Since 1817, it has spread worldwide to cause seven pandemics. Between outbreaks, the organism thrives in brackish waters in both harmless and disease-causing forms. Besides contributing to our understanding of how a microbe causes disease and survives in the environment, sequencing studies enable scientists to locate genes that may lead to potential new targets for vaccine candidates, drugs and diagnostic tools. When the team became aware of new research indicating that cholera strains may have two chromosomes, they rapidly assembled the final sequence into two separate elements. Besides illuminating the bacterium's role in disease, the sequence information will enable scientists to investigate specific questions about how V. cholerae survives and persists in the environment, which it sometimes does by colonizing algae and other sea life.
Cholera has a rapid onset and most often occurs in epidemics spread through contaminated water.
Oral rehydration is an effective treatment, but left untreated, cholera causes severe diarrhea that has a high mortality rate, particularly in young children. According to information reported to the World Health Organization in 1999, nearly 8,500 people died and another 223,000 were sickened with cholera worldwide.