Hepatitis B surface antigen (HBsAg) in leprosy patients of Calcutta: its prevalence and subtypes.

Hight incidence of hepatitis B surface antigen (HBsAg) in lepromatous leprosy patients have been reported by many workers. This paper reports on a study undertaken over a period of more than two years to determine the prevalence of HBsAg and its major antigenic subtypes amongst the various clinical types of leprosy and apparently healthy individuals of Calcutta population. The overall incidence of HBsAg in lepromatous leprosy is found to be 3.8% (9 out of 234) in our study. The incidence of HBsAg in tuberculoid leprosy and non leprosy control cases were almost identical, 2.5% (11 out of 431) and 2.7% (14 out of 519) respectively. The incidence of HBsAg in lepromatous leprosy in the present study was apparently higher than tuberculoid or non leprosy cases, although statistically not significant. Hence the association between HBsAg and lepromatous leprosy could not be established in our study. None of the major antigenic subtypes of HBsAg could be related to any particular type of leprosy. The subtypes 'ad', 'ay' and 'ar' were present at varying proportions in all the groups tested. The antigenic subtype 'ay' was found to be prevalent in Calcutta population in higher proportions.