Causative Organism is Vibrio Cholera
There are more than 60 serogroups of vibrio cholerae, but only sero group 01 and 0139 cause cholera.

V. Cholerae 01 occurs as two biotypes-classical and EL Tor. Each biotype also further divided each into three serological types Inaba, Ogawa and Hikojima.

Almost all the recent cholera have been caused by the EL Tor biotype.

In Maharashtra 01 and 0139 sero groups causing cholera biotype is found in sporadic form.

The vibrio is destroyed in an acidity of pH 5 or lower. Conditions that reduce gastric acidity may influence individual susceptibility.

V. Cholerae are killed within 30 minutes by heating at 56 degree.Celsius or within a few seconds by boiling. They remain in ice for 4 to 6 weeks or longer. They are easily destroyed by disinfectants such as cresol. Bleaching powder is another good disinfectant which kills vibros instantly at six miiligram per litre.

Human being is the only known reservoir of cholera infection.

The immediate source of infection are stools and vomit of cases and carriers.