Recombinant HBV Surface Antigen, Subtype ad

Background Post-transfusion hepatitis B virus (PTHB) infection is still a public health problem in the world. In many developed countries, nucleic acid testing (NAT) for detection of Hepatitis B Virus (HBV)-DNA has been implemented to enhance blood donation safety. In Libya, however, the testing for HBV infection is limited to the detection of HBV surface antigen (HBsAg) only. Objectives To determine the frequency of anti-Hepatitis B core antibody (HBc) and HBV-DNA in HBsAg-negative, anti-HBc-positive blood donors in the main Central Blood Bank Units (CBBUs) in eastern Libya. Methods One thousand blood samples were obtained from healthy blood donors at the five main CBBUs in eastern Libya. The samples were screened for HBsAg and anti-HBc. Real-time polymerase chain reaction (PCR) was carried out to detect HBV-DNA in all anti-HBc-positive samples. Results A total of 94 (9.4%) donors were positive for anti-HBc. Of the 94 anti-HBc-positive samples, 9 samples (9.5%) tested positive for HBV-DNA by real-time PCR. Conclusion The rate of anti-HBc among blood donors in this study (9.4%) was similar to that reported from other regions in the country. In the absence of advanced tests for the detection of HBV infection in blood donors, such as NAT, anti-HBc should be routinely tested for, at least for first-time donors.

Occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the liver or serum in the absence of detectable HBV surface antigen (HBsAg). OBI poses a risk for the development of cirrhosis and hepatocellular carcinoma. The prevalence of OBI in Kenya is unknown, thus a study was undertaken to determine the prevalence and molecular characterization of OBI in Kenyan populations at high risk of HBV infection. Sera from two Nairobi cohorts, 99 male sex workers, primarily having sex with men (MSM-SW), and 13 non-MSM men having HIV-positive partners, as well as 65 HBsAg-negative patients presenting with jaundice at Kenyan medical facilities, were tested for HBV serological markers, including HBV DNA by real-time PCR. Positive DNA samples were sequenced and MSMSW patients were further tested for hepatitis C virus (HCV) infection. Of the 166 HBsAg-negative samples tested, 31 (18.7%; 95% confidence interval [CI] 13.5-25.3) were HBV DNA positive (i.e., occult), the majority (20/31; 64.5%) of which were HBV core protein antibody positive. HCV infection was not observed in the MSM-SW participants, although the prevalence of HBsAg positivity was 10.1% (10/99; 95% CI 5.6-17.6). HBV genotype A was predominant among study cases, including both HBsAg-positive and OBI participants, although the data suggests a non-African network transmission source among MSM-SW. The high prevalence of HBV infection among MSM-SW in Kenya suggests that screening programmes be instituted among high-risk cohorts to facilitate preventative measures, such as vaccination, and establish entry to treatment and linkage to care.