Background: Hepatitis B virus is a partially double–stranded circular DNA virus and is a member of the Hepadnaviridae family. The virus consists of a core capsid which contains viral DNA and this is surrounded by an envelope containing surface antigen (HBsAg). Both whole, incomplete virus particles, consisting entirely of HBsAg, are produced during replication of HBV. The HBsAg particles vary greatly in morphology and are found in high concentrations in early acute infection and continue to be produced in chronic disease.1

Objective: To evaluate the seroprevalence of hepatitis B surface antigen among patients in a tertiary care health centre of Kumaun region of Uttarakhand.

Materials and methods: The prevalence of hepatitis B surface antigen (HBsAg) was studied in 37169 patients of all age groups and gender (19430 females and 17739 males) who required blood investigations for different medical reasons. Blood samples collected during January 2017 to August 2018, were tested for HBsAg using a sandwich ELISA based immunochromatic test.

Results: Of the 37169 patients tested, 719 (1.93%) were positive for HBsAg. Out of these, 387(53.82%) were females and 332 (46.18%) were males. The results revealed that hepatitis B infection was highest in age group of 21–30 years of age.

Conclusion: This study demonstrates that screening tests can be pivotal in identifying HBsAg and it is advocated that a program  for education, vaccination and prophylaxis must be implemented in all health care set ups.