Questionnaires for rapid screening of schistosomiasis in sub-Saharan Africa.
New initiatives are aiming to reduce the global burden of schistosomiasis, mainly through the large-scale application of chemotherapy. To target chemotherapy effectively, rapid assessment procedures are needed for identifying high-risk communities that are foci for the disease. In this review, we examine the development and validation of simple school questionnaires for screening communities for Schistosoma haematobium and S. mansoni rapidly and inexpensively. The focus is on sub-Saharan Africa, where 85% of the current schistosomiasis burden is concentrated. For more than a decade, the questionnaire approach has been validated in 10 countries, with 133 880 children interviewed in 1282 schools, and with 54 996 children examined for S. haematobium. The questionnaires were well accepted, highly reliable, and of low cost. The success of the questionnaires is explained by the fact that S. haematobium infections were easily perceived through the presence of blood in urine. Evidence from 48 258 children interviewed in 545 schools indicated that reported blood in stools and bloody diarrhoea are valuable indicators for community diagnosis of S. mansoni. However, the diagnostic performance of the questionnaires for S. mansoni was weaker than for S. haematobium, and although these results are encouraging, the questionnaires need additional validation. Recently, questionnaires were extended from community to individual diagnosis and showed considerable promise. Questionnaires are now available for promptly defining the magnitude of schistosomiasis in a large area, which will allow limited resources for morbidity control to be allocated optimally.
Lengeler
Christian
C
Department of Epidemiology and Public Health, Swiss Tropical Institute, Basel, Switzerland. christian.lengeler@unibas.ch
Utzinger
Jürg
J
Tanner
Marcel
M
D017954:Africa South of the Sahara / Q000453:epidemiology; D000818:Animals; D005243:Feces / Q000469:parasitology; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D011634:Public Health; D018570:Risk Assessment; D012548:Schistosoma haematobium / Q000302:isolation & purification; D012550:Schistosoma mansoni / Q000302:isolation & purification; D012552:Schistosomiasis / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires