Prevalence of occult hepatitis B infection in a highly endemic area for chronic hepatitis B: a study of a large blood donor population

• Published in: Gut Vol. 59; no. 10; pp. 1389 - 1393
• Main Authors: Yuen, Man-Fung, Lee, Cheuk-Kwong, Wong, Danny Ka-Ho, Fung, James, Hung, Ivan, Hsu, Axel, But, David Yiu-Kuen, Cheung, Ting-Kin, Chan, Pierre, Yuen, John Chi-Hang, Fung, Frederic Khe-Cheong, Seto, Wai-Kay, Lin, Che-Kit, Lai, Ching-Lung
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Society of Gastroenterology 01.10.2010; BMJ Publishing Group; BMJ Publishing Group LTD
• Subjects: Adolescent; Adult; Aged; Antigens; Biological and medical sciences; Blood & organ donations; Blood Donors - statistics & numerical data; Blood Transfusion; Blood transfusions; Carrier State - epidemiology; Carrier State - pathology; chronic hepatitis B; Cohort Studies; Deoxyribonucleic acid; DNA; DNA, Viral - analysis; Endemic Diseases; Female; Gastroenterology. Liver. Pancreas. Abdomen; HBV DNA; Hepatitis; Hepatitis B; Hepatitis B Surface Antigens - blood; Hepatitis B virus; Hepatitis B virus - isolation & purification; Hepatitis B, Chronic - epidemiology; Hepatitis B, Chronic - pathology; Histology; Hong Kong - epidemiology; Human viral diseases; Humans; Immunization; Infections; Infectious diseases; Interferon; Liver diseases; Male; Medical sciences; Middle Aged; nucleic acid test; Occult hepatitis B; Occult sciences; Population; Prevalence; Studies; Viral diseases; Viral hepatitis; Young Adult; Hong Kong; Hong Kong China; Asia; Infection; Viral hepatitis B; Prevalence; Viral disease; Gastroenterology; Digestive diseases; Hepatic disease; Epidemiology; Blood donor
• ISSN: 0017-5749; 1468-3288; 1468-3288
• DOI: 10.1136/gut.2010.209148

Background and aimsThe aim of the present study was to determine the population prevalence of occult hepatitis B (OHB) infection and its clinical profile in a highly endemic area of chronic hepatitis B virus disease.MethodsOHB was first identified by individual sample testing for hepatitis B surface antigen (HBsAg) followed by nucleic acid testing (NAT) and vice versa for 3044 (cohort 1, stored sera from donation within 1 year) and 9990 (cohort 2, prospective study) blood donors, respectively. OHB was confirmed meticulously by ≥2 out of 3 tests with detectable hepatitis B virus (HBV) DNA using a sensitive standardised assay. Detailed serology and viral load in the serum and liver were studied.ResultsThe prevalence of OHB was 0.13% (4/3044) and 0.11% (11/9967) for cohort 1 and 2, respectively. In cohort 2, 10 out of 11 OHB samples were positive for anti-HBc (hepatitis B core antigen) antibody (all were immunoglobulin G). Seven had detectable anti-HBs. The serum HBV DNA levels were extremely low (highest 14.1 IU/ml). Of the six donors who underwent liver biopsies, all had normal liver biochemistry, extremely low liver HBV DNA (highest 6.21 copies/cell) and nearly normal liver histology. For those with viral sequence generation, none had the common HBsAg mutant G145R.ConclusionsThe prevalence of OHB in a highly endemic area of chronic HBV was very low, thus implying a low impact on transfusion services. To implement universal screening, the high cost of NAT should be taken into account. OHB blood donors had very low HBV replication, and normal liver biochemistry and histology, conferring a favourable prognosis.