Scientists identify origin of current cholera pandemic

A team of scientists has successfully identified the original source of the current global cholera pandemic, a finding that could help scientists understand the mechanisms behind the spread of the disease, the Seoul-based International Vaccine Institute (IVI) said Thursday. By analyzing the genomes of the causative bacterium Vibrio cholera taken from 154 patients across the world over the past 40 years, the team traced the origin of the current cholera pandemic to an ancestor strain that broke out in India four decades ago. The study also suggested there have been at least three waves of intercontinental spread of cholera originating from a common strain that had emerged in the 1950s. "This goes against previous beliefs that cholera always arises from local strains," Julian Parkhill, senior author of the study and an official from the Wellcome Trust Sanger Institute, was quoted as saying. The study was co-authored by Prof. Chun Jong-sik of Seoul National University and IVI scientist Kim Dong-wook. "This study is among the first to link genetic information with emergence of new strains of Vibrio cholera and uses specific changes in the genome of these strains to retrospectively track the global evolutionary spread of cholera," Kim said, according to the IVI. The diarrheal disease affects 3 million to 5 million people each year and claims more than 100,000 lives throughout the world. The latest findings will help scientists understand why and how cholera pandemics begin and then spread as a wave across the world, which, in due course, may also help prevent the spread of the disease, the IVI said in a news release.