Snake bites in South Chad. Comparison between three different polyvalent anti-snake venom immunotherapies

Snake bites are of major public health importance in Africa as causes of morbidity and mortality, but are largely neglected in health care planning. Echis carinatus is probably the most dangerous snake in the world, and is responsible of the majority of envenomation cases in West Africa. Among the components in snake venom are a number which have profound effects on haemostatic mechanisms and others with neurotoxicity. Antivenom immunotherapy is the only specific treatment available for the patients with envenomation. A comparison between three different antivenoms was performed in Goundi hospital in South Chad: the "IPSER AFRIQUE PASTEUR", the "Su polyvalent anti-snake venom serum - Central Africa" and the "FAV-Afrique immunoglobulin fragments". From January 1997 to December 2001, 288 patients enrolled in the study have been divided in three different cohorts on the basis of immunotherapy performed. The results demonstrate that the "Sii polyvalent anti-snake venom serum - Central Africa" seems completely ineffective in treatment of African snake bites; differences between "IPSER AFRIQUE PASTEUR" and "FAV-Afrique" could be ascribed to different corticosteroid treatment other than to differences in immunotherapy efficacy. If a lack of efficacy of corticos-teroid treatment is postulated the whole antivenom serum seems more active than immunoglobulin fragments.