Age-specific seroprevalence of hepatitis a among school children in central Tunisia.

Hepatitis A virus (HAV) has different epidemiologic and clinical patterns, depending on the level of endemicity in a given geographic area. Tunisia is considered a region of high endemicity for hepatitis. Improvement of socioeconomic conditions in this country has made a determination of the seroprevalence of this disease advisable. We assessed the seroprevalence of HAV in Sousse in central Tunisia. A total of 2,400 school children 5-20 years of age (mean +/- SD age = 11.7 +/- 3.5 years) were selected by two-stage cluster sampling and tested serologically for IgG antibody to HAV by using an enzyme-linked immunosorbent assay. The overall seroprevalence among this population was 60% (44%, in children < 10 years old, 58% in those 10-15 years of age, and 83% in those > 15 years of age. Seroprevalence also varied according to area of residence. At the age of 10, 21.3% of school children living in the urban areas and 87.7% of those living in rural areas had antibodies to HAV. Other factors that increased seroprevalence included non-potable water, crowding, and a low education level of parents with odds ratios of 4.37, 2.96, and 2.62, respectively. This study has shown an increase of seroprevalence with age, suggesting that transmission among younger children has decreased, particularly in urban areas. Programs to prevent hepatitis A may need to be modified based upon the changing age distribution of the disease and mass vaccination program could be indicated if additional incidence and prevalence data confirm the intermediate endemicity of HAV.