Status of intestinal parasitic infections among rural and urban populations,southwestern Iran

Objective: To evaluate the prevalence and risk factors of intestinal parasitic infections in the urban and rural areas of Shushtar County,southwest Iran.Methods: A total of 1 008 fecal samples were analyzed by direct smear examination,formalinether concentration,and Ziehl-Neelsen and trichrome staining; furthermore,PCR was used to distinguish Trichostrongylus and hookworm species based on 28 S rRNA gene.Results: Totally,16.0% cases tested positive,either with a pathogenic or a non-pathogenic parasite. Protozoa were detected in 14.0%,helminths in 1.0%,protozoa and helminth coinfections were detected in 0.3%,and co-infections of two protozoa were detected in 0.7% of cases. The most common protozoa and helminths were Giardia duodenalis(7.7%) and Trichostrongylus spp.(0.5%),respectively. Among five microscopy Trichostrongylus positive cases,Trichostrongylus culbriformis was successfully identified in three isolates by sequencing. In the rural areas,the prevalence of parasitic infection was higher(9.8%) than that in the urban areas(6.2%). A significant association was found between educational level,type of drinking water,animals contact,hand-washing,and clinical symptoms. Conclusions: This study indicates that intestinal parasitic infections remain as a public health priority in Shushtar County. It seems that drinking water and environmental sanitation are the main risk factors of parasitic infections in rural areas.