03062nas a2200373   4500008004100000020001400041024001700055245017500072210006900247260002600316300001300342490000700355520187400362653004402236653002702280653003502307653001802342653003102360653001102391653001402402653000902416653002702425653001502452100002202467700002202489700001602511700002202527700001902549700001702568700001602585700002002601700001802621856004902639       2012                        eng d  a1537-2995  awdn, 041736000aHepatitis B virus transmission by blood transfusion during 4 years of individual-donation nucleic acid testing in South Africa: estimated and observed window period risk.0 aHepatitis B virus transmission by blood transfusion during 4 yea  aUnited Statesc2012//  a880 - 920 v523 aBACKGROUND: Since October 2005, a total of 2,921,561 blood donations have been screened by the South African National Blood Service for hepatitis B virus (HBV) by individual-donation nucleic acid testing (ID-NAT). Over 4 years, 149 hepatitis B surface antigen-negative acute-phase HBV NAT-positive donations were identified (1:19,608). The lookback program identified one probable HBV transmission., STUDY DESIGN AND METHODS: The complete genomes of HBV isolated from the donor and recipient were sequenced, cloned, and analyzed phylogenetically. The HBV window period (WP) transmission risk was estimated assuming a minimum infectious dose of 3.7 HBV virions and an incidence rate correction factor of 1.34 for transient detectability of HBV DNA., RESULTS: Of 149 acute-phase HBV NAT yields, 114 (1:25,627) were classified as pre-antibody to hepatitis B core antigen (anti-HBc) WP and 35 (1:83,473) as post-anti-HBc WP. The acute-phase transmission risk in the HBV DNA-negative pre- and post-anti-HBc WPs (of 15.3 and 1.3 days, respectively) was estimated at 1:40,000 and 1:480,000, respectively. One HBV transmission (1:2,900,000) was identified in a patient who received a transfusion from an ID-NAT-nonreactive donor in the pre-anti-HBc WP. Sequence analysis confirmed transmission of HBV Subgenotype A1 with 99.7% nucleotide homology between donor and recipient strains. The viral burden in the infectious red blood cell unit was estimated at 32 (22-43) HBV DNA copies/20 mL of plasma., CONCLUSION: We report the first known case of transfusion-transmitted HBV infection by blood screened using ID-NAT giving an observed HBV transmission rate of 0.34 per million. The estimated pre-acute-phase transmission risk in the ID-NAT screened donor population was 73-fold higher than the observed WP transmission rate.Copyright © 2011 American Association of Blood Banks.10a*Blood Transfusion/ae [Adverse Effects]10a*DNA, Viral/bl [Blood]10a*Hepatitis B/tm [Transmission]10aAcute Disease10aHepatitis B/di [Diagnosis]10aHumans10aPhylogeny10arisk10aSequence Analysis, DNA10aViral Load1 aVermeulen, Marion1 aDickens, Caroline1 aLelie, Nico1 aWalker, Evangelia1 aColeman, Charl1 aKeyter, Mark1 aReddy, Ravi1 aCrookes, Robert1 aKramvis, Anna  uhttps://www.notifylibrary.org/reference/4542