Snakebite envenomation in Costa Rica: a revision of incidence in the decade 1990-2000.

We reviewed snakebite records from the Costa Rican health system from the year 1990-2000. During this decade, a total of 5550 snakebite cases occurred in the country. While the average number of snakebites per year was relatively constant at 504 cases, the annual incidence per 100,000 people decreased. This reduction is mainly due to high population growth in Costa Rica, which increased 35% during the study period. The most affected population lives in rural areas characterized by high precipitation, and mainly includes young agricultural workers. The lancehead Bothrops asper is considered the most important species affecting humans.