Occult hepatitis B virus infection and blood transfusion
摘要
Transfusion-transmitted infections including hepatitis Bvirus （HBV） have been a major concern in transfusionmedicine. Implementation of HBV nucleic acid testing（NAT） has revealed occult HBV infection （OBI） in blooddonors. In the mid-1980s, hepatitis B core antibody（HBc） testing was introduced to screen blood donorsin HBV non-endemic countries to prevent transmissionof non-A and non-B hepatitis. That test remains inuse for preventing of potential transmission of HBVfrom hepatitis B surface antigen （HBsAg）-negativeblood donors, even though anti-hepatitis C virus testshave been introduced. Studies of anti-HBc-positivedonors have revealed an HBV DNA positivity rate of0%-15%. As of 2012, 30 countries have implementedHBV NAT. The prevalence of OBI in blood donors wasestimated to be 8.55 per 1 million donations, accordingto a 2008 international survey. OBI is transmissible byblood transfusion. The clinical outcome of occult HBVtransmission primarily depends on recipient immunestatus and the number of HBV DNA copies present in theblood products. The presence of donor anti-HBs reducesthe risk of HBV infection by approximately five-fold. Therisk of HBV transmission may be lower in endemic areasthan in non-endemic areas, because most recipientshave already been exposed to HBV. Blood safety forHBV, including OBI, has substantially improved, but thepossibility for OBI transmission remains.