TY - JOUR
T1 - Quantification of clinical morbidity associated with schistosome infection in sub-Saharan Africa
AU - Van Der Werf, Marieke J.
AU - De Vlas, Sake J.
AU - Brooker, Simon
AU - Looman, Caspar W.N.
AU - Nagelkerke, Nico J.D.
AU - Habbema, J. Dik F.
AU - Engels, Dirk
N1 - Funding Information:
The authors acknowledge the co-operation of H. Feldmeier, C.F. Hatz, J.R. Lambertucci, R. Olds, J. Richter. We thank J. Utzinger for providing data for the heterogeneity analysis. This study was performed within the WOTRO/NWO funded multidisciplinary programme ‘Model-based decision support for schistosomiasis control in Ghana, Mali, Niger and Senegal’ and was also funded by the department of Communicable Diseases Control, Prevention and Eradication, World Health Organisation, Geneva, Switzerland and the Wellcome Trust (in the form of a Wellcome Trust Prize Fellowship to SB (No. 062962).
PY - 2003/5/1
Y1 - 2003/5/1
N2 - Health policy making in developing countries requires estimates of the (global) burden of disease. At present, most of the available data on schistosomiasis is limited to numbers of individuals harbouring the infection. We explored the relationship between the presence of schistosome infection and clinical morbidity, in order to estimate numbers of individuals with disease-specific morbidity for Schistosoma haematobium and Schistosoma mansoni infection in sub-Saharan Africa. We searched the literature for cross-sectional data from field studies reporting both schistosome infection and morbidity. This was used to derive a functional relationship between morbidity and infection. After standardisation for diagnostic method, the number of individuals with specific types of clinical morbidity or pathology was predicted. As only aggregated prevalences of infection were available for countries or areas, we adjusted for heterogeneity in infection levels within communities in those countries. In total, 70 million individuals out of 682 million (2000 estimate) in sub-Saharan Africa were estimated to experience haematuria in the last 2 weeks associated with S. haematobium infection, and 32 million dysuria. Ultrasound detected serious consequences of S. haematobium, major bladder wall pathology and major hydronephrosis, were predicted at 18 and 10 million, respectively. Infection with S. mansoni was estimated to cause diarrhoea in 0.78 million individuals, blood in stool in 4.4 million and hepatomegaly in 8.5 million. As the associations between prevalence of S. mansoni infection and prevalence of diarrhoea and blood in stool were not very clear, the resulting estimates may be underestimations. Using the very limited data available, we estimated the mortality rates due to non-functioning kidney (from S. haematobium) and haematemesis (from S. mansoni) at 150 000 and 130 000 per year. Given the overall high number of cases with schistosomiasis-related disease and associated death, we conclude that schistosomiasis remains an important public health problem in sub-Saharan Africa.
AB - Health policy making in developing countries requires estimates of the (global) burden of disease. At present, most of the available data on schistosomiasis is limited to numbers of individuals harbouring the infection. We explored the relationship between the presence of schistosome infection and clinical morbidity, in order to estimate numbers of individuals with disease-specific morbidity for Schistosoma haematobium and Schistosoma mansoni infection in sub-Saharan Africa. We searched the literature for cross-sectional data from field studies reporting both schistosome infection and morbidity. This was used to derive a functional relationship between morbidity and infection. After standardisation for diagnostic method, the number of individuals with specific types of clinical morbidity or pathology was predicted. As only aggregated prevalences of infection were available for countries or areas, we adjusted for heterogeneity in infection levels within communities in those countries. In total, 70 million individuals out of 682 million (2000 estimate) in sub-Saharan Africa were estimated to experience haematuria in the last 2 weeks associated with S. haematobium infection, and 32 million dysuria. Ultrasound detected serious consequences of S. haematobium, major bladder wall pathology and major hydronephrosis, were predicted at 18 and 10 million, respectively. Infection with S. mansoni was estimated to cause diarrhoea in 0.78 million individuals, blood in stool in 4.4 million and hepatomegaly in 8.5 million. As the associations between prevalence of S. mansoni infection and prevalence of diarrhoea and blood in stool were not very clear, the resulting estimates may be underestimations. Using the very limited data available, we estimated the mortality rates due to non-functioning kidney (from S. haematobium) and haematemesis (from S. mansoni) at 150 000 and 130 000 per year. Given the overall high number of cases with schistosomiasis-related disease and associated death, we conclude that schistosomiasis remains an important public health problem in sub-Saharan Africa.
KW - Morbidity
KW - Pathology
KW - Schistosoma haematobium
KW - Schistosoma mansoni
KW - Schistosomiasis
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U2 - 10.1016/S0001-706X(03)00029-9
DO - 10.1016/S0001-706X(03)00029-9
M3 - Article
C2 - 12745133
AN - SCOPUS:0037847426
SN - 0001-706X
VL - 86
SP - 125
EP - 139
JO - Acta Tropica
JF - Acta Tropica
IS - 2-3
ER -