Epidemiology

Risk of occult hepatitis B virus infection from blood transfusion is low

Last Updated: 2011-02-22 17:28:24 -0400 (Reuters Health)

By Will Boggs, MD

NEW YORK (Reuters Health) - The transmissibility of occult hepatitis B virus (HBV) infection by blood transfusion from patients appears to be quite low, according to findings published in the January 18th online Clinical Infectious Diseases.

"Blood transfusion resulting in transmission of hepatitis B is nowadays quite rare, especially from donor blood with positive antibodies to HBsAg," Dr. Man-Fung Yuen from The University of Hong Kong, Queen Mary Hospital, told Reuters Health in an email.

Dr. Yuen and colleagues looked at 67 donors with occult HBV infection in a chimeric mice study and in a recipient look-back study. The 67 donors represented 0.031% of 217,595 healthy blood donors presenting to Hong Kong Red Cross Blood Transfusion Service.

Serum from two randomly selected donors with occult HBV infection was inoculated into four mice. One mouse had detectable serum HBV DNA 5 and 7 weeks later, whereas the other three mice had no detectable serum HBV DNA up to 9 weeks later. The mouse with detectable serum HBV DNA also had detectable total DNA and covalently closed circular DNA (cccDNA) in the liver, but the other three mice did not.

Twenty of 49 (40.8%) recipients of blood from 10 of these donors were positive for immunoglobulin G anti-HBc, but only the 15 recipients with both anti-HBc and anti-HBs were considered possibly HBV infected by transfusion.

Only two of these 15 recipients were HBV DNA positive, indicating occult HBV infection, and their viruses showed 83% and 95% sequence homology with the HBV DNA present in their donors.

Two additional recipients that tested positive for HBsAg had detectable HBV DNA, indicating chronic HBV carriage, and their viruses showed 88% and 86% homology with the HBV DNA in their donors.

"Discounting the three recipients who were probably infected with HBV before transfusion," the investigators say, "transmission of HBV resulting in chronic HBV disease was possible but uncommon (1 (2.2%) of 46 recipients). This may be an underestimation, because 13 of the recipients were positive for anti-HBs but negative for anti-HBc, possibly because of previous HBV vaccination."

"Physicians should test for HBsAg and antibody to HBcAg for hepatitis B infection," Dr. Yuen said. "If they suspect occult hepatitis B infection, HBV DNA (using a highly sensitive assay) should also be tested."

SOURCE: http://bit.ly/dIry4V

Clin Infect Dis 2011.