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 

DRAFT GUIDANCE 

This guidance is being distributed for comment purposes only.

Submit comments on this draft guidance by the date provided in the Federal Register

notice announcing the availability of the draft guidance. Submit comments to the Division 

of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, 

rm. 1061, Rockville, MD 20852. You should identify all comments by the docket number 

listed in the notice of availability that publishes in the Federal Register.

Additional copies of this draft guidance are available from the Office of Communication, 

Training and Manufacturers Assistance (HFM-40), Suite 200N, 1401 Rockville Pike, 

Rockville, MD 20852-1448, or by calling 1-800-835-4709 or 301-827-1800, or from the 

Internet at http://www.fda.gov/cber/guidelines.htm. 

For questions on the content of this draft guidance, contact Paul A. Mied, Ph.D., at 301-

827-3008. 

U.S. Department of Health and Human Services 

Food and Drug Administration 

Center for Biologics Evaluation and Research 

July 2005
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Table of Contents 

I. INTRODUCTION...................................................................................................1

II. DEFINITIONS ........................................................................................................2

III. BACKGROUND AND DISCUSSION ..................................................................3

IV. RECOMMENDATIONS........................................................................................9

V. IMPLEMENTATION ..........................................................................................24

VI. REFERENCES......................................................................................................24

FIGURE 1. Testing, Product Disposition, and Donor Management for an 

Individual Donor Sample that is Reactive on a Multiplex NAT 

After a Negative Antibody Screening Test ................................26 

FIGURE 2. Testing, Product Disposition, and Donor Management for an 

Individual Donor Sample that is Reactive on an Individual 

NAT After a Negative Antibody Screening Test.......................27 

FIGURE 3. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on a Multiplex NAT: Resolution 

by Testing Individual Donor Samples........................................28 

FIGURE 4. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on an Individual NAT: 

Resolution by Testing Individual Donor Samples ....................29 

FIGURE 5. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on a Multiplex NAT: Resolution 

by Testing Subpools .....................................................................30 

FIGURE 6. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on an Individual NAT: 

Resolution by Testing Subpools..................................................31 

FIGURE 7. Reentry for Donors Deferred Because of HIV-1 Test Results .32 

FIGURE 8. Reentry for Donors Deferred Because of HCV Test Results ...33 

TABLE 1. Testing, Product Disposition, and Donor Management for an 

Individual Donor Sample that is Reactive on a Multiplex NAT 

After a Negative Antibody Screening Test ................................34 

TABLE 2. Testing, Product Disposition, and Donor Management for an 

Individual Donor Sample that is Reactive on an Individual 

NAT After a Negative Antibody Screening Test.......................35 

TABLE 3. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on a Multiplex NAT: Resolution 

by Testing Individual Donor Samples........................................36 
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TABLE 4. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on an Individual NAT: Resolution 

by Testing Individual Donor Samples........................................37 

TABLE 5. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on a Multiplex NAT: Resolution 

by Testing Subpools .....................................................................38 

TABLE 6. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on an Individual NAT: Resolution 

by Testing Subpools .....................................................................39 

TABLE 7. Reentry for Donors Deferred Because of HIV-1 Test Results .40 

TABLE 8. Reentry for Donors Deferred Because of HCV Test Results ...41 
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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 

This draft guidance, when finalized, will represent the Food and Drug Administration’s 

(FDA’s) current thinking on this topic. It does not create or confer any rights for or on 

any person and does not operate to bind FDA or the public. You can use an alternate 

approach if the approach satisfies the requirements of the applicable statutes or 

regulations. If you want to discuss an alternate approach, contact the appropriate FDA 

staff. If you cannot identify the appropriate FDA staff, call the appropriate number listed 

on the title page of this guidance.

I. INTRODUCTION 

During the past decade there has been a dramatic reduction in the transmission of Human 

Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus (HCV) by human blood 

and blood components. Primarily, this is due to the implementation of sensitive tests for 

viral antibody, antigen (for HIV-1), and nucleic acids, and in the case of plasma 

derivatives, the use of effective virus removal and inactivation methods. The sources of 

remaining risk of HIV-1 and HCV transmission are 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), donors infected with 

immunovariant viral strains, persistent antibody-negative (immunosilent) carriers, and 

laboratory test procedure errors. According to a recent report, donations during the 

window period constitute most of the risk of HIV-1 and HCV transmission (Ref. 1). 

Therefore, measures to reduce the window period could further reduce significantly the 

low residual risk of HIV-1 and HCV transmission by human blood and blood 

components. 

Studies performed using seroconversion panels indicate the value of Nucleic Acid 

Testing (NAT) in reducing the window period for HIV-1 and HCV. The estimated mean 

window-period reduction for HIV-1 ribonucleic acid (RNA) by pooled sample NAT is 

approximately 11 to 15 days relative to antibody and 5 to 9 days relative to HIV-1 p24 

antigen testing (Refs. 2-4). NAT for detection of HCV has been estimated to reduce the 

window period by 50-60 days relative to that for HCV antibody. In large-scale studies 

performed nationwide, NAT for HIV-1 detected 4 antigen-negative/antibody-negative 
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window period donations and in the case of NAT for HCV, detected 42 additional 

antibody-negative window period donations. As a result, subsequent to implementation 

of NAT, the residual risk of HIV-1 and HCV in screened human blood and blood 

component donations is currently estimated to be approximately 1 in 2,135,000 donations 

for HIV-1 and 1 in 1,935,000 donations for HCV (Ref. 3). 

We, the Food and Drug Administration (FDA), have previously issued recommendations 

on serologic testing for HIV-1 and HCV and use of NAT to establishments that collect 

blood and blood components including Source Plasma and Source Leukocytes in “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.” In this guidance 

document we are providing recommendations to you, blood and plasma establishments, 

manufacturers, and testing laboratories that are implementing a licensed method for HIV1/HCV NAT, on testing individual samples or pooled samples from donors of human 

blood and blood components for HIV-1 RNA and HCV RNA. This document contains 

recommendations regarding product disposition (§ 610.40(h)), and donor management (§ 

610.41 and § 630.6) based on the results of NAT and serologic testing for markers of 

HIV-1 and HCV infection on samples, collected at the time of donation, from donors of 

human blood and blood component donations. 

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. 

This guidance, when final, is intended to supersede the recommendations in the FDA 

Memorandum to Blood Establishments dated April 23, 1992, August 5, 1993, and August 

8, 1995, for reentry of donors deferred because of anti-HIV-1 test results, HIV-1 p24 

antigen test results, and anti-HCV test results (Refs. 5-7). 

II. DEFINITIONS 

Master Pool: A pool of donor samples on which NAT is performed as a screening test. 

A Master Pool is formed by pooling of samples from subpools or by directly pooling 

samples from individual donors. 

Subpool: A pool of donor samples that was used with other (sub)pools to form the 

Master Pool or that was formed during “deconstruction” of the Master Pool. 

Deconstruction: Resolution of the reactivity of a Master Pool by testing subpools 

(original or freshly made) or samples from individual donors that formed the Master 

Pool. Deconstruction of a Reactive Master Pool to individual units is a required step for 

all approved tests. 

Multiplex NAT: A NAT that simultaneously detects HIV-1 RNA and HCV RNA. 
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Discriminatory NAT: A NAT that uses specific primers for HIV-1 or HCV to identify

the RNA in the Reactive multiplex NAT sample as HIV-1 RNA or HCV RNA. 

Performing a Discriminatory NAT is a required step for those establishments using a 

multiplex test such as the Procleix HIV-1/HCV NAT. 

Additional NAT: A NAT that uses an amplification technology and/or primers that are 

different from those that were used for the original NAT screening test, and that has been 

validated for use with samples from individual donors. This test is not used to make the 

initial determination of donor suitability, but is used for donor counseling and to 

determine whether lookback should include notification of transfusion recipients. 

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 prior donations 

from that donor 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 of prior 

collections from that donor that remain in inventory, notifying consignees to quarantine 

prior collections, further testing of the donor, destroying or relabeling potentially 

infectious prior collections, and notifying transfusion recipients who received human 

blood or blood components from that donor, when appropriate. 

In the proposed HCV lookback rule published in November 2000 (Ref. 8) we proposed 

changes to § 610.46 that would require lookback to be performed on the basis of a 

reactive NAT result, even when serological testing is non-reactive. When that rule 

becomes final, lookback for HIV-1 and for HCV will be required. In the meantime, we 

recommend that you perform lookback for HIV-1 and for HCV when donor samples test 

Reactive using HIV-1 NAT or HCV NAT. 

 

Donor Reentry: A procedure that qualifies a donor who was deferred 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 IV.7. and IV.8.). 

III. BACKGROUND AND DISCUSSION 

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. Because of the cost and labor intensiveness of NAT, there 

was much interest in testing pools of plasma donor samples (minipools) by NAT, and by 

1997, some manufacturers in Europe had voluntarily instituted NAT on minipools. At 

about that time, the European Union issued a directive that, by July 1, 1999, HCV RNA 
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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. 

Large-scale clinical studies were needed to demonstrate the efficacy of NAT because of 

the low frequency of window period donations. Small-scale studies would not identify 

adequate numbers of window period donations. Test kit manufacturers and testing 

laboratories submitted Investigational New Drug (IND) applications 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 and individual donor sample 

NAT. 

In December 1999 we issued guidance for industry on the validation of NAT methods to 

screen plasma donors (Ref. 9). 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) UltraQualTM HIV-1 and HCV Reverse Transcription Polymerase Chain Reaction 

(RT-PCR) assays. Under that license, NGI performs these assays on pooled samples 

from donors of Source Plasma. 

In February 2002 we licensed the ProcleixTM 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 AmpliScreenTM HCV Test, v 2.0 and the 

COBAS AmpliScreenTM 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 individual 

human donors, including donors of Whole Blood and blood components, Source Plasma, 

and other living donors. They are also intended for use in screening organ donors when 

specimens are obtained while the donor’s heart is still beating. 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.” 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 (January 31, 2002, 67 FR 4719) 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 (April 9, 2002, 67 FR 

17077). 
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That guidance informed establishments that collect blood and blood components that we 

have licensed NAT as tests to screen blood donors for HIV-1 RNA and HCV RNA, that 

these licensed tests can 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, and that we believe that these newly 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 products. 

In that guidance we recommend 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 or HCV, 

respectively. However, for donations that are reactive on a test for the detection of 

antibodies to HIV-1 and are to be discarded or used in the manufacture of non-injectable 

products, we do not believe that HIV-1 NAT and HCV NAT are necessary as part of the 

adequate and appropriate testing required under § 610.40(b). Nevertheless, you may 

decide to perform HIV-1 and HCV NAT for these donations in order to obtain useful 

information regarding the donor’s infection status. This information may be useful as part 

of donor notification. 

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 additional 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 (§ 610.40(b)). Note that 

screening of donors of human blood and blood components for HIV-1 p24 antigen may 

be replaced by a NAT that has been validated by the manufacturer as a replacement for 

the HIV-1 p24 antigen EIA. 

A. NAT Algorithms 

Under § 610.40(b), you must use approved screening tests "in accordance with the 

manufacturer's instructions.” If you perform NAT on pooled samples and obtain a 

Reactive NAT result on a Master Pool, the manufacturer’s instructions instruct you to 

perform subsequent testing to identify the individual unit(s) that contains the RNA 

identified in the Master Pool test. Once you have identified a positive unit, either by 

subsequent testing of a Master Pool, or by initial individual test, you must not use the 

donation for transfusion or for manufacturing into injectable products (§ 610.41(h)(1)) 

unless an exception applies (§ 610.40(h)(2)). You must defer the donor (§610.41(a)), and 

you must inform the donor of the deferral and the basis for the deferral including test 

results (§ 630.6). A Reactive NAT result may indicate ongoing infection of the donor, 

and thus prior donations from that donor, although NAT-Non-Reactive, may pose a risk 

to transfusion recipients. We recommend that you perform lookback when donor 

samples test Reactive for HIV-1 NAT or HCV NAT. 
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At the meeting of the Blood Products Advisory Committee (BPAC) in March 2001, we 

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 Master Pool 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 Master Pool 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 test 

results. 

This draft guidance document contains six recommended algorithms for use when NATReactive results are obtained on individual samples or pooled samples from donors of 

human blood and blood components. This draft guidance also contains recommendations 

on product disposition, donor deferral criteria, follow-up testing of the donor, donor 

notification and donor reentry criteria that combine NAT and serologic test results, and 

lookback. This guidance is not intended to replace manufacturers’ instructions for testing

using approved tests. 

The first and second algorithms (See Recommendations IV.1. and IV.2, Figures 1 and

2, and Tables 1 and 2) 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. 

The third and fourth algorithms (See Recommendations IV.3. and IV.4, Figures 3 and 

4, and Tables 3 and 4) recommend actions to deconstruct a comparatively small Reactive 

Master Pool by testing individual donors. The fifth and sixth algorithms (See 

Recommendations IV.5 and IV.6, Figures 5 and 6, and Tables 5 and 6) recommend 

actions to deconstruct a larger Reactive Master Pool by testing archived or freshly pooled 

subpools to identify the Reactive individual donor(s). 

B. Donor Reentry 

Each year, thousands of donors are deferred from donating blood for an indefinite period, 

because of a false positive test result on a serological test, followed by a Negative or 

Indeterminate supplemental test for antibodies to HIV-1 or HCV. In addition to these 

deferrals, the implementation of individual donor sample and pooled donor sample NAT 

for HIV-1 RNA and HCV RNA has resulted in deferrals of several hundred donors each 

year due to potentially false Reactive NAT results. 

These deferred donors are eligible to be considered for reentry to donate blood or blood 

components. Under § 610.41(b), a deferred donor subsequently may be found to be 

suitable as a donor by a re-qualification method or process found acceptable 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 
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inappropriately reentering a donor. Although we do not require reentry of donors 

deferred because of false positive test results, we issued guidance in April of 1992 and 

August of 1993 on reentry of donors deferred because of HIV or HCV test results (Refs. 

5, 7).

For those establishments that choose to perform donor reentry, this guidance recommends 

criteria for reentry of donors deferred because of Reactive HIV-1 or HCV NAT or certain 

other test results in accordance with § 610.41. We find these criteria to be acceptable 

within the meaning of § 610.41(b). 

These recommendations include two new reentry algorithms based on the combined use 

of NAT and serologic testing: one for donors deferred because of HIV-1 test results, and 

a second for donors deferred because of HCV test results. In this draft guidance we 

recommend that you consider for reentry three classes of donors deferred because of 

HIV-1 test results (See Recommendation IV.7, Figure 7, and Table 7): 

1. Donors who had HIV NAT-Reactive results but were seronegative. 

This includes donors previously deferred because of Reactive test 

results on an investigational HIV-1 NAT. 

2. Donors with Non-Reactive NAT who have a Repeatedly Reactive

screening test for HIV-1 antibody, and Negative or Indeterminate HIV1 Western Blot or immunofluorescence assay (IFA) results or an HIV-1 

Western Blot or IFA was not performed. This includes donors 

previously deferred because of Repeatedly Reactive HIV serologic test 

results prior to the initiation of testing by NAT. This class actually 

includes three subsets of donors, those with a Western Blot that was: 

(1) Indeterminate with viral bands present, (2) Indeterminate with nonviral bands only, and (3) Negative or not performed. 

3. Donors with a Repeatedly Reactive result on an HIV-1 p24 antigen test 

and with an Indeterminate (an invalid or a non-neutralized) result on 

the HIV-1 p24 Neutralization test (Ref. 6). In addition, donors with a 

Positive result on the HIV-1 p24 antigen Neutralization test also 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 anti-HIV-1/2 EIA. FDA has advised that 

it 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, the Negative NAT on follow-up testing 

would be evidence that any prior Reactive (but unconfirmed) NAT result was an error. 

Accordingly, for all three classes 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 

NAT and HIV-1 antibody enzyme immunoassay (EIA). Performing follow-up testing 

first on a sample from the donor before they donate again may prevent a potentially 

contaminated unit from being collected and placed in inventory at the blood 

establishment. If the NAT is Non-Reactive and the EIA 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 § 610.40(b). 

Thus, two HIV-1 NAT tests would be performed and must be Non-Reactive and two 

HIV-1 EIA 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 EIA 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 or an anti-HIV-1/2 EIA is Repeatedly 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. 

In this guidance we recommend that you consider for reentry two classes of donors 

deferred because of HCV test results. (See Recommendation IV.8., Figure 8, and Table 

8): 

1. Donors who had HCV NAT-Reactive results but were seronegative 

on the HCV antibody test. This includes donors previously 

deferred because of Reactive test results on an investigational 

HCV NAT. 

2. Donors with Non-Reactive NAT who have a Repeatedly Reactive

screening test for HCV antibody, and radioimmunoblot assay 

(RIBA) results that were Indeterminate or Negative or a RIBA was 

not performed. This includes donors previously deferred because 

of Repeatedly Reactive HCV serologic test results prior to the 

initiation of testing by NAT. 

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 serologic tests after at least 6 months have passed rule out HCV infection 

(Ref. 10). 

For purposes of reentering both of these classes of deferred donors, we recommend that a 

sample be taken from the donor, after a minimum time period of 6 months, for follow-up 

testing by both HCV NAT and anti-HCV EIA. Current research indicates that detectable 

viremia may be intermittent or may also be resolved in about 15-25% of cases of HCV 

infection (Refs. 11, 12). If the NAT is Non-Reactive and the EIA is Negative on the 
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follow-up sample, the donor may be reentered. 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 an anti-HCV EIA test at any time prior to the completion of this 6-month 

period after the original donation. However, if an HCV NAT is Reactive or an anti-HCV 

EIA is Repeatedly 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. 

IV. RECOMMENDATIONS 

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/or HCV RNA or separate tests for the RNA of the two viruses. 

1. Testing, Product Disposition, and Donor Management for an 

Individual Donor Sample that is Reactive on a Multiplex NAT after a 

Negative Antibody Screening Test 

If you obtain a Reactive Multiplex HIV-1 RNA/HCV RNA NAT result on 

an individual donor sample, you must do the following (See Figure 1 and

Table 1): 

a. Follow the manufacturer's instructions, which instruct you to test 

the Reactive donation using Discriminatory NAT(s) (§ 610.40(b)) (Ref. 

13). 

i. If the Discriminatory NAT is Reactive for HIV-1 RNA 

and/or HCV RNA, you must quarantine the unit (§ 

610.40(h)). You must not ship or use the unit unless one of 

the exceptions described in 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 re-label 

the unit consistent with the labeling requirements in § 

606.121(f) and § 610.40(h). The unit must be labeled as 

“Biohazard” and with one of the following cautionary 

statements as applicable: 

“Reactive for HIV-1 RNA” 

OR 

“Reactive for HCV RNA” 

OR 

“Reactive for HIV-1 RNA and HCV RNA” 
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AND EITHER 

“Caution: For Further Manufacturing Into In Vitro 

Diagnostic Reagents For Which There Are No Alternative 

Sources” 

OR 

“Caution: For Laboratory Research Use Only.” 

Further, we recommend that you include on the label after 

the appropriate Reactive test results one of the following 

statements: 

“Increased risk of transmission of HIV” 

OR 

“Increased risk of transmission of HCV” 

OR 

“Increased risk of transmission of HIV and HCV.” 

You must defer the donor (§ 610.41). The donor may be 

eligible for reentry (See sections IV.7 and IV.8). You must 

notify the donor of his/her deferral, providing information 

about the test results (§ 630.6). 

We recommend that you perform lookback (product 

quarantine/retrieval and notification of recipients of prior 

collections for HIV-1 and/or HCV), as appropriate. 

ii. If the Discriminatory NAT is Non-Reactive for both HIV-1 

RNA and HCV RNA, you must quarantine the unit and 

destroy or relabel the unit as described in section IV.1.a.i 

above. You must defer the donor (§ 610.41). The donor 

may be eligible for reentry (See sections IV.7 and IV.8). 

You must notify the donor of his/her deferral, providing 

information about the test results (§ 630.6). We 

recommend that you perform lookback for HIV-1 and 

HCV. 

Alternatively, for purposes of donor notification, you may 

choose to perform another NAT (the original NAT, or 

Discriminatory NAT(s), or an Additional NAT)) on a new
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sample or the same sample from the original donation. If 

an Additional NAT is performed, we recommend that the 

test be one that has been validated for use with individual 

donor samples. 

(a) If you perform another test on a sample from 

the original donation and it is Reactive, you 

must quarantine the unit and destroy or 

relabel the unit as described in section 

IV.1.a.i above. You must defer the donor (§ 

610.41). The donor may be eligible for 

reentry (See sections IV.7 and IV.8). You 

must notify the donor of his/her deferral, 

providing information about the test results 

(§ 630.6). We recommend that you perform 

lookback for HIV-1 and/or HCV, as 

appropriate. 

(b) If you perform another test on a sample from 

the donation and it is Non-Reactive, you 

must quarantine the unit and destroy or 

relabel the unit as described in section 

IV.1.a.i above. You must defer the donor (§ 

610.41). The donor may be eligible for 

reentry (See sections IV.7 and IV.8). You 

must notify the donor of his/her deferral, 

providing information about the test results 

(§ 630.6). In this case you may explain to 

the donor that the test result, while initially 

Reactive, is not conclusive. There is a slight 

risk that the initial test result was a Positive 

result that cannot be excluded without 

follow-up testing of the donor. We 

recommend that you quarantine/retrieve 

prior collections; however, due to the low 

probability that any of the prior collections 

was infectious, we do not recommend that 

you notify transfusion recipients. 

2. Testing, Product Disposition, and Donor Management for an 

Individual Donor Sample that is Reactive on an Individual NAT after 

a Negative Antibody Screening Test 

 
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Contains Nonbinding Recommendations 

12

If you obtain a Reactive HIV-1 RNA/HCV RNA NAT result for an 

individual donor sample (not by Multiplex NAT), you must do the 

following (See Figure 2 and Table 2): 

a. Quarantine the unit (§ 610.40(h)). 

You must not ship or use the unit unless one of the exceptions 

described in § 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 re-label the unit as described in section IV.1.a.i. 

b. Defer the donor (§ 610.41). The donor may be eligible for reentry 

if serologic test results are negative. (See sections IV.7. and IV.8). 

c. Notify the donor of his/her deferral including information about 

the test results (§ 630.6). 

d. We recommend that you perform lookback (product 

quarantine/retrieval and notification of recipients of prior 

collections for HIV-1 and/or HCV), as appropriate. 

Currently approved tests on Master Pools of donor samples for HIV-1 RNA and 

HCV RNA may be either Multiplex NAT for the simultaneous detection of HIV-1 

RNA and/or HCV RNA or separate tests for the RNA of the two viruses.

In general, there are two approaches to resolving a Master Pool that is Reactive on a 

Multiplex NAT or a Master Pool that is Reactive using separate tests for the RNA of the 

two viruses. If you would like to directly test all individual donor samples in a Reactive 

Master Pool, we recommend that you follow the test algorithms described in sections 

IV.3 and IV.4. These test algorithms are illustrated in Figures 3 and 4 and described in 

Tables 3 and 4. If you would like to test subpools that are used to construct a NATReactive Master Pool, we recommend that you follow the test algorithms described in 

sections IV.5 and IV.6. These test algorithms are illustrated in Figures 5 and 6 and 

described in Tables 5 and 6.
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Contains Nonbinding Recommendations 

13

3. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on a Multiplex NAT: Resolution by 

Testing Individual Donor Samples

If you obtain a Reactive Multiplex HIV-1 RNA/HCV RNA NAT result for 

a Master Pool, the test instructions for use instruct you to perform 

subsequent testing to identify the donor sample(s) that is (are) NATReactive as the basis for the NAT-Reactive result on the pool. For 

comparatively small Master Pools, you may wish to directly test 

individual donor samples (See Figure 3 and Table 3). You must follow 

the instructions in the package insert for a licensed NAT test that provides 

a specific testing algorithm. (§ 610.40(b).) 

a. If you directly test the samples from individual donors that 

constituted the Multiplex NAT-Reactive Master Pool, consistent 

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 Master Pool (§ 610.40(b)) 

(Ref.13). 

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 

Master Pool. 

i. If all individual donor samples are Non-Reactive, you may 

release from quarantine all individual donations (if 

serologic tests on those donor samples are Negative and the 

donations are otherwise suitable for release). However, 

you must investigate the unexplained discrepancy in testing 

(§ 211.192). Laboratory control procedures must make 

adequate provisions for monitoring the reliability, accuracy, 

precision, and performance of laboratory test procedures 

and instruments, and must include adequate identification 

and handling of all test samples (§ 606.140(b), (c)). Use of 

supplies and reagents must be in a manner consistent with 

the instructions provided by the manufacturer (§§ 

606.65(e), 610.40(b)). In addition, as part of an overall 

Quality Assurance program, we recommend that you 

conduct additional investigation to determine the cause of 

the initial reactivity of the Master Pool. 

ii. If one (or more) individual donor sample(s) is (are) 

Reactive, perform the steps in section IV.1.a. above. 
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Contains Nonbinding Recommendations 

14

You may release from quarantine all Non-Reactive

individual donations (if serologic tests on those donor 

samples are Negative and the donations are otherwise 

suitable for release).

4. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on an Individual NAT: Resolution 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 Master Pool, the test instructions for use 

instruct you to perform subsequent testing to identify the donor sample(s) 

that is (are) NAT-Reactive as the basis for the NAT-Reactive result on the 

pool. For comparatively small Master Pools, you may wish to directly test 

individual donor samples (See Figure 4 and Table 4). You must follow 

the instructions in the package insert for a licensed NAT that provides a 

specific testing algorithm (§ 610.40(b)). 

a. If you directly test the samples from individual donors that 

constituted the NAT-Reactive Master Pool, consistent with the 

manufacturer’s instructions you must test the individual donor 

samples using the same NAT method that was used in the original 

NAT on the Master Pool (§ 610.40(b)) (Ref. 13). 

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 

Master Pool. 

i. If all individual donor samples are Non-Reactive, you may 

release from quarantine all individual donations (if serologic 

tests on those donor samples are Negative and the donations 

are otherwise suitable for release). However, you must 

investigate the unexplained discrepancy in testing (§ 

211.192). Laboratory control procedures must make 

adequate provisions for monitoring the reliability, accuracy, 

precision, and performance of laboratory test procedures and 

instruments, and must include adequate identification and 

handling of all test samples (§ 606.140(b), (c)). Use of 

supplies and reagents must be in a manner consistent with 

the instructions provided by the manufacturer (§§ 606.65(e), 

610.40(b)). In addition, as part of an overall Quality 

Assurance program, we recommend that you conduct

additional investigation to determine the cause of the initial 

reactivity of the Master Pool. 
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Contains Nonbinding Recommendations 

15

ii. If one (or more) individual donor sample(s) is (are) 

Reactive, perform steps a-d in section IV.2. above. 

You may release from quarantine all Non-Reactive

individual donations (if serologic tests on those donor 

samples are Negative and the donations are otherwise 

suitable for release). 

5. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on a Multiplex NAT: Resolution by 

Testing Subpools

If you obtain a Reactive Multiplex HIV-1 RNA/HCV RNA NAT result for 

a Master Pool, the test instructions for use instruct you to perform 

subsequent testing to identify the donor sample(s) that is (are) NATReactive as the basis for the NAT-Reactive result on the pool. 

Deconstruction of the NAT-Reactive Master Pool may be performed by 

testing the subpools, (original or freshly made), that formed the Master 

Pool. This deconstruction of the Master Pool to determine the basis for 

the reactivity 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 5 and Table 5). You must follow 

the instructions in the package insert for a licensed NAT that provides a 

specific testing algorithm (§ 610.40(b)). 

a. If you test subpools that were used to construct a Multiplex NATReactive Master Pool, consistent 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 Master Pool (§ 610.40(b)) (Ref. 13).

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 

Master Pool. 

i. If all subpools are Non-Reactive, you may release from 

quarantine all individual donations that comprise the NonReactive subpools (if serologic tests on those donor 

samples are Negative and the donations are otherwise 

suitable for release). However, you must investigate the 

unexplained discrepancy in testing (§ 211.192). Laboratory 

control procedures must make adequate provisions for 

monitoring the reliability, accuracy, precision, and 

performance of laboratory test procedures and instruments, 

and must include adequate identification and handling of all 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

16

test samples (§ 606.140(b), (c)). Use of supplies and 

reagents must be in a manner consistent with the 

instructions provided by the manufacturer (§§ 606.65(e), 

610.40(b)). In addition, as part of an overall Quality 

Assurance program, we recommend that you conduct 

additional investigation to determine the cause of the initial 

reactivity of the Master Pool. 

ii. If one (or more) of the subpools is (are) Reactive, you may 

release from quarantine the individual donations that 

comprise the Non-Reactive subpools (if 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 

donor samples that comprise the Reactive subpool using the 

same Multiplex NAT method that was used in the original 

NAT on the Master Pool (§ 610.40(b)) (Ref. 13).

(1) If all individual donor samples are NonReactive, you may release from quarantine 

all individual donations (if serologic tests on 

those donor samples are Negative and the 

donations are otherwise suitable for release). 

However, you must investigate the 

unexplained discrepancy in testing (§ 

211.192). Laboratory control procedures 

must make adequate provisions for 

monitoring the reliability, accuracy, 

precision, and performance of laboratory test 

procedures and instruments, and must 

include adequate identification and handling 

of all test samples (§ 606.140(b), (c)). Use 

of supplies and reagents must be in a manner 

consistent with the instructions provided by 

the manufacturer (§§ 606.65(e), 610.40(b)). 

In addition, as part of an overall Quality 

Assurance program, we recommend that you 

conduct additional investigation to 

determine the cause of the initial reactivity 

of the Master Pool. 

(2) If one (or more) individual donor sample(s) 

is (are) Reactive, perform the steps in 

section IV.1.a. above. 
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Contains Nonbinding Recommendations 

17

You may release from quarantine all NonReactive individual donations (if serologic 

tests on those donor samples are Negative 

and the donations are otherwise suitable for 

release). 

6. Testing, Product Disposition, and Donor Management for a 

Master Pool that is Reactive on an Individual NAT: Resolution by 

Testing Subpools 

If you obtain a Reactive result for a NAT for HIV-1 RNA and/or HCV 

RNA performed separately on a Master Pool, the test instructions for use 

instruct you to perform subsequent testing to identify the donor sample(s) 

that is (are) NAT-Reactive as the basis for the NAT-Reactive result on the 

pool. Deconstruction of the NAT-Reactive Master Pool may be 

performed by testing the subpools (original or freshly made), that formed 

the Master Pool. This deconstruction of the Master Pool to determine the 

basis for the reactivity 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 6 and Table 6). You must 

follow the instructions in the package insert for a licensed NAT that 

provides a specific testing algorithm. (§ 610.40(b).) 

a. If you test subpools that were used to construct a NAT-Reactive 

Master Pool, consistent with the manufacturer’s instructions you 

must test the original subpools or freshly pooled subpools using the 

same NAT method that was used in the original NAT on the 

Master Pool (§ 610.40(b)) (Ref. 13). 

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 

Master Pool. 

i. If all subpools are Non-Reactive, you may release from 

quarantine all individual donations that comprise the NonReactive subpools (if serologic tests on those donor 

samples are Negative and the donations are otherwise 

suitable for release). However, you must investigate the 

unexplained discrepancy in testing (§ 211.192) . 

Laboratory control procedures must make adequate 

provisions for monitoring the reliability, accuracy, 

precision, and performance of laboratory test procedures 

and instruments, and must include adequate identification 

and handling of all test samples (§ 606.140(b), (c)). Use of 

supplies and reagents must be in a manner consistent with 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

18

the instructions provided by the manufacturer (§§ 

606.65(e), 610.40(b)). In addition, as part of an overall 

Quality Assurance program, we recommend that you 

conduct additional investigation to determine the cause of 

the initial reactivity of the Master Pool. 

ii. If one (or more) of the subpools is (are) Reactive, you may 

release from quarantine the individual donations that 

comprise the Non-Reactive subpools (if 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 using the 

same NAT method that was used in the original NAT on 

the Master Pool (§ 610.40(b)) (Ref. 13).

(1) If all individual donor samples are NonReactive, you may release from quarantine 

all individual donations (if serologic tests on 

those donor samples are Negative and the 

donations are otherwise suitable for release). 

However, you must investigate the 

unexplained discrepancy in testing (§ 

211.192). Laboratory control procedures 

must make adequate provisions for 

monitoring the reliability, accuracy, 

precision, and performance of laboratory test 

procedures and instruments, and must 

include adequate identification and handling 

of all test samples (§ 606.140(b), (c)). Use 

of supplies and reagents must be in a manner 

consistent with the instructions provided by 

the manufacturer (§§ 606.65(e), 610.40(b)). 

In addition, as part of an overall Quality 

Assurance program, we recommend that you 

to conduct additional investigation to 

determine the cause of the initial reactivity 

of the Master Pool.

(2) If one (or more) individual donor sample(s) 

is (are) Reactive, perform steps a-d in 

section IV.2. above. 

You may release from quarantine all NonReactive individual donations (if serologic 

tests on those donor samples are Negative 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

19

and the donations are otherwise suitable for 

release). 

7. Reentry for Donors Deferred Because of HIV-1 Test Results 

Currently, FDA has not approved a process for reentry of donors with 

the following HIV-1 test results:

o NAT-Reactive for HIV-1 (either by a Discriminatory NAT 

after a Reactive Multiplex NAT or by a separate NAT for 

HIV-1 RNA) and anti-HIV-1/2 EIA Repeatedly Reactive 

(regardless of HIV-1 Western Blot or IFA or HIV-1 p24 

EIA test result); 

OR 

o NAT-Reactive for HIV-1 (either by a Discriminatory NAT 

after a Reactive Multiplex NAT or by a separate NAT for 

HIV-1 RNA) and HIV-1 p24 EIA Repeatedly Reactive 

(regardless of anti-HIV-1/2 EIA test result); 

OR 

o NAT-Non-Reactive for HIV-1 (or HIV-1 NAT not 

performed) and anti-HIV-1/2 EIA Repeatedly Reactive, 

HIV-1 Western Blot Positive (regardless of HIV-1 p24 EIA 

test result). 

FDA has approved a method or process for reentry of deferred 

donors in the following classes:

o Donors who were NAT-Reactive 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. The HIV-1 Discriminatory 

NAT may have been either Positive or Negative. If an 

Additional NAT for HIV-1 (validated for use with 

individual donor samples) was performed, it must have 

been Non-Reactive. 

NOTE: If the original donation that was NAT-Reactive 

was Negative on the Discriminatory NAT for HIV-1 but 

was Positive on the Discriminatory NAT for HCV, you 

may attempt to reenter the donor according to the 
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Contains Nonbinding Recommendations 

20

recommendations in section IV.8. (See Figure 8 and Table 

8). If the original donor sample that was NAT-Reactive 

was Positive or Negative on both the Discriminatory NAT 

for HIV-1 and on the Discriminatory NAT for HCV, you 

may attempt to reenter the donor according to the 

recommendations in both sections IV.7 and IV.8 (See 

Figures 7 and 8, and Tables 7 and 8). 

o Donors who were NAT-Non-Reactive (or NAT was not 

performed) and who were Repeatedly Reactive on a 

screening test for HIV-1 antibody, with an HIV-1 Western 

blot or IFA that was Negative (or was not performed), or an 

HIV-1 Western blot result that was Indeterminate (viral 

bands may be present). This includes donors previously 

deferred because of Repeatedly Reactive HIV serologic test 

results prior to the initiation of testing by NAT. 

 

These donors may be eligible for reentry only if the HIV-1 

p24 antigen EIA (if done) was Negative and if a second, 

different, licensed HIV-2 EIA was Negative, or, if the 

second HIV-2 EIA was Repeatedly Reactive, an 

investigational HIV-2 supplemental test was not Positive. 

Currently, we have not approved a supplemental 

(additional, more specific) test for HIV-2. 

o Donors who were NAT Non-Reactive and who were 

Negative on a screening test for HIV-1 antibody, but who 

were Repeatedly Reactive on an HIV-1 p24 antigen EIA 

with a Positive or an Indeterminate (that is, an Invalid or a 

Non-Neutralized) result on the Neutralization test. 

a. 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 7 and Table 7): 

i. 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 HIV-1 NAT that is the same as 

the NAT (i.e., the Discriminatory NAT for 

HIV-1) that was run on the original donor 

sample or a licensed HIV-1 NAT that is 

labeled as sensitive for HIV-1 group O and 

HIV-1 group M variants; 
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Contains Nonbinding Recommendations 

21

AND 

(2) a licensed anti-HIV-1/2 EIA. If the original 

donor sample was Repeatedly Reactive on 

the anti-HIV-1/2 EIA, we recommend that 

you use that same EIA to test this follow-up 

sample. If the original donor sample was 

Negative on the anti-HIV-1/2 EIA, we 

recommend that you use an Alternate EIA 

that is labeled as sensitive for HIV-1 Group 

O.

NOTE: If you wish to perform follow-up testing on 

a donor who is deferred because of HIV-1 test 

results, you may do so prior to the end of this 8-

week waiting period for donor notification purposes 

or for medical reasons. Negative results on a 

follow-up HIV-1 test conducted before the 8 week 

period ends may be useful in donor counseling. 

However, only a Negative screening test result 

obtained at least 8 weeks after the NAT-Reactive or 

Repeatedly Reactive anti-HIV-1/2 or HIV-1 p24 

EIA test result would qualify the donor for reentry. 

If you again obtain a Reactive NAT or a Repeatedly 

Reactive anti-HIV-1/2 EIA result during this 8-

week waiting period, the donor would not be 

eligible for reentry and we recommend that you 

defer the donor permanently. 

ii. Evaluate the results of the follow-up testing on the donor’s 

new sample as follows: 

(1) If the NAT is Reactive and the anti-HIV-1/2 

EIA is Repeatedly Reactive, we recommend 

that you defer the donor permanently. 

(2) If the NAT is Reactive and the anti-HIV-1/2 

EIA is Negative, we recommend that you 

defer the donor permanently. 

(3) If the NAT is Non-Reactive and the antiHIV-1/2 EIA is Repeatedly Reactive, you 

may reconsider the donor for reentry by 

additional follow-up testing after a second 

waiting period of 8 weeks. 
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Contains Nonbinding Recommendations 

22

When there is a persistent anti-HIV-1/2 EIA 

Repeatedly Reactive result, you may wish to 

further test the donor’s new sample using an 

HIV-1 Western Blot. If the Western Blot 

test result is Negative, or an Indeterminate

blot pattern has not progressed, you may 

reconsider the donor for reentry by 

additional follow-up testing after a second 

waiting period of 8 weeks. If the Western 

blot result is Positive, we recommend that 

you defer the donor permanently. 

(4) If the NAT is Non-Reactive and the antiHIV-1/2 EIA 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). 

8. Reentry for Donors Deferred Because of HCV Test Results 

Currently, FDA has not approved a process for reentry of donors with 

the following HCV test results: 

o NAT-Reactive for HCV (either by a Discriminatory NAT 

after a Reactive Multiplex NAT or by a separate NAT for 

HCV RNA) and anti-HCV EIA Repeatedly Reactive 

(regardless of HCV RIBA test result). 

OR 

o NAT-Non-Reactive for HCV (or HCV NAT not 

performed) and anti-HCV EIA Repeatedly Reactive, HCV 

RIBA Positive. 

FDA has approved a method or a process for reentry of deferred 

donors in the following classes: 

o Donors who were NAT-Reactive and seronegative. This 

includes donors previously deferred because of Reactive 

test results on an investigational HCV NAT. The HCV 

Discriminatory NAT may have been either Positive or 

Negative. If an Additional NAT for HCV (validated for 

use with individual donor samples) was performed, it 

must have been Non-Reactive. 
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Contains Nonbinding Recommendations 

23

NOTE: If the original donor sample that was NATReactive was Negative on the Discriminatory NAT for 

HCV but was Positive on the Discriminatory NAT for 

HIV-1, you may attempt to reenter the donor according to 

the recommendations in section IV.7. (See Figure 7 and

Table 7). If the original donor sample that was NATReactive was Positive or Negative on both the 

Discriminatory NAT for HCV and on the Discriminatory 

NAT for HIV-1, you may attempt to reenter the donor 

according to the recommendations in both sections IV.7 

and IV.8 (See Figures 7 and 8 and Tables 7 and 8). 

o Donors who were NAT-Non-Reactive (or NAT was not 

performed) and who were Repeatedly Reactive on a 

screening test for HCV antibody, with an HCV RIBA that 

was Indeterminate or Negative (or was not performed). 

This includes donors previously deferred because of 

Repeatedly Reactive HCV serologic test results prior to 

the initiation of testing by NAT. 

 

a. 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 8 and Table 8): 

i. 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 HCV NAT 

AND 

(2) A licensed anti-HCV EIA. 

NOTE: If you wish to perform follow-up testing on a 

donor who is deferred because of HCV test results, you 

may do so prior to the end of this 6-month waiting period 

for donor notification purposes or for medical reasons. 

Negative results on a follow-up HCV test conducted before 

the 6-month period ends may be useful in donor 

counseling. However, only a Negative screening test result 

obtained at least 6 months after the NAT-Reactive or 

Repeatedly Reactive anti-HCV test result would qualify the 

donor for reentry. If you again obtain a Reactive NAT or a 

Repeatedly Reactive anti-HCV EIA result during this 6-

month waiting period, the donor would not be eligible for 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

24

reentry and we recommend that you defer the donor 

permanently. 

ii. Evaluate the results of the follow-up testing on the donor’s 

new sample as follows: 

(1) If the NAT is Reactive and the anti-HCV EIA is 

Repeatedly Reactive, we recommend that you defer the 

donor permanently. 

(2) If the NAT is Reactive and the anti-HCV EIA is 

Negative, we recommend that you defer the donor 

permanently. 

(3) If the NAT is Non-Reactive and the anti-HCV EIA is 

Repeatedly Reactive, you may reconsider the donor for 

reentry by additional follow-up testing after a second 

waiting period of 6 months. 

When there is a persistent anti-HCV EIA Repeatedly 

Reactive result, you may wish to further test the donor’s 

new sample using an HCV RIBA. If the RIBA test result is 

Negative, you may reconsider the donor for reentry by 

additional follow-up testing after a second waiting period 

of 6 months. If the RIBA test result is Positive or 

Indeterminate, we recommend that you defer the donor 

permanently. 

(4) If the NAT is Non-Reactive and the anti-HCV EIA 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).

V. IMPLEMENTATION 

This guidance is being distributed for comment purposes only. 

VI. REFERENCES 

1. 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. 

2. Glynn SA, Kleinman SH, Wright DJ, Busch MP. International application of the 

incidence rate/window period model. Transfusion 42:966-972 (2002). 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

25

3. Dodd RY, Notari EP, Stramer SL. Current prevalence and incidence of infectious 

disease markers and estimated window period risk in the American Red Cross blood 

donor population. Transfusion 42:975-979 (2002). 

4. 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). 

5. 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. 

6. FDA Memorandum to All Registered Blood and Plasma Establishments: 

“Recommendations for Donor Screening with a Licensed Test for HIV-1 Antigen,” 

August 8, 1995. 

7. 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. 

8. Federal Register, 11/16/00 (65 FR 69378), Proposed Rule: 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 HCV Infection (“Lookback”) 

9. Federal Register, 12/14/99 (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. 

10. Blood Products Advisory Committee, 69th Meeting, June 14, 2001, 

http://www.fda.gov/ohrms/dockets/ac/cber01.htm-Blood Products Advisory Committee. 

11. Alter HJ. To C or not to C: These are the questions. Blood 85:1681-1695 (1995). 

12. CDC, Recommendations for prevention and control of hepatitis C virus (HCV) 

infection and HCV-related chronic disease. MMWR 47, (RR-19) (1998). 

13. See 21 CFR 610.40(b) for licensed test kits or 21 CFR 601.20(a) for licensed inhouse assays. 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

26

FIGURE 1. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR AN INDIVIDUAL DONOR SAMPLE THAT IS 

REACTIVE ON A MULTIPLEX NAT AFTER A NEGATIVE ANTIBODY 

SCREENING TEST 

Individual Donor Sample Reactive on a Multiplex HIV-1/HCV NAT 

 

TEST USING DISCRIMINATORY NAT(s). 

 _________________________________________________________________________________ 

 Reactive for HIV-1 and/or HCV Non-Reactive for both HIV-1 and HCV 

 OPTION 1 OPTION 2 

 

 

 QUARANTINE AND DESTROY 

 OR RELABEL UNIT. 

 DEFER1 AND NOTIFY DONOR. 

 We recommend lookback We recommend another test on a 

 for HIV-1 and/or HCV, sample from the donor.2

 as appropriate. 

 

 

 _________________________________ 

 Reactive Non-Reactive 

 QUARANTINE AND DESTROY QUARANTINE AND DESTROY 

 OR RELABEL UNIT. OR RELABEL UNIT. 

 DEFER1

 AND NOTIFY DONOR. DEFER1 AND NOTIFY DONOR.3

 We recommend lookback We recommend quarantine/ 

 for HIV-1 and/or HCV, retrieval of prior collections.4

 as appropriate. 

________________________________________________________________________ 

1

 The donor may be eligible for reentry (See Figures 7 and 8). 2 If you test a new sample from the original donation, you may use the original NAT or 

Discriminatory NAT(s) or an Additional NAT. Alternatively, you may test the same sample as in the 

previous NAT tests (e.g., using an Additional NAT). 

3

 You may explain to the donor that the test result, while initially Reactive, is not conclusive. There is 

a slight risk that the initial test result was a Positive result that cannot be excluded without follow-up 

testing of the donor. 

4 We do not recommend that you notify transfusion recipients. 
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Contains Nonbinding Recommendations 

27

FIGURE 2. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR AN INDIVIDUAL DONOR SAMPLE THAT IS 

REACTIVE ON AN INDIVIDUAL NAT AFTER A NEGATIVE ANTIBODY 

SCREENING TEST 

Individual Donor Sample Reactive on HIV-1 NAT and/or HCV NAT 

QUARANTINE AND DESTROY OR RELABEL UNIT. 

DEFER DONOR1

NOTIFY DONOR. 

We recommend lookback for HIV-1 and/or HCV, as appropriate. 

1

The donor may be eligible for reentry (See Figures 7 and 8. 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

28

FIGURE 3. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR A MASTER POOL THAT IS REACTIVE ON A 

MULTIPLEX NAT: RESOLUTION BY TESTING INDIVIDUAL DONOR 

SAMPLES 

Master Pool Reactive on a Multiplex HIV-1/HCV NAT 

TEST INDIVIDUAL DONOR SAMPLES 

USING SAME MULTIPLEX NAT METHOD1 

 

 Reactive Non-Reactive 

 Donor Sample(s) Donor Samples 

 

 

 

 RELEASE2

 

PERFORM THE STEPS IN FIGURE 1 FOR TESTING, 

PRODUCT DISPOSITION, AND DONOR MANAGEMENT

 

1 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 Master Pool. 

2 Units may be released only if serologic tests for HIV-1 and HCV are Negative and the units are 

otherwise suitable for release.
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

29

FIGURE 4. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR A MASTER POOL THAT IS REACTIVE ON AN 

INDIVIDUAL NAT: RESOLUTION BY TESTING INDIVIDUAL DONOR 

SAMPLES 

Master Pool Reactive on HIV-1 NAT and/or HCV NAT 

TEST INDIVIDUAL DONOR SAMPLES 

USING SAME NAT METHOD1 

 

 Reactive Non-Reactive 

 Donor Sample(s) Donor Samples 

 

 

 

 RELEASE2

 

PERFORM THE STEPS IN FIGURE 2 FOR TESTING, 

PRODUCT DISPOSITION, AND DONOR MANAGEMENT 

 

1 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 Master Pool. 

2 Units may be released only if serologic tests for HIV-1 and HCV are Negative and the units are 

otherwise suitable for release.
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

30

FIGURE 5. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR A MASTER POOL THAT IS REACTIVE ON A 

MULTIPLEX NAT: RESOLUTION BY TESTING SUBPOOLS 

Master Pool Reactive on a Multiplex HIV-1/HCV NAT 

TEST SUBPOOLS1` 

USING SAME MULTIPLEX NAT METHOD2 

 

 Reactive Non-Reactive 

 Subpool(s) Subpools 

 

 

 RELEASE3

 

 ALL UNITS 

 TEST INDIVIDUAL DONOR SAMPLES 

 USING SAME MULTIPLEX NAT METHOD 2 

 

 

 

 Reactive Non-Reactive 

 Donor Sample(s) Donor Samples 

 

 

 RELEASE3

 

PERFORM THE STEPS IN FIGURE 1 FOR TESTING, 

PRODUCT DISPOSITION, AND DONOR MANAGEMENT

1 Can be several layers of deconstruction using original or freshly pooled Subpools. 

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 Master Pool. 

3

 Units may be released only if serologic tests for HIV-1 and HCV are Negative and the units are 

otherwise suitable for release.
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

31

FIGURE 6. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR A MASTER POOL THAT IS REACTIVE ON AN 

INDIVIDUAL NAT: RESOLUTION BY TESTING SUBPOOLS 

Master Pool Reactive on HIV-1 NAT and/or HCV NAT 

TEST SUBPOOLS1` 

USING SAME NAT METHOD2 

 

 Reactive Non-Reactive 

 Subpool(s) Subpools 

 

 

 RELEASE3 

 TEST INDIVIDUAL DONOR SAMPLES ALL UNITS 

 USING SAME NAT METHOD 2 

 

 

 

 Reactive Non-Reactive 

 Donor Sample(s) Donor Samples 

 

 

 RELEASE3

 

PERFORM THE STEPS IN FIGURE 2 FOR TESTING, 

PRODUCT DISPOSITION, AND DONOR MANAGEMENT 

1 Can be several layers of deconstruction using original or freshly pooled Subpools. 

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 Master Pool. 

3

 Units may be released only if serologic tests for HIV-1 and HCV are Negative and the units are 

otherwise suitable for release.
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

32

FIGURE 7. REENTRY FOR DONORS DEFERRED BECAUSE OF HIV-1 TEST 

RESULTS 

 NAT Reactive1/ NAT Non-Reactive or Not Done/ NAT Non-Reactive/ 

Additional NAT2

 Non-Reactive)/ Anti-HIV-1/2 EIA RR, Anti-HIV-1/2 EIA Negative/ 

Anti-HIV-1/2 EIA Negative/ HIV-1 Western Blot or IFA HIV-1 p24 EIA RR, 

 HIV-1 p24 EIA3 Negative Indeterminate or Negative4 Neut. Test Positive or Indeter.

 or Not Done/ (Non-Neutralized or Invalid) 

 HIV-1 p24 EIA3 Negative 

 

AFTER 8 WEEKS5, 

TEST FOLLOW-UP SAMPLE USING 

HIV-1 NAT6,7 AND ANTI-HIV-1/2 EIA8

 

________________________________________________________________________ 

 NAT Reactive / NAT Reactive / NAT Non-Reactive / NAT Non-Reactive / 

 Anti-HIV-1/2 EIA RR Anti-HIV-1/2 EIA Neg. Anti-HIV-1/2 EIA RR Anti-HIV-1/2 EIA Neg. 

 

DEFER DONOR DEFER DONOR DEFER DONOR REENTER DONOR 

PERMANENTLY PERMANENTLY AND CONTINUE (Donor Eligible for

 FOLLOW-UP9

 Future Donation, Provided Donor Meets

 Eligibility Criteria) 

________________________________________________________________________ 

1 HIV-1 Discriminatory NAT may be Positive or Negative; however, if Negative and if HCV Discriminatory NAT 

is Positive, use HCV Reentry Algorithm only (See Figure 8). 

2

 An Additional NAT that has been validated for use with individual donor samples. 3 May not have been performed, depending upon conditions of specific NAT approval. 4

 If a second, different, licensed HIV-2 EIA was Negative or, if Repeatedly Reactive, an investigational HIV-2 

Supplemental Test was not Positive. 

5

 HIV-1 NAT and/or anti-HIV-1/2 EIA, if performed prior to 8 weeks, must be Negative. 6

 If the original donor sample was Non-Discriminated using Discriminatory NAT for HIV-1 and HCV or was 

Positive on both of the Discriminatory NAT tests, test a follow-up sample using HCV NAT and Anti-HCV EIA 

also, as in HCV Reentry Algorithm (See Figure 8). 7

 Using the same NAT (i.e., the Discriminatory NAT for HIV-1) or a NAT labeled as sensitive for HIV-1 Group 

O and HIV-1 Group M variants. 

8

 If the original donor sample was Repeatedly Reactive on the anti-HIV-1/2 EIA, we recommend that you use 

that same EIA to test this follow-up sample. If the original donor sample was Negative on the anti-HIV-1/2 EIA, 

we recommend that you use an Alternate EIA that is labeled as sensitive for HIV-1 Group O. 

9

 At your option you may further test the donor’s sample using HIV-1 Western Blot. If Western Blot is 

Negative, or if an Indeterminate blot pattern has not progressed, you may reconsider the donor for reentry by 

additional follow-up testing after a second waiting period of 8 weeks. If Western Blot is Positive, defer the donor 

permanently.
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

33

FIGURE 8. REENTRY FOR DONORS DEFERRED BECAUSE OF HCV TEST 

RESULTS 

 NAT Reactive1/ NAT Non-Reactive or Not Done/ 

 (Additional NAT2

 Non-Reactive)/ Anti-HCV EIA RR, 

 Anti-HCV EIA Negative RIBA Indeterminate or Negative 

 or Not Done 

 

 

 

AFTER 6 MONTHS3, 

TEST FOLLOW-UP SAMPLE USING 

HCV NAT4 AND ANTI-HCV EIA

 

________________________________________________________________________ 

 NAT Reactive / NAT Reactive / NAT Non-Reactive / NAT Non-Reactive / 

Anti-HCV EIA RR Anti-HCV EIA Neg. Anti-HCV EIA RR Anti-HCV EIA Neg. 

 DEFER DONOR DEFER DONOR DEFER DONOR REENTER DONOR 

PERMANENTLY PERMANENTLY AND CONTINUE (Donor Eligible for

 FOLLOW-UP5 Future Donation,

 Provided Donor Meets

 Eligibility Criteria) 

________________________________________________________________________ 

1

 HCV Discriminatory NAT may be Positive or Negative; however, if Negative and if HIV-1 

Discriminatory NAT is Positive, use HIV-1 Reentry Algorithm only (See Figure 7). 

2

 An Additional NAT that has been validated for use with individual donor samples. 

3 HCV NAT and/or anti-HCV EIA, if performed prior to 6 months, must be Negative. 

4

 If the original donor sample was Non-Discriminated using Discriminatory NAT for HIV-1 and 

HCV or was Positive on both of the Discriminatory NAT tests, test a follow-up sample using HIV-1 

NAT and Anti-HIV-1/2 EIA also, as in HIV-1 Reentry Algorithm (See Figure 7). 

5

 At your option you may further test the donor’s sample using HCV RIBA. If RIBA is Negative, you 

may reconsider the donor for reentry by additional follow-up testing after a second waiting period of 

6 months. If RIBA is Positive or Indeterminate, defer the donor permanently. 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

34

TABLE 1. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR AN INDIVIDUAL DONOR SAMPLE THAT IS 

REACTIVE ON A MULTIPLEX NAT AFTER A NEGATIVE ANTIBODY 

SCREENING TEST

If: Then: After that 

if:

Then: After that 

if: 

Then: 

Individual 

Donor 

Sample 

Reactive on 

a Multiplex

HIV-1/HCV 

NAT 

Test the sample 

using 

Discriminatory 

NAT(s) 

Reactive for 

HIV-1 and/or 

HCV 

Non-Reactive 

for both HIV1 and HCV 

Quarantine 

and destroy or 

relabel unit; 

defer1

 and 

notify donor; 

we recommend 

lookback for 

HIV-1 and/or 

HCV as 

appropriate 

Quarantine 

and destroy or 

relabel unit; 

defer1

 and 

notify donor; 

we recommend 

lookback for 

HIV-1 and/or 

HCV as 

appropriate

OR: 

We recommend 

another test2

 on 

a sample from 

the donor.

Another test 

is Reactive 

Another 

test is Non- 

 Reactive

Quarantine and 

destroy or relabel 

unit; defer1

 and 

notify donor; we 

recommend 

lookback for HIV-1 

and/or HCV as 

appropriate 

Quarantine and 

destroy or relabel 

unit; defer1

 and 

notify donor3; We 

recommend 

quarantine/ 

retrieval of prior 

collections4

1

 The donor may be eligible for reentry (See Figures 7 and 8). 

2

 If you test a new sample from the original donation, you may use the original NAT or Discriminatory NAT(s) or an 

Additional NAT. Alternatively, you may test the same sample as in the previous NAT tests (e.g., using an Additional NAT). 3 You may explain to the donor that the test result, while initially Reactive, is not conclusive. There is a slight risk that the 

initial test result was a Positive result that cannot be excluded without follow-up testing of the donor. 

4 We do not recommend that you notify transfusion recipients. 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

35

TABLE 2. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR AN INDIVIDUAL DONOR SAMPLE THAT IS 

REACTIVE ON AN INDIVIDUAL NAT AFTER A NEGATIVE ANTIBODY 

SCREENING TEST 

If: Then: 

Individual Donor Sample 

Reactive on HIV-1 NAT and/or 

HCV NAT 

Quarantine the unit 

Destroy or relabel the unit 

Defer the donor1

Notify the donor 

We recommend lookback for HIV-1 and/or HCV, as 

appropriate 

1 The donor may be eligible for reentry (See Figures 7 and 8). 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

36

TABLE 3. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR A MASTER POOL THAT IS REACTIVE ON A 

MULTIPLEX NAT: RESOLUTION BY TESTING INDIVIDUAL DONOR 

SAMPLES 

If: Then: After that if: Then: 

Master Pool Reactive on a 

Multiplex HIV-1/HCV 

NAT 

Test the individual 

donor samples using 

same Multiplex NAT 

method1 

Reactive donor 

sample(s) 

Non-Reactive donor 

samples 

Perform the steps in 

Table 1 for Testing, 

Product Disposition, 

and Donor 

Management 

Release2

1 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 NAT on Master Pool. 

2

Units may be released only if serologic tests for HIV-1 and HCV are Negative and the units are 

otherwise suitable for release. 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

37

TABLE 4. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR A MASTER POOL THAT IS REACTIVE ON AN 

INDIVIDUAL NAT: RESOLUTION BY TESTING INDIVIDUAL DONOR 

SAMPLES 

If: Then: After that if: Then: 

Master Pool 

Reactive on HIV-1 

NAT and/or HCV 

NAT 

Test the individual 

donor samples using 

same NAT method1 

Reactive donor 

sample(s) 

Non-Reactive 

donor samples

Perform the steps in Table 2 

for Testing, Product 

Disposition, and Donor 

Management 

Release2

1 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 NAT on Master Pool. 

2

Units may be released only if serologic tests for HIV-1 and HCV are Negative and the units are 

otherwise suitable for release. 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

38

TABLE 5. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR A MASTER POOL THAT IS REACTIVE ON A 

MULTIPLEX NAT: RESOLUTION BY TESTING SUBPOOLS 

If: Then: After that if: Then: After that if: Then: 

Master Pool 

Reactive on a 

Multiplex 

HIV-1/HCV 

NAT 

Test 

subpools1

using same 

Multiplex

NAT 

method2 

Reactive subpool(s) 

Non-Reactive 

 subpool(s) 

Test the 

individual 

donor 

samples 

using same 

Multiplex

NAT 

method2 

Release all 

units3 

 Reactive donor 

 sample(s) 

 Non-Reactive 

 Donor samples 

Perform the 

steps in Table 1 

for Testing, 

Product 

Disposition, and 

Donor 

Management

Release3 

1 Can be several layers of deconstruction using original or freshly pooled Subpools. 

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 Master Pool. 

3

 Units may be released only if serologic tests for HIV-1 and HCV are Negative and the units are 

otherwise suitable for release.
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

39

TABLE 6. TESTING, PRODUCT DISPOSITION, AND DONOR 

MANAGEMENT FOR A MASTER POOL THAT IS REACTIVE ON AN 

INDIVIDUAL NAT: RESOLUTION BY TESTING SUBPOOLS 

If: Then: After that if: Then: After that if: Then: 

Master 

Pool 

Reactive 

on HIV-1 

NAT 

and/or 

HCV NAT 

Test subpools1

using same 

NAT method2 

Reactive 

Subpool(s) 

Non-Reactive 

Subpools 

Test the 

individual 

donor samples 

using same 

NAT Method2 

Release all 

units3 

Reactive donor 

sample(s) 

Non-Reactive 

donor samples 

Perform the steps 

in Table 2 for 

Testing, Product 

Disposition, and 

Donor 

Management 

Release3 

1 Can be several layers of deconstruction using original or freshly pooled Subpools. 

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 Master Pool. 

3

 Units may be released only if serologic tests for HIV-1 and HCV are Negative and the units are 

otherwise suitable for release. 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

40

TABLE 7. REENTRY FOR DONORS DEFERRED BECAUSE OF HIV-1 TEST 

RESULTS 

1

HIV-1 Discriminatory NAT may be Positive or Negative; however, if Negative and if HCV 

Discriminatory NAT is Positive, use HCV Reentry Algorithm only (See Table 8). 

2

An Additional NAT that has been validated for use with individual donations. 

3 May not have been performed, depending upon conditions of specific NAT approval. 4

If a second, different, licensed HIV-2 EIA was Negative or, if Repeatedly Reactive, an investigational 

HIV-2 Supplemental Test was not Positive.

5

HIV-1 NAT and/or anti-HIV-1/2 EIA, if performed prior to 8 weeks, must be Negative. 

6

If the original donor sample was Non-Discriminated using Discriminatory NAT for HIV-1 and HCV 

or was Positive on both of the Discriminatory NAT tests, test a follow-up sample using HCV NAT 

and Anti-HCV EIA also, as in HCV Reentry Algorithm (See Table 8). 

7

Using the same NAT (i.e., the Discriminatory NAT for HIV-1) or a NAT labeled as sensitive for 

HIV-1 Group O and HIV-1 Group M variants. 

8

If the original donor sample was Repeatedly Reactive on the anti-HIV-1/2 EIA, we recommend that 

you use that same EIA to test this follow-up sample. If the original donor sample was Negative on 

the anti-HIV-1/2 EIA, we recommend that you use an Alternate EIA that is labeled as sensitive for 

HIV-1 Group O. 

9

At your option you may further test the donor’s sample using HIV-1 Western Blot. If Western Blot 

is Negative, or if an Indeterminate blot pattern has not progressed, you may reconsider the donor for 

reentry by additional follow-up testing after a second waiting period of 8 weeks. If Western Blot is 

Positive, defer the donor permanently. 

If: Then: After that if: Then: 

NAT Reactive1 / 

(Additional NAT2

 NonReactive)/ 

Anti-HIV-1/2 EIA Negative/ 

HIV-1 p24 EIA3

 Negative 

OR 

NAT Non-Reactive or Not 

Done/ 

Anti-HIV-1/2 EIA RR, HIV-1 

WB or IFA Indeterminate or 

Negative4

 or Not Done/ 

HIV-1 p24 EIA3

 Negative 

OR 

NAT Non-Reactive/ 

Anti-HIV-1/2 EIA Negative/ 

HIV-1 p24 EIA RR, Neut.Test 

Positive or Indeterminate 

(Non-Neutralized or Invalid) 

After 8 weeks5 

test follow-up 

sample using 

HIV-1 NAT6,7

and Anti-HIV1/2 EIA8 

 NAT Reactive/ 

 Anti-HIV-1/2 EIA RR 

 NAT Reactive/ 

 Anti-HIV-1/2 EIA Negative 

 NAT Non-Reactive/ 

 Anti-HIV-1/2 EIA RR 

 NAT Non-Reactive/ 

 Anti-HIV-1/2 Negative 

Defer donor 

permanently 

Defer donor 

permanently 

Defer donor and 

continue followup9 

REENTER 

DONOR 

(Donor eligible 

for future 

donation, 

provided donor 

meets eligibility 

criteria) 
Draft –Not For Implementation 

Contains Nonbinding Recommendations 

41

TABLE 8. REENTRY FOR DONORS DEFERRED BECAUSE OF HCV TEST 

RESULTS

1

 HCV Discriminatory NAT may be Positive or Negative; however, if Negative and if HIV-1 

Discriminatory NAT is Positive, use HIV-1 Reentry Algorithm only (See Table 7). 

2

 An Additional NAT that has been validated for use with individual donations. 

3 HCV NAT and/or anti-HCV EIA, if performed prior to 6 months, must be Negative. 

4

 If the original donor sample was Non-Discriminated using Discriminatory NAT for HIV-1 and 

HCV or was Positive on both of the Discriminatory NAT tests, test a follow-up sample using HIV-1 

NAT and Anti-HIV-1/2 EIA also, as in HIV-1 Reentry Algorithm (See Table 7). 

5

 At your option you may further test the donor’s sample using HCV RIBA. If RIBA is Negative, you 

may reconsider the donor for reentry by additional follow-up testing after a second waiting period of 

6 months. If RIBA is Positive or Indeterminate, defer the donor permanently. 

If: Then: After that if: Then: 

NAT Reactive1

/ 

(Additional NAT2 NonReactive)/ 

Anti-HCV EIA Negative 

OR 

NAT Non-Reactive or Not 

Done/ 

Anti-HCV EIA RR, 

RIBA Indeterminate or 

Negative or Not Done 

After 6 months3

test follow-up 

sample using HCV 

NAT4 and AntiHCV EIA 

NAT Reactive/ 

Anti-HCV EIA RR 

NAT Reactive/ 

Anti-HCV EIA Negative 

NAT Non-Reactive/

Anti-HCV EIA RR

NAT Non Reactive/ 

Anti-HCV EIA Negative

Defer donor 

permanently

Defer donor 

permanently

Defer donor 

and 

continue 

follow-up5

REENTER 

DONOR 

(Donor 

eligible for 

future 

donations, 

provided 

donor meets 

eligibility 

criteria)