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pdfReport of Sample Shipment Results, December 2007
DEPARTMENT OF HEALTH & HUMAN SERVICES
HIV-1 Rapid Testing MPEP December 2007 Report of Results
Report of the December 2007 Human Immunodeficiency Virus Type 1 (HIV-1) Rapid Testing
(RT) Performance Evaluation Sample Results Provided by Participant Facilities in the Model
Performance Evaluation Program (MPEP), Centers for Disease Control and Prevention (CDC).
Coordination
of report
production
The production of this report was coordinated in CDC by:
Division of Laboratory Systems ……................... D. Joe Boone, Ph.D., Acting Director
Laboratory Practice Evaluation and
Genomics Branch................................................ Dev Howerton, Ph.D., Chief
The material in this report was developed and prepared by:
Report
content
Model Performance Evaluation Program (MPEP)……… G. David Cross, M.S., Manager
MPEP HIV-1 Rapid Testing Performance Evaluation..... Leigh Inge Vaughan, B.A.,
HIV Rapid Testing Project Coordinator
MPEP acknowledges the contributions of Laura Goubeaux, B.S. and Courtney Rodi, B.A., PMP
of Constella Group, LLC for their help in preparing this report.
Use of trade names and commercial sources is for identification only and does not constitute
endorsement by the Public Health Service or the U.S. Department of Health and Human
Services.
Comments and inquiries regarding this report should be directed to:
Contact
information
Ms. Leigh Vaughan: telephone (404) 718-1005; email [email protected]
1
Table of Contents
page
Donor Report (Table 1)................................................................................................................. 3
Report of Results: Overview........................................................................................................
Purpose............................................................................................................................
Response rate..................................................................................................................
Overall performance.........................................................................................................
Table 2: Percentages of positive and negative results by donor type..............................
MPEP Plasma samples, summary results.......................................................................
Changes in specimen type…...........................................................................................
Confirmatory testing practices..........................................................................................
4
4
4
4
4
5
5
5
Challenge Samples........................................................................................................................ 6
Sample description........................................................................................................... 6
Description of challenge samples..................................................................................... 6
Demographics................................................................................................................................
Overview...........................................................................................................................
Figure 1: Number of U.S. participants returning results...................................................
Table 3: Number of non-U.S. participants returning results............................................
Figure 2: Type of testing sites, by U.S. & non-U.S...........................................................
7
7
7
8
9
Detailed Performance Results..................................................................................................... 10
Table 4: Results by donor.............................................................................................. 10
Table 5: Accuracy for all samples by kit type………...................................................... 11
Kit Types Used by Participants.................................................................................................... 12
Overview........................................................................................................................... 12
Figure 3: Kit types............................................................................................................. 12
Figure 4: Testing site by kit type....................................................................................... 13
Specimen Types Used by Participants........................................................................................14
Overview........................................................................................................................... 14
Figure 5: Specimen types................................................................................................. 14
Quality Control (QC)...................................................................................................................... 15
Overview........................................................................................................................... 15
Figure 6: Frequency of use of controls............................................................................. 15
Confirmatory Testing.................................................................................................................... 16
Overview.......................................................................................................................... 16
Figure 7: Types of confirmatory testing............................................................................ 17
Conclusions and Discussion....................................................................................................... 18
Overall performance......................................................................................................... 18
Specimen types................................................................................................................ 18
Errors on positive samples............................................................................................... 18
Confirmatory testing......................................................................................................... 19
Guidelines........................................................................................................................ 19
References....................................................................................................................... 20
Topical Issues in HIV Rapid Testing............................................................................................ 21
Introduction....................................................................................................................... 21
FAQs: December 2007 survey........................................................................................ 21
Highlights of previous FAQs............................................................................................. 21
CDC websites.................................................................................................................. 22
HIV rapid testing resources.............................................................................................. 22
2
Donor Report
HIV Rapid Testing MPEP December 2007
Panel and Vial Designations, CDC Donor Bulk Numbers,
CDC HIV Rapid Test Results and Donor HIV Status
Panel
Letter
Vial
Label
CDC Donor
Bulk Number
CDC Test
Result1,3
Donor HIV
Status
Laboratory Interpretation2
and/or Results
Test Result
Interpretation
A
A1
A2
A3
A4
A5
A6
27
13
23
13*
23*
24
Negative (N)
Positive (S)
Positive (W)
Positive (S)
Positive (W)
Positive (W)
Uninfected
Infected
Infected
Infected
Infected
Infected
__________
__________
__________
__________
__________
__________
____________
____________
____________
____________
____________
____________
B
B1
B2
B3
B4
B5
B6
13
27
23
23*
24
13*
Positive (S)
Negative (N)
Positive (W)
Positive (W)
Positive (W)
Positive (S)
Infected
Uninfected
Infected
Infected
Infected
Infected
__________
__________
__________
__________
__________
__________
____________
____________
____________
____________
____________
____________
C
C1
C2
C3
C4
C5
C6
23
24
27
13
13*
23*
Positive (W)
Positive (W)
Negative (N)
Positive (S)
Positive (S)
Positive (W)
Infected
Infected
Uninfected
Infected
Infected
Infected
__________
__________
__________
__________
__________
__________
____________
____________
____________
____________
____________
____________
D
D1
D2
D3
D4
D5
D6
23
13
13*
27
23*
24
Positive (W)
Positive (S)
Positive (S)
Negative (N)
Positive (W)
Positive (W)
Infected
Infected
Infected
Uninfected
Infected
Infected
__________
__________
__________
__________
__________
__________
____________
____________
____________
____________
____________
____________
* Duplicate donors
1
The CDC result was obtained after pre-shipment testing for the presence of HIV-1 antibody with all commercially available HIV
Rapid Testing kits licensed by the Food and Drug Administration (FDA) and with selected FDA-licensed Enzyme Immunoassay
(EIA) kits. The CDC result is consistent with the manufacturers’ criteria for interpretation of results.
2
Laboratory Interpretation space (to be completed by participant laboratory) provided to facilitate comparison of participant laboratory
result with CDC result.
3
Strong (S) and Weak (W) designations are based on qualitative observations of the colorimetric test results for reactive samples.
3
Report of Results: Overview
Introduction
This report describes the results of the eleventh HIV Rapid Testing Model Performance
Evaluation Program (HIV-RT MPEP) shipment survey. It represents a collection of results
reported by a variety of testing sites using different HIV rapid test kits on six samples.
The six survey samples were derived from four individual donors and included two
duplicate samples.
The major findings are summarized below.
Response
rate
The survey shipment was sent to 684 testing sites within and outside of the United States.
Responses were received from 622 (90.9%) of the testing sites. Of those responding:
° 557 (89.5%) were U.S. testing sites, and
° 65 (10.5%) were non-U.S. testing sites.
Note:
Fourteen testing sites submitted two result forms, indicating the use of two different test kits,
so that the total number of responses was 636.
Overall
performance
Overall accuracy (percent of correct results) for all samples, by all sites with all kit types,
was 98.4% (3724/3783). “Indeterminate” result interpretations were considered to be
incorrect, and “Invalid” result interpretations were not included in the analyses. (Eight invalid
results were reported by seven testing sites. These tended to be related to the use of flowthrough testing devices, e.g. possible absorption difficulties.)
A summary of results for all challenges is shown in the following table:
Table 2: Percentages of positive and negative results by donor type
Positive Donors
Total # Total # Positive/
of
of
Reactive
facilities** Results Results
618
3783
3099
Ind*
12 ( 0.3%)
Negative Donors
Negative/
False Negative Non-Reactive
(% False Neg.)
Results
41 (1.1%)
625
Ind
0 (0.0%)
False Positives
(% False Pos.)
Overall Performance
(TP + TN/Total # of
Results)
6 (0.16%)
98.4%
* Ind= Indeterminate
** Note: Four sites returning responses were not included in the testing result analyses,
although the other laboratory practice information they supplied was included in the
data. One of the sites gave no sample panel testing results; the other three sites
reported rapid testing results for which the sample code did not match the sample
panel they were shipped and their answers were inconsistent with the sample code
they reported.
Continued on next page
4
Report of Results: Overview, Continued
MPEP
plasma
samples,
summary
results
•
The MPEP plasma positive challenges included one strong-positive sample (donor 13)
and two weak-positive samples (Donors 23 and 24).
•
The 41 false-negative and 12 indeterminate results represent a rate of error less than
that of the June 2007 and December 2006 surveys, both of which had notably higher
error rates than in previous surveys. The current survey’s error rate was similar to
surveys conducted prior to December 2006.
•
Of the 53 incorrect results reported for positive challenges:
6 (11.3%) were reported for Donor 13 (strong positive),
33 (62.3%) were reported for Donor 23 (weak positive) and
14 (26.4%) were reported for Donor 24 (weak positive).
o Overall accuracy for MPEP plasma positive samples was 98.3% (3099/3152).
o Accuracy varied with test kit used (88.9% - 100%).
o The three (3) most frequently used kit types were as follows:
•
Changes in
specimen
type
Rapid HIV kit type
# sites
316
# false-negatives
(n=41)
36
# indeterminates
(n=12)
7
OraQuick ADVANCE
Trinity Biotech Unigold Recombigen
122
1
1
MedMira Reveal G3
63
1
0
Six false positive and no indeterminate results were reported on the
negative challenge (Donor 27).
o
Overall accuracy was 99.0% (625/631).
o
Five out of the six false positive results were associated with use of the OraSure
OraQuick ADVANCE Rapid HIV 1/2 Ab Test.
• Oral fluid (oral mucosal transudate) as a normally used specimen type:
o was indicated in 140 responses, by 138 U.S. sites* using OraQuick Advance
Rapid HIV-1/2 and by two non-U.S. sites using Determine HIV-1/2.
o
was similar in usage to the 142 responses reported to
MPEP in the June 2007 survey,
was used primarily in the U.S. (138/140, 98.6%) by sites identified as:
health department (37/138, 26.8%),
community based organization (CBO) (33/138, 23.9%)
counseling and testing (28/138, 20.3%)
family planning center (10/138, 7.2%)
hospital (7/138, 5.1%) or
sexually transmitted disease (STD) clinic (6/138, 4.3%).
*Note: 43.3% (138/319) of U.S. sites that reported using OraQuick ADVANCE Rapid HIV-1/2
indicated use of oral fluid as a specimen type.
o
Confirmatory
testing
practices
Twenty-four U.S. testing sites indicated that only EIA (in-house or sent out) was done for
confirmation of a preliminary positive (reactive) rapid test result.
CDC guidelines state that reactive rapid HIV tests should be confirmed with Western blot
(WB) or indirect immunofluorescence assay (IFA), even if a subsequent EIA is nonreactive.
It is the responsibility of each testing site to ensure that appropriate guidelines are
being followed, regardless of where the confirmatory tests are performed.
5
Challenge Samples
Sample
description
The plasma samples for this challenge shipment of the HIV-RT MPEP were shipped in
December 2007.
The six samples for this shipment were from four donors:
• one strong HIV-1 antibody positive, in duplicate,
• two weak HIV-1 antibody positive (one in duplicate), and
• one HIV-1 antibody negative.
Description
of challenge
samples
All sample plasma were single bleeds drawn from individual donors. The resulting plasma
for all samples was tested to determine HIV-1 antibody reactivity.
The samples for the December 2007 HIV Rapid Testing MPEP survey were processed
as follows:
• All donor samples were clarified prior to dispensing and tested to ensure they were
free of bacterial contamination.
• HIV-1 antibody-positive plasma samples were heat-treated at 56ºC for 60 minutes to
inactivate infectious agents, whereas HIV-antibody-negative samples were not heattreated.
• The serostatus of both positive and negative samples was confirmed by all
FDA-approved rapid HIV antibody tests, as well as selected FDA-approved EIA and
Western blot kits.
• The Western blot results for the weak positive samples (e.g. highly reactive gp41 and p24,
weak or absent gp120 bands) indicated that the sera came from donors in the early
stages of HIV infection (i.e. these donors are seroconverters).
• Negative samples were negative for HIV-1 antigen using an FDA-approved monoclonal
antibody-based p24 antigen test. These samples were also HIV-negative by the FDAapproved HIV rapid testing kits that detect both HIV-1 and HIV-2 antibodies.
• Positive samples were selected using the following criteria:
o reactive by the Genetic Systems rLAV enzyme immunoassay kit at a signalto-cutoff ratio between 3 and 5 for the weak-positive seroconverter samples
and greater than 5 for the strong-positive samples, and
o
positive by the APHL/CDC interpretive criteria for Western blot (WB)
patterns.
The strong-positive and one of the weak-positive samples were included in the shipment in
duplicate.
6
Demographics
A total number of 622 different testing sites (foreign and domestic) submitted result forms.
Of these:
• the 557 domestic testing sites are depicted in Figure 1, and
Overview
• the 65 non-U.S. testing sites are listed in Table 3.
The types of testing site participants responding are depicted in Figure 2:
• The number of non-U.S. participants in the current survey (65) was similar to
the previous survey (June 2007, n = 69).
• Of the 65 non-U.S. participants, 53 (81.5%) are located in countries which are part
of the President’s Emergency Plan for AIDS Relief (PEPFAR).
• The number of U.S. participants in the current survey (557) was greater by
9.0% from that of the previous survey (511), primarily due to 44 new enrollees from
California and Maryland.
• In the U.S., hospital testing sites predominated.
Figure 1
Number of MPEP HIV Rapid Testing Laboratories Returning Results
in the United States and Territories
2
Maine
1 New Hampshire
0 Vermont
17
Washington
5
Oregon
11
Montan a
3
Idaho
2
Wyoming
3
Nevad a
Min neso ta
0
8
N. Dakota
40
20
Wisconsin Michigan
0
S. Dakota
68
California
10
Arizon a
0
Hawaii
6
Co lorado
1
New Mexico
38 Massachusetts
19
3 Connecticut
41 New Jersey
22 Delaware
29 Maryland
4 Dist. Columbia
Pennsy lvania
12
8 Ohio 5
9
10
Indi ana
Virginia
WV
Illino is
3
21
2
1
u cky
K ent
N. Car olina
Kansas
Missouri
7
Tennessee
8
Arkansas
7
SC
21
2
Oklahoma
5
Georgia
7 Alaba ma
Miss.
17
Florid a
6
Texas
8
4
Iowa
7
Nebraska
0
Utah
31
New
York
0 Rhode Island
0-5
6-10
11+
Louisiana
3
Alaska
Virgin Islands = 0
N = 557
Continued on next page
7
Demographics, Continued
The following table shows the breakdown of participants outside the United States.
Table 3
Country
Number
Country
Number
Albania
1
Kenya
1
Australia
2
Liberia
1
Bahamas
1
Malawi
1
Belgium
1
Malaysia
1
Botswana
3
Mali
1
Brazil
1
Nepal
1
Burkina Fas o
1
Niger
1
Burundi
1
Nigeria
1
Cameroon
2
Panama
1
Canada
2
Peru
1
Columbia
1
Philippines
3
Congo
1
Republic of Yemen
1
Cote d’I voire
1
Senegal
1
Dominican Republic
1
Slovakia
1
El Salvador
1
South Korea
1
Eritrea
1
Suriname
1
Ethiopia
2
Taiwan
1
Ghana
1
Tanzania
6
Guyana
1
Thailand
6
Honduras
1
Zambia
2
India
3
Zimbabwe
2
Indonesia
1
N = 65
Continued on next page
8
Demographics, Continued
The types of testing sites for all participants in the current survey are shown in Figure 2,
by U.S. and non-U.S. participants.
Figure 2:
Type of
testing
sites,
by U.S. &
non-U.S.
231
Hospital
12
72
Health Department
CBO*
FP Ctr*
15
65
0
60
0
51
CT Site*
4
26
24
Other**
19
Physician's Office
2
N = 622
13
Independent
4
STD Clinic
1
Blood Bank
3
0
U.S. (N=557)
Non-U.S. (N=65)
11
9
50
100
150
# of facilities
*Abbreviations:
CBO = community based organization
CT Site = counseling and testing site
FP Ctr = family planning center
STD clinic = sexually transmitted disease clinic
** “Other” facility type includes:
health maintenance organization (HMO)
correctional facility
drug use treatment center (DTC)
mobile unit (other than blood donation)
9
200
250
Detailed Performance Results
Table 4 below gives the reactivity results by donor.
Table 4
Reactiv ity
Donor Number
27
(Negative)
13
(Strong Pos)
23
( Weak Pos)
24
(W eak Pos)
# of
P articipant s
# of
Result s*
# P os.
# Neg.
# Ind
% Correct
618**
631
6
625
0
99.0%
618
1262
1256
4
2
99.5%
618
1262
1229
28
5
97.4%
618
628
614
9
5
97.8%
* Some testing sites used more than one type of testing kit, therefore, the total
number of results may exceed the total number of participants.
** Note: Four sites returning responses did not have their MPEP sample testing results
included in the analyses. One of the sites gave no testing results; the other
three sites reported rapid testing results for which the sample code did not
match the sample panel they were shipped and their answers were inconsistent
with the sample code they reported.
MPEP
plasma
samples,
detailed
performance
results
MPEP Negative Sample (Donor 27):
¾ Six false-positive results were reported; five by U.S. sites, and one by a non-U.S. site.
¾ No indeterminate results were reported.
MPEP Positive Samples:
¾ 53 incorrect results were reported on the MPEP HIV-positive samples. Of these:
o
41 were false negative errors (39 by U.S. and 2 by non-U.S. sites), with
28 errors reported for weak-positive Donor 23,
9 errors reported for weak-positive Donor 24, and
4 errors reported for strong-positive Donor 13.
o
12 were indeterminate results.
o
Of these positive sample errors, 39/53 (74%) were made as multiple errors by
13 testing sites.
Continued on next page
10
11
Non-Reactive/Negative
1577
311
210
205
610
45
25
45
4
10
20
10
80
316
63
42
41
122
9
5
9
1
2
4
2
16
4
10
20
10
79
40
45
25
608
205
209
310
1534
0
0
0
0
1
1
0
0
1
0
1
1
36
0
0
0
0
0
4
0
0
1
0
0
0
7
100.0%
100.0%
100.0%
100.0%
98.8%
88.9%
100.0%
100.0%
99.7%
100.0%
99.5%
99.7%
97.3%
**The site using this kit reported the one false negative in the “Other” category
1
2
4
2
16
9
9
5
121
41
42
63
316
1
2
4
2
16
9
9
5
121
41
42
63
316
0
1
0
0
0
0
0
0
0
0
0
0
5
1
1
4
2
16
9
9
5
121
41
42
63
311
0
0
0
0
0
0
0
0
0
0
0
0
0
100.0%
50.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
98.4%
5
12
24
12
96
54
54
30
731
246
252
374
1893
5
11
24
12
95
49
54
30
729
246
251
373
1845
100.0%
91.7%
100.0%
100.0%
99.0%
90.7%
100.0%
100.0%
99.7%
100.0%
99.6%
99.7%
97.5%
Totals
Total #
# of
# of
#
# Non#
# of # of
#
# Non#
%
#
% Correct
of
% Correct
Sites Results Reactive Reactive Indeter
Sites Results Reactive Reactive Indeter Correct
Correct
Results
Reactive/Positive
Bioline HIV 1/2 3.0 (Standard Diagnostics); 4 sites;
Doublecheck II (Orgenics), 3 sites;
Hexagon HIV (Human), 3 sites, and one site each reported using:
HIV Cadispots (Cadila Pharm.), Biolytical, NEVA (Cadila Pharm.),
Retrocheck HIV (QualPro Diag.)**, ImmunoComb II HIV 1/2 (Biospot
Orgenics), & CombAIDS RS Advantage (Span Diagnostics)
*Other kit types included:
Oraquick ADVANCE Rapid HIV-1/2
Ab Test (OraSure)
Reveal G3 Rapid HIV-1
Antibody Test (MedMira)
Determine HIV-1/2 (Abbott)
Clearview HIV 1/2 Stat-Pak
(Inverness Medical)
Uni-Gold Recombigen HIV
(Trinity Biotech)
Uni-Gold HIV (Trinity Biotech)
Capillus HIV (Trinity Biotech)
Multispot HIV-1/HIV-2
(Bio-Rad)
Genie II HIV-1/HIV-2 (Bio-Rad)
Serodia HIV (Fujirebio)
Serodia HIV 1/2 (Fujirebio)
HIV 1/2 Stat-Pack (CASSETTE)
Other*
Kit Type (manufacturer)
Table 5: Results by test kit
Detailed Performance Results, Continued
Table 5 gives the accuracy for all samples by kit type
Kit Types Used By Participants
Overview
This section describes the kit types used by participants.
• The predominant kit type used in the U.S. was OraQuick ADVANCE Rapid HIV 1/2 Ab
test (57.1%, 319/559 ), as shown in Figure 3:
• The predominant kit type used in non-U.S. testing sites was Abbott Determine HIV-1/2
(53.2%; 41/77).
• Kit usage by lab type is shown in Figure 4.
Figure 3:
Uni-Gold Recombigen
(Trinity Biotech)
319
1
122
0
62
Reveal G3 or G2 Rapid HIV-1
(MedMira)
Kit Type
Kit types
OraQuick ADVANCE HIV-1/2 Ab
(Orasure)
1
1
Determine HIV-1/2
(Abbott Diagnostics)
41
40
Clearview HIV 1/2 Stat-Pak
(Inverness Medical)
1
8
Multi-Spot HIV-1/HIV-2
(BioRad)
1
6
Uni-Gold
(Trinity Biotech)
Other *
3
(n = 636 responses)
(N = 622 unique facilities)
1
U.S. (n=559)
29
0
25
Non-U.S. (n=77)
50
75 100 125 150 175 200 225 250 275 300 325 350 375
# of Responses
* “Other” kit types include:
HIV 1/2 Stat-Pak (Cassette) (2 non-US, 0 US responses)
Capillus (Trinity Biotech) (5 non-US, 0 US responses)
Serodia HIV-1/2 (Fujirebio) (4 non-US, 0 US responses)
Serodia HIV (Fujirebio) (2 non-US, 0 US responses)
Genie II HIV-1/HIV-2 (BioRad) (0 non-US, 1 US responses)
Other kit type, specified (16 non-US, 0 US responses); see
Table 5 for complete list.
Continued on next page
12
Kit Types Used By Participants, Continued
The following figure illustrates the usage of the kit types by type of testing site. The methods for
which there were seventeen or less results are included in the “other kit type” category.
The predominate test kit used was OraQuick ADVANCE Rapid HIV 1/2 Ab Test. The percent
of sites using this kit, by type of facility, is as follows:
• hospitals, 41.7%
• health departments, 64.8%
• outreach sites (family planning centers, CT sites, DUTCs, STD clinics, mobile
units, correctional facilities, independent sites, and HMOs)*, 50.9%
• CBOs*, 73.8%
• blood banks, 46.2%
• physician offices, 57.1%
Note: Some testing sites used more than one type of testing kit.
Testing
site
by kit type
140
(n = 636 responses)
120
1 03
100
# of responses
Figure 4:
80
59
58
60
48
43
42
42
40
25
24
20
11
16
14
8
75
18
16
12
6
0
0 0
1
0
00
2
0
2
5
3 4
0
3 3
5 74
0
3
3 3
6
0
1 0
98
41 1
1
0 0
0
Hospital
Health
Dept
CBO*
Family
Planning
Center
CT Site*
DTC*, STD, Physician's
MU, CF, IND,
Office
or HMO
Blood Bank
Other
Testing Site
Abbott Determine HIV-1/2
Inverness Medical Clearview HIV 1/2 Stat-Pak
OraQuick ADVANCE Rapid HIV-1/2 Ab
Other kit type, specified
Trini ty Biotech Uni-Gold Recombigen HIV
Reveal G3 Rapid HIV-1 Antibody Test
*Abbreviations:
CBO = community based organization
DTC = drug treatment center
STD = sexually transmitted disease clinic
IND = independent
CT Site = counseling and testing site
13
CF = correctional facility
MU = mobile unit
HMO = health maintenance organization
Specimen Types Used By Participants
Overview
Participants were asked what type of specimens they normally use for HIV rapid tests.
° The breakdown in specimen types reported is shown in Figure 5.
° Testing sites could report using more than one specimen type.
300
Figure 5:
(n = 1,085 responses)
258
Specimen
types
250
233
# of res ponses
200
173
142
150
140
100
75
62
50
2
0
Serum
Fresh
Serum
Frozen
Plasma
Fresh
Plasma
Frozen
Whole
Blood
[Finger S tick]
Whole
Blood
Oral
Fluid
Other*
[Venous]
Type of Specimen
* Both “Other” specimen types were indicated as dried blood spots
The type of specimen(s) used in performing HIV rapid testing varied by the type of facility
and the method of rapid testing (kit type).
The number and percentage of reports indicating use of oral fluid (140/1085, 12.9%) was similar
to the previous survey (142/1036, 13.7%).
14
Quality Control (QC)
Overview
Testing sites were asked if they used quality control (QC) samples, either positive or
negative, when performing HIV rapid tests. The frequency of use of quality control
materials is shown in Figure 6.
• 621 of the 622 facilities that returned responses answered the
question regarding use of quality control samples (question #5).
• Most of these facilities (94.7%, 588/621) indicated the use of QC samples
for at least one of the kit types they use at their testing site.
• Of the 1,566 responses indicating the source(s) from which the QC samples
(positive and/or negative) were obtained, the sources identified were as follows:
− controls obtained from the same manufacturer as the test kit (91.2%, 1428/1566),
33.3% (476/1428) were included in the test kit, and
66.7% (952/1428) were purchased from the kit manufacturer separately.
− in-house controls (6.4%, 100/1566).
− “Other” manufacturer (manufacturer not the same as for the test kit) controls
(2.4%, 38/1566).
Notes: 1. Testing sites could provide more than one answer.
2. Testing sites reporting the use of multiple kit types answered the question separately
for each kit type.
Figure 6:
45 0
Frequency
of use of
quality
controls
40 0
434
(n = 1 ,82 0 r espo nse s)
# of Re sponses
35 0
31 7
30 0
27 3
269
25 0
20 0
166
15 0
1 05
10 0
69
56
53
50
27
28
23
0
r
ft e
i
sh
of
ft
te
st
s*
st
te
ch
ea
y
er
Ev
A
r#
r
n
ru
r
15
te
Af
e
th
ly
y
y
kl
x
ch
ea
bo
t
en
to
ra
pm
pe
O
i
sh
t
lo
l
th
on
ee
ai
O
D
M
W
it h
ew
ew
ew
ew
W
N
N
N
N
* The most frequent response was ‘after 25 tests’ (Range 10-250)
Confirmatory Testing
Overview
The types of confirmatory testing reported by laboratories varied (as shown in Figure 7).
Note: Testing sites could answer by indicating more than one confirmatory test.
•
Most responses given (644/988; 65.2%) indicated that reactive (preliminary positive)
specimens were sent to another facility.
•
In several cases, EIA was performed alone (29/988; 2.9%) or in combination
with other testing (203/988; 20.5%).
•
Some responses given (140/988; 14.2%) indicated using a second rapid test for
confirmatory testing. Of these, 21/140 (15.0%) indicated using a second
rapid test with no other type of confirmatory testing.
Twenty-four respondents indicated that no confirmatory testing was required to confirm a
positive result for the HIV rapid testing kit listed on at least one form. Of these:
•
Eighteen sites did not indicate the use of confirmatory testing with any HIV rapid test kit;
o
eleven were U.S. facilities, with the purpose for using the specified kit being
¾ HIV initial testing (e.g. for patients/clients, needlestick and/or source
patient): six testing sites.
¾ non-clinical testing (e.g. research, training, etc.) and/or determination of
HIV-1 vs. HIV-2 reactivity: four testing sites.
¾ used for confirmatory testing and determination of HIV-1 vs. HIV-2
reactivity: one testing site.
o
seven were non-U.S. facilities, with the purpose for using the specified kit being
¾ HIV initial testing: five testing sites.
¾ non-clinical HIV testing: two testing sites.
Continued on next page
16
Confirmatory Testing, continued
Figure 7:
Types of
confirmatory
testing
463
WB, sent out
10
61
EIA, in our facility
28
136
EIA, sent out
7
91
2nd Rapid Test, same test kit, in our facility
10
49
WB, in our facility
20
12
25
2nd Rapid Test, different test kit, in our facility
18
IFA, sent out
0
(N = 622 unique facilities)
3
2
IFA, in our facility
U.S. Participant
Responses, n=8 64
12
7
Other in our facility
0
2
2nd Rapid Test, different test kit, sent out
Non-U.S. P articipant
Responses, n=1 24
8
0
Other, sent out
0
17
(n = 988 responses)
11
13
No confirmatory testing required
50
100
150
200 250 300 350
# of Re sponses
400
450
500
Conclusions and Discussion
Overall
performance
Overall accuracy in this shipment was 98.4%:
• 98.3% for the positive samples;
o 99.5% for Donor 13 (strong positive),
o 97.4% for Donor 23 (weak positive), and
o 97.8% for Donor 24 (weak positive).
• 99.0% for the negative sample (Donor 27).
Specimen
types
The number of testing sites reporting the use of oral fluid as one of their normal specimen types
(140 responses) remained approximately the same as the previous survey (142 responses). Of
these, 138 were U.S. testing sites that tended to be health departments (37/138), community
based organizations (CBO) (33/138), counseling and testing sites (28/138), or family planning
centers (10/138). The 138 U.S. sites reporting oral fluid use represented 43.3% (138/319) of
U.S. sites using the OraQuick ADVANCE HIV-1/2 Antibody test kits.
In this survey, 56 U.S. testing sites reported using serum and/or frozen plasma as specimen
types for the OraQuick ADVANCE HIV-1/2 Antibody test kits. It should be noted that:
• The OraQuick test is not FDA approved for serum (fresh or frozen) or for frozen plasma
specimens.
Use of non-FDA approved specimen types for either of these test kits is considered a
modification of the OraQuick testing procedure and makes these non-waived under the
Clinical Laboratory Improvement Amendments (CLIA). U.S. facilities should be aware of the
CLIA regulations requiring the establishment of performance specifications when modifying an
FDA-approved test (Sec. 493.1253).5
Errors on
positive
samples
The results from the current survey show a low number of errors on the positive challenge
plasma samples (53/3152, 1.7%), lower than the previous two surveys (December 2007
and June 2007), but similar to the June 2006 survey and other previous surveys. The
unusually high error rate in the June 2007 & December 2006 surveys has been previously
discussed in their respective reports (http://wwwn.cdc.gov/mpep/hiv-1rt.aspx).
A summary of error rates for the past five HIV Rapid Testing MPEP sample surveys is
shown below:
o
o
o
o
o
216/3043 (7.1%) for the June 2007 survey
169/2184 (7.7%) for the December 2006 survey
21/1489 (1.4%) for the June 2006 survey,
4/1464 (0.3%) for the December 2005 survey, and
27/2414 (1.1%) for the June 2005 survey.
The majority of the false-negative errors in the current survey (28/41; 68.3%) were reported
for the weak Donor 23 samples in the performance evaluation panels.
It should be emphasized that all donor material undergoes extensive validation testing prior
to inclusion in an HIV Rapid Testing MPEP survey panel.
Continued on next page
18
Conclusions and Discussion, Continued
Some U.S. testing sites that use HIV rapid tests for HIV initial testing purposes (i.e. screening)
continue to use confirmatory testing algorithms that do not include Western blot (WB) or
indirect immunofluorescence assay (IFA) as recommended by the CDC.
Confirmatory
testing
U.S. participants are reminded that:
1) HIV rapid tests (RT) are screening tests and reactive results are considered to be
“preliminary positives” that must be confirmed by either a WB or IFA test.1,2
2) EIA tests for HIV are also considered to be screening, not confirmatory, tests. Some RT
reactive specimens confirmed positive by WB or IFA produce negative results using EIAs.
3) CDC Guidelines recommend that preliminary positive (reactive) HIV rapid tests be
confirmed with WB or IFA, even if a subsequent EIA test is nonreactive.3
Guidelines
Testing sites are advised to follow appropriate guidelines with respect to performing HIV rapid
tests and reporting results.1,2 Attention to recognized guidelines and good testing practices is
crucial to patient safety and to the delivery of accurate test results.
For example, the CDC has published quality assurance guidelines for testing using the waived
HIV rapid tests1 These guidelines can be applied to other HIV rapid tests performed in U.S.
sites.
The guidelines:
•
stress that a testing site must have an adequate quality assurance (QA) program in place
before offering rapid HIV testing,
•
provide recommendations for a comprehensive QA program,
•
include recommendations regarding test verification to ensure that the test kits work as
expected in a given testing environment,
•
encourage participation in an external quality assessment program, such as the MPEP, and
address the logistics for providing confirmatory testing for preliminary positive (reactive)
results.1,2
Continued on next page
19
Conclusions and Discussion, Continued
References
1. Quality Assurance Guidelines for Testing Using Rapid HIV Antibody Tests Waived Under the
Clinical Laboratory Improvement Amendments of 1988. Centers for Disease Control and
Prevention, U.S. Dept. of Health and Human Services. July 24, 2007.
http://www.cdc.gov/hiv/topics/testing/resources/guidelines/qa_guide.htm
2. CDC. Revised guidelines for HIV counseling, testing, and referral. MMWR 2001; 50(No. RR19):1-57. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5019a1.htm
3. Notice to Readers: Protocols for Confirmation of Reactive Rapid HIV Tests. MMWR 2004;
53(10): 221-222. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5310a7.htm
4. Notice to Readers: Approval of a New Rapid Test for HIV Antibody. MMWR 2002; 51(46):
1051-1052. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5146a5.htm
5. Code of Federal Regulations: Laboratory Requirements, 42 C.F.R. Chapter IV,
Part 493 (2003). http://www.phppo.cdc.gov/clia/regs/toc.aspx
20
Topical Issues in HIV Rapid Testing
Introduction
The HIV Rapid Testing Model Performance Evaluation Program (HIV-RT MPEP)
strives to be a resource for facilities using HIV rapid testing kits. This section of the HIV-RT
MPEP Report of Results, “Topical Issues in HIV Rapid Testing,” is intended to address that part
of our mission. We are including:
° Frequently Asked Questions (FAQs) by HIV RT MPEP participants to share with
all participants our responses to some recent queries,
° CDC websites to provide participants with access to timely relevant material
published online by the CDC, and
° HIV Rapid Testing Resources as a link to long-term references.
This section provides answers to some of our participants’ frequently asked questions (FAQs).
FAQs:
December
2007 survey
Highlights
of previous
FAQs
Q: Will we be getting an individual report (or grade) from the MPEP?
A: No. The MPEP provides a “Donor Report”, which is mailed one to two weeks after the
submission deadline, for our participants to self-grade. The Donor Report (see Table 1, pg 3)
provides the correct results for each donor and panel shipped for the current survey.
Q: (from U.S. testing sites) If we participate in your program, will we be satisfying the
legal requirements for performing HIV rapid testing on client/patient samples?
A: Not necessarily. The MPEP is not part of any regulatory body; we maintain the confidentiality
of our participants’ results. You should check with your state department of health for specific
information regarding legal approval for performing HIV rapid testing on clinical specimens.
Q: Can I use an expired kit to do my MPEP sample panel (or patients) if the device control
(the control line/dot) within the testing device develops properly?
A: No.
The expiration dates set by the manufacturers reflect the ability of the test kits to produce a valid
result for all samples over a specific time frame; while proper development of the device control
must occur for a valid test, a valid test result also depends on the tester adhering to ALL of the
manufacturer’s instructions–including using a non-expired test kit.
Q: May we use as QC material the positive and/or negative MPEP samples left over
from the panels you send us?
A: No, this is an inappropriate use of MPEP samples.
Our samples are validated only for the purpose of performance evaluation (PE) in HIV rapid
testing. While we recognize that extra sample volume (i.e. not used to do the test for the survey
shipment) in our panels has been, and will continue to be used effectively for training/practice
purposes, the “left-over” sample material is not designed to be used in the very important role of
Quality Control (QC) samples. Appropriate QC material can be purchased from a number of
commercial sources.
For more information on proper specimen labeling and other good laboratory testing practices,
please see Good Laboratory Practices for Waived Testing Sites, [MMWR 54(RR13):1-25] at:
http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5413a1.htm
Continued on next page
21
Topical Issues in HIV Rapid Testing, Continued
Highlights
of previous
FAQs
(continued)
Q: What types of specimens can be used in performing HIV rapid testing?
A: The type(s) of specimens (e.g. whole blood, serum, plasma, oral fluid, etc.) that are
appropriate to use for HIV rapid testing depends on the test kit used. Each manufacturer
includes information regarding approved specimen type(s) in the package insert for their HIV
rapid testing kit.
Q: Can I read my HIV rapid test results as soon as the control line/spot appears?
A: You need to wait the minimum time as specified in the directions given by the manufacturer
(as found in the package insert) before reading the result for a client/patient. Even if the withindevice control line/spot can be seen, positive specimens may need the full minimum time for the
color to develop properly. Please note that you should not read results after the specified
maximum time limit.
To view other FAQs in previous HIV RT MPEP reports, please visit our website at:
http://wwwn.cdc.gov/mpep/hiv-1rt.aspx
CDC
websites
Quick Facts: Rapid Testing
http://www.cdc.gov/hiv/topics/testing/index.htm
MMWR: Notice to Readers: Protocols for Confirmation of Reactive Rapid HIV Tests
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5310a7.htm
Quality Assurance Guidelines for Testing Using Rapid HIV Antibody Tests Waived Under the
Clinical Laboratory Improvement Amendments of 1988. Centers for Disease Control and
Prevention, U.S. Dept. of Health and Human Services. July 24, 2007.
http://www.cdc.gov/hiv/topics/testing/resources/guidelines/qa_guide.htm
International Laboratory-related Resource and Activity Directory
http://wwwn.cdc.gov/dls/default.aspx
MMWR: Good Laboratory Practices for Waived Testing Sites
http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5413a1.htm
HIV
rapid
testing
resources
HIV Rapid Testing MPEP website: http://wwwn.cdc.gov/mpep/hiv-1rt.aspx
Model Performance Evaluation Program (MPEP) Home page: http://wwwn.cdc.gov/mpep/
Food and Drug Administration (FDA) Licensed / Approved HIV, HTLV and Hepatitis Tests
http://www.fda.gov/cber/products/testkits.htm
The National Center for HIV, STD, and TB Prevention (NCHSTP)
Divisions of HIV/AIDS Prevention (DHAP) website: http://www.cdc.gov/hiv/default.htm
The National Center for HIV, STD, and TB Prevention (NCHSTP) Home page
http://www.cdc.gov/nchhstp/
The World Health Organization: http://www.who.int/en/
22
| File Type | application/pdf |
| File Title | report cover 0506.ai |
| File Modified | 2008-04-23 |
| File Created | 2008-04-16 |