Seroprevalence and risk factors for hepatitis B virus infection among general population in Northern India.

Background: Infection with hepatitis-B virus has been a significant cause of morbidity claiming more than a million lives every year. Epidemiological data reveals that there are 360 million carriers of hepatitis-B virus throughout the globe and 78% of the world populations' hail from Asia. Though several studies from Indian sub-continent have provided an estimate of the prevalence of this viral infection, there exist only few studies, which reflect the status in the general population.

Aim: The present study was designed to investigate the prevalence of hepatitis-B infection in North Indian general population.

Methods: The study population comprised of 20,000 healthy blood donors who were screened for hepatitis-B surface antigen (HBsAg) status using third generation ELISA kit. Seroprevalence rate of seropositive donors was calculated and stratified by age, sex and blood groups. Statistical analysis was performed using tests of proportions, chi-square and confidence interval.

Results: The study showed that out of 20,000 donors, 450 (2.25%) were HBsAg positive (95% confidence interval (CI), 2.0445-2.4554). Higher prevalence of HbsAg was found among males (440/19235) than females (10/765). The age specific prevalence rose from 1.78% (108/6058) in donors aged 19-25 years to a maximum of 3.03% (96/3161) in donors aged 35-45 years and decreased in older age groups. The peaks were detected in male donors aged 35-45 years and in females aged 25-35 years. Rh-negative blood group donors (21/873) and Rh-positive group donors (429/19127) had almost equivalent prevalence rates of HBsAg. HBsAg was more prevalent in blood group B donors (174/7426) and less prevalent in AB blood group donors (38/2032).

Conclusion: It was found that variables including gender and age were significantly associated with HBsAg positivity. HBsAg positivity in our population was statistically not associated with ABO blood groups.