 Snake bite Envenomation is a Public Health Problem especially for tropical and subtropical countries. The WHO estimates 40 000 annual deaths in the world for this cause. In México the Ministry of Health estimated 3 882 cases on 2005, being the age of 15-44 the most affected. There are not official numbers of mortality, although the thought is that there are few cases of death, most of them related with a delay on treatment. 