title: Exposure, infection and immune responses to Schistosoma haematobium in young children.
abstract: Behavioural, parasitological and immunological data were obtained from 48 children up to 6 years old, resident in a Schistosoma haematobium endemic area in Zimbabwe. The children averaged more than 1 contact with infective water bodies every 3 days and all showed immunological evidence of exposure (an anti-cercarial and/or anti-egg antibody response). IgM was the dominant isotype and appeared in the youngest children, followed by IgA, IgE and IgG3. However, only 38 children showed evidence of infection (an anti-egg response or eggs in urine) and only 14 were excreting eggs. The best estimates from these data are that less than 1 in 100 contacts results in infection and less than 1 in 1000 result in egg output. This suggests that there may be substantial attrition of invading cercaria even in naïve individuals.
authors.affiliation: Centre for Veterinary Tropical Medicine, University of Edinburgh, Scotland. mark.woolhouse@ed.ac.uk
authors.forename: M E
authors.initials: ME
authors.lastname: Woolhouse
authors.forename: F
authors.initials: F
authors.lastname: Mutapi
authors.forename: P D
authors.initials: PD
authors.lastname: Ndhlovu
authors.forename: S K
authors.initials: SK
authors.lastname: Chandiwana
authors.forename: P
authors.initials: P
authors.lastname: Hagan
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use; D000909:Antibodies, Helminth / Q000097:blood*; D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth / Q000097:blood; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000469:parasitology; D006801:Humans; D007136:Immunoglobulins / Q000097:blood; D007223:Infant; D016013:Likelihood Functions; D008954:Models, Biological; D010270:Parasite Egg Count; D011223:Praziquantel / Q000627:therapeutic use; D015995:Prevalence; D012548:Schistosoma haematobium / Q000276:immunology*; D012553:Schistosomiasis haematobia / Q000097:blood / Q000453:epidemiology / Q000276:immunology* / Q000652:urine; D014867:Water / Q000469:parasitology*; D015030:Zimbabwe / Q000453:epidemiology
chemical_list: D000871:Anthelmintics; D000909:Antibodies, Helminth; D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth; D007136:Immunoglobulins; D014867:Water; D011223:Praziquantel