[Intestinal parasite infections in a semiarid area of Northeast Brazil: preliminary findings differ from expected prevalence rates].

We report on intestinal parasite infection prevalence in a population sample from S o Raimundo Nonato, Southeast Piau State, Brazil, aimed at comparison with previous studies on Trichuris trichiura and Ascaris lumbricoides infection. A total of 265 stool specimens were collected and examined by spontaneous sedimentation. Approximately 57% of specimens were infected with at least one parasite species. Entamoeba coli (35.8%), Endolimax nana (13.6%), Hymenolepis nana (9.4%), and hookworm (9.4%) were the most frequently observed parasites. Two cases of roundworm infection were detected, probably acquired outside the region. T. trichiura eggs were not found. Interestingly, neither A. lumbricoides nor T. trichiura has been found in local prehistoric human coprolites. Nevertheless, hookworm infection has been present in the region for at least 7,000 years.