Age related seroprevalence of antibodies to hepatitis A virus in Hyderabad, India.

BACKGROUND: Hepatitis A virus (HAV) is an enterically transmitted viral disease endemic in many developing countries including India. Infection is often subclinical or asymptomatic in children while with increasing age symptomatic acute infections are more common. In some developing countries improvements in living conditions have led to change in epidemiology of HAV infection. In our country there are very few reports on prevalence of HAV.

OBJECTIVE: The present study was undertaken to determine the seroprevalence of hepatitis A virus antibodies in relation to age in Hyderabad.

MATERIAL AND METHODS: Serum samples were collected from 90 subjects in the age group 2-64 years in a mass vaccination camp for Hepatitis B. All the subjects were investigated with a uniform social and medical history questionnaire. Sera were tested for antibody to HAV (total anti-HAV) using enzyme immunoassay (General Biologicals, Taiwan).

RESULTS: The subjects included 48 males and 42 females. There were 54 children (< 12 yrs) and 36 adults. Of the 90 serum samples tested 51 (56%) were positive for anti HAV antibodies. The seropositivity in males and females was similar. The seroprevalence was 31.8% (17/54) in children (< 12 years) and 94.4% (34/36) in adults (p < 0.001). Age related seroprevalence revealed that a majority of children below 10 years (33/48, 69%) remain anti HAV negative, while only 25% of children below 15 years were anti HAV negative. The anti HAV antibody positivity was similar in different income groups.

CONCLUSION: The prevalence of HAV is high in Hyderabad. A majority of children below 10 years and 25% of children < 15 years remain susceptible to HAV infection. Child immunization against HAV therefore should be considered in our population too.