Impact of nucleic acid testing for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus on the safety of blood supply in Italy: A 6-year survey
ABSTRACT Nucleic acid testing (NAT) for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) has been implemented in several European countries and in the United States, while hepatitis B virus (HBV) NAT is still being questioned by opinions both in favor and against such an option, depending on the HBV endemicity, health care resources, and expected benefits.
This survey was aimed to assess the NAT impact in improving the safety of blood supply in Italy, 6 years after implementation. The study involved 93 Italian transfusion centers and was carried out in 2001 through 2006. A total of 10,776,288 units were tested for the presence of HCV RNA, 7,932,430 for HIV RNA, and 3,405,497 for HBV DNA, respectively.
Twenty-seven donations or 2.5 per million tested were HCV RNA-positive/anti-HCV-negative; 14 or 1.8 per million units tested were HIV RNA-positive/anti-HIV-negative; and 197 or 57.8 per million donations tested were HBV DNA-positive/hepatitis B surface antigen-negative. Of the latter, 8 (2.3/10(6)) were collected from donors in the window phase of infection and 189 (55.5/10(6)) from donors with occult HBV. Sixty-eight percent of the latter donors had hepatitis B surface antibody, 74.5 percent of whom with concentrations considered protective (>or=10 mIU/mL).
NAT implementation has improved blood safety by reducing the risk of entering 2.5 HCV and 1.8 HIV infectious units per million donations into the blood supply. The yield of NAT in detecting infectious blood before transfusion was higher for HBV than for HCV or HIV. However, the benefit of HBV NAT in terms of avoided HBV-related morbidity and mortality in blood recipients needs to be further evaluated.
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- "Given the paucity of solid clinical data, the decision to adopt HBV DNA or anti-HBc screening was based on economics and feasibility rather than clinical outcomes. In particular, the use of anti-HBc screening is considered problematic in areas with an intermediate or high prevalence of HBV, because only a small percentage of anti-HBc positive units contains detectable HBV viraemia, and screening would lead to a substantial shortage in the blood supply, particularly in Italy where anti-HBc prevalence is approximately 8%   . "
ABSTRACT: In Italy, hepatitis B virus (HBV) DNA screening of blood donations was introduced to prevent the transmission of window period and occult HBV infection. Anti-HBc screening is not recommended to avoid shortage of the blood supply. To contain costs, donor samples are generally pooled before testing. We evaluated the safety of this national policy using a prospective repository of donors/recipient pairs. We used highly sensitive Nucleic Acid Testing (NAT) assays to test repository and follow-up samples from donors initially classified as negative by minipool NAT assays (6-MP), later found to carry occult HBV DNA. When available, we also analysed recipients' pre- and post-transfusion samples, collected in the context of a repository financed by the European Commission (the BOTIA project). Between 2008 and 2011 6-MP NAT identified 18 carriers of occult HBV infection among 12,695 donors; 28 samples from previous donations were available from 13 of these carriers. Highly sensitive HBV DNA detection methods showed that 6-MP HBV DNA screening failed to identify 14/28 (50%) viraemic donations, that were released for transfusion. HBV marker testing of such blood product recipients revealed two cases of transfusion-transmitted HBV infection, documented by donor-recipient sequence identity. Viraemic blood donations from occult HBV infection carriers remain undetected by current minipool HBV DNA screening, and transfusion-transmission of HBV continues to occur in susceptible patients. More effective individual HBV DNA screening and/or tests for antibodies to HBV core antigen should be considered to improve blood safety. Copyright © 2015. Published by Elsevier B.V.Journal of Hepatology 06/2015; DOI:10.1016/j.jhep.2015.06.016 · 10.40 Impact Factor
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- "For the whole country, HBV NAT yield between 2001 and 2006 was evaluated at 5.78 per 100.000 donors or 1 : 17.301, largely due to OBI which was detected in 96% of the yield cases . In the Latium region, HBV NAT yield was 1 : 25.021 over HBsAg, mainly for early WP infections but also for the late phase of resolving HBV infection, for serologically silent chronic HBV, and for rare HBsAg mutants . "
ABSTRACT: Despite a considerable reduction of the risk of HBV-infected blood donation entering blood supply (residual risk) due to improved screening by HBV NAT in the developed countries, the bulk of the people with HBV living in the developing countries still needs to be screened by serologic tests such as HBsAg and anti-HBc. Many of these countries lack resources for implementing NAT and are likely to remain so in the next decade or longer, thus depending on the HBV residual risk monitoring based on serologic testing and corresponding estimation methods. This paper reviews main HBV residual risk findings worldwide and the methods based on serology used for their calculation with repeat donors, as well as their extension to the first-time donors. Two artificial datasets with high (4.36%) and low (0.48%) HBV prevalence were generated to test the performance of five methods: the original incidence/window-period model based solely on HBsAg, its modification by Soldan in 2003, the Müller-Breitkreutz model, the HBsAg yield model, and its extension to include anti-HBc seroconversions within a year. The last model was closest to the true values of residual risk and had smallest variation of the estimates in both high and low prevalence data. It may be used for residual risk evaluation in relatively small samples, such as regional blood banks data.06/2013; 2013. DOI:10.5402/2013/839896
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- "This is because of the fact, that there is no clear cut evidence to prove, that NAT implementation can reduce significant HBV transmission by blood transfusion (AABB 17th Ed). Studies have not been able to clearly state avoided HBV related morbidity and mortality (Velati et al., 2008). On the other hand, it has commented on theoretical increased possibility of finding NAT reactive blood donors because of immunisation (AABB 17th Ed, Stramer SL et al., 2011). "
ABSTRACT: Aim: To develop algorithm focussed on increasing the availability of blood components & cost effectiveness, without compromising blood safety, in a setup where NAT and serological methodological are available. Background: There is increasing usage of total Anti-HBV Core Antibody (anti-HBcAb) &Journal of Interdisciplinary and Multidisciplinary Research 05/2013; 03(05):192-200.