Estimates of the frequency of HBV, HCV, and HIV infectious donations entering the blood supply in the United Kingdom, 1996 to 2003.
ABSTRACT Several new tests have been recently introduced by the United Kingdom Blood Services to improve safety. The frequency (or risk) of hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV infectious donations entering the UK blood supply during 1996-2003 has been estimated. These years span the introduction of nucleic acid testing (NAT) for HCV, HIV combination antigen and antibody test and NAT for HIV. The frequency of an infectious donation entering the blood supply due to i) the window period, ii) assay failures and iii) human and technical errors in testing and processing, was estimated. The window period risk was estimated using the incidence of infection in donors and the length of the window period for tests in use, with an adjustment for atypical inter-donation intervals in seroconverting donors. The estimated frequency of infectious donations entering the blood supply during 1996-2003 was 1.66, 0.80 and 0.14 per million for HBV, HCV and HIV respectively. HCV NAT resulted in an over 95% fall in the risk of HCV. Current usage of HIV combined antibody-antigen tests and of HIV NAT reduced the estimated risk of HIV by 10%. Since 1996, the risk of transfusion-transmitted HBV, HCV and HIV infection in the UK has been lowered by several improvements to donation testing, although the absolute reduction in risk has been small. Vigilance for errors and the affects of donor selection may be as or more important than further reductions to window periods of tests for improving blood safety with respect to HBV, HCV and HIV.
SourceAvailable from: Shuaibu Abdullahi Hudu[Show abstract] [Hide abstract]
ABSTRACT: Hepatitis B virus surface mutants are of enormous importance because they are capable of escaping detection by serology and can infect both vaccinated and unvaccinated populations, thus putting the whole population at risk. This study aimed to detect and characterise hepatitis B-escaped mutants among blood donors and vaccinees. One thousand serum samples were collected for this study from blood donors and vaccinees. Hepatitis B surface antigen, antibodies and core antibodies were tested using a commercial enzyme-linked immunosorbent assay (ELISA) kit. DNA detection was performed via nested polymerase chain reaction (PCR), and the S gene was sequenced and analysed using bioinformatics. Of the 1,000 samples that were screened, 5.5 % (55/1,000) were found to be HBsAg-negative and anti-HBc- and HBV DNA-positive. All 55 isolates were found to belong to genotype B. Several mutations were found across all the sequences from synonymous and non-synonymous mutations, with the most nucleotide mutations occurring at position 342, where adenine was replaced by guanine, and cytosine at position 46 was replaced by adenine in 96.4 % and 98 % of the isolates, respectively. Mutation at position 16 of the amino acid sequence was found to be common to all the Malaysian isolates, with 85.7 % of the mutations occurring outside the major hydrophilic region. This study revealed a prevalence of 5.5 % for hepatitis B-escaped mutations among blood donors and vaccinated undergraduates, with the most common mutation being found at position 16, where glutamine was substituted with lysine.European Journal of Clinical Microbiology 03/2015; DOI:10.1007/s10096-015-2358-1 · 2.54 Impact Factor
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ABSTRACT: Evaluation of trends in the rate of transfusion-transmitted infections (TTIs) in blood donors is essential for monitoring blood supply safety and donor screening effectiveness. The aim of this study was to determine the trends and prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and syphilis seromarkers among blood donors referred to Tehran Blood Transfusion Center (TBTC) from 2008 to 2013. The data of all blood donors referred to TBTC between 2008 and 2013 were collected. The prevalence of HBV, HCV, HIV, and syphilis infections were expressed by donation year and donors' characteristics (age, gender, educational level and donor status). Among 1,796,090 individuals who donated blood at TBTC from 2008 to 2013, analysis of trend for the prevalence of HBV showed a significant decrease from 423 to 153 per 10(5) donors. The similar pattern of decrease was observed for the prevalence of HCV from 139 to 69 per 10(5) donors, however the rate of decrease in HCV prevalence was slower than the rate of decrease in HBV prevalence. The prevalence of HIV was constant while the prevalence of syphilis showed a sharp decrease in 2009 and a constant prevalence from 2010 to 2013. The top three parameters influenced the rate of TTIs were donor status, age, and educational level. The decreasing prevalence and trends of TTIs among the studied donors demonstrated that the safety measures which were employed in recent years in Iranian Blood Transfusion Organization have been effective. Copyright © 2015 Elsevier Ltd. All rights reserved.Transfusion and Apheresis Science 03/2015; DOI:10.1016/j.transci.2015.03.003 · 1.07 Impact Factor