A study of hepatitis A virus seropositivity among children aged between 1 and 5 years of age: Implications for universal immunization.

Hepatitis A virus (HAV) causes an enterically transmitted viral disease mainly affecting children and endemic in many developing countries, including India. There is an epidemiological shift with an increased incidence of symptomatic cases among children. This study was conducted to assess the seroprevalence of HAV among young children aged below 5 years and the need for universal immunization.This cross-sectional study was conducted at two tertiary care hospitals in Northern India, from Apr 2014 to Jul 2015, among healthy children aged between 1 and 5 years. The sample size was calculated based on the prevalence of HAV seropositivity of 40% among children aged <10 years [16-60%] and alpha error of 5%. Analysis of serum IgG against HAV was performed by enzyme-linked immunosorbent assay method, and results were analyzed.A total of 1084 children aged between 12 and 60 months were enrolled, with male-to-female ratio of 1.86:1. A total of 471 children (43.5%) were found to be positive for IgG against HAV. The seroprevalence of HAV was lower among younger children aged 12-23 months (odds ratio [OR] = 0.73, 95% confidence interval [CI] = 0.52-0.87, p = 0.03), which was statistically significant. Seropositivity of HAV was lower among boys and families consuming safe drinking water and having improved sanitation facilities.The study observed lower seropositivity against HAV among younger children, making them susceptible of contracting the disease. Possible underlying risk factors were younger age, unsafe drinking water, poor sanitation, and low education status of parents. Therefore, vaccination may be recommended as optional vaccine at one year of age, along with improved public health efforts for safe drinking water, hygiene practices, and food safety.