Enterically transmitted hepatitis in Saudi Arabia: an epidemiological study.

Rates of exposure to two, enterically transmitted viruses, hepatitis E virus (HEV) and hepatitis A virus (HAV), were investigated among the populations of two areas of Saudi Arabia: Gizan (a rural area) and Riyadh (an urban area, with relatively good sanitation). In Riyadh, 24.7% and 1.2% of children were seropositive for HAV and HEV, respectively, by the age of 12 years. There was a sharp increase in exposure to HAV between 13 and 20 years of age (to 63.5%) and most (80.0%) of the subjects aged 50 years had apparently been exposed to HAV. Although seropositivity to HEV also increased with subject age, it only reached 18.8% (in subjects aged > 50 years). The age-specific patterns of exposure to HAV and HEV in Gizan were similar to those in Riyadh but the rates of exposure were generally higher; mean rates of exposure to HAV and HEV were 76.3% and 14.9% in Gizan and 61.3% and 8.37% in Riyadh, respectively. That rates of exposure to HEV in Gizan were almost twice those in Riyadh emphasizes the importance of sanitation as an effective measure in controlling the spread of HEV in developing countries.