Prevalence of hepatitis B and C virus infection in rural ethnic populations of Northern Thailand

Background: In Thailand, the population is composed of multiethnic stocks. However, many epidemiological studies on HBV and HCV have focused on blood donors with Thai and,or Chinese ethnic background. Available information on HBV and HCV infections among ethnic minorities in Thailand is limited. Objective: So as to contribute to the local public health planning, we have conducted an ethno-epidemiological survey for the HBV and HCV infections among several minorities in a multiethnic center, Northern Thailand. Study design: A total of 658 individuals from seven ethnic groups, Lahu, Lisa, Shan, Red Karen, White Karen, Hmong and Akha, living in northern Thailand were studied for the prevalence of HBV and HCV infections by the use of particle agglutination tests. Results: An overall prevalence of HBs-Ag, anti-HBs and anti-HCV in the seven groups was 10.3, 33.0 and 3.8%, respectively. The positivity rate of HBV and HCV infection in each tribe ranged 4.7% (Akha)-22.6% (Lahu) and 2.0% (Hmong and Akha)-8.1% (Sham), respectively. Sexual difference in the prevalence of HBV was not observed, whereas the prevalence of HCV was significantly higher in the males (P < 0.05). The prevalence of HBV was significantly different (P < 0.005) by the groups but that of HCV was not. Conclusions: The prevalence of HBV and HCV infection in Thai ethnic minorities was investigated. We demonstrated that HBV was a more common infectious agent found in this populations than HCV. The prevalence of HBV infection was different by tribe but not by sex. In contrast, the prevalence of HCV infection was not different by tribe but by sex (males were infected more than females). The present study showed that HBV and HCV infection are widely spread in rural ethnic populations of northern Thailand. Thus, a nation wide but community-base epidemiological survey is required for the public health planning to control their related serious diseases. (C) 2002 Elsevier Science B.V. All rights reserved.