GREENSBORO, N.C. — Summer might be winding down, but mosquitoes haven’t gotten the memo. They’re still out there biting, and in some cases spreading diseases, including one that hasn’t spread in the U.S. in 20 years.
Malaria was virtually wiped out in the U.S. in the 1950s, but this summer the Centers for Disease Control and Prevention announced nine cases of “locally acquired malaria.” That means the people infected had not traveled to areas where malaria is common.
"The most likely scenario is that a mosquito bit someone who was infected in a foreign country and then traveled back to the U.S., and then that mosquito bit another person, spreading the infection to them," said Catherine Roberts of Consumer Reports.
At least seven people in Florida, two in Texas, and one in Maryland tested positive for what is believed to be locally acquired malaria.
"The other more worrisome but less likely scenario is that the U.S. has a previously undetected new strain of malaria-infected mosquitoes," said Roberts.
Symptoms of Malaria
The most common symptoms are flu-like and include fever, shaking chills, sweats, headache, body aches, nausea, and vomiting, and typically start seven to 30 days after infection.
Why is malaria returning now? According to Consumer Reports, there has always been the case that malaria could become reestablished in the U.S. because the mosquitoes that transmit it are common here. Factors like a warming climate and increasing global travel can make the environment friendlier to mosquitoes and the diseases they carry.
Still, public health measures have had a good track record of stopping malaria transmission in the U.S.
Despite these new cases, the risk of locally acquired malaria in the U.S. is extremely low, while other mosquito-borne infections like West Nile are far more common, and can be dangerous.
Your best bet is to prevent mosquito bites before they happen.
Always use a safe, effective insect repellent. Consumer Reports tests show the most effective repellents include those that contain 25% to 30% deet. The top picks are:
3M Ultrathon Insect Repellent8
Ben’s Tick and Insect Repellent Wilderness Formula Pump
It’s also important to keep mosquitoes away from your yard. Keep your space free of containers filled with water, and keep your lawn mowed and free of leaves and other debris. And you’ll lessen your risk of getting bitten when you avoid going outside at prime feeding times: That’s dawn and dusk.