Relationship between Intestinal Parasitic Infection in Children and Soil Contamination in an Urban Slum

Abstract

Urban slums are well known for their high infant mortality and morbidity rates, and parasitic infections seem to be a common problem among these children. The aim of the present study was to determine protozoa and nematodes prevalence among children of a selected community located in São Paulo, Brazil, and access the relation between soil and children infection. Soil contamination samples from 15 strategic locations in the slum area as well as stool samples (examined for protozoa and nematodes through five different methods) from 120 children aged 2-14 years (49% M: 51% F, mean +/- SD = 7.9 +/- 3.8 years) were assessed in a cross-sectional study. Children's domicile locations were determined, and a comparative analysis was undertaken to correlate children and soil infection. Overall infection rate was 30.8% (n = 37), without difference between genders. The most frequent intestinal protozoa were Endolimax nana (20.8%), Entamoeba coli (15.8%) and Giardia lamblia (16.7%). Frequencies of Ascaris lumbricoides and Enterobius vermicularis in stool samples were 2.5 and 1.7%, respectively. No cases of hookworms, Schistosoma mansoni or Tricuris trichiura were identified. Polyparasitism occurred in 10.8% of the children, while 69.2% were free of parasitic infections. Out of the 15 soil samples analyzed, Ascaris sp. eggs were found in 20% and hookworm eggs in 6.7%. Helminth infection is not as prevalent as previously reported in urban slums in São Paulo, neither as clinical disease nor in soil samples. Protozoa intestinal infection, however, is still frequent in some marginalized populations in São Paulo. Improvement in living standards, mostly sanitation might decrease the prevalence of these diseases.