Leptospirosis is a zoonotic disease caused by the pathogenic bacterium Leptospira, which remains in the renal tubules of certain animals. Humans become infected when they come into contact with infected animals or with the contaminated environment. Leptospirosis has an endemic behavior, with epidemic outbreaks in several continents, and is considered the most widespread zoonosis in the world. It has been reported in different regions of the world. The distribution of the reservoirs of infection and of the different leptospira serovars is worldwide; it occurs in urban and rural areas, both in developing and developed countries. This is why the evolution of this entity can be observed in all continents. However, it predominates in tropical areas, in Southeast Asia, in China it is endemic, 74.8% of farmers are affected, according to a study conducted by Hu Jing from 1960 to 1995. In India, it is very frequent. In Latin America and in developing countries it is frequent, where socioeconomic conditions and poor sanitary conditions are conducive to the disease.