Bothrops asper (family Viperidae) is the most important snake from the medical standpoint in Central America. It is distributed in the humid tropical lowlands and provokes the majority of cases, and the most serious ones. It is also responsible for the majority of fatal cases in the region. This snake adapts very well to altered environments, such as agricultural fields and pastures. Photo by Mahmood Sasa and reprinted from “Confronting the neglected problem of snake bite envenoming: the need for a global partnership” by Gutiérrez et al., PLOS Medicine, 2006, 3(6), e150 . Creative Commons Attribution License (CCAL).