Reply to comment on: Severe malaria attack is associated with high prevalence of Ascaris lumbricoides infection among children in rural Senegal

Abstract

Some of the remarks made by M. Nacher about potential biases that may have occurred in our field study are interesting but I do not think that they call into question our results in such a radical way. In particular the arguments concerning the definition of severe malaria do not appear to be compatible with a negative association between severity of malaria and Ascaris infection as he suggests in his letter. Firstly repeated vomiting is indeed a recognized clinical criterion of severity of malaria according to the WHO definition. Secondly a significant proportion of these children presented not only with repeated vomiting but also with other unquestionable criteria of severity such as alterations in consciousness coma or convulsions which would bring our figures far beyond the 60% figure of ‘really severe malaria’ quoted by M. Nacher. Lastly an ideal situation would be to have a complete clinical parasitological and biological definition of the cases. This is very seldom possible particularly in a rural area of Senegal where the latest biological techniques are not available. We were therefore obliged to define severity on a clinical basis with the utmost rigour in the assessment of diagnostic criteria. Cases were identified by skilled nurses or physicians and systematically checked by parasitologists from the IRD (Institut de recherche pour le developpement) team who have had a long experience of malaria surveys in such rural settings. (excerpt)