West Nile virus hasn’t spread because of climate change.
“Climate change is not going to invent any new diseases; it’s going to make controlling existing diseases harder,” said Diarmid Campbell-Lendrum, head of the climate change team at the World Health Organization’s headquarters. “We’ve been describing the links between climate change and health for quite a long time.”
Diseases spread by mosquitoes are particularly affected by climate change, since the insects lay their eggs in standing water, be it in puddles, ponds, lakes or tide pools. Standing water varies with rainfall, humidity and temperature, with wetter weather typically showing a greater number of mosquitoes. When a female mosquito matures, she can spread infections by drawing blood from an infected host and transmitting the illness to a different host with another bite.
But mosquitoes aren’t affected by climate change — they thrive in any environment regardless of temperature where there is:
- Standing water from poor stormwater management; and
- Poor vector control (i.e., no pesticide use).