Hepatitis A is endemic in the Indian subcontinent. Poor sanitary conditions tend to expose most of the population to the virus in childhood. The disease at this age is asymptomatic and tends to provide life-long protection. However, rapid socioeconomic development has enabled certain groups of the population reach adolescence/adulthood without prior exposure to the virus. These groups are thus vulnerable to infection. At these ages, there is a greater likelihood of symptomatic disease and complications, including mortality.

A review was conducted that included epidemiology and burden of disease studies in the Indian subcontinent, published since 2005. The findings pointed to an increasing evidence of a shift from high to intermediate endemicity in high-income-typically urban-populations.

The prevalence of anti-HAV antibodies, which was previously reported at >90%, has been found to be lower now in adolescents and young adults; it is around 80% in Bangladesh and 55% in 5-15 years age group in India. Consequently, HAV accounts for more acute viral hepatitis predominantly in this age group. Several outbreaks due to HAV have been reported across the subcontinent - Sri Lanka (2009-2010): >13,000 affected; Kashmir (2015-2017): 12 outbreaks; Kerala (2012-2016): 84 outbreaks – due to water or food contamination.

As a result of shifts in endemicity, a large proportion of the population is no longer exposed to the infection in childhood. Well-tolerated and effective vaccines are available to help prevent disease burden and provide long-term protection. These should be more extensively used to protect more patients from the growing disease burden of hepatitis A.

Source: Agrawal A, Singh S, Kolhapure S, et al. Increasing Burden of Hepatitis A in Adolescents and Adults and the Need for Long-Term Protection: A Review From the Indian Subcontinent. Infect Dis Ther. 2019 Dec;8(4):483-497.