Intestinal parasitic diseases in Riyadh, Saudi Arabia: prevalence, sociodemographic and environmental associates

Our objectives were to assess the prevalence of intestinal parasitic infect ions in Riyadh and to determine associated sociodemographic and environment al factors. The study was conducted through a household survey. Three healt h centres were chosen from each of the five Riyadh urban regions and 15 fro m rural areas. Based on the average family size, a random sample of househo lds were chosen. All household members were asked to participate in the stu dy. Data were collected using a pre-designed questionnaire eliciting data o n sociodemographic and environmental factors. A stool specimen of each indi vidual was examined microscopically for the presence of trophozoites and cy sts. Six thousand and twelve participants with a mean age of 23.3 +/- 17.4 (median 19 years, 48.6% males) were studied and 32.2% were infected. The in fection rate was high in urban areas (33.3%), among children <12 years (34. 4%), non-Saudis (42.2%), single persons (34.9%), illiterate individuals (33 .8%), those who obtained drinking water from tankers (36.1%) and those who disposed of sewage in open channels (47.1%). Stratified analysis showed tha t for Saudis <12 years parasitic infections were significantly higher among tanker users (39.5%) and septic tank users (36.8%). For Saudis greater tha n or equal to 12 years low education, water storage and open sewage disposa l were statistically associated with parasitic infections (P < 0.05). Among expatriates, infections were high among males (47.6%), urban residents (48 .3%), single persons (46.9%), tanker users (39.5%) and septic tank users (7 8.6%). Multivariate logistic regression analysis showed that age <12 years, non-Saudi nationalities, educational level below secondary school, tanker as source of water and open sewage disposal were independently associated w ith high intestinal parasitic infection.