Analyses of blood donor samples from eight provinces in Lao PDR suggest considerable variation concerning HBV exposure and carriage.

INTRODUCTION: Hepatitis B is endemic in Lao PDR and about 9% of the adult population is chronically infected. In this study, we investigated regional, occupational, age and sex-related differences in hepatitis B epidemiology in Lao blood donors. METHODS: 5017 voluntary blood donors from 8 different provinces were tested for hepatitis B markers by ELISA. Predictors for the prevalence of hepatitis B surface antigen (HBsAg) and antibodies against the core antigen (anti-HBc) were assessed by bivariate and multivariable analyses. RESULTS: In total, 41% of the participants were positive for anti-HBc; the HBsAg prevalence was estimated at 6.9% among all participants (9.2% among first-time donors and 3.9% among repeat donors). Among first-time donors, HBsAg positivity was associated independently with being male (p<0.001), being from the North (p<0.001) and being soldier (p<0.001). Participants were more likely to be anti-HBc positive when they were male (p<0.001), from the Northern provinces (p<0.001) and older than 20 years (p<0.01). CONCLUSION: In conclusion, our study confirmed an overall high HBsAg and anti-HBc prevalence in Lao PDR, albeit with considerable regional variation. The identification of a sizeable number of HBsAg positives among repeat donors warrants a thorough investigation of current blood screening, record keeping, donor identification and counselling practises.

Seroprevalence of hepatitis B and C virus infections among Lao blood donors.

There have been no previous reports of the prevalence of hepatatis B virus (HBV) and hepatitis C virus (HCV) infections in Lao PDR. From 2003 to 2005, 13,897 first-time blood donors were screened for the presence of hepatitis B surface antigen (HBsAg) and hepatitis C virus antibody (anti-HCV). The seroprevalence of HBsAg positive blood donors was 8.7%. The prevalence among males (9.7%) was higher than in females (6.2%). The prevalence of anti-HCV positive blood donors was 1.1%, with no significant differences between males (1.1%) and females (1.0%). Annual positive rates for HBsAg and anti-HCV during the years 2003 to 2005 did not differ significantly. Lao PDR has a high endemicity of HBV carriers (8.7%). Dual infection with HBV and HCV was 0.12%. For preventing HBV infection, the country introduced DPT-Hepatitis B vaccines into the National Immunization Program in 2001. The large reservoir of HBV and HCV infections will cause an enormous burden of patients with cirrhosis and hepatocellular carcinoma in the future.