Water contact and Schistosoma haematobium infection: a case study from an upper Egyptian village.

The quantitative relationship between water contact and Schistosoma haematobium infection was studied in a cohort of male school children aged 6-17 in El Ayaisha village, Upper Egypt, during a two-year study. An exposure index (total body minutes, TBM) was used to identify the activities responsible for exposure to cercariae-infested water and to examine the relationship between water contact and infection. Results show that 65% of all contacts and 86% of all TBM were due to swimming in the Nile and canals and that swimming was the most important exposure and contamination activity.

Schistosome heat-shock proteins are immunologically distinct host-like antigens.

Constitutively expressed schistosome homologues of heat-shock protein Hsp70 elicit a dominant antibody response in humans infected with either Schistosoma japonicum or Schistosoma mansoni; in each case the parasite antigens are immunologically distinct and noncrossreactive. The antigenic site of the homologues is located near their carboxyl terminus where phylogenetic divergence between Hsp70 proteins is greatest. Nucleotide sequence comparison between these regions predicts very few amino acid differences between the schistosome protein and that of their human host.

A longitudinal study of Schistosoma haematobium infection in Qena governorate, Upper Egypt. 1. Initial epidemiological findings.

An epidemiological study was conducted as an initial phase of a longitudinal study on the immunology of Schistosoma haematobium in Upper Egypt. The study area was confined to three villages in Qena governorate, a region endemic solely for S. haematobium.