How La Niña could affect the spread of Zika
La Niña is characterized by the cooling of ocean surface waters in the equatorial Pacific and affects many of the same regions as El Niño. Based on previous years, this means above-average rainfall and potential flooding in southern Africa, Southeast Asia, and northern South America, and drier than average conditions in eastern Africa and the west coast of South America. There’s a 55 to 60 percent chance La Niña will develop during the upcoming months, according to an August forecast from NOAA. For example, while increased rainfall and flooding can increase mosquito-breeding habitats, people may also spend more time inside and therefore be less susceptible, Lessler said. Conversely, in times of drought people tend to store water. These water containers can concentrate and boost mosquito-human contact, leading to increased rates of infection.
