New reporting from Grist finds that although the world’s climate has been “dominated by a natural cycle called La Niña” in the past few years––an oceanic phenomenon which results in lower average temperatures worldwide––experts predict that its opposite, El Niño, will take effect sometime this year. The El Niño cycle temporarily causes warmer temperatures and increased precipitation, and will likely result in increased disease spread. 

ZOYA TEIRSTEIN; zteirstein@grist.org 
    Teirstein is a staff writer at Grist, a climate change magazine. She covers the impacts of rising temperatures on human health.

Teirstein told the Institute for Public Accuracy that in the last three years, we have lived under La Niña’s cooling effects. But the climate makeup of the planet is about to change, Teirstein warned, and the arrival of El Niño may “speed up the record-breaking weather events” associated with climate change by creating “above average temperatures on the ocean and on land.” 

Teirstein noted that because “ticks and mosquitoes thrive in warmer conditions,” El Niño is associated with a rise in tick-borne illnesses, dengue fever, and malaria. Some vulnerable regions may also see increases in the spread of cholera, a water-borne disease that is most prevalent in nations without access to sanitation infrastructure. Warmer waters also lead to increases in algae, which can be home to toxic cyanobacteria, as well as the spread of shellfish-related illnesses. 

She added: “Experts told me that places like coastal Venezuela and Brazil” are particularly at-risk of increased malaria spread. A 2003 study found that those regions saw spikes in malaria during and after El Niño years. Other regions where mosquitoes may proliferate more widely, like Colombia, India, Pakistan, and Peru, will also likely be affected.