Hepatitis B problem in Thailand.

ABSTRACT

HBV infection is hyperendemic in Thailand. Approximately 5 million Thais are chronic HBV carriers. The prevalence of HBV markers in general population varies from 40-60%. Approximately 10-20% of children between the ages 1-5 years have serologic evidence of HBV infection and this prevalence increases with age reaching a plateau of 40-60% by age 20. High risk groups are household contacts of HBsAg carriers and babies born to HBsAg positive mothers. Approximately 75% of the babies born to HBsAg & HBeAg positive mothers become HBsAg positive at 3 months after birth. A few studies showed that the HBV prevalence of hospital personnel and other high risk groups is similar to that of the general population. The prevalence of chronic HBsAg carrier varies from 5-10% and is highest among age groups 10-30 years. Primary hepatocellular carcinoma (PHC) is the first and third most common cancer among Thai males and females, respectively. Approximately 35%-75% of PHC in adults are HBsAg positive. Histological studies showed that 47.3% of cryptogenic cirrhosis, 58%-66% of PHC and 35%-85% of cryptogenic cirrhosis with PHC were HBsAg positive. Studies on Hepatitis B immune globulin and Hepatitis B vaccine revealed a 70% and 56%, respectively, reduction in the HBsAg prevalence of infants born to HBsAg and HBeAg positive mothers. More epidemiologic, clinical and laboratory studies on HBV infection are being carried out by groups of scientists and investigators in the Ministry of Public Health and many medical schools. A national committee has been appointed to plan strategy for controlling HBV.