Epidemiological, clinical and biological features of malaria among children in Niamey, Niger

Background: Malaria takes a heavy toll in Niger, one of the world's poorest countries. Previous evaluations conducted in the context of the strategy for the Integrated Management of Childhood Illness, showed that 84% of severe malaria cases and 64% of ordinary cases are not correctly managed. The aim of this survey was to describe epidemiological, clinical and biological features of malaria among < 5 year-old children in the paediatric department of the National Hospital of Niamey, Niger's main referral hospital. Methods: The study was performed in 2003 during the rainy season from July 25(th) to October 25(th). Microscopic diagnosis of malaria, complete blood cell counts and measurement of glycaemia were performed in compliance with the routine procedure of the laboratory. Epidemiological data was collected through interviews with mothers. Results: 256 children aged 3 - 60 months were included in the study. Anthropometrics and epidemiological data were typical of a very underprivileged population: 58% of the children were suffering from malnutrition and all were from poor families. Diagnosis of malaria was confirmed by microscopy in 52% of the cases. Clinical symptoms upon admission were non-specific, but there was a significant combination between a positive thick blood smear and neurological symptoms, and between a positive thick blood smear and splenomegaly. Thrombopaenia was also statistically more frequent among confirmed cases of malaria. The prevalence of severe malaria was 86%, including cases of severe anaemia among < 2 year-old children and neurological forms after 2 years of age. Overall mortality was 20% among confirmed cases and 21% among severe cases. Conclusions: The study confirmed that malaria was a major burden for the National Hospital of Niamey. Children hospitalized for malaria had an underprivileged background. Two distinctive features were the prevalence of severe malaria and a high mortality rate. Medical and non-medical underlying factors which may explain such a situation are discussed.