Nucleic Acid Testing (NAT) for Human Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus (HCV): Testing, Product Disposition, and Donor Deferral and Reentry: Guidance for Industry

Administrative guidance, not enacted legislation. This captured publisher edition preserves the listed document and attachments; later developments are not independently consolidated.

Nucleic Acid Testing (NAT) for
Human Immunodeficiency
Virus Type 1 (HIV-1) and
Hepatitis C Virus (HCV):
Testing, Product Disposition, and
Donor Deferral and Reentry
Guidance for Industry
This guidance is for immediate implementation.
FDA is issuing this guidance for immediate implementation in accordance with
21 CFR 10.115(g)(4)(i). Submit one set of either electronic or written comments on this
guidance at anytime. Submit electronic comments to https://www.regulations.gov. Submit
written comments to the Dockets Management Staff (HFA-305), Food and Drug Administration,
5630 Fishers Lane, Rm. 1061, Rockville, MD 20852. You should identify all comments with
docket number FDA-2005-D-0140.
Additional copies of this guidance are available from the Office of Communication, Outreach
and Development (OCOD), 10903 New Hampshire Ave., Bldg. 71, Rm. 3128, Silver Spring,
MD 20993-0002, or by calling 1-800-835-4709 or 240-402-8010, or email ocod@fda.hhs.gov, or
from the Internet at
https://www.fda.gov/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guid
ances/default.htm.
For questions on the content of this guidance, contact OCOD at the phone numbers or email
address listed above.
U.S. Department of Health and Human Services
Food and Drug Administration
Center for Biologics Evaluation and Research
May 2010
Updated December 2017

Nucleic Acid Testing (NAT) for Human
Immunodeficiency Virus Type 1 (HIV-1) and
Hepatitis C Virus (HCV): Testing, Product
Disposition, and Donor Deferral and Reentry
Guidance for Industry
Note: Changes have been made to update the “Guidance for Industry: Nucleic Acid Testing
(NAT) for Human Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus (HCV):
Testing, Product Disposition, and Donor Deferral and Reentry,” dated May 2010, including:
• 	Revised recommendations for reentry of donors deferred because of reactive HCV test
results in Section V.B. The recommendations have been revised because of the
discontinuation of the CHIRON® RIBA® HCV 3.0 SIA (RIBA), that was intended for
use as an additional, more specific test on human serum or plasma specimens found to be
repeatedly reactive using a licensed anti-HCV screening test.
• 	Updated the definition of “Discriminatory NAT” in Section II. and made corresponding
editorial revisions to recommendations in Section IV.C. and Sections V.A and V.B. to
reflect approval of multiplex NAT assays that directly detect HIV-1 RNA and HCV RNA
and simultaneously detect and discriminate HIV RNA and HCV RNA.
• 	Updated regulation citations for consistency with the current Code of Federal
Regulations.
• 	Updated the Background and Discussion in Section III. to include the current estimates of
HIV-1 and HCV in blood donations and the donor screening tests licensed since
publication of the May 2010 guidance.
U.S. Department of Health and Human Services
Food and Drug Administration
Center for Biologics Evaluation and Research
May 2010
Updated December 2017

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Table of Contents
I. 	INTRODUCTION..............................................................................................................1
II. 	DEFINITIONS ...................................................................................................................2
III. 	BACKGROUND AND DISCUSSION .............................................................................3
A. 	NAT Algorithms .....................................................................................................6
B. 	Donor Reentry ........................................................................................................7
IV. 	RECOMMENDATIONS FOR NAT ALGORITHMS .................................................10
A. 	Testing, Product Disposition, Donor Management, and Lookback for a
Minipool that is Reactive on a Multiplex NAT (MP-NAT): Resolution by
Testing Subpools or by Testing Individual Donor Samples .............................10
B. 	Testing, Product Disposition, Donor Management, and Lookback for a
Minipool that is Reactive on a Single Virus NAT (MP-NAT): Resolution by
Testing Subpools or by Testing Individual Donor Samples .............................15
C. 	Testing, Product Disposition, Donor Management, and Lookback for an
Individual Donor Sample that is Reactive on a Multiplex NAT (ID-NAT)
after Negative Antibody Screening Tests ...........................................................19
D. 	Testing, Product Disposition, Donor Management, and Lookback for an
Individual Donor Sample that is Reactive on a Single Virus NAT (ID-NAT)
after Negative Antibody Screening Tests ...........................................................23
V. 	RECOMMENDATIONS FOR DONOR REENTRY ...................................................26
A. 	Reentry for Donors Deferred Because of Reactive HIV-1/2 Test Results ......26
B. 	Reentry for Donors Deferred Because of Reactive HCV Test Results ...........33
VI. 	REFERENCES .................................................................................................................39

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Nucleic Acid Testing (NAT) for Human Immunodeficiency Virus
Type 1 (HIV-1) and Hepatitis C Virus (HCV): Testing, Product
Disposition, and Donor Deferral and Reentry
Guidance for Industry
This guidance represents the current thinking of the Food and Drug Administration (FDA or
Agency) on this topic. It does not establish any rights for any person and is not binding on FDA
or the public. You can use an alternative approach if it satisfies the requirements of the
applicable statutes and regulations. To discuss an alternative approach, contact the FDA staff
responsible for this guidance as listed on the title page.
I. 	INTRODUCTION
We, the Food and Drug Administration (FDA), are providing recommendations to you, blood
and plasma establishments, manufacturers, and testing laboratories for testing individual samples
or pooled samples from donors of human blood and blood components for Human
Immunodeficiency Virus Type 1 (HIV-1) ribonucleic acid (RNA) and Hepatitis C Virus (HCV)
RNA using the Nucleic Acid Test (NAT). This guidance also contains recommendations
regarding product disposition and donor management based on the results of NAT testing for
markers of HIV-1 and HCV infection on samples, collected at the time of donation, from donors
of human blood and blood components.
This guidance amends the guidance entitled, “Nucleic Acid Testing (NAT) for Human
Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus (HCV): Testing, Product
Disposition, and Donor Deferral and Reentry” dated May 2010 (75 FR 22814). The May 2010
guidance finalized the draft guidance of the same title, dated July 2005 and also superseded the
recommendations for reentry of donors deferred because of anti-HIV-1 test results, HIV-1 p24
antigen test results, and anti-HCV test results that were provided in the FDA memoranda
entitled, “Revised Recommendations for the Prevention of Human Immunodeficiency Virus
(HIV-1) Transmission by Blood and Blood Products” April 23, 1992; “Revised
Recommendations for Testing Whole Blood, Blood Components, Source Plasma and Source
Leukocytes for Antibody to Hepatitis C Virus Encoded Antigen (Anti-HCV)” August 5, 1993;
“Recommendations for Donor Screening with a Licensed Test for HIV-1 Antigen” August 8,
1995 (Refs. 1 through 3).
FDA’s guidance documents, including this guidance, do not establish legally enforceable
responsibilities. Instead, guidances describe the FDA’s current thinking on a topic and should be
viewed only as recommendations, unless specific regulatory or statutory requirements are cited.
The use of the word should in FDA guidances means that something is suggested or
recommended, but not required.

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II. 	DEFINITIONS
Anti-HIV-1 or -2 Test or Anti-HIV-1/2 Test or Anti-HCV Test: A screening test, such as an
enzyme immunoassay, performed on donations of blood and blood components, that FDA has
licensed, approved or cleared for such use (hereinafter referred to as “licensed”).
Deconstruction: Resolution of the reactivity of a minipool by testing subpools (original or
freshly made) or samples from individual donors that formed the minipool. Deconstruction of a
reactive minipool to individual units is a required step for all approved tests.1
Discriminatory NAT: A NAT that uses specific primers for HIV-1 or HCV to identify the
RNA in a reactive multiplex NAT sample that might contain either HIV-1 RNA or HCV RNA
based on the assay. Performing a Discriminatory NAT assay on a reactive sample is a required
step for those establishments using certain multiplex tests that do not simultaneously detect and
discriminate HIV RNA and HCV RNA in the same reaction.2
Donor Reentry: A procedure that qualifies a deferred donor as eligible to donate again. Donor
reentry procedures may be used following a false positive test result and typically require the
passage of time to allow for possible seroconversion prior to the performance of additional
serologic testing and NAT (see sections V.A. and V.B. of this document).
Lookback: A series of actions taken by a blood establishment based on donor test results
indicating infection with HIV-1 or HCV. These actions relate to the donor’s prior donations that
possibly were donated during the window period when HIV-1 or HCV RNA and antibody were
not detectable by screening tests but the infectious agent might be present in the donor’s blood.
These actions include: quarantining the remaining inventory of prior collections from that donor,
notifying consignees to quarantine prior collections, further testing of the donor, destroying or
re-labeling potentially infectious prior collections, and when appropriate, notifying transfusion
recipients who received human blood or blood components from that donor.
Minipool: A pool of donor samples on which NAT (minipool NAT or MP-NAT) is performed
as a screening test. A minipool is formed by pooling of samples from subpools or by directly
pooling samples from individual donors.
Multiplex NAT: A NAT that simultaneously detects HIV-1 RNA and HCV RNA.
Single Virus NAT: A NAT that separately detects either HIV-1 RNA or HCV RNA.
Subpool: A pool of donor samples that was used with other (sub)pools to form the minipool or
that was formed as a result of “deconstruction” of the minipool.
1 Under Title 21 of the Code of Federal Regulations (CFR) 610.40(b) (21 CFR 610.40(b)), you must use screening
tests that FDA has licensed, approved, or cleared for such use, in accordance with the manufacturer’s instructions.
2 Id.

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III. 	BACKGROUND AND DISCUSSION
FDA has progressively strengthened the overlapping safeguards that protect patients from
unsuitable blood and blood products. Blood donors are now asked specific and very direct
questions about risk factors that could indicate possible infection with a transmissible disease.
This “up-front” screening eliminates approximately 90 percent of ineligible donors. In addition,
FDA requires blood centers to maintain lists of deferred donors to prevent the use of collections
from them.
During the past decade blood establishments have implemented new donor screening tests,
including sensitive tests for viral antibody, antigen (for HIV-1), and nucleic acids, and there has
been a dramatic reduction in the transmission of HIV-1 and HCV by human blood and blood
components. Sources of remaining risk for HIV-1 and HCV transmission by human blood
products include: 1) marker-negative “window period” donations (made during the period that
the donor is infected with a virus, but neither the virus nor antibodies to the virus are detectable
by current tests); 2) donors infected with genetic and immunovariant viral strains; 3) persistent
antibody-negative (immunosilent) carriers; and 4) laboratory errors. According to a recent
report, donations during the window period constitute most of the risk of HIV-1 and HCV
transmission (Ref. 4). Therefore, measures to reduce the window period might further reduce the
residual risk of HIV-1 and HCV transmission by human blood and blood components.
Studies performed using seroconversion panels indicate the value of NAT in reducing the
window period for HIV-1 and HCV. The estimated mean window-period reduction for HIV-1
RNA by pooled sample NAT is approximately 11 to 15 days relative to antibody testing and 5 to
9 days relative to HIV-1 p24 antigen testing (Refs. 5 through 7). NAT for detection of HCV has
been estimated to reduce the window period by 50 to 60 days relative to that for HCV antibody.
During a ten-year period (1999-2008), approximately 66 million donations were screened with
32 HIV (1:2 million) and 244 HCV (1:270,000) NAT yield (RNA-positive but antibody-
negative) donations identified (Ref. 6). Subsequent to implementation of NAT, the residual risk
of HIV-1 and HCV in screened human blood and blood component donations in 2007-2008 was
estimated to be approximately 1 in 1,467,000 donations for HIV-1 and 1 in 1,149,000 donations
for HCV (Ref. 6).
In September 1994, we held a workshop to discuss the potential application of nucleic acid based
methods to donor screening for HIV-1. We concluded at the time that these methods clearly
were sensitive, but they were not ready for implementation on a large scale.
The industry actively pursued the development of NAT for screening donors of human blood and
blood components. There was much interest in testing pools of plasma donor samples
(minipools) by NAT because of the cost and labor intensiveness of testing individual donor
samples. By 1997, some manufacturers in Europe had voluntarily instituted NAT on minipools.
In 1998, the European Union issued a directive that by July 1, 1999, HCV RNA testing would be
required in Europe for all plasma for fractionation and that the requirement for HIV-1 RNA
testing would follow at a later date.

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Large-scale clinical studies were needed to demonstrate the efficacy of NAT because of the
expected low frequency of window period donations. Test kit manufacturers and testing
laboratories submitted Investigational New Drug applications (INDs) describing their test
method and in-house validation of that method. Blood organizations and establishments
intending to use the assay for donor screening also filed INDs to describe their clinical trial
protocol for validation of pooled-donor sample NAT (MP-NAT) and individual donor sample
NAT (ID-NAT).
In December 1999, we issued a guidance for industry on the validation of NAT methods to
screen plasma donors (Ref. 8). This document provided guidance on test standards,
manufacturing requirements, and clinical trial requirements for licensure of the test method for
use in donor screening for transfusion-transmitted viruses.
In September 2001, we licensed the first NAT system, the National Genetics Institute (NGI)
UltraQual HIV-1 and HCV Reverse Transcription Polymerase Chain Reaction (RT-PCR) assays.
Under that license, NGI performs RT-PCR assays on pooled samples from donors of Source
Plasma.
In February 2002, we licensed the Procleix HIV-1/HCV Assay, a qualitative NAT for detection
of HIV-1 RNA and/or HCV RNA in plasma from donors of human blood and blood components
for transfusion. This assay was approved for use with individual donor samples or pooled donor
samples.
In December 2002, we licensed the COBAS AmpliScreen HCV Test, v 2.0 and the COBAS
AmpliScreen HIV-1 Test, v 1.5. These tests are qualitative in vitro tests for the direct detection
of HCV RNA and HIV-1 RNA in plasma samples from human donors, including donors of
Whole Blood, blood components, and Source Plasma, and from other living donors. These
assays were approved for use with individual donor samples or pooled donor samples.
In October 2004, we issued a final guidance, “Use of Nucleic Acid Tests on Pooled and
Individual Samples from Donors of Whole Blood and Blood Components (including Source
Plasma and Source Leukocytes) to Adequately and Appropriately Reduce the Risk of
Transmission of HIV-1 and HCV” dated October 2004 (October 2004 guidance). That guidance
combined and finalized the draft guidance “Use of Nucleic Acid Tests on Pooled Samples from
Source Plasma Donors to Adequately and Appropriately Reduce the Risk of Transmission of
HIV-1 and HCV” dated December 2001, and the draft guidance “Use of Nucleic Acid Tests on
Pooled and Individual Samples from Donors of Whole Blood and Blood Components for
Transfusion to Adequately and Appropriately Reduce the Risk of Transmission of HIV-1 and
HCV” dated March 2002.
The October 2004 guidance informed establishments collecting blood and blood components that
we have licensed NAT to screen blood donors for HIV-1 RNA and HCV RNA and that these
licensed tests could detect evidence of infection at a significantly earlier stage than is possible
under previously approved tests using antibody or antigen detection technology, including the
HIV-1 p24 antigen test. We also informed those establishments that we believe these newly

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licensed tests are now widely available and meet the criteria in 21 CFR 610.40(b) for screening
tests that are necessary to reduce adequately and appropriately the risk of transmission of
communicable disease through blood and blood products.
In the October 2004 guidance, we recommended the use of HIV-1 NAT and HCV NAT on units
that are not reactive on a donor-screening test for the detection of antibodies to HIV-1 or HCV,
respectively. However, for donations that are reactive on a test for the detection of antibodies to
HIV-1 or HCV and are to be discarded or used in the manufacture of non-injectable products, we
do not consider HIV-1 NAT and HCV NAT to be necessary as part of the adequate and
appropriate testing required under 21 CFR 610.40(b). We informed the establishments that even
though testing for these products is not required under 21 CFR 610.40(b), they may decide to
perform HIV-1 NAT and HCV NAT for these donations in order to obtain useful information
regarding the donor’s infection status. This information might be useful as part of donor
notification.
In October 2006, we licensed the Procleix Ultrio Assay, a qualitative in vitro assay system to
screen for HIV-1 RNA and HCV RNA in plasma and serum specimens from human donors,
including donors of Whole Blood, blood components, and Source Plasma, and from other living
donors. This assay was also approved for use with individual donor samples or pooled donor
samples.
In February 2007, we licensed the BioLife Plasma Services HIQ-PCR HIV-1 RT-PCR assay and
the HIQ-PCR HCV RT-PCR assay for the qualitative detection of HIV-1 RNA and HCV RNA,
respectively, in pools of human Source Plasma.
In December 2008, we licensed the cobas TaqScreen MPX Test, a qualitative in vitro screening
test for individual human donors, including donors of Whole Blood and blood components, and
other living donors, for the presence of HIV-1 Group M RNA, HCV RNA, and Hepatitis B Virus
(HBV) DNA. Plasma from all donors may be screened as individual specimens. For donations
of Whole Blood and blood components, plasma specimens may be tested individually or in
pools.
In May 2012, we licensed the Gen-Probe Procleix Ultrio Plus Assay, a qualitative in vitro test for
use on the Procleix TIGRIS System to screen for HIV-1 RNA, HCV RNA and HBV DNA in
plasma and serum specimens from individual human donors, including donors of whole blood,
blood components, and source plasma, and from other living donors. This assay was also
approved for use with individual donor samples or pooled donor samples.
In December 2014, we licensed the cobas TaqScreen MPX Test, version 2.0, for use the cobas s
201 system, a qualitative in vitro screening test for the direct detection of HIV-1 Group M RNA,
HIV-1 Group O RNA, HIV-2 RNA, HCV RNA and HBV DNA in plasma specimens from
individual human donors, including donors of Whole Blood, blood components, Source Plasma
and other living donors. Plasma specimens may be tested individually or in pools. For an
individual specimen, results are simultaneously detected and discriminated for HIV, HCV, and
HBV.

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In October 2016, we licensed the cobas MPX Test, for use on the cobas 6800/8800 Systems, a
qualitative in vitro test screening test for the direct detection of HIV-1 Group M RNA, HIV-1
Group O RNA, HIV-2 RNA, HCV RNA, and HBV DNA in human plasma and serum. The
cobas MPX Test simultaneously detects and discriminates for HIV, HCV and HBV and does not
discriminate between HIV-1 Group M, HIV-1 Group O, and HIV-2.
This guidance is intended to assist you with testing, product disposition, donor deferral, donor
notification, donor reentry, and lookback. We have written this document in general form
because other NAT may be approved in the future. However, where appropriate, we will
identify sections that apply to NAT that are already approved. You must follow manufacturers’
instructions regarding testing under 21 CFR 610.40(b).
A. 	NAT Algorithms
Under 21 CFR 610.40(b), you must use screening tests that FDA has licensed, approved,
or cleared for such use, in accordance with the manufacturer’s instructions. If you
perform NAT on pooled samples and obtain a reactive NAT result on a minipool, the
manufacturer’s instructions instruct you to perform subsequent testing to identify the
individual unit(s) that contains the RNA identified in the minipool test. Once you have
identified a positive unit, either by subsequent testing of a minipool or by initial
individual donor sample testing, you must not use the donation for transfusion or for
manufacturing into injectable products (21 CFR 610.40(h)(1)) unless an exception
applies (21 CFR 610.40(h)(2)). You must defer the donor (21 CFR 610.41(a)), and you
must inform the donor of the deferral and the reason for the deferral, including test results
if they were the basis for the deferral (21 CFR 630.40). You must also perform
“lookback” to identify blood products previously donated (21 CFR 610.46 and 610.47).
A reactive NAT result may indicate ongoing infection of the donor. Thus, prior
donations from that donor, although NAT-non-reactive, may pose a risk to transfusion
recipients.
In the FEDERAL REGISTER of August 24, 2007 (72 FR 48765), FDA published the
final rule entitled “Current Good Manufacturing Practice for Blood and Blood
Components; Notification of Consignees and Transfusion Recipients Receiving Blood
and Blood Components at Increased Risk of Transmitting Hepatitis C Virus Infection
(“Lookback”)” (Lookback rule) (Ref. 9). The Lookback rule established lookback
requirements related to HCV infection and revised the requirements related to HIV
infection. It requires that you perform lookback for HIV-1 and for HCV when donor
samples test reactive using HIV-1 NAT or HCV NAT. Donors infected with HIV-1 or
HCV may experience intermittent viremias for a variable period of time prior to a
persistently detectable viremia or an antibody response. Since these episodes of transient
viremia may extend over a longer window period than previously estimated, the
Lookback rule requires you to review all records for a period of 12 months before the
donor’s reactive NAT. A 12-month timeframe is necessary to encompass with sufficient
confidence the window period for HIV-1 or for HCV prior to the detection of antibody.

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We have not established an alternative (possibly shorter than 12 months) lookback period
based on the last non-reactive NAT, in order to minimize operational complexity and
because the appropriate period has not been well established scientifically.
At the meeting of the Blood Products Advisory Committee (BPAC) in March 20013,
FDA requested advice on appropriate algorithms for management of donations of human
blood and blood components tested by pooled donor sample NAT for both HIV-1 RNA
and HCV RNA. In particular, FDA sought comment on actions to be taken in the event
of discrepant testing results, such as when the minipool is reactive but individual donor
samples test non-reactive. Data generated using NAT under IND that was presented in
the BPAC meeting showed that in each discrepant case it was the minipool that was
falsely reactive, due to contamination either during specimen handling or during the
assay run. In response to FDA questions the BPAC voted to consider the NAT result on
samples from individual donors as the definitive test result, and recommended release
from quarantine for donations from those donors, on the basis of non-reactive individual
test results.
This guidance contains four recommended algorithms for use when NAT-reactive results
are obtained on individual samples or pooled samples from donors of human blood and
blood components. Note that these algorithms apply when only the HIV-1 NAT or HCV
NAT result is reactive (i.e., serologic tests for HIV-1/2 and HCV are negative). This
guidance also contains recommendations on product disposition, donor deferral criteria,
follow-up testing of the donor, donor notification, and lookback (product retrieval and
recipient notification). This guidance is not intended to replace manufacturers’
instructions for testing using approved tests.
The first and second algorithms (see sections IV.A. and IV.B, Figures 1 and 2, and Tables
1 and 2 of this document) recommend actions to deconstruct a reactive minipool by
testing archived or freshly pooled subpools or by testing individual donor samples. The
third and fourth algorithms (see sections IV.C. and IV.D, Figures 3 and 4, and Tables 3
and 4 of this document) recommend actions to be taken when a NAT-reactive result is
obtained on an individual sample from a donor of human blood or blood components.
B. 	Donor Reentry
Each year many donors are deferred from donating blood for an indefinite period because
of a false positive test result on a serologic test, followed by a negative or indeterminate
supplemental test for antibodies to HIV-1 or HCV. In addition to these deferrals the
implementation of NAT for HIV-1 RNA and HCV RNA has resulted in additional
deferrals of donors each year due to potentially false reactive NAT results.
These deferred donors may be eligible to be considered for reentry to donate blood or
blood components. Under 21 CFR 610.41(b), a deferred donor subsequently may be
found to be eligible as a donor by a re-qualification method or process found acceptable
3 https://wayback.archive-
it.org/7993/20170403222320/https://www.fda.gov/ohrms/dockets/ac/cber01.htm#Blood%20Products

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for such purposes by FDA. However, some establishments are not attempting to reenter
donors because of the complexity of the current reentry algorithms and concerns about
inappropriately reentering a donor. Although we do not require reentry of donors
deferred because of false positive test results, we issued guidance in April 1992 on
reentry of donors deferred because of a repeatedly reactive (RR) test for antibodies to
HIV-1 or HIV-2, and in August 1993 on reentry of donors deferred because of a RR test
for antibodies to HCV (Refs. 1 and 3).
This guidance contains recommendations for reentry of donors deferred because of
reactive HIV-1 NAT or HCV NAT or certain other test results in accordance with
21 CFR 610.41(a). We find these reentry methods to be acceptable within the meaning
of 21 CFR 610.41(b). Note that the reentry of a donor permits prospective donations
from a reentered donor who meets donor eligibility criteria. It does not affect the status
of previous collections from that donor, including donations subject to lookback.
Reentry of Donors (HIV Test Results)
In this guidance, we recommend that you consider for reentry three groups of donors
deferred because of reactive HIV-1 NAT or RR anti-HIV-1 or -2 test or RR anti-HIV-1/2
test or RR HIV-1 p24 antigen test results (see section V.A., Figure 5, and Table 5 of this
document). These three groups of donors include:
1. 	Donors with a reactive HIV-1 NAT result but who were seronegative for
antibodies to HIV-1 and HIV-2;
2. 	Donors with non-reactive HIV-1 NAT (or NAT was not performed) who had a
RR anti-HIV-1/2 test and an HIV-1 Western Blot (WB) or immunofluorescence
assay (IFA) that was indeterminate (viral bands may be present), unreadable,
negative, or was not performed; and
3. 	Donors with a positive or indeterminate result on the HIV-1 p24 Neutralization
test (Ref. 2), even on more than one occasion. This last group of donors may be
eligible for reentry because there are many donors who had (false) positive
Neutralization test results who are currently non-reactive by HIV-1 NAT and
negative by an anti-HIV-1 or anti-HIV-1/2 test.
FDA no longer recommends that blood and plasma establishments using certain approved
NAT methods perform screening for HIV-1 p24 antigen. If antigen testing continues to
be performed concurrent with NAT and antibody testing, donors deferred because of
HIV-1 p24 test results would continue to be eligible for reentry.
Data presented at the June 2001 BPAC meeting demonstrated that an 8-week waiting
period encompasses the pre-seroconversion window period for HIV-1 with sufficient
confidence that negative tests, after at least 8 weeks have passed, rule out HIV-1 infection

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(Ref. 10). Absent evidence for seroconversion, a negative NAT on follow-up testing
provides evidence that the prior reactive (but unconfirmed) NAT result was likely an
error.
Accordingly, for all three groups of donors, after a minimum time period of 8 weeks we
recommend that you take a follow-up sample from the donor for testing by both HIV-1
ID-NAT and an anti-HIV-1/2 test. Performing follow-up testing first on a new sample
from the donor, collected before another donation, may prevent a potentially
contaminated unit from being collected and placed in inventory at the blood
establishment. If the ID-NAT is non-reactive and the anti-HIV-1/2 test is negative on the
follow-up sample, the donor may be reentered. The donor would then be tested again at
the time of his/her next donation using the battery of screening tests required under
21 CFR 610.40. That donation may be tested by NAT as part of a minipool (i.e., MP-
NAT) or as an individual donation (i.e., ID-NAT). Thus, two HIV-1 NAT tests would be
performed and must be non-reactive and two anti-HIV-1/2 tests would be performed and
must be negative before a unit from that donor could be used. For purposes of donor
counseling, you may choose to test the deferred donor with an HIV-1 NAT and an anti-
HIV-1/2 test at any time prior to the end of this 8-week waiting period after the original
donation. However, if an HIV-1 NAT is reactive prior to the end of this 8-week waiting
period, the donor would not be eligible for reentry and we recommend that you defer the
donor permanently. If an anti-HIV-1/2 test is RR prior to the end of this 8-week waiting
period, and a licensed supplemental test for antibodies to HIV-1 (i.e., WB or IFA), if
performed, is not positive, you may take another follow-up sample from the donor for
testing by both HIV-1 ID-NAT and an anti-HIV-1/2 test after another 8-week waiting
period has passed.
Reentry of Donors (HCV Test Results)
In this guidance, we recommend that you consider for reentry two groups of donors
deferred because of reactive HCV NAT or RR anti-HCV test results (see section V.B.,
Figure 6, and Table 6 of this document). These two groups of donors include:
1. 	Donors with a reactive HCV NAT result but who were seronegative for antibodies
to HCV; and
2. 	Donors with a non-reactive HCV NAT result (or NAT was not performed) who
had RR anti-HCV test results4. This group includes donors who were RR on a
second, different licensed screening test for HCV antibody, if it was used in
further testing of the index donation.
Data presented at the June 2001 BPAC meeting demonstrated that a 6-month follow-up
period encompasses the pre-seroconversion window period with sufficient confidence
that negative tests after at least 6 months have passed rule out HCV infection (Ref. 10).
4 This group includes deferred donors with an historical HCV RIBA that was indeterminate, negative or was not
performed.

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For purposes of reentering both of these groups of deferred donors we recommend that
you take a follow-up sample from the donor after a minimum period of 6 months from
the original donation for testing by an HCV ID-NAT and two different, licensed anti-
HCV screening tests. Current scientific data indicate that detectable viremia may be
intermittent or may be resolved in about 15-25% of cases of HCV infection (Refs. 11 and
12). If the ID-NAT is non-reactive and both anti-HCV tests are negative on the follow-
up sample, the donor may be reentered. The donor would then be tested again at the time
of his/her next donation using the battery of screening tests required under
21 CFR 610.40(b). That donation may be tested by NAT as part of a minipool (i.e., MP-
NAT) or as an individual donation (i.e., ID-NAT). Thus, two HCV NAT tests would be
performed and must be non-reactive and three anti-HCV tests would be performed and
must be negative before a unit from that donor could be used.
If the ID-NAT is non-reactive and both of the licensed anti-HCV tests are RR after a 6-
month waiting period, we recommend that you defer the donor permanently.
For purposes of donor counseling and to detect possible HCV viremia, you may also
choose to test the deferred donor with an HCV NAT and two different, licensed anti-
HCV screening tests at any time prior to the completion of this 6-month period after the
original donation. If an HCV NAT is reactive prior to the end of this 6-month period, the
donor would not be eligible for reentry and we recommend that you defer the donor
permanently. If an HCV NAT is non-reactive and one anti-HCV test is RR prior to the
end of the 6-month period, you may take one more follow-up sample from the donor for
testing by HCV ID-NAT and two different, licensed anti-HCV screening tests after a
second 6-month waiting period. If an anti-HCV test is still RR on a second follow-up
sample at any time after the original donation, we recommend that you defer the donor
permanently.
IV. 	RECOMMENDATIONS FOR NAT ALGORITHMS
As discussed in sections A and B below, currently approved tests on minipools of donor samples
for HIV-1 RNA and HCV RNA may be either Multiplex NAT for the simultaneous detection of
HIV-1 RNA and HCV RNA or Single Virus NATs conducted separately for the RNA of the two
viruses.
A. 	Testing, Product Disposition, Donor Management, and Lookback for a
Minipool that is Reactive on a Multiplex NAT (MP-NAT): Resolution by
Testing Subpools or by Testing Individual Donor Samples
If you obtain a reactive Multiplex HIV-1 RNA/HCV RNA NAT result for a minipool, the
test instructions for use instruct you to perform subsequent testing to identify the donor
sample(s) that are NAT-reactive as the basis for the NAT-reactive result on the pool. In

Contains Nonbinding Recommendations
11
general, the manufacturer’s instructions for a licensed NAT describe two methods for
resolving a minipool that is reactive on a Multiplex NAT, and you must follow the
instructions in the package insert that provide specific testing algorithms
(21 CFR 610.40(b)).
METHOD 1: Deconstruction of the NAT-reactive minipool may be performed by testing
the subpools (original or freshly made) that formed the minipool. This deconstruction of
the minipool to identify the donor sample(s) that are NAT-reactive as the basis for the
NAT-reactive result on the pool may involve several layers of testing using original or
freshly pooled subpools, followed by testing of individual donor samples in the reactive
subpool(s) (see Figure 1 and Table 1 below).
1. 	If you test subpools that were used to construct a Multiplex NAT-reactive
minipool, in accordance with the manufacturer’s instructions you must test the
original subpools or freshly pooled subpools using the same Multiplex NAT method
that was used in the original NAT on the minipool (21 CFR 610.40(b)).
NOTE: In some cases the manufacturer’s instructions provide for a different sample
preparation procedure. However, the primers and probes would be the same as those
used in the original NAT on the minipool.
a. 	If all subpools are non-reactive, we recommend that you release from
quarantine all individual donations that comprise the non-reactive subpools,
provided that serologic tests on those donor samples are negative and the
donations are otherwise suitable for release.
NOTE: Laboratory control procedures must make adequate provisions for
monitoring the reliability, accuracy, precision, and performance of laboratory
test procedures and instruments (21 CFR 606.140(b)). This includes
monitoring the frequency of reactive minipools that, upon deconstruction,
remain unresolved. Laboratory control procedures must also include adequate
identification and handling of all test samples (21 CFR 606.140(c)). Use of
supplies and reagents must be in a manner consistent with the instructions
provided by the manufacturer (21 CFR 606.65(e), 21 CFR 610.40(b)). You
must conduct and record a thorough investigation including the conclusions
and followup, of any unexplained discrepancy (21 CFR 606.100(c)), such as
when the frequency of unresolved reactive minipools exceeds the threshold
defined in your laboratory control procedures, or when there are indications of
possible laboratory contamination of negative donor samples with positive
samples. This investigation must include a determination of the cause of the
initial reactivity of the unresolved minipool.
b. 	If one or more of the subpools are reactive, we recommend that you
release from quarantine the individual donations that comprise the non-
reactive subpools, provided that serologic tests on those donor samples are
negative and the donations are otherwise suitable for release. Consistent with

Contains Nonbinding Recommendations
12
the manufacturer’s instructions, you must test the individual donor samples
that comprise the reactive subpool(s) using the same Multiplex NAT method
that was used in the original NAT on the minipool (21 CFR 610.40(b)).
(1) If all individual donor samples are non-reactive, we recommend
that you release from quarantine all individual donations (if serologic
tests on those donor samples are negative and the donations are
otherwise suitable for release). See the NOTE in section IV.A.1.a. of
this document on laboratory control procedures and the possible need
to conduct additional analyses to determine the cause of the initial
reactivity of the unresolved minipool.
(2) If one or more individual donor sample(s) are reactive, perform the
steps in section IV.C.1. of this document (including testing using
Discriminatory NAT when necessary, product disposition, donor
management, and lookback).
We recommend that you release from quarantine all non-reactive individual
donations provided that serologic tests on those donor samples are negative
and the donations are otherwise suitable for release.
METHOD 2: For comparatively small minipools, for example, minipools that consist of
up to 24 individual samples, deconstruction of the NAT-reactive minipool may be
performed by directly testing the individual donor samples that formed the minipool (see
Figure 1 and Table 1 below).
2. 	If you directly test the samples from individual donors that constituted the
Multiplex NAT-reactive minipool, in accordance with the manufacturer’s instructions
you must test the individual donor samples using the same Multiplex NAT method
that was used in the original NAT on the minipool (21 CFR 610.40(b)).
NOTE: In some cases the manufacturer’s instructions provide for a different sample
preparation procedure. However, the primers and probes would be the same as those
used in the original NAT on the minipool.
a. 	If all individual donor samples are non-reactive, we recommend that you
perform the steps in section IV.A.1.b.(1) of this document.
b. 	If one or more individual donor sample(s) are reactive, perform the steps in
section IV.C.1. of this document (including testing using Discriminatory NAT
when necessary, product disposition, donor management, and lookback).
We recommend that you release from quarantine all non-reactive individual donations
provided that serologic tests on those donor samples are negative and the donations
are otherwise suitable for release.

Contains Nonbinding Recommendations
13
FIGURE 1. Testing, Product Disposition, Donor Management, and Lookback for a
Minipool that is Reactive on a Multiplex NAT (MP-NAT): Resolution by Testing Subpools
or by Testing Individual Donor Samples
Minipool Reactive on a Multiplex HIV-1/HCV MP-NAT
METHOD 1 	METHOD 2
TEST SUBPOOLS 1`
USING SAME MULTIPLEX
NAT METHOD2
Non-Reactive
Subpools
Reactive 	RELEASE3
Subpool(s) 	ALL UNITS
TEST INDIVIDUAL DONOR SAMPLES
USING SAME MULTIPLEX NAT METHOD2
Reactive 	Non-Reactive
Donor Sample(s) 	Donor Samples
PERFORM THE STEPS IN FIGURE 3 FOR TESTING USING DISCRIMINATORY NAT,
PRODUCT DISPOSITION, DONOR MANAGEMENT, AND LOOKBACK
RELEASE3
ALL UNITS
1 Several layers of deconstruction using original or freshly pooled subpools, may be needed.
2 In some cases a different sample preparation procedure may be used per manufacturer’s instructions.
However, primers and probes should be same as those used in the NAT on the minipool.
3 Units may be released only if serologic tests for HIV-1 and HCV are negative and the units are otherwise
suitable for release.

Contains Nonbinding Recommendations
14
TABLE 1. Testing, Product Disposition, Donor Management, and Lookback for a
Minipool that is Reactive on a Multiplex NAT (MP-NAT): Resolution by Testing Subpools
or by Testing Individual Donor Samples
If: 	Then: 	After that if: 	Then:	
After that if:	
Then:
Minipool
Reactive on
a
Multiplex
HIV-1/HCV
MP-NAT
METHOD 1:
Test
subpools1
using same
Multiplex
NAT method2
OR
METHOD 2:
Test the
individual
donor
samples using
same
Multiplex
NAT method2
Reactive
subpool(s)
Non-reactive
subpool(s)
Reactive donor
sample(s)
Non-reactive
donor samples
Test the
individual
donor samples
using same
Multiplex NAT
method2
Release 3 all
units
Perform the
steps in Table 3
for testing
(discriminatory
NAT), product
disposition,
donor
management,
lookback
Release 3
all units
Reactive donor
sample(s)
Non-reactive
donor samples
Perform the
steps in Table 3
for testing
(discriminatory
NAT), product
disposition,
donor manage-
ment, lookback
Release 3
all units
1 Several layers of deconstruction using original or freshly pooled subpools may be needed.
2 In some cases a different sample preparation procedure may be used per manufacturer’s instructions. However,
primers and probes should be same as those used in the NAT on the minipool.
3 Units may be released only if serologic tests for HIV-1 and HCV are negative and the units are otherwise suitable for
release.

Contains Nonbinding Recommendations
15
B. 	Testing, Product Disposition, Donor Management, and Lookback for a
Minipool that is Reactive on a Single Virus NAT (MP-NAT): Resolution by
Testing Subpools or by Testing Individual Donor Samples
If you obtain a reactive result for a NAT for HIV-1 RNA and/or HCV RNA performed
separately on a minipool, the test instructions for use instruct you to perform subsequent
testing to identify the donor sample(s) that are NAT-reactive as the basis for the NAT-
reactive result on the pool. In general, the manufacturer’s instructions for a licensed
NAT describe two methods for resolving a minipool that is reactive on a Single Virus
NAT, and you must follow the instructions in the package insert that provide specific
testing algorithms (21 CFR 610.40(b)).
METHOD 1: Deconstruction of the NAT-reactive minipool may be performed by testing
the subpools (original or freshly made) that formed the minipool. This deconstruction of
the minipool to identify the donor sample(s) that are NAT-reactive as the basis for the
NAT-reactive result on the pool, may involve several layers of testing using original or
freshly pooled subpools, followed by testing of individual donor samples in the reactive
subpool(s) (see Figure 2 and Table 2).
1. 	If you test subpools that were used to construct a NAT-reactive minipool, in
accordance with the manufacturer’s instructions you must test the original
subpools or freshly pooled subpools using the same Single Virus NAT method
that was used in the original NAT on the minipool (21 CFR 610.40(b)).
NOTE: In some cases the manufacturer's instructions provide for a different
sample preparation procedure. However, the primers and probes would be the
same as those used in the original NAT on the minipool.
a. 	If all subpools are non-reactive, we recommend that you release from
quarantine all individual donations that comprise the non-reactive
subpools provided that serologic tests on those donor samples are negative
and the donations are otherwise suitable for release. See the NOTE in
section IV.A.1.a. on laboratory control procedures and the possible need to
conduct additional analyses to determine the cause of the initial reactivity
of the unresolved minipool.
b. 	If one or more of the subpools are reactive, we recommend that you
release from quarantine the individual donations that comprise the non-
reactive subpools provided that serologic tests on those donor samples are
negative and the donations are otherwise suitable for release. Consistent
with the manufacturer’s instructions, you must test the individual
donations that comprise the reactive subpool(s) using the same Single
Virus NAT method that was used in the original NAT on the minipool
(21 CFR 610.40(b)).

Contains Nonbinding Recommendations
16
(1) If all individual donor samples are non-reactive, we recommend that
you release from quarantine all individual donations provided that
serologic tests on those donor samples are negative and the donations
are otherwise suitable for release. See the NOTE in section IV.A.1.a.
of this document on laboratory control procedures and the possible
need to conduct additional analyses to determine the cause of the
initial reactivity of the unresolved minipool.
(2) If one or more individual donor sample(s) are reactive, perform steps 1
through 4 in section IV.D. of this document (including product
disposition, donor management, and lookback).
We recommend that you release from quarantine all non-reactive individual donations
provided that serologic tests on those donor samples are negative and the donations
are otherwise suitable for release.
METHOD 2: For comparatively small minipools, for example, minipools that consist of
up to 24 individual samples, deconstruction of the NAT-reactive minipool may be
performed by directly testing the individual donor samples that formed the minipool (see
Figure 2 and Table 2 below).
2. 	If you directly test the samples from individual donors that constituted the NAT-
reactive minipool, in accordance with the manufacturer’s instructions you must
test the individual donor samples using the same Single Virus NAT method that
was used in the original NAT on the minipool (21 CFR 610.40(b)).
NOTE: In some cases the manufacturer's instructions provide for a different sample
preparation procedure. However, the primers and probes would be the same as those
used in the original NAT on the minipool.
a. 	If all individual donor samples are non-reactive, we recommend that you
perform the steps in section IV.B.1.b.(1) of this document.
b. 	If one or more individual donor sample(s) are reactive, perform steps 1
through 4 in section IV.D. of this document (including product
disposition, donor management, and lookback).
We recommend that you release from quarantine all non-reactive individual donations
provided that serologic tests on those donor samples are negative and the donations
are otherwise suitable for release.

Contains Nonbinding Recommendations
17
FIGURE 2. Testing, Product Disposition, Donor Management, and Lookback for a
Minipool that is Reactive on a Single Virus NAT (MP-NAT): Resolution by Testing
Subpools or by Testing Individual Donor Samples
Minipool Reactive on HIV-1 NAT and/or HCV MP-NAT
METHOD 1 	METHOD 2
TEST SUBPOOLS 1`
USING SAME SINGLE VIRUS
NAT METHOD2
Non-Reactive
Subpools
Reactive 	RELEASE3
Subpool(s) 	ALL UNITS
TEST INDIVIDUAL DONOR SAMPLES USING
SAME SINGLE VIRUS NAT METHOD2
Reactive 	Non-Reactive
Donor Sample(s) 	Donor Samples
PERFORM THE STEPS IN FIGURE 4 FOR PRODUCT DISPOSITION,
DONOR MANAGEMENT, AND LOOKBACK
RELEASE3
ALL UNITS
1 Several layers of deconstruction using original or freshly pooled subpools, may be needed.
2 In some cases a different sample preparation procedure may be used per manufacturer’s instructions.
However, primers and probes should be same as those used in the NAT on the minipool.
3 Units may be released only if serologic tests for HIV-1 and HCV are negative and the units are otherwise
suitable for release.

Contains Nonbinding Recommendations
18
TABLE 2. Testing, Product Disposition, Donor Management, and Lookback for a
Minipool that is Reactive on a Single Virus NAT (MP-NAT): Resolution by Testing
Subpools or by Testing Individual Donor Samples
If: 	Then: 	After that if: 	Then:	
After that if: 	Then:
Minipool
Reactive on
HIV-1 MP-
NAT
and/or
HCV MP-NAT
METHOD 1:
Test
subpools1
using same
Single Virus
NAT
method2
OR
METHOD 2:
Test the
individual
donor
samples
using
same Single
Virus NAT
method2
Reactive
subpool(s)
Non-reactive
subpool(s)
Reactive donor
sample(s)
Non-reactive
donor samples
Test the
individual
donor
samples
using same
Single Virus
NAT
method2
Release 3
all units
Perform the
steps in
Table 4 for
product
disposition,
donor
management,
and
lookback
Release 3
all units
Reactive donor
sample(s)
Non-reactive
donor samples
Perform the
steps in Table 4
for product
disposition,
donor
management,
and lookback
Release 3
all units
1 Several layers of deconstruction using original or freshly pooled subpools may be needed.
2 In some cases a different sample preparation procedure may be used per manufacturer’s instructions.
However, primers and probes should be same as those used in the NAT on the minipool.
3 Units may be released only if serologic tests for HIV-1 and HCV are negative and the units are otherwise
suitable for release.

Contains Nonbinding Recommendations
19
As discussed in Sections C and D below, currently approved tests on individual donor samples
for HIV-1 RNA and HCV RNA may be either Multiplex NAT for the simultaneous detection of
HIV-1 RNA and HCV RNA, or Single Virus NATs conducted separately for the RNA of the two
viruses.
C. 	Testing, Product Disposition, Donor Management, and Lookback for an
Individual Donor Sample that is Reactive on a Multiplex NAT (ID-NAT)
after Negative Antibody Screening Tests
If you obtain a reactive Multiplex HIV-1 RNA/HCV RNA NAT result on an individual
donor sample (ID-NAT), you must do the following (see Figure 3 and Table 3):
1. 	Follow the manufacturer's instructions, which instruct you to test the reactive
donation using Discriminatory NATs, when necessary (21 CFR 610.40(b)).
a. 	If the sample is reactive for HIV-1 RNA and/or HCV RNA, you must
quarantine the unit (21 CFR 610.40(h)). You must not ship or use the unit
unless one of the exceptions described in 21 CFR 610.40(h)(2) applies.
If you choose not to destroy the unit, you may release it for research or further
manufacture with written approval from FDA (21 CFR 610.40(h)(2)(ii)(A). If
released for one of these uses, you must appropriately label such blood or
blood components as required under 21 CFR 606.121 and with the
“BIOHAZARD” legend (21 CFR 610.40(h)(2)(ii)(B)). Under
21 CFR 610.40(h)(2)(ii)(C), except for autologous donations, you must label
such human blood and blood components as reactive for the appropriate
screening test for evidence of infection due to the identified communicable
disease agent(s). We recommend that you use one of the following
statements, as applicable:
• 	“Reactive for HIV-1 RNA” or
• 	“Reactive for HCV RNA” or
• 	“Reactive for HIV-1 RNA and HCV RNA”.
Under 21 CFR 610.40(h)(2)(ii)(E), you must also include the following
statement, as applicable:
• 	“Caution: For Further Manufacturing Into In Vitro Diagnostic
Reagents For Which There Are No Alternative Sources” or
• 	“Caution: For Laboratory Research Use Only”.
You must defer the donor (21 CFR 610.41). The donor may be eligible for
reentry (see sections V.A. and V.B.). You must notify the donor of his/her
deferral, providing information about the test results that were the basis for the
deferral (21 CFR 630.40).

Contains Nonbinding Recommendations
20
Under 21 CFR 610.46 and 21 CFR 610.47 you must perform lookback
(product quarantine/retrieval and notification of recipients of prior collections)
for HIV-1 and/or HCV, respectively, as follows:
• 	If you are an establishment that collects Whole Blood or blood
components, including Source Plasma and Source Leukocytes, within
3 calendar days after a donor tests reactive for evidence of HIV-1
and/or HCV infection using the Discriminatory NATs, you must
review records dating back 12 months prior to the donor’s reactive
NAT to identify blood and blood components previously donated by
the donor. You must quarantine identified in-date blood and blood
components if intended for transfusion or if intended for further
manufacture into injectable products (except if pooled), notify
consignees so that they may quarantine previously collected in-date
blood and blood components, and notify transfusion recipients.
• 	If you are a consignee of Whole Blood or blood components, including
Source Plasma and Source Leukocytes, when notified by the collecting
establishment you must quarantine identified previously collected in-
date blood and blood components if intended for transfusion or if
intended for further manufacture into injectable products (except if
pooled). You must notify transfusion recipients who were transfused
with blood and blood components collected during the 12 months
before the date of the Discriminatory NAT-reactive donation, or notify
the recipient’s physician of record, of the need for recipient HIV-1 or
HCV testing and counseling. You must make reasonable attempts to
perform the notification within 12 weeks after receiving the donor’s
Discriminatory NAT-reactive result for HIV-1 or HCV. If both
Discriminatory NATs were reactive, notification of transfusion
recipients should specify that the patient should be tested for both
HIV-1 and HCV.
b. 	If the Discriminatory NATs are non-reactive for both HIV-1 RNA and
HCV RNA, the sample is “Non-Discriminated Reactive” (NDR)
You must quarantine the unit and destroy or re-label the unit as described in
section IV.C.1.a.
You must defer the donor (21 CFR 610.41). We recommend that you defer
the donor for 6 months. The donor is eligible for reentry after the 6-month
waiting period. If you chose to reenter the donor, you may do so at that time
without testing a follow-up sample. You must notify the donor of his/her
deferral, providing information about the test results that were the basis for the
deferral (21 CFR 630.40). We recommend that you counsel the donor that the

Contains Nonbinding Recommendations
21
initial test result was very likely a false positive result and that the donor is not
infected, but that because of the initial reactive test result he or she will be
deferred for 6 months.
You must perform lookback for HIV-1 and HCV under 21 CFR 610.46 and
610.47, respectively, as described in section IV.C.1.a. above.
FIGURE 3. Testing, Product Disposition, Donor Management, and Lookback for
an Individual Donor Sample that is Reactive on a Multiplex NAT (ID-NAT) after
Negative Antibody Screening Tests
Individual Donor Sample Reactive on a Multiplex HIV-1/HCV ID-NAT
TEST TO DISCRIMINATE HIV-1 AND HCV, AS NECESSARY
_________________________________________________________________________________
Reactive for HIV-1 and/or HCV 	Non-Reactive for both HIV-1 and HCV
(“Non-Discriminated Reactive”)
QUARANTINE AND DESTROY 	QUARANTINE AND DESTROY
OR RE-LABEL UNIT. 	OR RE-LABEL UNIT.
DEFER1 AND NOTIFY DONOR. 	DEFER3 AND NOTIFY DONOR. 4
PERFORM LOOKBACK2 FOR 	PERFORM LOOKBACK2
HIV-1 AND/OR HCV, 	FOR HIV-1 AND HCV.
AS APPROPRIATE.
1The donor may be eligible for reentry (see Figures 5 and 6).
2 If both Discriminatory NATs were reactive or if both Discriminatory NATs were non-reactive, notification
of transfusion recipients should specify that the patient should be tested for both HIV-1 and HCV.
3 We recommend that you defer the donor for 6 months and, if you choose to reenter the donor, you may do
so at that time without testing a follow-up sample.
4 We recommend that you counsel the donor that the test result was very likely a false positive result and that
the donor is not infected, but that because of the initial reactive test result he or she will be deferred for 6
months.

Contains Nonbinding Recommendations
22
TABLE 3. Testing, Product Disposition, Donor Management, and Lookback for an
Individual Donor Sample that is Reactive on a Multiplex NAT (ID-NAT) after Negative
Antibody Screening Tests
If: 	Then: 	After that if: 	Then:
Individual
Donor
Sample
Reactive on
a Multiplex
HIV-1 /HCV
ID-NAT
Test to
discriminate
HIV-1 and
HCV, as
necessary
Reactive for
HIV-1 and/or
HCV
Non-Reactive
for both HIV-1
and HCV
Quarantine and
destroy or re-label
unit;
Defer 1 and notify
donor; perform
lookback2 for HIV-1
and/or HCV, as
appropriate
Quarantine and
destroy or re-label
unit;
Defer 3 and notify
donor 4; perform
lookback2 for HIV-1
and HCV
1The donor may be eligible for reentry (see Tables 5 and 6).
2 If both Discriminatory NATs were reactive or if both Discriminatory NATs were non-reactive, notification
of transfusion recipients should specify that the patient should be tested for both HIV-1 and HCV.
3 We recommend that you defer the donor for 6 months and, if you choose to reenter the donor, you may do
so at that time without testing a follow-up sample.
4 We recommend that you counsel the donor that the test result was very likely a false positive result and that
the donor is not infected, but that because of the initial reactive test result he or she will be deferred for 6
months.

Contains Nonbinding Recommendations
23
D. 	Testing, Product Disposition, Donor Management, and Lookback for an
Individual Donor Sample that is Reactive on a Single Virus NAT (ID-NAT)
after Negative Antibody Screening Tests
If you obtain a reactive HIV-1 RNA NAT and/or reactive HCV RNA NAT result for an
individual donor sample from a test other than a Multiplex NAT, you must do the
following (see Figure 4 and Table 4):
1. 	Quarantine the unit (21 CFR 610.40(h)). You must not ship or use the unit unless
one of the exceptions described in 21 CFR 610.40(h)(2) applies. If you choose
not to destroy the unit, you may release it for research or further manufacture with
written approval from FDA. If released for one of these uses, you must
appropriately label the unit as described in section IV.C.1.a. (21 CFR 606.121).
2. 	Defer the donor (21 CFR 610.41). The donor may be eligible for reentry (see
sections V.A. and V.B.).
3. 	Notify the donor of his/her deferral, providing information about the test results
that were the basis for the deferral (21 CFR 630.40).
4. 	Perform lookback (product quarantine/retrieval and notification of recipients of
prior collections) for HIV-1 and/or HCV under 21 CFR 610.46 and
21 CFR 610.47 respectively, as appropriate.
• 	If you are an establishment that collects Whole Blood or blood
components, including Source Plasma and Source Leukocytes, within
3 calendar days after a donor tests reactive for evidence of HIV-1
and/or HCV infection you must review records dating back 12 months
prior to the donor’s reactive NAT to identify blood and blood
components previously donated by the donor. You must quarantine
identified in-date blood and blood components if intended for
transfusion or if intended for further manufacture into injectable
products (except if pooled), notify consignees so that they may
quarantine previously collected in-date blood and blood components,
and notify transfusion recipients.
• 	If you are a consignee of Whole Blood or blood components,
including Source Plasma and Source Leukocytes, when notified by the
collecting establishment you must quarantine identified previously
collected in-date blood and blood components if intended for
transfusion or if intended for further manufacture into injectable
products (except if pooled). You must notify transfusion recipients
who were transfused with blood and blood components collected
during the 12 months before the date of the NAT-reactive donation, or
notify the recipient’s physician of record, of the need for recipient
HIV-1 or HCV testing and counseling. You must make reasonable

Contains Nonbinding Recommendations
24
attempts to perform the notification within 12 weeks after receiving
the donor’s reactive NAT screening test result for HIV-1 or HCV. If
both Single Virus NATs were reactive, notification of transfusion
recipients should specify that the patient should be tested for both
HIV-1 and HCV.

Contains Nonbinding Recommendations
25
FIGURE 4. Testing, Product Disposition, Donor Management, and Lookback for an
Individual Donor Sample that is Reactive on a Single Virus NAT (ID-NAT) after Negative
Antibody Screening Tests
Individual Donor Sample Reactive on HIV-1 ID-NAT and/or HCV ID-NAT
QUARANTINE AND DESTROY OR RE-LABEL UNIT.
DEFER DONOR.1
NOTIFY DONOR.
PERFORM LOOKBACK FOR HIV-1 AND/OR HCV, AS APPROPRIATE.
1The donor may be eligible for reentry (see Figures 5 and 6).
TABLE 4. Testing, Product Disposition, Donor Management, and Lookback for an
Individual Donor Sample that is Reactive on a Single Virus NAT (ID-NAT) after Negative
Antibody Screening Tests
If: 	Then:
Individual Donor Sample
Reactive on HIV-1 ID-NAT
and/or HCV ID-NAT
Quarantine the unit
Destroy or re-label the unit
Defer the donor 1
Notify the donor
Perform lookback for HIV-1 and/or HCV, as appropriate
1 The donor may be eligible for reentry (see Tables 5 and 6).

Contains Nonbinding Recommendations
26
V. 	RECOMMENDATIONS FOR DONOR REENTRY
Note that the reentry of a donor permits prospective donations from a reentered donor who meets
donor eligibility criteria. It does not affect the status of previous collections from that donor,
including donations subject to lookback.
A. 	Reentry for Donors Deferred Because of Reactive HIV-1/2 Test Results
Currently, FDA has not found acceptable a process for reentry of deferred donors with
the following HIV-1 test results:
• 	NAT-reactive for HIV-1 (e.g., a Discriminatory NAT after a reactive
Multiplex NAT or by a Single Virus NAT for HIV-1 RNA) and anti-HIV-1 or
-2 or anti-HIV-1/2 test RR (regardless of HIV-1 WB or IFA or HIV-1 p24
EIA test result);
OR
• 	NAT-reactive for HIV-1 (e.g., a Discriminatory NAT after a reactive
Multiplex NAT or by a Single Virus NAT for HIV-1 RNA) and HIV-1 p24
EIA RR (regardless of anti-HIV-1 or -2 or anti-HIV-1/2 test result);
OR
• 	NAT-non-reactive for HIV-1 (or HIV-1 NAT not performed) and anti-HIV-1
or -2 or anti-HIV-1/2 test RR, HIV-1 WB positive (regardless of HIV-1 p24
EIA test result).
OR
• 	NAT-non-reactive for HIV-1 (or HIV-1 NAT not performed) and anti-HIV-1
or -2 or anti-HIV-1/2 test RR (regardless of WB or IFA result) and HIV-1 p24
EIA RR (regardless of Neutralization test result).
1. 	FDA has accepted a method or process for reentry of deferred donors in the
following three groups (see Figure 5 and Table 5):
• 	Group I: Donors who were HIV-1 NAT-reactive (i.e., reactive on a
Discriminatory NAT for HIV-1 or on a Single Virus NAT for HIV-1 or a
Multiplex NAT that detects and discriminates HIV) and seronegative.
This includes donors previously deferred because of reactive test results
on an investigational HIV-1 NAT. The HIV-1 p24 antigen EIA may not
have been performed if it was replaced by an approved NAT that was
validated to replace the HIV-1 p24 antigen test.

Contains Nonbinding Recommendations
27
NOTE: If the original donor sample that was NAT-reactive was negative on
the Discriminatory NAT for HIV-1 or on the Single Virus NAT for HIV-1 but
was reactive on the Discriminatory NAT for HCV or on the Single Virus NAT
for HCV, you may attempt to reenter the donor according to the
recommendations in section V.B. (see Figure 6 and Table 6). If the original
donor sample that was NAT-reactive was reactive on both of the
Discriminatory NATs for HIV-1 and HCV or on both of the Single Virus
NATs for HIV-1 and HCV, or reactive for both HIV-1 and HCV on the
Multiplex test that detects and discriminates HIV and HCV, you may attempt
to reenter the donor according to the recommendations in both sections V.A
and V.B (see Figures 5 and 6, and Tables 5 and 6).
• 	Group II: Donors who were NAT-non-reactive (or NAT was not performed)
and who were RR on a screening test for HIV-1 or -2 or HIV-1 and -2 or HIV-
1/2 antibody, with an HIV-1 WB or IFA that was indeterminate (viral bands
may be present), unreadable, negative, or was not performed. If an HIV-1
IFA was performed to resolve an indeterminate or unreadable HIV-1 WB, the
IFA result must not have been positive. This group includes donors
previously deferred because of RR HIV-1 or HIV-2 (or combination HIV-1/2)
serologic test results prior to the initiation of testing by NAT.
These donors may be eligible for reentry only if:
o 	the HIV-1 p24 antigen EIA (if performed) was negative, and
o 	if a second, different, licensed HIV-2 test performed on the index
donation was negative, or, if the second HIV-2 test was RR, an
investigational HIV-2 supplemental test (if performed) was not
positive. Performance of an investigational HIV-2 supplemental test
(if available) is optional at the present time. Currently, we have not
approved a supplemental test for HIV-2. If a supplemental test for
HIV-2 is licensed in the future, that test must be performed in
accordance with 21 CFR 610.40(e), and the result of the supplemental
test for HIV-2 must not be positive for the donor to be eligible for
reentry.
• 	Group III: Donors who were NAT-non-reactive (or NAT was not
performed) and who were negative on a screening test for HIV-1 and -2 or
HIV-1/2 antibody, but who were RR on an HIV-1 p24 antigen EIA with an
indeterminate (that is, a non-neutralized or an invalid) or a positive result on
the Neutralization test, even on more than one occasion.

Contains Nonbinding Recommendations
28
2. 	To reenter a donor who meets FDA eligibility criteria (i.e., the donor is otherwise
eligible to donate again), we recommend that you do the following (see Figure 5
and Table 5):
a. 	At least 8 weeks after the original donation obtain a new sample from
the donor (no donation is made at this time) and perform follow-up testing
using:
(1) A licensed ID-NAT for HIV-1 (e.g., a Discriminatory NAT for
HIV-1 or a Single Virus NAT for HIV-1).
If the original donor sample was reactive on the NAT for HIV-1
(Group I donors), we recommend that you use the same ID-NAT
(i.e., the Discriminatory NAT for HIV-1 or the Single Virus NAT
for HIV-1 or Multiplex NAT that detects and discriminates HIV)
that was run on the original donor sample. If the original NAT is
no longer available (e.g., an investigational NAT), we recommend
that you use a NAT that has the same sensitivity claims as the
original NAT, or greater sensitivity claims (e.g., a NAT labeled in
the Intended Use as sensitive for HIV-1 including Group O, if
available).
AND
(2) A licensed anti-HIV-1/2 test.
If the original donor sample was RR on the anti-HIV-1 or anti-
HIV-1/2 test (Group II donors), we recommend that you use that
same test to test this follow-up sample. If the original donor
sample was negative on the anti-HIV-1 or anti-HIV-1/2 test
(Group I donors or Group III donors), or if the original test is no
longer available, we recommend that you use an anti-HIV-1/2 test
that is labeled in the Intended Use as sensitive for HIV-1 Group O.
NOTE: For purposes of donor counseling, you may choose to test
the deferred donor with an HIV-1 ID-NAT and an anti-HIV-1/2
test at any time prior to the end of this 8-week waiting period after
the original donation. However, if an HIV-1 ID-NAT is reactive
prior to the end of this 8-week waiting period, the donor would not
be eligible for reentry and we recommend that you defer the donor
permanently. If an anti-HIV-1/2 test is RR prior to the end of this
8-week waiting period, and a licensed supplemental test for
antibodies to HIV-1 (e.g., WB or IFA), if performed, is not
positive, you may take another follow-up sample from the donor
for testing by both HIV-1 ID-NAT and an anti-HIV-1/2 test after
another 8-week waiting period has passed.

Contains Nonbinding Recommendations
29
b. 	Evaluate the results of the follow-up testing on the donor’s new
sample as follows:
(1) If the ID-NAT is reactive and the anti-HIV-1/2 test is RR, we
recommend that you defer the donor permanently.
(2) If the ID-NAT is reactive and the anti-HIV-1/2 test is negative,
we recommend that you defer the donor permanently.
(3) If the ID-NAT is non-reactive and the anti-HIV-1/2 test is RR,
you may reconsider the donor for reentry by conducting additional
follow-up testing after a second waiting period of 8 weeks.
(4) When there is a persistent anti-HIV-1/2 RR result, you may
wish to further test the donor’s new sample using a licensed
supplemental test for antibodies to HIV-1 such as a WB or IFA. If
the WB or IFA test result is indeterminate, unreadable, or negative,
you may reconsider the donor for reentry by conducting follow-up
testing after one or more additional waiting period of 8 weeks. If
the WB or IFA test result is positive, we recommend that you defer
the donor permanently.
(5) If the ID-NAT is non-reactive and the anti-HIV-1/2 test is
negative, you may reenter the donor (i.e., the donor is eligible to
donate in the future, provided the donor meets all donor eligibility
criteria).

Contains Nonbinding Recommendations
30
FIGURE 5. Reentry for Donors Deferred Because of Reactive HIV-1/2 Test Results
Group I 	Group II 	Group III
NAT Reactive 1 	NAT Non-Reactive or Not Done 	NAT Non-Reactive or Not Done
Anti-HIV-1/2 Test Negative 	Anti-HIV-1/2 Test RR 	Anti-HIV-1/2 Test Negative
HIV-1 p24 EIA 2 Negative 	HIV-1 WB or IFA 	HIV-1 p24 EIA RR,
Indeterminate, Unreadable, 	Neutralization Test(s)
Negative, or Not Done 	Positive or Indeterminate
HIV-1 p24 EIA 2 Negative 	(Non-Neutralized or Invalid)
Second, different HIV-2 Test
Negative or, if RR,
Investigational3 HIV-2
Supplemental test (if
performed) was not Positive
AFTER 8 WEEKS 4 ,
TEST FOLLOW-UP SAMPLE USING
HIV-1 ID-NAT 5,6 AND ANTI-HIV-1/2 TEST7
________________________________________________________________________
ID-NAT Reactive / 	ID-NAT Reactive / 	ID-NAT Non-Reactive / 	ID-NAT Non-Reactive /
Anti-HIV-1/2 	Anti-HIV-1/2 	Anti-HIV-1/2 	Anti-HIV-1/2
Test RR 	Test Negative 	Test RR 	Test Negative
DEFER DONOR 	DEFER DONOR 	DEFER DONOR 	REENTER DONOR
PERMANENTLY 	PERMANENTLY 	AND CONTINUE 	(Donor Eligible for
FOLLOW-UP8 	Future Donation,
Provided Donor Meets
Eligibility Criteria)
______________________________________________________________________________

Contains Nonbinding Recommendations
31
Footnotes for FIGURE 5.
1 Reactive for HIV-1 (i.e., a Discriminatory NAT for HIV-1 or on a Single Virus NAT for HIV-1 or a
Multiplex NAT that detects and discriminates HIV)
2 May not have been performed, depending upon the conditions of the specific NAT approval.
3 Performance of an investigational HIV-2 supplemental test (if available) is optional. If a supplemental test
is licensed in the future it must be performed in accordance with 21 CFR 610.40(e) and it must not have been
positive for the donor to be eligible for reentry.
4 HIV-1 ID-NAT and/or an anti-HIV-1/2 test, if performed during the 8 week waiting period, must be
negative for the donor to be eligible for reentry.
5 If the original donor sample was reactive on both of the Discriminatory NAT tests for HIV-1 and HCV, we
recommend that you test a follow-up sample using HCV ID-NAT and an anti-HCV test also, as in the HCV
Reentry Algorithm (see Figure 6).
6 If the original donor sample was reactive on the NAT for HIV-1 (Group I donors), we recommend that you
use the same ID-NAT (i.e., the Discriminatory NAT for HIV-1 or the Single Virus NAT for HIV-1 or the
Multiplex NAT that detects and discriminates HIV) that was run on the original donor sample. If the
original NAT is no longer available (e.g., an investigational NAT), we recommend that you use a NAT that
has the same sensitivity claims as the original NAT or greater sensitivity claims (e.g., a NAT labeled in the
Intended Use as sensitive for HIV-1 including Group O, if available).
7 If the original donor sample was RR on the anti-HIV-1/2 test (Group II donors) we recommend that you use
that same test to test this follow-up sample. If the original donor sample was negative on the anti-HIV-1/2
test (Group I donors or Group III donors) or if the original test is no longer available, we recommend that
you use an anti-HIV-1/2 test that is labeled in the Intended Use as sensitive for HIV-1 including Group O.
8 At your option you may further test the donor’s sample using HIV-1 WB or IFA. If WB or IFA is negative,
unreadable, or indeterminate, you may reconsider the donor for reentry by conducting follow-up testing after
one or more additional waiting period of 8 weeks. If WB or IFA is positive, we recommend that you defer the
donor permanently.

Contains Nonbinding Recommendations
32
TABLE 5. Reentry for Donors Deferred Because of Reactive HIV-1/2 Test Results
If: 	Then: 	After that if: 	Then:
Group I:
NAT Reactive 1
Anti-HIV-1/2 Test Negative
HIV-1 p24 EIA 2 Negative
OR
Group II:
NAT Non-Reactive or Not
Done
Anti-HIV-1/2 Test RR
HIV-1 WB or IFA
Indeterminate, Unreadable,
Negative, or Not Done
HIV-1 p24 EIA2 Negative
Second, different HIV-2 Test
Negative, or if RR,
Investigational 3 HIV-2
Supplemental test (if
performed) was not
Positive
OR
Group III:
NAT Non-Reactive or
Not Done
Anti-HIV-1/2 Test Negative
HIV-1 p24 EIA RR,
Neut. Test(s) Positive or
Indeterminate (Non-
Neutralized or Invalid)
After 8 weeks4,
test follow-up
sample using
HIV-1 ID-
NAT5,6 and
Anti-HIV-1/2
Test 7
ID-NAT Reactive/
Anti-HIV-1/2 Test RR
ID-NAT Reactive/
Anti-HIV-1/2 Test Negative
ID-NAT Non-Reactive/
Anti-HIV-1/2 Test RR
ID-NAT Non-Reactive/
Anti-HIV-1/2 Test Negative
Defer donor
permanently
Defer donor
permanently
Defer donor and
continue follow-
up8
REENTER
DONOR
(Donor eligible
for future
donation,
provided donor
meets eligibility
criteria)

Contains Nonbinding Recommendations
33
Footnotes for TABLE 5.
1 Reactive for HIV-1 (i.e., on a Discriminatory NAT for HIV-1 or on a Single Virus NAT for HIV-1 or the
Multiplex NAT that detects and discriminates HIV).
2 May not have been performed, depending upon the conditions of the specific NAT approval.
3 Performance of an investigational HIV-2 supplemental test (if available) is optional. If a supplemental test
is licensed in the future it must be performed in accordance with 21 CFR 610.40(e) and it must not have been
positive for the donor to be eligible for reentry.
4 HIV-1 ID-NAT and/or an anti-HIV-1/2 test, if performed during the 8 week waiting period, must be
negative for the donor to be eligible for reentry.
5 If the original donor sample was reactive on both of the Discriminatory NAT tests for HIV-1 and HCV, we
recommend that you test a follow-up sample using HCV ID-NAT and an anti-HCV test also, as in the HCV
Reentry Algorithm (see Figure 6).
6 If the original donor sample was reactive on the NAT for HIV-1 (Group I donors), we recommend that you
use the same ID-NAT (i.e., the Discriminatory NAT for HIV-1 or the Single Virus NAT for HIV-1 or the
Multiplex NAT that detects and discriminates HIV) that was run on the original donor sample. If the
original NAT is no longer available (e.g., an investigational NAT), we recommend that you use a NAT that
has the same sensitivity claims as the original NAT or greater sensitivity claims (e.g., a NAT labeled in the
Intended Use as sensitive for HIV-1 including Group O, if available).
7 If the original donor sample was RR on the anti-HIV-1/2 test (Group II donors) we recommend that you use
that same test to test this follow-up sample. If the original donor sample was negative on the anti-HIV-1/2
test (Group I donors or Group III donors) or if the original test is no longer available, we recommend that
you use an anti-HIV-1/2 test that is labeled in the Intended Use as sensitive for HIV-1 including Group O.
8 At your option you may further test the donor’s sample using HIV-1 WB or IFA. If WB or IFA is negative,
unreadable, or indeterminate, you may reconsider the donor for reentry by conducting follow-up testing after
one or more additional waiting period of 8 weeks. If WB or IFA is positive, we recommend that you defer the
donor permanently.
B. 	Reentry for Donors Deferred Because of Reactive HCV Test Results
Currently, FDA has not found acceptable a process for reentry of deferred donors with
the following HCV test results:
• 	NAT-reactive for HCV (e.g., a Discriminatory NAT after a reactive Multiplex
NAT or by a separate NAT for HCV RNA) and anti-HCV test RR (regardless
of historical HCV RIBA result)
OR
• 	NAT-non-reactive for HCV (or HCV NAT not performed) and anti-HCV test
RR and historical HCV RIBA positive
1. 	FDA has accepted a method or process for reentry of deferred donors in the
following two groups (see Figure 6 and Table 6):
• 	Group A: Donors who were HCV NAT-reactive (e.g., reactive on a
Discriminatory NAT for HCV or on a Single Virus NAT for HCV) and
seronegative. This includes donors previously deferred because of
reactive test results on an investigational HCV NAT.

Contains Nonbinding Recommendations
34
NOTE: If the original donor sample that was NAT-reactive was negative
on the Discriminatory NAT for HCV or on the Single Virus NAT for
HCV but was reactive on the Discriminatory NAT for HIV-1 or on the
Single Virus NAT for HIV-1, you may attempt to reenter the donor
according to the recommendations in section V.A. (see Figure 5 and Table
5). If the original donor sample that was NAT-reactive was reactive on
both of the Discriminatory NATs for HIV-1 and HCV or on both of the
Single Virus NATs for HIV-1 and HCV or for both HIV-1 and HCV on
the Multiplex test that detects and discriminates HIV and HCV, you may
attempt to reenter the donor according to the recommendations in both
sections V.A and V.B (see Figures 5 and 6 and Tables 5 and 6).
• 	Group B: Donors who were NAT-non-reactive (or NAT was not
performed) and who were RR on a screening test for HCV antibody.5 This
group includes donors who were RR on a second, different licensed
screening test for HCV antibody if it was used in further testing of the
index donation in accordance with 21 CFR 610.40(e).
2. 	To reenter a donor who meets FDA eligibility criteria (i.e., the donor is otherwise
eligible to donate again), we recommend that you do the following (see Figure 6
and Table 6):
a. 	At least 6 months after the original donation obtain a new sample from the
donor (no donation is made at this time) and perform follow-up testing using:
(1) A licensed ID-NAT for HCV (e.g., a Discriminatory NAT for
HCV or a Single Virus NAT for HCV)
If the original donor sample was reactive on the NAT for HCV
(Group A donors), we recommend that you use the same ID-NAT
(i.e., the Discriminatory NAT for HCV or the Single Virus NAT
for HCV or the Multiplex NAT that detects and discriminates
HCV) that was run on the original donor sample. If the original
NAT is no longer available (e.g., an investigational NAT) we
recommend you use a NAT that has the same sensitivity claims as
the original NAT or greater sensitivity claims.
AND
(2) Two different, licensed anti-HCV screening tests.
If the original donor sample was RR on the anti-HCV test (Group B
donors), we recommend that you use the same anti-HCV test that was
performed on the original donor sample or a more sensitive version (i.e.,
5 This group includes deferred donors with an historical HCV RIBA that was indeterminate, negative or was not
performed.

Contains Nonbinding Recommendations
35
HCV EIA version 3.0 or later) as one of the two licensed-anti HCV
screening tests to test this follow-up sample.
NOTE: For purposes of donor counseling and to detect possible HCV
viremia, you may also choose to test the deferred donor with an HCV ID-
NAT and two different, licensed anti-HCV screening tests at any time
prior to the completion of the 6-month period after the original donation.
However, if an HCV ID-NAT is reactive prior to the end of this 6-month
period, the donor would not be eligible for reentry and we recommend that
you defer the donor permanently. If an anti-HCV test is RR prior to the
end of this 6-month waiting period, you may take one more follow-up
sample from the donor after a waiting period of at least 6 months for
testing by HCV ID-NAT and two different, licensed anti-HCV screening
tests. If an anti-HCV test is still RR on a second follow-up sample at any
time after the original donation, we recommend that you defer the donor
permanently.
b. 	Evaluate the results of the follow-up testing on the donor’s new sample as
follows:
(1) If the ID-NAT is reactive regardless of anti-HCV test results, we
recommend that you defer the donor permanently.
(2) If the ID-NAT is non-reactive and both of the anti-HCV tests
are RR, we recommend that you defer the donor permanently.
(3) If the ID-NAT is non-reactive and only one anti-HCV test is RR,
you may reconsider the donor for reentry by testing a follow-up
sample after one more waiting period of at least 6 months. 	If an
anti-HCV test is still RR on a second follow-up sample at any time
after the original donation, we recommend that you defer the donor
permanently.
(4) If the ID-NAT is non-reactive and both anti-HCV tests are
negative, you may reenter the donor (i.e., the donor is eligible to
donate in the future, provided the donor meets all donor eligibility
criteria).

Contains Nonbinding Recommendations
36
FIGURE 6. Reentry for Donors Deferred Because of Reactive HCV Test Results
Group A 	Group B
NAT Reactive1 	NAT Non-Reactive or Not Done
Anti-HCV Test Negative 	Anti-HCV Test(s) RR2
AFTER 6 MONTHS 3 ,
TEST FOLLOW-UP SAMPLE USING
HCV ID-NAT 4,5 AND TWO DIFFERENT, LICENSED ANTI-HCV SCREENING TESTS 6
________________________________________________________________________
ID-NAT Reactive/ 	ID-NAT Non-Reactive/ 	ID-NAT Non-Reactive/ ID-NAT Non-Reactive/
Regardless of 	Both Anti-HCV 	One Anti-HCV 	Both Anti-HCV
Anti-HCV Test 	Tests RR 	Test RR and 	Tests Negative
Results 	One Anti-HCV
Test Negative
DEFER DONOR 	DEFER DONOR 	DEFER DONOR 	REENTER DONOR
PERMANENTLY 	PERMANENTLY 	AND CONTINUE 	(Donor Eligible for
FOLLOW-UP7 	Future Donation,
Provided Donor Meets
Eligibility Criteria)
________________________________________________________________________

Contains Nonbinding Recommendations
37
Footnotes for FIGURE 6.
1 Reactive on a Discriminatory NAT for HCV or on a Single Virus NAT for HCV or on a Multiplex NAT that
detects and discriminates HCV.
2 Group B includes deferred donors with an historical HCV RIBA that was indeterminate, negative or was
not performed. Donors can be RR in a second, different licensed screening test for HCV antibody if it was
used for further testing of the index donation.
3 HCV ID-NAT, if performed prior to 6 months, must be negative for the donor to be eligible for reentry.
4 If the original donor sample was reactive on both of the Discriminatory NAT tests for HIV-1 and HCV, test
a follow-up sample using HIV-1 ID-NAT and an anti-HIV-1/2 test also, as in the HIV-1 Reentry Algorithm
(see Figure 5).
5 If the original donor sample was reactive on the NAT for HCV (Group A donors), we recommend that you
use the same ID-NAT (i.e., the Discriminatory NAT for HCV or the Single Virus NAT for HCV or the
Multiplex NAT that detects and discriminates HCV) that was run on the original donor sample. If the
original NAT is no longer available (e.g., an investigational NAT) we recommend you use a NAT that has the
same sensitivity claims as the original NAT or greater sensitivity claims.
6 If the original donor sample was RR on the anti-HCV test (Group B donors) we recommend that you use the same anti-
HCV test that was run on the original donor sample or a more sensitive version (i.e., HCV EIA version 3.0 or later) as one
of the two licensed-anti HCV screening tests to test this follow-up sample.
7 You may reconsider the donor for reentry by testing a follow-up sample after one more waiting period of at least 6
months using an HCV ID NAT and two different, licensed anti-HCV screening tests. If an anti-HCV test is still RR on a
second follow-up sample at any time after the original donation, we recommend that you defer the donor permanently.

Contains Nonbinding Recommendations
38
TABLE 6. Reentry for Donors Deferred Because of Reactive HCV Test Results
1 Reactive on a Discriminatory NAT for HCV or on a Single Virus NAT for HCV or on a Multiplex NAT that
detects and discriminates HCV.
2 Group B includes deferred donors with an historical HCV RIBA that was indeterminate, negative or was
not performed. Donors can be RR in a second, different licensed screening test for HCV antibody if it was
used for further testing of the index donation.
3. HCV ID-NAT, if performed prior to 6 months, must be negative for the donor to be eligible for reentry.
4 If the original donor sample was reactive on both of the Discriminatory NAT tests for HIV-1 and HCV, test
a follow-up sample using HIV-1 ID-NAT and an anti-HIV-1/2 test also, as in the HIV-1 Reentry Algorithm
(see Figure 5).
5. If the original donor sample was reactive on the NAT for HCV (Group A donors), we recommend that you
use the same ID-NAT (i.e., the Discriminatory NAT for HCV or the Single Virus NAT for HCV or the
Multiplex NAT that detects and discriminates HCV) that was run on the original donor sample. If the
original NAT is no longer available (e.g., an investigational NAT) we recommend you use a NAT that has the
same sensitivity claims as the original NAT or greater sensitivity claims.
6 If the original donor sample was RR on the anti-HCV test (Group B donors), we recommend that you use
the same anti-HCV test that was run on the original donor sample or a more sensitive version (i.e., HCV EIA
version 3.0 or later) as one of the two licensed-anti HCV screening tests to test this follow-up sample.
7 You may reconsider the donor for reentry by testing a follow-up sample after one more waiting period of at least 6
months using an HCV ID NAT and two different, licensed anti-HCV screening tests. If an anti-HCV test is still RR on a
second follow-up sample at any time after the original donation, we recommend that you defer the donor permanently.
If: 	Then: 	After that if: 	Then:
Group A:
NAT Reactive 1
Anti-HCV Test Negative
OR
Group B:
NAT Non-Reactive
or Not Done
Anti-HCV Test(s) RR 2
After 6 months3,
test follow-up
sample using HCV
ID-NAT4,5 and two
different licensed
Anti-HCV
Screening Tests6
ID-NAT Reactive/
Regardless of Anti-HCV
Test Results
ID NAT Non-Reactive/
Both Anti-HCV Tests
RR
ID-NAT Non-Reactive/
One Anti-HCV Test RR
and One Anti-HCV Test
Negative
ID-NAT Non-Reactive/
Both Anti-HCV Test
Negative
Defer donor
permanently
Defer donor
permanently
Defer donor
and
continue
follow-up7
REENTER
DONOR
(Donor
eligible for
future
donation,
provided
donor meets
eligibility
criteria)

Contains Nonbinding Recommendations
39
VI. 	REFERENCES
1. 	FDA Memorandum to All Registered Blood Establishments: “Revised Recommendations
for the Prevention of Human Immunodeficiency Virus (HIV-1) Transmission by Blood and
Blood Products,” April 23, 1992.
2. 	FDA Memorandum to All Registered Blood and Plasma Establishments: “Recommendations
for Donor Screening with a Licensed Test for HIV-1 Antigen,” August 8, 1995.
3. 	FDA Memorandum to All Registered Blood Establishments: “Revised Recommendations
for Testing Whole Blood, Blood Components, Source Plasma and Source Leukocytes for
Antibody to Hepatitis C Virus Encoded Antigen (Anti-HCV),” August 5, 1993.
4. 	Busch MP. Closing the windows on viral transmission by blood transfusion. In Stramer SL
ed. Blood Safety in the New Millenium. Bethesda, MD: American Association of Blood
Banks, 2001: Chapter 2, p.36.
5. 	Glynn SA, Kleinman SH, Wright DJ, Busch MP. International application of the incidence
rate/window period model. Transfusion 42:966-972 (2002).
6. 	Zou S, Dorsey KA, Notari EP, Foster GA, et al. Prevalence, incidence and residual risk of
human immunodeficiency virus and hepatitis C virus infections among United States blood
donors since the introduction of nucleic acid testing. Transfusion 50:1495-1504 (2010).
7. 	Fiebig EW, Wright DJ, Rawal BD, et. al. Dynamics of HIV-1 viremia and antibody
seroconversion in plasma donors: Implications for diagnosis and staging of primary HIV-1
infection. AIDS 17:1871-1879 (2003).
8. 	Federal Register, December 14, 1999 (64 FR 71147), Guidance for Industry: In the
Manufacture and Clinical Evaluation of In Vitro Tests to Detect Nucleic Acid Sequences of
Human Immunodeficiency Viruses Types 1 and 2, December 1999.
https://www.fda.gov/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/
Guidances/Blood/ucm077067.htm
9. 	Federal Register, August 24, 2007 (72 FR 48765), Current Good Manufacturing Practice for
Blood and Blood Components; Notification of Consignees and Transfusion Recipients
Receiving Blood and Blood Components at Increased Risk of Transmitting Hepatitis C Virus
Infection (“Lookback”); Final Rule. https://www.gpo.gov/fdsys/pkg/FR-2007-08-24/pdf/E7-
16607.pdf
10. Blood Products Advisory Committee, 69th Meeting, June 14, 2001,
https://www.fda.gov/ohrms/dockets/ac/cber01.htm
11. Alter HJ. To C or not to C: These are the questions. Blood 85:1681-1695 (1995).
12. Centers for Disease Control, Recommendations for prevention and control of hepatitis C
virus (HCV) infection and HCV-related chronic disease. MMWR 47; (RR-19) (1998).