Climate change, cyclones and cholera - Implications for travel medicine and infectious diseases

Abstract

Cholera, although largely underreported, is thought to be responsible for around 3 million diarrheal cases and an estimated 100,000 deaths in 69 endemic countries, predominantly in sub-Saharan Africa and Asia [1,2]. Cholera causes acute diarrheal episodes which result from the ingestion of the enterotoxin producing Vibrio cholerae, a highly motile, flagellated Gram-negative rod that exists in aquatic environments, like coastal waters and estuaries [3]. There are more than 200 serogroups based on the O antigen of its membrane's lipopolysaccharide. Only two serogroups cause epidemic cholera: O1 and O139. Since Vibrio Cholerae was first observed by Pacini more than 160 years ago, there have been several epidemics, mainly caused by serogroup O1 which may be divided into two biotypes: classical and El Tor. The latter is responsible for the current seventh pandemic and has substituted the classical biotype which is supposed to have caused the previous pandemics [3]. Each biotype is classified in three serotypes: Inaba, Ogawa (the most prevalent) and Hijokima (more rare).