Summary
The authors evaluated the prevalence of intestinal parasites among inhabitants at four localities along the Rio Negro. Results for the Lutz method performed on fecal samples of 213 persons and Kato-Katz method, in 154, gave prevalences of, respectively, 40.4% and 50.0% for hookworms, 54.5% and 65.6% for A. lumbricoides, 52.1% and 87.0% for T. trichiura and 0.0% and 0.6% for E. vermicularis. Results from iron-hematoxylin staining carried out with 190 samples gave prevalences of 17.9% for E. histolytica, 11.0% for E. coli, 2.1% for I. bütschlii, 4.7% for E. nana and 17.9 for G. lamblia. Infection by S. stercoralis, in 147 persons, was 1.4%, using the Baermann-Moraes method. The Harada-Mori method used in 161 patients revealed 50.3% of those with larvae, of which 97.5% were N. americanus. The intensity of parasitism by hookworms, as evaluated by the Kato-Katz method in 71 patients, was mild (< 2,599 eggs/g of stool) in 95.8%. In 103 samples with A. lumricoides the median was 14,160 eggs/g and the median for T. trichiura in 103 stools was 1,320 eggs/g. The authors concluded that the prevalence of intestinal parasites did not diffed greatly from earlier data from the the Amazonian region, and the intensity of parasitism by worms was mild.