Chronic hepatitis B in Nepal: An Asian country with low prevalence of HBV Infection.

Sandwiched between China, a country with high prevalence of hepatitis B surface antigen (HBsAg) and 30% of the world’s HBsAg carriers, and India which has intermediate HBsAg prevalence and 10% of the world’s carriers, Nepal has the lowest prevalence of hepatitis B virus (HBV) infection in Asia, with an HBsAg carrier rate of 0.9%. This treatise discusses the probable causes of this low prevalence based on published literature on the subject. The HBsAg prevalence among pregnant women in Nepal is low (0.5%) and none of those examined were HBeAg positive. The highest prevalence of HBsAg was found in the 6-15 years age group. The low prevalence of this infection in the country was due to an absence of significant vertical transmission and its predominant spread by horizontal transmission among the adolescent age group.

Antigenic relationship between reactivity to hepatitis B e antigen and 19 kDa protein of Mycobacterium tuberculosis among the Tibetan settlers in Karnataka.

McGlynn and her co-workers have reported that among the Vietnamese refugees in Philadelphia and among Alaskan natives who are hepatitis B carriers, there is a statistically significant association between a negative tuberculin test and the presence of hepatitis B e antigen. A repetition of this work among the population of Bangalore did not yield any significant results because of the very low incidence of hepatitis found among this population. However, on the basis of available data that hepatitis B infection is more prevalent among the Mongolian population than among people of other populations, the work was repeated among Tibetans who had settled down in Karnataka. This set of experiments showed that, contrary to the report of McGlynn et al, there is a statistically significant association between a positive tuberculin test and the presence of hepatitis B e antigen and that those individuals who showed the presence of hepatitis B e antigen exhibited less severe form of the disease than those who were negative to this antigen. These findings suggested that immunity to tuberculosis and hepatitis B infections may have a common underlying principle. Data bank search revealed a stretch of amino acid sequences which is common to hepatitis B e antigen and 19 kDa antigen of Mycobacterium tuberculosis. The significance of these results is discussed.