Transmission of Hepatitis B Virus from Blood Donors with Occult Infection?

Transmission of Hepatitis B Virus from Blood Donors with Occult Infection?
Occult HBV infection was uncommon among blood donors in Hong Kong, and HBV transmission from donors with such infection was relatively rare.


Occult infection with hepatitis B virus (HBV) is characterized by detectable levels of HBV DNA in individuals who test negative for hepatitis B surface antigen. Such individuals may or may not have detectable levels of antibody to hepatitis B core antigen or to hepatitis B surface antigen. Because detection of very low HBV DNA levels requires the use of nucleic acid testing and highly sensitive polymerase chain reaction, we know little about the prevalence of occult HBV infection (OHB) or the transmissibility of HBV from blood donors with this condition.

In a recent two-part study conducted in Hong Kong, researchers screened 217,595 blood donors and identified 67 (0.03%) with OHB; 44 consented to further evaluation. In part one, samples from two donors with OHB were used to inoculate four chimeric mice whose livers had been humanized. Serum samples (taken weekly at postinoculation weeks 4–9) and liver specimens (obtained at week 9, after the animals were killed) revealed HBV in only one mouse. In part two, 49 blood transfusion recipients from 10 donors with OHB were tested for HBV infection. Four tested positive for HBV DNA. Genomic sequencing with phylogenetic analysis showed that only one of these recipients could have acquired HBV from the donor.

Comment: Much of the information generated in this study is from smaller subsets of the cohort, so the results might not be completely generalizable. However, the findings do suggest that OHB is uncommon among blood donors and that transmission of HBV from donors with OHB is relatively rare.

— Neil M. Ampel, MD

Published in Journal Watch Infectious Diseases
http://infectious-diseases.jwatch.org/cgi/content/full/2011/323/1