Epidemiology of snakebite and use of antivenom in Argentina

Background: The incidence and case fatality rate of snakebite in Argentina are poorly known. Methods: The authors used questionnaires provided with antivenoms by the primary manufacturer of anti-venoms in Argentina. Results: A total of 8083 completed questionnaires was collected between 1978 and 1998. The annual incidence of snakebite was 1.8 bites per 100 000 inhabitants, with a high geographical heterogeneity; in the northern provinces of the country, the incidence can exceed 150 snakebites per 100 000 people per year. Bothrops (pit viper) bites predominated, accounting for 96.6 (6720/6957) of envenomations, bites from Crotalus (rattlesnake) accounted for 2.8 (195/6957), and bites from Micrurus (coral snake) for 0.6 (42/6957). Most patients were young men, who were generally bitten during agricultural activities, i.e. while working in the fields. Most snakebites (78.9, 5852/7419) were to the lower limb, including 58.3 (4322/7419) to the foot. The case fatality rate was 0.04 (3/8083). Most envenomations (90, 7275/8083) were treated with specific antivenom during the first 4 h after the bite. The median dose of antivenom was two vials for viper bites (Bothrops and Crotalus) and three vials for Micrurus bites. Conclusion: These preliminary results should enable manufacturers to increase the availability of appropriate antivenom and health authorities to improve the management of snakebites where they are most common.