Volume 77, Issue 4
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


Where prevalence of geohelminths and schistosomes is high, co-infections with multiple parasite species are common. Previous studies have shown that the presence of geohelminths either promotes or is a marker for greater prevalence and intensity of infections. Some of this apparent synergy may simply represent shared conditions for exposure, such as poor sanitation, and may not suggest a direct biologic interaction. We explored this question in a study of 13,279 school children in Jequié, Bahia, Brazil, with a survey of demographic characteristics and stool examinations. Cross-sectional analysis revealed a statistically significant increase in the prevalence and intensity of infection with increasing numbers of geohelminth species (OR 2.5, 95% CI 1.38–3.64). Less than 20% of the strength of this association was contributed by socioeconomic status or environmental conditions. Thus, polyparasitism itself, as well as intrinsic host factors, appears to produce greater susceptibility to additional helminth infections.


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  • Received : 06 Sep 2006
  • Accepted : 09 May 2007

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