ID-NAT and serology are complementary in detecting HBV infection in first-time donors, but HBV-DNA is superior to HBsAg detection in repeat donors.

AIM:To identify blood donors with occult hepatitis B virus (HBV) infection (OBI) to promote safe blood donation. METHODS:Descriptive cross sectional study was conducted on 3167 blood donors negative for hepatitis B surface antigen (HBsAg), hepatitis C antibody (HCV Ab) and human immunodeficiency virus Ab. They were subjected to the detection of alanine aminotransferase (ALT) and aspartate transaminase (AST) and screening for anti-HBV core antibodies (total) by two different techniques; [Monoliza antibodies to hepatitis B core (Anti-HBc) Plus-Bio-Rad] and (ARC-HBc total-ABBOT). Positive samples were subjected to quantitative detection of antibodies to hepatitis B surface (anti-HBs) (ETI-AB-AUK-3, Dia Sorin-Italy). Serum anti-HBs titers > 10 IU/L was considered positive. Quantitative HBV DNA by real time polymerase chain reaction (PCR) (QIAGEN-Germany) with 3.8 IU/mL detection limit was estimated for blood units with negative serum anti-HBs and also for 32 whose anti-HBs serum titers were > 1000 IU/L. Also, 265 recipients were included, 34 of whom were followed up for 3-6 mo. Recipients were investigated for ALT and AST, HBV serological markers: HBsAg (ETI-MAK-4, Dia Sorin-Italy), anti-HBc, quantitative detection of anti-HBs and HBV-DNA. RESULTS: 525/3167 (16.6%) of blood units were positive for total anti-HBc, 64% of those were antiHBs positive. Confirmation by ARCHITECT anti-HBc assay were carried out for 498/525 anti-HBc positive samples, where 451 (90.6%) confirmed positive. Reactivity for anti-HBc was considered confirmed only if two positive results were obtained for each sample, giving an overall prevalence of 451/3167 (14.2%) for total anti-HBc. HBV DNA was quantified by real time PCR in 52/303 (17.2%) of anti-HBc positive blood donors (viral load range: 5 to 3.5 x 10 5

BACKGROUND Knowledge about the viral load (VL) distributions in different stages of hepatitis C virus (HCV) infection is essential to compare the efficacy of serologic screening and nucleic acid testing (NAT) in preventing transfusion transmission risk. We studied HCV‐RNA levels in Egyptian blood donors in the preseroconversion window period (WP) and in later anti‐HCV–positive stages of infection. STUDY DESIGN AND METHODS Subsets of individual‐donation (ID)‐NAT and anti‐HCV–yield samples from a screening study among 119,756 donors were tested for VL by quantitative polymerase chain reaction (qPCR). Low viremia levels below the quantification limit of qPCR were determined by probit analysis using the proportion of reactive results on replicate NATs. Poisson distribution statistics were used to estimate transmission risk in different stages of HCV infection based on 50% minimum infectious doses (MID50) of 3.2 (1‐10) and 316 (100‐1000) virions in the absence and presence of anti‐HCV, respectively. RESULTS Rates of total HCV infections and WP‐NAT–yield donations in two Egyptian blood centers varied between 2.6% to 4.5% and 1:3100 to 1:9500, respectively. VLs ranged from 82 to 3 × 107 copies/mL in WP and from fewer than 1600 to 1.6 × 106 copies/mL in anti‐HCV–positive carrier donations. Only two (1.1%) of 175 donors with probable resolved infection had detectable RNA on replicate testing (estimated VLs of 0.5 and 1.8 copies/mL). This translates to an estimated transmission risk of 0.028% if ID‐NAT‐nonreactive, anti‐HCV–positive donations would be used for RBC transfusions. CONCLUSION Almost 99% of anti‐HCV–reactive donations without detectable HCV‐RNA on initial ID‐NAT screening had eradicated the virus from the circulation, while 1% had extremely low VLs and are likely not infectious. The incremental safety offered by serologic testing of ID‐NAT–screened blood seems minimal.

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