| prevalence and intensity of soil-transmitted helminthiasis in the city of portoviejo (ecuador). | we studied the stool samples of 151 school children in a district of the city of portoviejo (ecuador) in order to determine the prevalence and intensity of soil-transmitted helminthiasis (sth) and their relationships with anthropometric indices. the samples were analyzed with the semiquantitative kato-katz technique and the intensity of infections was categorized as light, moderate or high according to the thresholds set by the world health organization. prevalence of soil transmitted helmintias ... | 2001 | 11784925 |