Intestinal parasitic infection in the Surui Indians, Brazilian Amazon

Abstract

This study reports the results of a cross-sectional survey carried out in 2005 to investigate the epidemiology of intestinal parasitism among the Suruí Indians, Brazilian Amazon. A total of 519 stool samples were examined by zinc-sulphate-flotation and formol-ether-sedimentation. Entamoeba histolytica/E. dispar-positive samples were further tested by ELISA. Thirty-six percent of the subjects were positive for one more helminth species; 70.7% harbored at least one protozoan species. The most frequent helminth was Hymenolepis nana (29.5%). Nematodes were rare (hookworm= 3.3%; Strongyloides stercoralis= 0.2%). Capillaria sp. was identified in 5.2% of the samples and one case of parasitism by Dipylidium caninum was detected. Prevalence of Giardia duodenalis and E. histolytica/E. dispar was 16.2% and 12.3%, respectively. Based on ELISA, the prevalence of E. histolytica infection was 3.2%. The overall prevalence of intestinal nematode infections depicted in this study was surprisingly low compared to what is often reported for other indigenous populations in the Brazilian Amazon. It is argued that the prevalence of helminths in the Suruí are associated with anthelminthic mass treatment schemes undertaken by the Indian health service, in the absence of other measures. The authors propose that a special program aimed at controlling intestinal parasitism in indigenous communities should step beyond the top-down distribution of medication, but rather be designed in collaboration with the target population, encompassing education, better housing, alternative sewage disposal systems and safe water supply to all villagers.