According to a new study to be published in mBio®, the online open-access journal of the American Society for Microbiology, the strains of cholera that has sickened thousands in Haiti came from single source.
The results of this latest study are consistent with earlier findings that Vibrio Cholerae bacteria were introduced to Haiti by Nepalese solider working as United Nation Soliders between July and October 2010. This study is the latest study which attributed Nepalese solider behind Haiti cholera epidemic.
The genome sequences of V. cholerae strains from Haiti reveal they have not gained any new genetic material since their introduction and that they have a limited ability to acquire genes from other organisms through a process called transformation.
Cholera disease had never before been documented in Haiti until 2010 and the cholera outbreak of 2010 killed tens of thousands of Haitians.
Studies of the outbreak indicate that poor sanitation at a United Nations camp resulted in sewage contamination of local water supplies, and phylogenetic analysis of the Haiti V. cholerae strains and strains from around the globe indicate the strain was most likely accidentally brought to the camp by U.N. troops from Nepal.
This result indicates that “Nepalese isolates are the closest relatives to the Haiti strain identified to date, even when placed into a phylogeny with a larger collection of isolates representing recent cholera epidemics,” write the authors. This means that the outbreak originated from a single introduction of bacteria, and PFGE variants arose from gradual evolution of the organisms, not from any secondary introduction.
The article can be found online at http://bit.ly/mbiotip0712a.