Intestinal parasitic infections, with a special emphasis on cryptosporidiosis, in Amerindians from western Venezuela

The prevalences of intestinal parasites and intensities of helminth infections were studied in two Amerindian villages in Venezuela. Single stool specimens were collected from 303 individuals from Saimadoyi and 130 from Campo Rosario. Wet mounts, iron-hematoxylin-stained smears, and formalin-ether concentrates were examined for the presence of parasites; modified Ziehl-Neelsen carbol-fuchsin staining of 10% formalin-preserved stool was used to identify Cryptosporidium parvum. Helminth ova counts were made using the standard smear egg count technique. Mixed infections (Campo Rosario = 69.9%, Saimadoyi = 71.6%) were frequent. Overall infection rates with one or more species (Campo Rosario = 79.2%, Saimadoyi = 95.4%; P < 0.01) and with any protozoans (Campo Rosario = 60.8%, Saimadoyi = 72.3%; P < 0.05) were high and predominant (P < 0.05) in Saimadoyi. Cryptosporidiosis was identified in 38 subjects (8.8%) in both villages; 60.6% were asymptomatic carriers. The mean egg counts of helminths were heavier in Campo Rosario (P < 0.05), which was probably due to the drastic reduction of their lands along with their low standard of living. This study documents the change of intestinal parasitism pattern and deterioration of the health of Amerindians by the process of acculturation.