This summer, a mosquito bite may be a lot worse than annoying. Thanks in part to climate change helping these bugs breed among us in record numbers, there is an uptick in exotic diseases coming to the U.S. Viral diseases like dengue fever, which are typically found in Southeast Asia, Central America, and other tropical regions, are popping up in the Florida Keys, the Texas border with Mexico – a country where dengue is near rampant – and New York, primarily brought in by international travelers who contracted them abroad. "The world is getting smaller, and it can work against us," says Joseph Conlon of the American Mosquito Control Association. "Add rain and increased temperatures [which promote mosquito-breeding habitats], and dengue might be here to stay – with more diseases on the way."
It's impossible to count the exact mosquito population, but climate change has clearly caused it to boom. Standing water in the aftermath of hurricanes, excessive rainfall, and warmer temperatures, which shorten the time it takes for a mosquito egg to mature, are leading to more of these pests.
At present, few vaccines exist to combat the diseases the bugs carry. Either the diseases themselves are so complex that vaccines won't work for the long term or manufacturers haven't perceived a large-enough market in the U.S. to start the costly process of conceiving and testing them. Prevention primarily means buying fitted screens for your windows and doors and stocking up on deet.
On the bright side, extreme climate change could actually end up eradicating some of these problems. "It's wrong to think that things will uniformly get worse," says Dr. John Balbus, an adviser at the National Institute of Environmental Health Sciences. For example, "a drought-filled summer will kill off insects." Still, "we shouldn't be complacent and expect better treatments to pop up in the near future," says Diarmid Campbell-Lendrum, a climate-change scientist at the World Health Organization. "It's the capacity for surprise that's a real concern to us." Here's a look at four diseases that experts are worried may spread in the U.S.