studies on intestinal helminthiasis in, north-east of iran

prevalence of various intestinal helminthiasis has been established among the population of 42 villages in gonbad kavus in the north-east of the caspian littoral during a longitudinal health survey undertaken in this area. stool examination by formaline ether technique been performed among 1240 randomly selected population. surprisingly and contrary to most other areas in iran; very low infection rate with ascaris (0.2%), trichostrongylus (1.2%), hookworm (2.4%) and trichuris (0.2%) were foundt among the population. prevalence of infection with hymenolepis nana was rather high (overall prevalence. of 12.5%). significant variation has only been observed in the prevalence of hymenolepis nana in various age groups. simultaneous infection with two or more helminths has been found in 16.5% of people and 9.6% were infected with one, worm. infection with all helminths except hymenolepis was very low in 20 villages where 20 or more people were examined. strongyloides stercoralis with a maximum rate of infection of 4% was found among the population of 5 out of 20 villages. dicrocoelium dendriticum was also found in 7 persons. reasons for low prevalence of helminthiasis and its reverse correlation with the high incidence of 4 esophageal cancers in that area are discussed.