lengths of stay, hospitalizations and readmissions,
increased healthcare costs, and mortality due to more severe illnesses and limited treatment
options. CDI can present a variety of ways including uncomplicated diarrhea, pseudomembranous
colitis, and toxic megacolon, which can, in some instances, lead to sepsis and even death.
Infections from C. difficile represent a subset of gastroenteritis and gastrointestinal tract infections.
Standard definitions for CDI should be incorporated into infection surveillance programs to obtain
a more complete understanding of how C. difficile can manifest and be transmitted in LTCFs.
The Laboratory-identified (LabID) Event Module of the NHSN LTCF Component is a tool
designed for use in certified skilled nursing facilities/nursing homes (LTC:SKILLNURS) and
intermediate/chronic care facilities for the developmentally disabled (LTC:DEVDIS) to help meet
criteria outlined in guidelines for the prevention, control, and surveillance of MDRO & CDI 1-5.
As outlined in these guidelines, these pathogens may require specialized monitoring to evaluate if
intensified infection control efforts are required to reduce the occurrence of these organisms and
related infections. The goal of this module is to provide a mechanism for facilities to collect,
report, and analyze data that will inform infection control staff of the impact of prevention efforts.
This module contains two options, one focused on CDI and the second on select MDROs.

References:
1: Smith et al. SHEA/APIC Guideline: Infection Prevention and Control in the Long-Term Care Facility. Infection
Control and Hospital Epidemiology 2008;29:785-814.
2: Healthcare Infection Control Practices Advisory Committee (HICPAC) approved guidelines for the control of
multidrug resistant organism (MDRO). Available at www.cdc.gov/hicpac/pdf/MDRO/MDROGuideline2006.pdf
3: Cohen et al. Clinical Practice Guideline for Clostridium difficile infection in Adults: 2010 Update by SHEA and
IDSA. Infection Control and Hospital Epidemiology 2010;31:431-55.
4: Simor et al. Clostridium difficile in Long-Term Care Facilities for the Elderly. SHEA Position Paper. Infection
Control and Hospital Epidemiology 2002;23:696-703.
5: Cohen et al. Recommendations for Metrics for Multidrug-Resistant Organisms in Healthcare Settings:
SHEA/HICPAC Position Paper. Infection Control and Hospital Epidemiology 2008;29:901-13.

January 2016

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NHSN Long-term Care Facility Component
MDRO & CDI

I. Clostridium difficile Infection (CDI) Surveillance by Laboratory-identified (LabID) Event
Methods: Facilities may choose to monitor Clostridium difficile infections (CDI) using
laboratory-identified (LabID) event surveillance. This surveillance method allows laboratory data
to be used without clinical evaluation of the resident for signs or symptoms, allowing for a less
labor intensive method to track C. difficile. This method provides proxy measures of C. difficile
infections and healthcare exposure based solely on laboratory data and limited resident
admission/transfer data.
The data collected will enable participating facilities and CDC to calculate several infection
measures for CDI (listed below). NHSN forms should be used to collect all required data, using
the definitions of each data field as indicated in the Table of Instructions.
Settings: CDI LabID Event reporting is currently available for certified skilled nursing
facilities/nursing homes (LTC:SKILLNURS) and intermediate/chronic care facilities for the
developmentally disabled (LTC:DEVDIS). Events reported should include C. difficile positive
laboratory assays obtained from any resident who is receiving care at the facility. Laboratory
results available from other healthcare facilities before the resident was admitted to your facility
should not be reported as LabID Events.
Requirements: Facilities must report numerators (CDI LabID Events) and denominators
(number of resident admissions, number of resident-days, and number of residents who are
receiving antibiotic treatment for C. difficile at the time of admission into the LTCF) for the
entire facility, referred to as facility-wide inpatient (FacWideIN), each month for at least 6
consecutive months to provide meaningful measures. C. difficile laboratory testing should be
performed only on liquid or watery stool samples (i.e., conforming to the shape of the specimen
collection container).
Facilities must indicate their reporting for the calendar month in the Monthly Reporting Plan for
LTCF (CDC 57.141).
Definitions:
C. difficile positive laboratory assay: A positive result for a laboratory test for C. difficile toxin A
and/or B (e.g., enzyme immunoassay, or EIA test), OR a toxin-producing C. difficile organism
detected in the stool specimen by culture or other laboratory means (e.g., nucleic acid
amplification testing by polymerase-chain reaction, or PCR).
CDI Laboratory-identified (LabID) Event: All non-duplicate C. difficile positive
laboratory assays tested on liquid or watery stool samples (i.e., conforming to the shape
of the specimen collection container), and obtained while a resident is receiving care in
the long-term care facility. See Figure 1 - C. difficile Test Result Algorithm for

January 2016

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NHSN Long-term Care Facility Component
MDRO & CDI

Laboratory-identified (LabID) Events. NOTE: Laboratory results obtained from outside
facilities, before a resident’s admission, should not be entered as LabID Events.
Duplicate C. difficile-positive laboratory assay: Any C. difficile positive laboratory test
obtained from the same resident while receiving care in the LTCF following a previous
C. difficile positive test within the past two weeks (14 days) that was also was collected
while the resident was receiving care in the LTCF. The day of specimen collection is
considered as Day 1.
NOTE: LabID event rules apply to specimens collected while the resident is
receiving care in the LTCF. Specimens collected while the resident is receiving
care outside of the LTCF are not taken into consideration for LabID Event
reporting for the LTCF.
EXAMPLE: Mr. T is a long-term resident in your LTCF and has not recently transferred in
or out of the facility. On January 1, a liquid stool specimen is collected from Mr. T, and the
test result is positive for C. difficile toxin. After verifying that Mr. T does not have a
positive C. difficile positive laboratory assay test in the previous 14 days, you enter a CDI
LabID Event into the NHSN. Over the next week, Mr. T seems to improve and the diarrhea
resolves. However, on January 13, he has several episodes of diarrhea, and a liquid stool
specimen is collected, which subsequently tests positive C. difficile toxin. It has not been
more than 14 days since the most recent C. difficile toxin-positive laboratory result for Mr.
T, so this C. difficile test result is considered a duplicate CDI LabID Event, and is not
entered into the NHSN. On January 20, Mr. T has another C. difficile toxin-positive
laboratory result. While it has been more than 14 days since the initial positive C. difficile
toxin-positive laboratory result was entered into NHSN (January 1), it has not been more
than 14 days since his most recent C. difficile toxin-positive laboratory result (January 13).
Therefore, the C. difficile toxin-positive laboratory result collected on January 20 is
considered a duplicate, and is not entered into the NHSN. On February 10, Mr. T has
another C. difficile toxin-positive laboratory result. Since it has been more than 14 days
since his most recent C. difficile toxin-positive laboratory result (January 20) while in your
facility, this CDI LabID Event is entered into the NHSN.
EXAMPLE: Classification of CDI LabID Events as Duplicate
Date of Positive C. difficile Lab
Test for a Resident (collected while
in the LTCF)
January 1
January 13

Duplicate Enter as a CDI LabID Event?
No
Yes

Yes
No (within 2 weeks of positive test, January 1)

January 20
February 10

Yes
No

No (within 2 weeks of positive test, January 13)
Yes

January 2016

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NHSN Long-term Care Facility Component
MDRO & CDI

Categorizations of CDI LabID Events: All CDI LabID Events will be categorized by NHSN.
Categorizations are based on specimens collected while the resident was receiving care in the
LTCF.
Incident CDI LabID Event: Either the first CDI LabID Event ever entered for an individual
resident in the facility, or a subsequent LabID Event entered > 8 weeks after the most recent CDI
LabID Event reported for an individual resident while receiving care in the LTCF.
Recurrent CDI LabID Event: Any CDI LabID Event entered > 2 weeks and ≤ 8 weeks after the
most recent CDI LabID Event reported for an individual resident while receiving care in the
LTCF.

EXAMPLE: NHSN Classification of CDI LabID Events as Incident or Recurrent
Resident ID

Current
Admit Date

CDI Event Date (i.e., date
of specimen collection)

Categorization

1111

01/01/2015

01/05/2015

Incident

1111

01/01/2015

01/07/2015

Duplicate (Not
reported in NHSN)

1111

01/01/2015

01/25/2015

Recurrent

1111

01/01/2015

02/2/2015

Duplicate (Not
reported in NHSN)

1111

01/01/2015

03/11/2015

Recurrent

1111

01/01/2015

05/20/2015

Incident

Further Categorizations of CDI LabID Events: All incident or recurrent LabID Events will

be further categorized by NHSN into Community-onset vs. LTCF-onset. These additional
categorizations are based on date of current admission to facility and date of specimen
collection. Because of variability in documenting time of admission to the LTCF, calendar
days are used to categorize LabID Events.
Community-onset (CO) LabID Event: Date specimen collected ≤ 3 calendar days from date of
current admission to the facility (i.e., days 1, 2, or 3 of admission).

January 2016

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NHSN Long-term Care Facility Component
MDRO & CDI

Long-term Care Facility-onset (LO) LabID Event: Date specimen collected > 3 calendar days
after current admission to the facility (i.e., on or after day 4).
LO LabID Events can be further sub-classified as:
Acute Care Transfer-Long-term Care Facility-onset (ACT-LO): LTCF-onset (LO)
LabID Event with date specimen collected ≤ 4 weeks following date of last transfer
from an Acute Care Facility (Hospital, Long-term acute care hospital, or acute
inpatient rehabilitation facility only).
EXAMPLE: NHSN Classification of Lab ID Events as Community-onset or LTCF-onset
Admission date
June 4th

June 5th

June 6th

June 7th

June 8th

day 1

day 2

day 3

day 4

day 5

Community-onset (CO)

Long-term Care Facility-onset (LO)

Numerator and Denominator Data:
Numerator: Data on each CDI LabID Event will be reported using the Laboratory-identified
MDRO or CDI Event for LTCF form (CDC 57.138). (See Table of Instructions) information on
how to complete this form.)
Denominator: Monthly totals for resident-days, resident admissions, and residents on C.difficile
treatment at the time of admission are collected using the Denominators for LTCF form (CDC
57.142). (See Table of Instructions) for information on how to complete this form.)
CDI Data Analysis: Data are stratified by time (e.g., month, quarter, etc.), whether an episode is
incident or recurrent, community-onset or LTCF-onset, and summarized for the entire facility.
Calculated CDI Rates and Metrics:
Line lists of CDI LabID Events and the measures and calculations listed below are available as
part of the CDC-defined analysis outputs within the NHSN LTCF component.
Total CDI Rate/10,000 resident-days = Number of CDI LabID Events per month regardless of
time spent in the facility (i.e., CO + LO) / Number of resident-days per month x 10,000.

January 2016

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NHSN Long-term Care Facility Component
MDRO & CDI

CDI Treatment Prevalence on Admission = Admissions on C. difficile Treatment / Number of
Admissions x 100.
CDI Long-term Care Facility-onset Incidence Rate/10,000 resident-days* = Number of all
incident LO CDI LabID Events per month / Number of resident-days x 10,000.
*NOTE: This formula excludes recurrent CDI events.
Percent that is Community-onset = Number of CDI LabID Events that are CO / Total number of
CDI LabID Events x 100.
Percent that is Long-term Care Facility-onset = Number of CDI LabID Events that are LO / Total
number of CDI LabID Events x 100.
Percent of LO that is Acute Care Transfer-Long-term Care Facility-onset = Number of
ACT-LO CDI LabID Events / Total number of LO CDI LabID Events x 100.
Percent that is Recurrent CDI = Number of CDI LabID Events that are recurrent / Total number
of CDI LabID Events x 100.

Figure 1. C. difficile Test Result Algorithm for Laboratory-identified (LabID) Events.

Positive C. difficile test result,
tested on liquid stool specimen

NO

Report as CDI
LabID Event

Incident if no previous
positive, or prior
positive >8 weeks

January 2016

Prior Positive < 2
weeks (14 days or
less), collected
while receiving care
in the LTC Facility

Recurrent if prior positive
>2 and < 8 weeks

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YES
Duplicate – Not a
CDI LabID Event

NHSN Long-term Care Facility Component
MDRO & CDI

II. MDRO Surveillance by Laboratory-identified (LabID) Event
Methods: Facilities may choose to monitor one or more of the following MDROs:
Staphylococcus aureus, both methicillin-resistant (MRSA) and methicillin-susceptible (MSSA),
vancomycin-resistant Enterococcus spp. (VRE), cephalosporin-resistant Klebsiella spp.,
carbapenem-resistant Enterobacteriaceae (CRE), and multidrug-resistant Acinetobacter spp.
Laboratory-identified (LabID) Event reporting allows laboratory data to be used without clinical
evaluation of the resident for signs or symptoms, creating a less labor intensive method to track
MDROs. This method provides proxy measures of MDRO infections, and healthcare exposure
based solely on laboratory data and limited resident admission/transfer data.
LabID Event reporting is ONLY for collecting and tracking isolates from positive cultures that are
taken for "clinical" purposes (i.e., for diagnosis and treatment), which means that Active
Surveillance Culture/Testing (e.g., nasal swabs for MRSA or perirectal swabs for VRE) results are
not reported as LabID Events. Laboratory results available from other healthcare facilities before
the resident was admitted to your facility should not be reported as LabID Events.
The data collected will enable participating facilities and CDC to calculate several measures,
depending on which MDROs the facility chooses to track. NHSN forms should be used to collect
all required data, using the definitions of each data field as indicated in the Table of Instructions.
Setting: MDRO LabID Event reporting is currently available for certified skilled nursing
facilities/nursing homes (LTC:SKILLNURS) and intermediate/chronic care facilities for the
developmentally disabled (LTC:DEVDIS). Events reported should include MDRO positive
laboratory cultures obtained from any resident who is receiving care at the facility.
Requirements: Facilities must report LabID Events and denominators (number of resident
admission and number of resident-days) for the entire facility, referred to as facility-wide inpatient
(FacWideIN), each month for at least 6 consecutive months to provide meaningful measures.
Report only one LabID Event organism (positive isolate) per form.
Facilities must indicate their reporting for the calendar month in the Monthly Reporting Plan for
LTCF (CDC 57.141).
Definitions: The following MDROs can be selected for tracking in the LabID Event module:
Gram-stain positive organisms:
•

MRSA: Any S. aureus testing resistant to oxacillin, methicillin, or cefoxitin, by standard
susceptibility testing methods or by a positive result from an FDA-approved test for direct
MRSA detection from that specimen source.

January 2016

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NHSN Long-term Care Facility Component
MDRO & CDI

•

MSSA: Any S. aureus testing intermediate or susceptible to oxacillin, methicillin, and
cefoxitin by standard susceptibility testing methods; a positive result from an FDAapproved test for direct MSSA detection from that specimen source; or a negative result
from an FDA-approved test for direct MRSA detection from a specimen source.

•

VRE: Any Enterococcus species that is resistant to vancomycin, by standard susceptibility
testing methods or by a positive result from an FDA-approved test for VRE detection from
that specimen source.

Gram-stain negative organisms:
•

CephR-Klebsiella: Any Klebsiella species testing non-susceptible (i.e., resistant or
intermediate) to cephalosporin antibiotics like ceftazidime, cefotaxime, ceftriaxone, or
cefepime.

•

CRE- Any Escherichia coli (E. coli), Klebsiella species, or Enterobacter species testing
resistant to imipenem, meropenem, doripenem, or ertapenem by standard susceptibility
testing methods (i.e., minimum inhibitory concentrations of ≥4 mcg/mL for doripenem,
imipenem and meropenem or ≥2 mcg/mL for ertapenem) OR by production of a
carbapenemase (i.e., KPC, NDM, VIM, IMP, OXA-48) demonstrated using a recognized
test (e.g., polymerase chain reaction, metallo-β-lactamase test, modified-Hodge test,
Carba-NP). NOTE: CRE surveillance requires facilities to monitor for all three organisms
(CRE-E. coli, CRE-Klebsiella spp., and CRE-Enterobacter spp.).

•

MDR-Acinetobacter: Any Acinetobacter species testing non-susceptible (i.e., resistant or
intermediate) to at least one agent in at least 3 antimicrobial classes of the following 6
antimicrobial classes:

January 2016

Antimicrobial Class

Agents

-lactams and -lactam/-lactamase
inhibitor combinations

Piperacillin, Piperacillin/tazobactam

Sulbactam

Ampicillin/sulbactam

Cephalosporins

Cefepime, Ceftazidime

Carbapenems

Imipenem, Meropenem, Doripenem,
Ertapenem

Aminoglycosides

Amikacin, Gentamicin, Tobramycin

Fluoroquinolones

Ciprofloxacin, Levofloxacin

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NHSN Long-term Care Facility Component
MDRO & CDI

MDRO positive laboratory isolate: Any laboratory specimen source, from which a MDRO
is identified, obtained for clinical decision making (as defined above) while a resident is
receiving care in the facility. Note: Excludes tests related to active surveillance testing.
Duplicate MDRO laboratory isolate: Any MDRO isolate collected from the same resident
while receiving care in the LTCF after an initial isolation of the same organism during a
calendar month, regardless of the specimen source except when a unique blood source is
identified (see definition below and Figure 2). Note: LabID event rules apply to
specimens collected while the resident is receiving care in the LTCF. Specimens
collected while the resident is receiving care outside of the LTCF are not taken into
consideration for LabID Event reporting for the LTCF.
NOTE: A duplicate MDRO laboratory isolate should not be reported as a LabID Event.
Unique blood source MDRO laboratory isolate: A MDRO isolate identified in a blood culture
from a resident with no prior isolation of the MDRO in blood in the past 2 weeks, while receiving
care in the LTCF, even across calendar months. A unique blood source isolate should be reported
even if the resident had this same MDRO previously isolated in a non-blood specimen earlier
during the same calendar month (See Figure 2).
NOTE: As a general rule, at a maximum, there should be no more than 2 blood isolates
(which would be very rare) and 1 other specimen source isolate per MDRO type reported
for the same resident during a calendar month.
MDRO Laboratory-identified (LabID) Event: All non-duplicate MDRO positive laboratory
isolates from any culture specimen, regardless of specimen source or MDRO unique blood source
isolates obtained while a resident is receiving care in the facility.
NOTE: Laboratory data available from outside facilities, before a resident’s admission,
should not be entered as LabID Events.
Categorizations of MDRO LabID Events: All MDRO LabID Events will be categorized by NHSN
into Community-onset vs. LTCF-onset based on date of current admission to facility and date of
specimen collected. Because of variability in documenting time of admission to the LTCF,
calendar days are used to categorize LabID Events.
Community-onset (CO) LabID Event: Date specimen collected ≤ 3 calendar days after resident
admission to the facility (i.e., days 1, 2, or 3 of admission).

January 2016

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NHSN Long-term Care Facility Component
MDRO & CDI

Long-term Care Facility-onset (LO) LabID Event: Date specimen collected > 3 calendar days
after admission to the facility (i.e., on or after day 4).
LO can be further sub-classified as:
Acute Care Transfer-Long-term Care Facility-onset (ACT-LO): LTCF-onset (LO)
LabID Event with date specimen collected ≤ 4 weeks following date of last transfer
from an Acute Care Facility (Hospital, Long-term acute care hospital, or acute
inpatient rehabilitation facility only).
Example: NHSN Classification of Lab ID Events as Community-onset or LTCF-onset
Admission date
June 4th

June 5th

June 6th

June 7th

June 8th

day 1

day 2

day 3

day 4

day 5

Community-onset (CO)

Long-term Care Facility-onset (LO)

Numerator and Denominator Data:
Numerator: Data on each MDRO LabID Event will be reported using the Laboratory identified
MDRO or CDI Event for LTCF form (CDC 57.138). (See Table of Instructions) for information on
how to complete this form.)
Denominator: Monthly totals for resident admissions and resident-days are collected using the
Denominators for LTCF (CDC 57.142). (See Table of Instructions) for information on how to
complete this form.)
MDRO Data Analysis: Data are stratified by time (e.g., month, quarter, etc.), whether an episode
is community-onset or LTCF-onset and summarized for the entire facility.
Calculated MDRO Rates and Metrics*:
Line lists of MDRO LabID Events and the measures and calculations listed below are available as
part of the CDC-defined analysis outputs within the NHSN LTCF component.
*NOTE: These calculations will be performed for each specific MDRO included in the reporting
plan during a month (e.g., MRSA, VRE, etc.)

January 2016

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NHSN Long-term Care Facility Component
MDRO & CDI

Total MDRO Rate/1,000 resident-days = Number of MDRO LabID Events per month (regardless
of time spent in the facility i.e., CO + LO) / Number of resident-days per month x 1,000.
MDRO Long-term Care Facility-onset Incidence Rate/ 1,000 resident-days = Number of all LO
MDRO LabID Events per month / Number of resident-days x 1,000.
Percent of MDRO LabID Events that is Community-onset = Number of MDRO LabID Events
that are CO / Total number of MDRO LabID Events x 100.
Percent of MDRO LabID Events that is Long-term Care Facility-onset = Number of MDRO
LabID Events that are LO / Total number of MDRO LabID Events x 100.
Percent of LO LabID Events that is Acute Care-Transfer-Long-term Care Facility-onset =
Number of ACT-LO MDRO LabID Events / Total number of LO MDRO LabID Events x
100.

Figure 2. MDRO Test Result Algorithm for Laboratory-identified (LabID) Events.
MDRO isolate
from any specimen
source

YES

Report as
MDRO LabID
Event

1st in calendar
month

NO

Duplicate
MDRO
isolate

Source =
BLOOD

Duplicate Not an MDRO
LabID Event

YES

Prior positive with same MDRO
from blood in < 2 weeks (including
across calendar months) while
receiving care in the LTCF
NO
Unique blood source MDRO
Report as LabID Event

January 2016

NO

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YES

Duplicate - Not
an MDRO
LabID Event