Guidance for Industry 
 
Use of Nucleic Acid Tests on Pooled 
and Individual Samples from Donors 
of Whole Blood and Blood 
Components, including Source Plasma, 
to Reduce the Risk of Transmission of 
Hepatitis B Virus 
 
 
 
 
 
 
 
 
 
Additional copies of this guidance are available from the Office of Communication, Outreach 
and Development (OCOD), (HFM-40), 1401 Rockville Pike, Suite 200N, Rockville, MD 20852-
1448, or by calling 1-800-835-4709 or 301-827-1800, or e-mail ocod@fda.hhs.gov, or from the 
Internet at 
http://www.fda.gov/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/Guida
nces/default.htm. 
 
For questions on the content of this guidance, contact OCOD at the phone numbers or e-mail 
address listed above. 
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Biologics Evaluation and Research 
October 2012
  Contains Nonbinding Recommendations 
 
Table of Contents 
 
I.  INTRODUCTION..............................................................................................................1 
II.  DEFINITIONS...................................................................................................................2 
III.  BACKGROUND................................................................................................................3 
A.  Rationale for Donor Screening Using HBV NAT..............................................4 
B.  Donor Requalification..........................................................................................7 
IV.  RECOMMENDATIONS...................................................................................................8 
A.  Donor Screening Using HBV NAT......................................................................8 
B.  Management of Donors and Units Based on Hepatitis B Test Results..........10 
C.  Requalification Methods for Donors on the Basis of HBV NAT and HBV 
Serologic Test Results on the Follow-Up Sample.............................................13 
V.  LABELING......................................................................................................................16 
A.  Circular of Information for Whole Blood and Blood Components Intended 
for Transfusion....................................................................................................16 
B.  Blood Components Intended for Further Manufacture..................................16 
C.  Reactive Units and Product Disposition...........................................................17 
VI.  REPORTING CHANGES TO AN APPROVED APPLICATION.............................17 
A.  Test Implementation...........................................................................................17 
B.  Labeling...............................................................................................................18 
C.  Procedures for Requalification of Donors........................................................18 
VII.  REFERENCES.................................................................................................................20 
 
i  Contains Nonbinding Recommendations 
 
Guidance for Industry 
 
Use of Nucleic Acid Tests on Pooled and Individual Samples from 
Donors of Whole Blood and Blood Components, including Source 
Plasma, to Reduce the Risk of Transmission of Hepatitis B Virus 
 
 
This guidance represents the Food and Drug Administrations (FDAs) 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 alternative approach if the approach satisfies the 
requirements of the applicable statutes and regulations.  If you want to discuss an alternative 
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 
 
We, FDA, are providing you, blood establishments that collect Whole Blood and blood 
components for transfusion or for further manufacture, including recovered plasma, Source 
Plasma and Source Leukocytes, with recommendations concerning the use of FDA-licensed 
nucleic acid tests (NAT) to screen blood donors for hepatitis B virus (HBV) deoxyribonucleic 
acid (DNA).  We are also providing you with recommendations for product testing and 
disposition, donor management, methods for donor requalification, and product labeling.   
 
In addition, we are notifying you in this guidance that we consider the use of an FDA-licensed 
HBV NAT to be necessary to reduce adequately and appropriately the risk of transmission of 
HBV.  FDA-licensed HBV NAT can detect evidence of infection at an earlier stage than is 
possible using previously approved hepatitis B surface antigen (HBsAg) and antibody to 
hepatitis B core antigen (anti-HBc) tests.  Therefore, we recommend that you use FDA-licensed 
HBV NAT, in accordance with the requirements under Title 21 Code of Federal Regulations, 
610.40(a) and (b) (21 CFR 610.40(a) and (b)). 
 
This guidance finalizes the draft guidance of the same title dated November 2011.  This guidance 
supplements previous memoranda and guidance from FDA to blood establishments concerning 
the testing of donations for HBsAg and anti-HBc, and the management of donors and units 
mentioned in those documents (Refs. 1 through 5).  Note that when you implement HBV NAT 
testing, you should continue testing for HBsAg and anti-HBc in Whole Blood and blood 
components intended for transfusion and Source Leukocytes intended for further manufacture, 
1  Contains Nonbinding Recommendations 
 
and continue testing for HBsAg in Source Plasma.1 FDA may consider advancements in 
technology for testing blood donations, as well as data obtained following the implementation of 
HBV NAT, to make future recommendations on adequate and appropriate testing for HBV.    
 
FDAs guidance documents, including this guidance, do not establish legally enforceable 
responsibilities.  Instead, guidances describe the FDAs 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 FDAs guidances means that something is suggested or 
recommended, but not required. 
 
 
II.  DEFINITIONS  
 
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.  
 
Discriminatory NAT:  A NAT that uses specific primers for HIV-1 or HBV or HCV to identify 
the RNA or DNA in the reactive multiplex NAT sample as HIV-1 RNA or HBV DNA or HCV 
RNA.  Performing a discriminatory NAT on a reactive sample is a required step for those 
establishments using an approved multiplex test.  The labeling for licensed multiplex NATs 
specifies that discriminatory NAT is to be performed.  Under  610.40(b) (21 CFR 610.40(b)), 
you must use FDA-approved screening tests in accordance with the manufacturers instructions. 
 
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. 
 
HBV NAT assay with a limited supplemental test indication:  Some HBV NAT assays have 
received a limited supplemental indication for repeatedly reactive HBsAg test results.  If a 
donation tests HBV NAT-positive for HBV DNA using an HBV NAT with such a limited 
supplemental test indication, and if that donation also tests HBsAg repeatedly reactive in a 
screening test, the HBsAg test result can be recorded as HBsAg positive.  In this case, an HBsAg 
neutralization test need not be performed.  However, if a donation tests HBV NAT-negative for 
HBV DNA using an HBV NAT with such a limited supplemental test indication, and if that 
                                                 
 
1 FDA does not currently recommend that Source Plasma donors be tested for anti-HBc.  If anti-HBc reactive units 
were excluded from pools used for the manufacture of plasma derivatives, titers of neutralizing antibody to hepatitis 
B surface antigen (anti-HBs) in those pools would be expected to diminish, as both these antibodies usually occur 
together.  The presence of neutralizing anti-HBs is believed to contribute to the safety of certain plasma products. 
(Ref. 2).  Plasma units that are untested, non-reactive (NR), or repeatedly reactive (RR) for anti-HBc are currently 
acceptable for the manufacture of plasma derivatives (Ref. 2).  Consistent with  610.40(h)(2)(v), recovered plasma 
from donations of Whole Blood that test anti-HBc reactive may be used for further manufacture into plasma 
derivatives.   
 
2  Contains Nonbinding Recommendations 
 
donation tests HBsAg repeatedly reactive in a screening test, an HBsAg neutralization test 
should be performed.  In this case, the result of the neutralization test serves as the test of record 
(Ref. 1). 
 
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, HBV DNA, and HCV RNA. 
 
Single Virus NAT:  A NAT that separately detects either HIV-1 RNA or HBV DNA 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. 
 
 
III.  BACKGROUND  
 
Under  610.40(a), establishments that collect blood or blood components must test each 
donation of human blood or blood component intended for use in preparing a product, including 
donations intended as a component of, or used to prepare, a medical device, for evidence of 
infection due to certain communicable disease agents, including HBV.  In addition, under  
 610.40(b), you must perform one or more such tests as necessary to reduce adequately and 
appropriately the risk of transmission of communicable disease.   
 
Currently, all Whole Blood and blood components intended for transfusion and all Source 
Leukocytes intended for further manufacture are routinely tested for HBsAg and anti-HBc in 
order to reduce the risk of transmission of HBV (Refs. 1, 2, 3 and 5).  In addition, all Source 
Plasma collections intended for further manufacture into plasma derivatives are routinely tested 
for HBsAg in order to reduce the risk of transmission of HBV in manufacturing pools of plasma 
derivatives.2   
 
In the preamble to the final rule entitled Requirements for Testing Human Blood Donors for 
Evidence of Infection Due to Communicable Disease Agents, published in the Federal Register 
of June 11, 2001 (66 FR 31146), we discussed the approved donor screening tests that we 
considered, as of that date, to be necessary to reduce adequately and appropriately the risk of 
transmission of HBV.  We also stated that as technology advances, we intend to issue guidance 
describing those tests that we consider to reduce adequately and appropriately the risk of 
transmission of communicable disease agents.  Accordingly, in this guidance document, we are 
notifying you that we consider FDA-licensed HBV NAT to be necessary to reduce adequately 
and appropriately the risk of transmission of HBV.   
 
                                                 
 
2  See Footnote 1. 
3  Contains Nonbinding Recommendations 
 
We note that the tests referenced in this document have been licensed by FDA for the screening 
of donors for HBV DNA and have the ability to detect the evidence of infection at an earlier 
stage than is possible using previously approved HBsAg and anti-HBc tests.  Because FDA-
licensed HBV NAT are now widely available, we recommend that establishments use these tests, 
in accordance with  610.40. 
  
A.  Rationale for Donor Screening Using HBV NAT  
 
HBV is a major human pathogen that may cause acute and chronic hepatitis, cirrhosis and 
hepatocellular carcinoma (Ref. 6).  Most primary infections in adults are self-limited, the 
virus is cleared from blood and liver, and individuals develop a lasting immunity.  Fewer 
than 5% of infected adults develop persistent asymptomatic infections (i.e., a carrier 
state).  However, infants and young children have a much higher likelihood of developing 
a chronic hepatitis B infection than do older children and adults.  According to data 
obtained in 2004 from the Centers for Disease Control and Prevention, about 1% of 
adults without other preexisting conditions are estimated to get chronic hepatitis B if 
infected, but 2% to 10% of children more than 5 years of age get chronic hepatitis B, and 
30% to 90% of children less than 5 years of age develop chronic hepatitis B if infected 
(Ref. 7).  In addition, many patients receiving blood are immunocompromised because of 
their underlying disease and/or because of medications that suppress the immune system 
making them more susceptible to severe HBV infection than otherwise healthy 
individuals.  About 20% of chronically infected individuals can develop cirrhosis.  
Chronically infected subjects have 100 times higher risk of developing hepatocellular 
carcinoma than non-carriers (Ref. 6).  
 
Currently, HBV is transmitted by blood transfusions more frequently than hepatitis C 
virus (HCV) or human immunodeficiency virus (HIV).  The residual risk of post-
transfusion HBV infection is estimated to be about 1:357,000 to 1:280,000 per 
transfusion.  In comparison, those risks for HIV and HCV are estimated to be 1:1,467,000 
and 1:1,149,000, respectively (Ref. 8).  Depending on the sensitivity of the test, 
implementation of HBV NAT has the potential to reduce risk of infection to levels 
similar to those for HIV and HCV.  HBV can be transmitted by blood from asymptomatic 
donors with acute HBV infections who have not yet developed HBsAg or anti-HBc (i.e., 
donors in the seronegative window period), when HBV DNA can be detected in the 
donors blood (Refs. 9 and 10).  Depending on the relative sensitivities of HBsAg and 
HBV NAT assays used, HBV DNA can be detected 2 to 5 weeks after infection, and up 
to 40 days (mean 6 to 15 days) before HBsAg (Ref. 7).  HBV DNA levels rise slowly and 
are present at relatively low levels during the seronegative window period of early 
infection.  HBV DNA can also be detected along with HBsAg and anti-HBc in chronic 
hepatitis B infections, and sometimes in recovered infections that are negative for HBsAg 
and positive for antibodies to hepatitis B surface antigen (anti-HBs) and anti-HBc (Refs. 
6 and 11).  Rarely, HBV DNA can be detected in the absence of HBsAg, anti-HBc and 
anti-HBs (Ref. 12).   
 
Blood for transfusion in the United States (U.S.) is also tested for anti-HBc.  Anti-HBc 
develops a few days after the appearance of HBsAg and usually remains detectable for 
4  Contains Nonbinding Recommendations 
 
life, irrespective of whether the individual recovers from acute hepatitis B or whether 
chronic HBV infection develops.  Because of the availability and use of tests to detect 
anti-HBc, HBV NATs potential utility in further reducing risk of HBV transmission by 
blood transfusion is mainly restricted to the early HBsAg-negative phase of infection 
(i.e., a potential reduction of the infectious window period of up to 40 days depending on 
sensitivity of the HBsAg test).  
 
There are currently three FDA-licensed HBV NAT assays for screening Whole Blood 
and blood components available in the U.S.  Following licensure of the first HBV NAT 
assay in April 2005 (the Roche COBAS AmpliScreen HBV NAT that uses pools of up to 
24 donation samples for testing Whole Blood and blood components for transfusion and 
pools of up to 96 donation samples for testing Source Plasma), FDA did not recommend 
use of HBV NAT.  At that time, FDAs position on the use of HBV NAT was based, in 
part, upon discussions by the Blood Products Advisory Committee (BPAC or Committee) 
at the meeting on July 23, 2004 (Ref. 13), and on a recommendation from the Department 
of Health and Human Services Secretarys Advisory Committee on Blood Safety and 
Availability (ACBSA) on August 27, 2004 (Ref. 14).  In making its recommendations, 
the ACBSA considered a number of broad public health issues including cost-
effectiveness, feasibility, and overall public health benefit, in addition to scientific data 
on detection of HBV in donors.  FDAs principal reason for not recommending HBV 
NAT at that time was that the sensitivity of HBV NAT in the available format, when 
compared to the then-available serologic testing, did not provide sufficient additional 
safety to the blood supply to warrant recommending its use.  FDAs reasoning was based 
on then current information that most blood establishments would have to test pools of 24 
samples (thus diluting the individual samples by 1:24), because it was not feasible for 
most blood establishments to test single samples from donations or even small pools of 
samples.   
 
Since licensure of the first HBV NAT in 2005, the following changes have occurred: 
 
1.  FDA has licensed two additional HBV NAT assays with indications for 
blood donor screening:  Procleix ULTRIOPlus Assay (Gen-Probe, Inc., 
San Diego, California), which uses up to 16 donation samples in a pool for 
testing Whole Blood and blood components for transfusion and Source 
Plasma; and COBAS TaqScreen MPX Test (Roche Molecular Systems, 
Inc., Pleasanton, California), which uses up to 6 donation samples in a 
pool for testing Whole Blood and blood components for transfusion and 
pools of up to 96 donation samples for testing Source Plasma.  These 
multiplex assay systems can simultaneously detect HIV, HCV and HBV in 
a single donation, thus improving the feasibility of routine NAT testing for 
HBV.  FDA has also licensed the UltraQualTM HBV PCR Assay (National 
Genetics Institute, Los Angeles, California), which provides results of 
HBV NAT of Source Plasma samples or of plasma samples from Source 
Plasma donors at the time of donation.  This assay is an in-house test; no 
kit is sold.  This assay tests up to 512 donation samples in a pool.    
 
5  Contains Nonbinding Recommendations 
 
2.  With the recent advance in technology and increased automation enabling 
the performance of NAT with smaller pools of samples and individual 
samples, more sensitive HBV NAT testing of blood donations is now 
possible, resulting in an increase in the number of window period HBV 
DNA positive/HBsAg negative units that can be detected.   
 
3.  There is now more information available on the role of vaccination of 
donors and recipients against HBV infection that indicates that protection 
for the long term is not absolute (i.e., breakthrough infections can occur in 
previously vaccinated individuals who are exposed to the virus) (Refs. 10 
and 15).  Breakthrough infections are characterized by HBV NAT 
positivity, the presence of HBV-neutralizing anti-HBs (developed as a 
result of hepatitis B vaccination), low viral load and lack of symptoms.  
HBsAg and anti-HBc may not subsequently develop or their appearance 
may be delayed.  The infectivity of units obtained from hepatitis B-
vaccinated donors with breakthrough HBV infections is unknown at the 
present time.   
 
As mentioned above, in breakthrough HBV infections, HBsAg and anti-HBc may not 
develop or their appearance may be delayed.  However, should development occur, it is 
more likely to be detected by HBV NAT, particularly in the early stages of infection.  As 
younger cohorts in the population, who have received hepatitis B vaccine in a greater 
proportion than older cohorts (Refs. 16, 17, and 18), become eligible to donate blood, the 
proportion of vaccinated donors compared to non-vaccinated donors is expected to 
increase.  Therefore, the proportion of donors with HBV breakthrough infections, 
compared to those with non-breakthrough, wild-type, HBV infections, also is expected to 
increase.  These donors asymptomatic breakthrough infections are more likely to be 
detected by HBV NAT than to be detected by HBsAg or anti-HBc assays because HBsAg 
and anti-HBc development might be delayed or might not occur, even though HBV DNA 
is present and detectable by HBV NAT in the initial stage of the infection.  In addition, 
HBV mutants appear to be more likely to be detected by HBV NAT than by HBsAg 
assays (Ref. 10).     
 
Much of the available literature does not support transmission of HBV by HBV NAT 
positive/anti-HBs positive/HBsAg negative blood, irrespective of anti-HBc test results, 
(Refs. 11, 12, 19, 20, 21, and 22).  However, there are at least two reports of such 
possible transmissions by hematopoietic stem cells and blood (Refs. 23 and 24), and one 
report that appears to have confirmed transmission of HBV by HBV NAT positive/anti-
HBs positive/HBsAg negative blood (Ref. 25).  Therefore, there can be no assumption of 
non-infectivity of units from donors with breakthrough infections containing HBV DNA 
and vaccine-induced, HBV-neutralizing anti-HBs when transfused into recipients.  Nor 
can we assume a lack of morbidity and mortality in recipients, especially when many 
recipients are immunocompromised, as previously mentioned.   
 
At the April 1, 2009 BPAC meeting (Ref. 26), the Committee agreed with FDAs 
position that there is no assumption of non-infectivity to recipients of units from donors 
6  Contains Nonbinding Recommendations 
 
with breakthrough infections.  Therefore, in this guidance, we are recommending that all 
units of Whole Blood and blood components used for transfusion should be tested by an 
FDA-licensed HBV NAT.  The Committee also advised that FDA should set a sensitivity 
standard of 200 IU/mL HBV DNA for detection of HBV DNA in an individual donation 
when HBV NAT assays are used to test blood and blood components intended for 
transfusion.  However, because of technological advances that have occurred since the 
April 2009 BPAC meeting, we are now recommending a sensitivity standard of 100 
IU/mL for HBV DNA detection in an individual donation (see section IV.A).  Because of 
advances in technology and automation, FDA considers a sensitivity standard of 100 
IU/mL to be both attainable and practical for blood establishments that collect donations 
of Whole Blood and blood components intended for transfusion.  
 
With regard to testing Source Plasma units for further manufacture into injectable plasma 
derivatives for HBV DNA, we believe that such testing adds another layer of safety for 
plasma derivatives by limiting the viral load in plasma pools for fractionation (in viral 
inactivation and/or removal steps during their manufacture and the presence of 
neutralizing anti-HBs in manufacturing pools).  During the BPAC meeting held on April 
28, 2011 (Ref. 27), the Committee agreed with FDA that the available scientific data 
supports the concept that testing Source Plasma donations by HBV NAT increases the 
safety margin of plasma derivatives.  Therefore, FDA is recommending that all units of 
Source Plasma intended for manufacture into injectable plasma derivatives be tested by 
an FDA-licensed HBV NAT.  In consideration of viral inactivation and removal steps in 
plasma fractionation, FDA also is recommending a sensitivity standard of 500 IU/mL for 
detection of HBV DNA in an individual collection, rather than 100 IU/mL (see section 
IV.A).  BPAC endorsed this sensitivity standard at the April 28, 2011 meeting (Ref. 27).   
 
Similar to plasma derivatives, the HBV safety of products made from Source Leukocytes 
depends in large measure on viral removal and inactivation during manufacturing.  
However, since Source Leukocytes are obtained from Whole Blood donors, consistent 
with our recommendation for Whole Blood and blood components intended for 
transfusion, we are also recommending a sensitivity standard of 100 IU/mL for HBV 
DNA detection in the individual donation of Source Leukocytes. 
 
B.  Donor Requalification 
  
Under  610.41(b), [a] deferred donor subsequently may be found to be suitable as a 
donor of blood or blood components by a requalification method or process found 
acceptable for such purposes by FDA. 3   
 
At the July 21, 2005 BPAC meeting (Ref. 28), the Committee agreed with FDAs 
proposed requalification criteria for donors of Whole Blood and blood components for 
transfusion and Source Plasma for further manufacture, who tested positive by HBV 
                                                 
 
3  A deferred donor may serve as an autologous donor in accordance with  610.40 and  610.41.  Note that a 
deferred donor who donates for autologous use is not deemed to be reentered and remains deferred, until the criteria 
for reentry are met. 
7  Contains Nonbinding Recommendations 
 
NAT, when a follow-up sample is tested using HBV NAT and serologic tests.  Data 
presented at the meeting demonstrated that a 6-month follow-up period encompasses the 
pre-seroconversion window period with sufficient confidence that negative test results for 
HBsAg, anti-HBc and HBV DNA by NAT, after a 6-month period, rule out HBV 
infection.  For purposes of reentry, we recommend that you use an FDA-licensed HBV 
NAT labeled as having a sensitivity of < 2 IU/mL at 95% detection rate [1 IU = ~5 copies 
of HBV DNA/mL].4  Donors with negative results for HBV DNA at this level of 
sensitivity are highly unlikely to be infected with HBV (Ref. 29).  Depending upon the 
assay and the platform used, this sensitivity may only be achieved when testing 
individual donor samples.  Recommended criteria for donor requalification are presented 
in section IV.C.  
 
 
IV.  RECOMMENDATIONS 
 
A.  Donor Screening Using HBV NAT 
 
Under  610.40(b), you must use screening tests that FDA has approved for such use, in 
accordance with the manufacturers instructions.  Under this provision, you also must 
perform one or more such tests as necessary to reduce adequately and appropriately the 
risk of transmission of communicable disease, including HBV.   
 
1.  In order to meet the requirement under  610.40(b) for Whole Blood and 
blood components intended for transfusion and Source Leukocytes 
intended for further manufacture, we recommend that you use an FDA-
licensed donor screening test for HBV DNA by NAT, in addition to 
testing for HBsAg and anti-HBc.  If the FDA-licensed tests for detection 
of both HBsAg and anti-HBc are negative or non-reactive, we recommend 
that you test the donation further using an FDA-licensed HBV NAT that 
has a lower limit of detection of < 100 IU/mL HBV DNA for HBV DNA 
detection in an individual donation.  The FDA-licensed screening HBV 
NAT that you use may be in a minipool donation-sample testing format or 
an individual donation testing format, and may include multiplex NAT 
with testing of other agents, such as HIV and HCV or may be single virus 
NAT for HBV only.  Testing for HBsAg, anti-HBc and HBV DNA by 
NAT may be performed concurrently. 
 
                                                 
 
4 COBAS AmpliScreen HBV Test (Roche Molecular Systems, Inc., Pleasanton, California):  Triplicate testing using 
the multiprep specimen processing procedure.  See package insert.   
Procleix ULTRIOPlus Assay (Gen-Probe, Inc., San Diego, California):  Testing 3 replicates.  See package inserts. 
8  Contains Nonbinding Recommendations 
 
2.  In order to meet the requirement under  610.40(b) for testing Source 
Plasma intended for further manufacture into plasma derivatives, we 
recommend that you use an FDA-licensed donor screening test for the 
detection of HBsAg.  If the FDA-licensed test for detection of HBsAg is 
negative or non-reactive, we recommend that you test the donation further 
using an FDA-licensed HBV NAT that has a lower limit of detection of    
< 500 IU/mL HBV DNA for HBV DNA detection in an individual 
donation.  The FDA-licensed screening HBV NAT that you use may be in 
a minipool donation-sample testing format or an individual donation 
testing format, and may include multiplex NAT with testing of other 
agents, such as HIV and HCV, or may be single virus NAT for HBV only.  
Testing for HBsAg and HBV DNA by NAT may be performed 
concurrently.  As explained in footnote 1, FDA does not currently 
recommend that Source Plasma donors be tested for anti-HBc (Ref. 2).  
 
As a general matter, under  610.40(h)(1), if any of the FDA-licensed tests 
for the detection of either HBsAg or anti-HBc is reactive, the donation 
must not be shipped or used.5  In this instance, we believe that you have 
met the standard for adequate and appropriate screening for HBV and you 
do not need to test the unit further using an FDA-licensed HBV NAT.  
However, you may choose to test such a reactive donation by using an 
FDA-licensed HBV NAT to provide useful information to the donor, or if 
you wish to reenter the donor as described below in this guidance. 
 
We note that in regard to HBsAg reactivity, as required by  610.40(e), 
you must proceed to supplemental testing for HBsAg to determine 
whether or not a reactive HBsAg test result can be confirmed positive, and 
is not a false positive (i.e., test result recorded HBsAg negative), using 
either an additional, more specific test, such as an HBsAg neutralization 
test or an HBV NAT assay with a limited supplemental test indication.  
Some HBV NAT assays have received this limited supplemental 
indication for repeatedly reactive HBsAg test results.  If a donation tests 
HBV NAT-positive for HBV DNA using an HBV NAT with a limited 
supplemental test indication, and if that donation also tests HBsAg 
repeatedly reactive in a screening test, the HBsAg test result can be 
recorded as HBsAg positive.  In this case, an HBsAg neutralization test 
need not be performed.  However, if a donation tests HBV NAT-negative 
for HBV DNA using an HBV NAT with a limited supplemental test 
indication, and if that donation tests HBsAg repeatedly reactive in a 
screening test, an HBsAg neutralization test should be performed.  In this 
case, the result of the neutralization test serves as the test of record (Ref. 
1).  We further note that there is no licensed supplemental test for anti-
HBc at the present time.  Donors with anti-HBc reactive results may be 
                                                 
 
5 Whole Blood or blood components that are reactive for HBsAg and/or anti-HBc may be shipped or used if they 
meet the conditions for an exception as described in  610.40(h)(2). 
9  Contains Nonbinding Recommendations 
 
requalified as described in the FDA guidance entitled, Guidance for 
Industry:  Requalification Method for Reentry of Blood Donors Deferred 
Because of Reactive Test Results for Antibody to Hepatitis B Core 
Antigen (Anti-HBc), dated May 2010 (Ref. 3). 
 
B.  Management of Donors and Units Based on HBV Test Results 
 
1.  Donor and Unit Management When the HBV DNA NAT Result is 
Negative 
 
a.  If a unit tests negative by individual donation NAT (ID-NAT) for 
HBV DNA or is part of a minipool that tests negative, then the donor 
and the unit should be managed consistent with FDA guidances and 
recommendations, as appropriate (Refs. 1 through 5), provided that the 
donor satisfies all applicable regulatory requirements, including donor 
eligibility criteria in  640.3 and 640.63, and the unit is otherwise 
suitable for release.   
 
b.  Units of Whole Blood and blood components and units of Source 
Leukocytes that test negative for HBV using FDA-licensed HBV NAT 
and HBsAg and anti-HBc assays may be used for transfusion or 
further manufacture (as appropriate), provided that the donor satisfies 
the donor eligibility criteria in  640.3, and that all other donor 
screening tests for communicable disease agents required in  
 610.40(a) and (i) for Whole Blood and blood components, including 
Source Leukocytes, are negative, and that the units are otherwise 
suitable for release.   
 
c.  Units of Source Plasma and recovered plasma that test negative for 
HBV using FDA-licensed HBV NAT and HBsAg assays may be used 
for further manufacture, provided that the donor satisfies the donor 
eligibility criteria in  640.63 (for Source Plasma) and  640.3 (for 
recovered plasma), and that the requirements in  610.40 are met and 
that all other screening tests for communicable disease agents required 
in  610.40(a) and (i) are negative, and that the units are otherwise 
suitable for release (see footnote 1). 
 
2.  Donor and Unit Management when the HBV DNA NAT Result is Positive 
 
a.  In accordance with  610.40(h), except for autologous donations under 
 610.40(h)(2)(i) or where you have obtained FDAs written approval 
for the shipment or use in accordance with  610.40(h)(2)(ii)(A), you 
must not ship or use a unit of Whole Blood or blood components for 
transfusion, or a unit of Source Leukocytes for further manufacture, if 
it tests positive by HBV ID-NAT (either from direct screening by ID-
NAT or from deconstruction of a NAT-positive minipool) (Table 1, 
10  Contains Nonbinding Recommendations 
 
Categories 1 through 6). 
 
b.  In accordance with  610.41, you must defer a donor who tests 
reactive for HBV, and in accordance with 21 CFR Part 630 (Part 630) 
you must notify the blood donor.  You should permanently defer a 
donor of Whole Blood or blood components, including Source 
Leukocytes for further manufacture, whose NAT and serologic test 
results are as follows (the donor is not eligible for reentry):   
 
 
i.  HBV NAT-positive, HBsAg RR and confirmed positive, either 
by neutralization or when using a NAT with a limited 
supplemental claim, regardless of anti-HBc results (Table 1, 
Categories 1 and 2); or  
 
ii.  HBV NAT-positive when using a NAT that does not have a 
limited supplemental test indication and HBsAg RR is not 
confirmed by neutralization, and anti-HBc is RR (Table 1, 
Category 3).  
 
c.  In accordance with  610.41, you must defer a donor who tests 
reactive for tests for HBV, and in accordance with Part 630, you must 
notify the donor.  You should indefinitely defer a donor of Whole 
Blood or blood components, including Source Leukocytes, whose 
NAT and serologic test results are as follows (note that the donor may 
be eligible for reentry, as described in section IV.C):  
 
i.  HBV NAT-positive, HBsAg non-reactive (NR), anti-HBc RR 
(Table 1, Category 4); or  
 
ii.  HBV NAT-positive, and both HBsAg and anti-HBc are NR 
(Table 1, Category 5); or  
 
iii. HBV NAT-positive using a NAT that does not have a limited 
supplemental test indication and HBsAg RR is not confirmed 
by neutralization, and is anti-HBc NR (Table 1, Category 6). 
11  Contains Nonbinding Recommendations 
 
 
Table 1.  Donor and Unit Management (Whole Blood and Blood Components for 
Transfusion, and Source Leukocytes for Further Manufacture) when the HBV DNA 
NAT Result is Positive  
 
Category      HBV NAT Result  HBsAg Result  Anti-HBc Result  Donor and Unit 
         1               Positive  Repeatedly  Non-Reactive  Discard unit;  
Reactive /  Permanently defer donor; 
Confirmed Positive* 
Donor not eligible for 
          2              Positive  Repeatedly  Repeatedly  reentry 
Reactive /  Reactive   
Confirmed Positive*   
          3              Positive  Repeatedly  Repeatedly 
Reactive / Not  Reactive 
Confirmed 
          4              Positive  Non-Reactive  Repeatedly 
Reactive 
Discard unit;  
          5              Positive  Non-Reactive  Non-Reactive  Indefinitely defer donor; 
Donor may be eligible  
          6              Positive  Repeatedly  Non-Reactive 
for reentry 
Reactive / 
Not Confirmed 
*Using either an HBsAg neutralization test or an HBV NAT with a limited supplemental test indication, as 
described in section IV.A.2.  
 
d.  In accordance with  610.40(h), except where you have obtained 
FDAs written approval for the shipment or use in accordance with  
 610.40(h)(2)(ii)(A), you must discard and not use for further 
manufacture a unit of Source Plasma that tests positive by HBV ID-
NAT (Table 2, Categories 1 through 3). 
 
e.  In accordance with  610.41, you must defer a donor who tests 
reactive for tests for HBV, and in accordance with Part 630, you must 
notify the donor.  You should permanently defer a donor of Source 
Plasma whose donation tests HBV NAT-positive and is HBsAg RR, 
confirmed positive either by neutralization, or when using a NAT with 
a limited supplemental test indication.  The donor is not eligible for 
reentry (Table 2, Category 1).   
  
f.  In accordance with  610.41, you must defer a donor who tests 
reactive for tests for HBV, and in accordance with Part 630 you must 
notify the blood donor.  You should indefinitely defer a donor of 
Source Plasma whose donation tests HBV NAT-positive when using a 
NAT that does not have a limited supplemental claim, and is either 
HBsAg NR or is HBsAg RR not confirmed by neutralization (Table 2, 
Categories 2 and 3).  The donor may be eligible for reentry, as 
described in section IV.C.  
12  Contains Nonbinding Recommendations 
 
Table 2.  Donor and Unit Management (Source Plasma for Further Manufacture) 
when the HBV DNA NAT Result is Positive 
 
Category  HBV NAT Result  HBsAg Result  Donor and Unit 
  Repeatedly Reactive /  Discard unit; 
        1               Positive  Confirmed Positive*  Permanently defer donor; 
Donor not eligible for reentry 
        2               Positive  Non-Reactive  Discard unit; 
Indefinitely defer donor; 
  Repeatedly Reactive/
Donor may be eligible  
        3               Positive  Not Confirmed 
for reentry  
* Using either an HBsAg neutralization test or an HBV NAT with a limited supplemental test 
indication, as described in section IV.A.2. 
 
C.  Requalification Methods for Donors on the Basis of HBV NAT and HBV 
Serologic Test Results on the Follow-up Sample  
 
For purposes of reentry, we recommend that you use an FDA-licensed HBV NAT having 
a sensitivity of < 2 IU/mL at 95% detection rate.  
 
1.  Requalification of a Donor of Whole Blood or Blood Components for 
Transfusion, and Source Leukocytes for Further Manufacture 
 
To reenter an indefinitely deferred donor of Whole Blood or blood components 
for transfusion, or Source Leukocytes for further manufacture, you should obtain 
a follow-up sample from the donor (no donation is made at this time) at least 6 
months after the collection of the sample that gave test results described in section 
IV.B.2.c. You should perform follow-up testing using HBV NAT (having a 
sensitivity of < 2 IU/mL at 95% detection rate), HBsAg and anti-HBc FDA-
licensed assays.   
 
a.  If the new follow-up sample tests positive by HBV NAT, regardless of 
HBsAg and/or anti-HBc test results, we recommend that you 
permanently defer the donor (Table 3, Category 1).   
 
b.  If the new follow-up sample tests negative by HBV NAT and NR by 
HBsAg and anti-HBc assays, the donor may be reentered (i.e., the 
donor is eligible to donate in the future), provided the donor meets all 
donor eligibility criteria in  640.3 (Table 3, Category 2).   
 
c.  If the new follow-up sample tests negative by HBV NAT and RR by 
HBsAg and/or RR by anti-HBc, we recommend that you evaluate the 
donor further as described in the FDA guidance documents cited in 
References 1, 2 and 3 (Table 3, Category 3) in this document.   
 
13  Contains Nonbinding Recommendations 
 
NOTE: If you wish to perform follow-up testing on a donor of Whole 
Blood or blood components for transfusion or on a donor of Source 
Leukocytes for further manufacture who is deferred because of HBV NAT 
test results, you may do so before the end of the 6-month waiting period 
for donor notification purposes or for medical reasons.  Negative test 
results on follow-up for HBsAg, anti-HBc and HBV DNA by NAT 
(sensitivity at 95% detection rate of < 2 IU/mL), may be useful in donor 
counseling.  However, only negative results for all three tests (HBsAg, 
anti-HBc and HBV NAT), obtained at least 6 months after the collection 
of the sample that gave the test results described in section IV.B.2.c, 
would qualify the donor for reentry.  If you obtain a positive HBV NAT, 
or RR anti-HBc, or RR HBsAg that is positive by neutralization during 
this 6-month waiting period, the donor would not be eligible for reentry, 
and we recommend that you defer the donor permanently. 
 
A donor of Whole Blood or blood components for transfusion, or a donor 
of Source Leukocytes for further manufacture who has been requalified as 
described above in section IV.C.1., may on subsequent occasions be 
indefinitely deferred because of HBV NAT reactive results.  You may 
reenter such a donor into the donor pool by again following all the 
procedures described in section IV.C.1. 
 
2.  Requalification of a Donor of Source Plasma for Further Manufacture 
 
To reenter an indefinitely deferred donor of Source Plasma, you should 
obtain a follow-up sample from the donor (no donation is made at this 
time) at least 6 months after the collection of the sample that gave the test 
results described in section IV.B.2.f.  You should perform follow-up 
testing using HBV NAT (having a sensitivity of < 2 IU/mL at 95% 
detection rate) and HBsAg FDA-licensed assays.  
  
a.  If a new follow-up sample tests positive by HBV NAT, regardless of 
the HBsAg test result, you should permanently defer the donor (Table 
3, Category 1).   
 
b.  If a new follow-up sample tests negative by HBV NAT and NR by 
HBsAg, the donor is eligible to donate in the future, provided the 
donor satisfies all donor eligibility criteria in  640.63 (Table 3, 
Category 2).    
 
c.  If a new follow-up sample tests negative by HBV NAT and RR 
HBsAg, you should evaluate the donor further, as described in the 
FDA document cited in Reference 1 (Table 3, Category 3).  
 
NOTE: If you wish to perform follow-up testing on a donor of Source 
Plasma who is deferred because of HBV NAT test results, you may do so 
14  Contains Nonbinding Recommendations 
 
before the end of the 6-month waiting period for donor notification 
purposes or for medical reasons.  Negative test results on follow-up for 
HBsAg and HBV DNA by NAT (sensitivity at 95% detection rate of < 2 
IU/mL), may be useful in donor counseling.  However, only negative 
results for both tests (HBsAg and HBV NAT), obtained at least 6 months 
after the collection of the sample that gave the test results described in 
section IV.B.2.f, would qualify the donor for reentry.  If you obtain a 
positive HBV NAT, or a RR HBsAg that is positive by neutralization, the 
donor would not be eligible for reentry, and we recommend that you defer 
the donor permanently.  
 
A donor of Source Plasma who has been requalified as described above in 
section IV.C.2, may on subsequent occasions be indefinitely deferred 
because of HBV NAT positive results.  You may reenter such a donor into 
the donor pool by again following all procedures described in section 
IV.C.2.  
 
Table 3.  Reentry of Donors of Whole Blood and Blood Components for Transfusion 
or Further Manufacture on the Basis of HBV NAT and HBV Serologic Test Results 
on the Follow-up Sample     
 
For purposes of reentry, we recommend that you use an FDA-licensed HBV NAT labeled 
as having a sensitivity of < 2 IU/mL at 95% detection rate.  
 
  HBV NAT Result 
HBsAg and/or Anti-
Category  (sensitivity of < 2 
HBc Result (Anti-HBc  Donor 
IU/mL at 95% 
not required for SP) 
detection rate) 
1  Positive  Any test result  Permanently defer donor 
2  Negative  Non-Reactive  Donor may be reentered if all 
other eligible criteria are met  
3  Negative  Repeatedly Reactive   For further evaluation, see 
FDA guidance documents that 
discuss donor testing for 
HBsAg and anti-HBc (Refs. 1, 
2 and 3).  
 
 
3.  Management of Donors and Units with Non-Discriminated Reactive Test 
Results 
 
If you obtain a reactive Multiplex HIV-1 RNA/HCV RNA/HBV DNA 
NAT result on an individual donor sample, and if the Discriminatory 
NATs are non-reactive for HIV-1 RNA, HCV RNA and HBV DNA, the 
sample is Non-Discriminated Reactive.  The unit must be quarantined 
and destroyed ( 610.40(h)) or, if released for research or further 
15  Contains Nonbinding Recommendations 
 
manufacture, be appropriately relabeled as described in section V.C.  The 
donor must be deferred ( 610.41).  Note that the donor should be deferred 
for 6 months and is eligible for reentry after the 6-month waiting period.  
If you choose to reenter the donor, you may do so at the time of a donation 
without prior testing of a follow-up sample.   
 
 
V.  LABELING 
 
A.  Circular of Information for Whole Blood and Blood Components Intended 
for Transfusion 
 
Under  606.122, your circular of information must include a statement that the product 
was prepared from blood that was found negative when tested for communicable disease 
agents, as required under  610.40, including each test that was performed.  When an 
FDA-licensed NAT for HBV DNA is used to screen donors and the results of testing are 
negative, we recommend that the circular of information include the following statement:  
 
Licensed nucleic acid test (NAT) for HBV DNA has been performed and found 
to be Non-Reactive.  
  
B.  Blood Components Intended for Further Manufacture  
 
Under  606.121(c)(11), if your product is intended for further manufacturing use, a 
statement listing the results of all the tests for communicable disease agents required 
under  610.40 for which the donation has been tested and found negative, is required on 
the container label.6  Upon implementation of an FDA-licensed NAT,7 we recommend 
that you include the following statement on the container label for blood components 
intended for further manufacture into injectable or non-injectable products that test non-
reactive:  
 
Non-Reactive for HBV DNA.  
 
This statement may be placed at the end of the current statement on the container label 
which lists the results of the tests for communicable disease agents for which the 
donation has been tested and found negative.  Alternatively, you may incorporate this 
information into your current statement without making it a separate sentence.   
                                                 
 
6 Note that the container label for Source Plasma is not required to list the negative results of serological syphilis 
testing under  610.40(i) and 640.65(b).   
7 See the preamble to the final rule entitled Revisions to Labeling Requirements for Blood and Blood Components, 
Including Source Plasma, published in the Federal Register of January 3, 2012 (77 FR 7), for additional 
information on labeling Source Plasma with NAT results.    
 
16  Contains Nonbinding Recommendations 
 
See paragraph C of this section for recommendations for donations that test reactive for 
HBV. 
 
C.  Reactive Units and Product Disposition  
 
NAT reactive units must not be shipped or used, except as provided in  610.40(h)(2).  If 
released for these uses, the units must be relabeled consistent with the labeling 
requirements in  606.121 and 610.40.  Thus, for example, you must label the reactive 
unit with the BIOHAZARD legend and with the following cautionary statements, as 
applicable:  
 
Reactive for HBV DNA  
 
and  
 
Caution:  For Further Manufacturing into In Vitro Diagnostic Reagents For 
Which There Are No Alternative Sources. 
 
In addition, you should label the reactive unit with the following legend, if applicable: 
 
Caution:  For Laboratory Research Use Only. 
 
 
VI.  REPORTING CHANGES TO AN APPROVED APPLICATION 
 
Under 21 CFR 601.12 ( 601.12), FDA-licensed blood establishments are required to report 
changes to an approved biologics license application to FDA.  FDA-licensed blood 
establishments must report the changes in paragraphs A, B, and C.1 and C.2.a of this section, as 
described below.  However, except as specified in paragraph C.2.b of this section, unlicensed 
blood establishments are not required to report the changes to FDA. 
 
A.  Test Implementation 
 
1.  If you begin using an FDA-licensed NAT for the detection of HBV DNA 
in your facility according to the manufacturers instructions, you must 
notify FDA of the testing change in your annual report (AR), in 
accordance with  601.12(d), indicating the date that the revised standard 
operating procedures were implemented.   
 
2.  If you are already approved to use a registered contract donor testing 
laboratory to perform infectious disease testing of Whole Blood and blood 
components, including Source Plasma and Source Leukocytes, and the 
contract testing laboratory will now perform a NAT for HBV DNA, you 
must report this change in your AR ( 601.12(d)).  
 
3.  If you will use a new contract testing laboratory to perform a NAT for 
HBV DNA, report as follows:  
17  Contains Nonbinding Recommendations 
 
a.  If the new testing laboratory is registered with FDA and has been 
performing infectious disease testing for Whole Blood and blood 
components, including Source Plasma and Source Leukocytes, report 
this as a Supplement - Changes Being Effected (CBE), in 
accordance with  601.12(c)(5).   
 
b.  If the new testing laboratory has not previously performed infectious 
disease testing for Whole Blood and blood components, including 
Source Plasma and Source Leukocytes, you must report this as a Prior 
Approval Supplement (PAS), in accordance with  601.12(b).  The 
new testing laboratory must register with FDA in accordance with  
21 CFR Part 607 and  610.40(f). 
 
4.  Donor screening with a licensed NAT for HBV DNA should be 
implemented no later than 6 months after publication of this guidance 
document. 
 
B.  Labeling  
 
Labeling refers to the circular of information, required under  606.122, and the container 
labels on blood and blood components required under, among other provisions,  
 606.121 and 610.40. 
 
1.  If you revise your labeling to include the statements in this guidance in 
their entirety and without modification, you must submit the revised 
labeling in a Special Labeling Supplement-Changes Being Effected in 
accordance with  601.12(f)(2).   
 
2.  If you revise your labeling to include alternative statements, then you must 
submit the labeling change in a labeling supplement in accordance with  
 601.12(f)(1).  
 
C.  Procedures for Requalification of Donors 
 
1.  We consider the implementation of recommendations in this guidance in 
their entirety and without modification to be a minor change to an 
approved license application.  Therefore, FDA-licensed establishments are 
not required to have FDA prior approval and may submit a statement of 
this change in their ARs under  601.12(d), indicating the date that the 
revised standard operating procedures were implemented.   
 
2.  Under  610.41(b), you may reenter a previously deferred donor using a 
requalification method found acceptable by FDA for such purposes.  We 
consider the requalification methods described in this guidance to be 
acceptable.  If you choose to use an alternative requalification method, 
you must report this as follows:  
18  Contains Nonbinding Recommendations 
 
 
a.  FDA-licensed blood establishments must submit the alternative 
requalification method as a PAS ( 601.12(b)). 
 
b.  FDA must find an alternative requalification method proposed by an 
unlicensed establishment to be acceptable before it is implemented.  
( 610.41(b)).    
 
19  Contains Nonbinding Recommendations 
 
 
VII.  REFERENCES 
 
1.  FDA Memorandum to All Registered Blood Establishments: Recommendations for the 
Management of Donor and Units that are Initially Reactive for Hepatitis B Surface Antigen 
(HBsAg), December 2, 1987.            
http://www.fda.gov/biologicsbloodvaccines/guidancecomplianceregulatoryinformation/oth
errecommendationsformanufacturers/memorandumtobloodestablishments/default.htm. 
 
2.  FDA Memorandum to All Registered Blood Establishments: Recommendations 
Concerning Testing for Antibody to Hepatitis B Core Antigen (Anti-HBc), September 10, 
1991. 
http://www.fda.gov/biologicsbloodvaccines/guidancecomplianceregulatoryinformation/oth
errecommendationsformanufacturers/memorandumtobloodestablishments/default.htm. 
 
3.  Guidance for Industry: Requalification Method for Reentry of Blood Donors Deferred 
Because of Reactive Test Results for Antibody to Hepatitis B Core Antigen (Anti-HBc), 
May 2010. 
http://www.fda.gov/BiologicsBloodVaccines/GuidanceComplianceRegulatoryInformation/
Guidances/Blood/default.htm. 
 
4.  FDA Memorandum to All Registered Blood Establishments: Recommendations for the 
Quarantine and Disposition of Units from Prior Collections from Donors with Repeatedly 
Reactive Screening Tests for Hepatitis B Virus (HBV), Hepatitis C Virus (HCV) and 
Human T-Lymphotropic Virus Type I (HTLV-1), July 19, 1996.    
http://www.fda.gov/biologicsbloodvaccines/guidancecomplianceregulatoryinformation/oth
errecommendationsformanufacturers/memorandumtobloodestablishments/default.htm. 
 
5.  FDA Memorandum to All Registered Blood Collecting Facilities: Collection of Human 
Leukocytes for Further Manufacturing (Source Leukocytes), January 28, 1981.     
http://www.fda.gov/biologicsbloodvaccines/guidancecomplianceregulatoryinformation/oth
errecommendationsformanufacturers/memorandumtobloodestablishments/default.htm. 
 
6.  Ganem, D., Prince, A.M., Hepatitis B infection  Natural History and Clinical 
Consequences.  New England Journal of Medicine, 350, 1118-1129 (2004). 
 
7.  Alter, M.J., Centers for Disease Control and Prevention, Epidemiology of HBV Infection 
and Prevention Programs. Presentation to the Advisory Committee on Blood Safety and 
Availability, August 27, 2004. 
 
8.  Epstein, J.S., Holmberg, J.A., Progress in monitoring blood safety.  Transfusion, 50, 1408-
1412 (2010). 
 
9.  Roth, W.K., Weber, et al., NAT for HBV and Anti-HBc Testing Increase Blood Safety.  
Transfusion, 42, 869-875 (2002). 
 
20  Contains Nonbinding Recommendations 
 
10.  Kleinman S.H., Lelie, N., et al., Infectivity of Human Immunodeficiency Virus-1, Hepatitis 
C Virus and Hepatitis B Virus and Risk of Transmission by Transfusion.  Transfusion, 49, 
2454-2489 (2009). 
 
11.  Prince, A.M., Lee, D.H., Brotman, B., Infectivity of blood from PCR-positive, HBsAg-
negative, anti-HBs-positive cases of resolved hepatitis B infection. Transfusion, 41, 329-
332 (2001). 
 
12.  Hollinger, F.B., Hepatitis B infection and Transfusion Medicine: Science and the Occult.  
Transfusion, 48,1001-1026 (2008). 
 
13.  Blood Products Advisory Committee Meeting, July 23, 2004. 
http://www.fda.gov/ohrms/dockets/ac/04/transcripts/2004-4057t2%20.htm. 
 
14.  Advisory Committee on Blood Safety and Availability 24th Meeting; Transcript August 
27, 2004. http://www.hhs.gov/ophs/bloodsafety/pastmeetings/pastmeetings.html. 
 
15.  Stramer, S.L., Wend, U., Candotti, D., et al., Nucleic Acid Testing to Detect HBV Infection 
in Blood Donors.  New England Journal of Medicine, 364, 236-247 (2011).  
 
16.  National Center for Health Statistics and Centers for Disease Control and Prevention.  
National Health Interview Survey, 2006 (machine readable data file and documentation).  
2007. Hyattsville, Maryland. 
 
17.  Royston, P. and Sauerbrei, W., Multivariable Modeling With Cubic Regression Splines: A 
Principled Approach. The Stata Journal 7.1 (2007): 45-70.7. 
 
18.  StataCorp. Stata Statistical Software: Release 10.  2007. College Station, TX, StataCorp 
LP. 
 
19.  Dreier, J., Kroger, M., et al., Low-Level Viremia of Hepatitis B Virus in an Anti-HBc- and 
Anti-HBs- Positive Blood Donor.  Transfusion Medicine, 14, 97-103(2004). 
 
20.  Gerlich, W.H., Breakthrough of Hepatitis B Virus Escape Mutants After Vaccination and 
Virus Reactivation. Journal of Clinical Virology, 36 (Suppl. 1):S18-S22 (2006). 
 
21.  Mosley J.W., Stevens, C.E., et al., Donor Screening for Antibody to Hepatitis B Core 
Antigen and Hepatitis B Virus Infection in Transfusion Recipients.  Transfusion, 35, 5-12 
(1975). 
 
22.  Satake, Tairo, R., et al., Infectivity of Blood Components with Low Hepatitis B Virus DNA 
Levels Identified in a Lookback Program. Transfusion, 47, 1197-1205 (2007). 
 
23.  Hui, C.K., Sun, J., et al., Occult Hepatitis B Virus Infection in Hematopoietic Stem Cell 
Donors in a Hepatitis B Virus Endemic Area.  Journal of Hepatology, 42, 813-819 (2005). 
 
21  Contains Nonbinding Recommendations 
 
24.  Gerlich, W.H., Wagner, F.F., et al., HBsAg Non-Reactive HBV Infection in Blood Donors: 
Transmission and Pathogenicity.  Journal of Medical Virology, 2007, 79 (Suppl. 1), S32-
S36 (2007). 
 
25.  Levicnick-Stezinar, S., Rahne-Potocar, Urska, et al., Anti-HBs Positive Occult Hepatitis B 
Virus Carrier Blood Infectious in Two Transfusion Recipients. Journal of Hepatology, 48, 
1022-1025 (2008). 
 
26.  Blood Donor Screening for Hepatitis B Virus (HBV) Infection by Nucleic Acid Testing 
(NAT): Blood Products Advisory Committee 94th Meeting; Transcript April 1, 2009.  
http://www.fda.gov/AdvisoryCommittees/CommitteesMeetingMaterials/BloodVaccinesand
OtherBiologics/BloodProductsAdvisoryCommittee/ucm121612.htm. 
 
27.  Blood Products Advisory Committee Meeting, April 28, 2011.  
http://www.fda.gov/AdvisoryCommittees/CommitteesMeetingMaterials/BloodVaccinesand
OtherBiologics/BloodProductsAdvisoryCommittee/ucm247665.htm.  
 
28.  Blood Products Advisory Committee Meeting, July 21, 2005. 
http://www.fda.gov/ohrms/dockets/ac/05/transcripts/2005-4164t1.htm. 
 
29.  Reesink, H.W., Engelfriet, C.P., et al., Occult Hepatitis B Infection in Blood Donors.  Vox 
Sanguinis, 94, 153-166 (2008). 
 
22