Seroprevalence of hepatitis A in Iranian adolescents: is it time to introduce a vaccine?

Abstract

Universal vaccination of children for hepatitis A virus (HAV) has emerged as a cost-effective strategy to prevent this infection in regions with high incidence of symptomatic disease. Age-specific seroprevalence surveys are practical and reliable methods to estimate the rate of susceptibility in populations, and to help the implementation of vaccination policies. We surveyed the age-specific HAV seroprevalence in a nationally representative sample of Iranian adolescent students aged 10-18 years. Serum samples (n = 2494) were tested by enzyme immunoassay for total anti-HAV antibody. The overall rate of HAV seropositivity was 64% [95% confidence interval (CI), 62-66), which increased sharply from 14·8% (95% CI 7-23) at age 10 years to 72·9% (95% CI 68-78) at age 13 years, without a significant increase up to age 18 years. No significant difference in HAV seroprevalence was observed between males and females (63% vs. 65·1%), or urban and rural areas (63·4% vs. 65·2%); the seropositivity rate was similar in four different socioeconomic regions of Iran. We conclude that the seroconversion rate of HAV is high in Iranian adolescents and therefore mass vaccination of children may be necessary and should be considered by national health authorities.

Comparison of the Prevalence and Risk Factors of Hepatitis A in 10 to 18-Year-Old Adolescents of Sixteen Iranian Provinces: The CASPIAN-III Study

“…As previously reported, the overall rate of HAV seropositivity in Iran is 64%, which increases sharply from 14.8% at age 10 to 72.9% at age 13 (3). Iran is a vast country consisting of 31 provinces with differing sanitary conditions and socioeconomic properties, so the prevalence of this infection is expected to vary across various parts of the country.…”

“…Previously, we reported that HAV seropositivity was not related to gender or to residence area (urban/rural), and that seropositivity increased with age (3). This study investigated the household- and provincial-level risk factors for HAV.…”

Hepatitis A seroprevalence in Erzurum, Turkey

“…This view is further supported by the IgG prevalence being the lowest in the age group 10-14 years which is not covered by the HAV immunisation schedule by the Ministry. Some studies have shown that two doses of HAV vaccine administered to children would lead to a significant decrease in acute HAV incidence in all age groups [24]. In addition, the HAV immunity rate, which increases with increasing age, leads to a decrease in anti-HAV IgM positivity rates in older age groups.…”

A Seroepidemiologic Study of Hepatitis A in Seven to Eighteen-Year-Old School Children in Birjand: New Concerns and Opportunities

“…However, it seems that there is a declining trend in terms of immunity level against hepatitis A in Iranian children and a gradual shift for occurrence of HAV infection in adulthood that urge active immunization via vaccination against this virus (25). Currently, vaccination against HAV is not included in the national immunization program of Iran (26), however, given the high seroconversion rate of HAV among Iranian adolescents, extensive vaccination of children seems reasonable (27).…”