A method for estimating the residual risk of transfusion‐transmitted HBV infection associated with occult hepatitis B virus infection in a donor population without universal anti‐HBc screening. Issue 4 (27th June 2013)

• Record Type: Journal Article
• Authors: Seed, C. R.; Kiely, P.
• Is Part Of: Vox sanguinis. Volume 105:Issue 4(2013)
• Page Start: 290
• Page End: 298
• Publication Date: 2013-06-27
• Subjects: Blood -- Periodicals; Blood -- Transfusion -- Periodicals; Immunohematology -- Periodicals; Immunopathology -- Periodicals; 615.39
• DOI: 10.1111/vox.12060
• Languages: English
• ISSNs: 0042-9007

Abstract

<abstract abstract-type="main" id="vox12060-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="vox12060-sec-0001" sec-type="section"> <title>Background and Objectives</title> <p>This report describes a method for estimating the risk of transfusion‐transmitted HBV infection attributable to blood components from donors with occult hepatitis B virus infection (OBI) applicable where universal anti‐HBc screening is not performed.</p> </sec> <sec id="vox12060-sec-0002" sec-type="section"> <title>Materials and Methods</title> <p>In the context of parallel HBsAg and individual donation HBV DNA testing, we developed a mathematical function <italic>p(OBI)</italic> to estimate the probability of failing to detect [<italic>p(NAT nondetection)]</italic> a potentially infectious [<italic>p(transmission)]</italic> donation from a donor with OBI.</p> </sec> <sec id="vox12060-sec-0003" sec-type="section"> <title>Results</title> <p>Among 1 312 451 donations tested for HBsAg and HBV DNA, 29 (from 17 anti‐HBc reactive donors classified as OBI) were individual donation NAT negative, giving a <italic>p(NAT nondetection)</italic> of 2·2096 (95 CI: 1·538–3·173) × 10<sup>−5</sup>. To date, lookback on OBI donors has identified 35 (8·2%) recipients with evidence of current or past HBV infection among 427 tested recipients. After correcting for the background anti‐HBc rate in recipients, this results in a <italic>p(transmission)</italic> of 0·0384 (0·0167–0·0601). The product, <italic>pOBI</italic> is 1 in 981 920 (95% CI: 437 181–3 223 701). When this is summed with the WP risk for the 2011–2012 period, the overall HBV residual risk estimate is 1 in 538 224 (95% CI: 209 732–1 552 443).</p> </sec> <sec id="vox12060-sec-0004" sec-type="section"> <title>Conclusion</title> <p>We estimate the OBI residual risk in Australia is approximately 1 in 982 000 per unit transfused, and this risk represents 55% of the total HBV residual risk and is declining as consequence of ID‐NAT identifying repeat donors with OBI.</p> </sec> </abstract>