In 2015, a prolific outbreak of mosquito-borne Dengue Fever
struck Southeast Asia. In fact, something was causing outbreaks to pop up all over the world.
So, what happened?
Two to three months earlier, the ocean water in the equatorial
Pacific began to dramatically warm-up resulting in a cascading series
of events that eventually lead to disease outbreaks worldwide.
This warming event is commonly known as El Nino.
The same El Nino that causes heavy rainfall in some parts of the world
and droughts in others, the 2015-2016 El Nino was the strongest seen in the last 50 years.
Here’s what happened:
The El Nino-Southern Oscillation began showing signs of warming in early 2015.
That led to changes in rainfall worldwide which directly impacted land surface temperatures across all continents.
In the case of Southeast Asia, the region actually got less than average rain
which caused the surface of the land to heat up and therefore produce drier conditions.
That drew mosquitoes into populated, urban areas containing open water they needed for laying eggs.
As the air warmed, mosquitoes grew hungrier and reached sexual maturity faster
…which meant more mosquito bites.
The purple columns represent reported incidents of Dengue Fever.
Mosquito-borne epidemics have a lag time of two to three months following these weather changes
which is why the Dengue Amplification Period kicks in several months after land temperature begins heating up.
The good news?
Seasonal forecasts are an early warning system with the real potential to save lives.
With an assist from scientists, countries can take strategic measures to prevent disease outbreaks
…especially when they know they’re coming.