[Geoclimatology and severity of snake bite envenomations in Benin]

Envenomations following snakebite are common in Benin where they constitute, particularly in certain areas, a significant problem for the local populations and health workers. The present epidemiological study describes the snakebite envenomations which occurred in 18 medical centres of the country (6 departmental hospitals and 12 provincial hospitals). The studied variables were: prevalence, length of hospitalisation, major complications, quality of therapeutic management and development of the disease according to area. The study covered a period from April 2000 to March 2001. 486 cases of snakebite necessitating hospitalisation were notified including 413 (85%) in the two northern departments: Atacora and Borgou. Males were largely predominant (90%) and patients under 40 years were the most numerous (82%). The dry season seemed a period of higher risk (75% of the cases). The delay between the bite and admission to hospital, studied for 120 patients in the area of Atacora (North-West Benin), was relatively long: the average was 4 days, with extremes ranging from 10 hours to 21 days. This delay explained the severity of the complications diagnosed. They can be listed according to decreasing frequency: shock, coagulopathy, acute renal failure, respiratory distress. Less than 20% of the patients could benefit from antivenom. Management in emergency care units was impossible in most cases, none of the medical centres (except in Porto-Novo, the capital) having an intensive care unit with artificial ventilation available. Average mortality was 22%. Poisonous snakebites remain serious in Benin, mainly in the northern part of the Country. Access to health care and the quality of the management must be improved. This will require significant efforts from health workers, medical authorities as well as the local population. It is urgent to plan a national therapeutic consensus to reduce the high mortality due to snakebites.