The South Asian Times

22 March 2019 04:32 AM

El Nino may transport cholera-like diseases: Study


London, March 2: El Nino, the climate cycle that develops along the tropical west coast of South America every 3 to 7 years, could be transporting cholera-like diseases through bacteria that thrive in seawater, a study said.

A team of international researchers observed that reported illnesses caused by waterborne bacteria in Latin America seemed to be moving in tandem with when and where warm El Nino waters made contact with the land.

Drawing on new data derived from whole genome sequencing of bacterial strains, they suggested there were links between organisms that were causing illnesses in Asia with those that emerged in South America.

The study, published in the journal Nature Microbiology, found that over the past 30 years, coinciding with the last three significant El Nino events, new variants of waterborne pathogens emerged in Latin America.

The study linked the phenomenon with the 1990 cholera outbreak in Peru that claimed over 13,000 lives, and two instances in 1997 and 2010 where new variants of the bacterium Vibrio parahaemolyticus led to a widespread human illness through contaminated shellfish.

"Through our findings we suggest that so-called vibrios, microscopic bacteria commonly found in seawater, can attach to larger organisms such as zooplankton to travel oceans," said lead author Dr Jaime Martinez-Urtaza from the University of Bath.

"The effects of El Nino events and their impacts on local weather, fisheries and the risk of more extreme meteorological events are already well documented. Understanding the role, the ocean currents are playing in transporting these diseases, has a huge significance for public health campaigns in those countries," he added.

"An El Nino event could represent an efficient long-distance 'biological corridor', allowing the displacement of marine organisms from distant areas," said study co-author Dr Craig Baker-Austin from Britain's Centre for Environment, Fisheries and Aquaculture.

"This process could provide both a periodic and unique source of new pathogens in America with serious implications for the spread and control of diseases," he warned.

Update: 02 March, 2016