How concerned should Minnesotans be about malaria’s spread?

ST. PAUL, Minn. – Not much was bugging a trio of disc golfers Tuesday at Acorn Park in Roseville. The drought has dried up the marshes where mosquitoes thrive along the wooded course. But they’ve also experienced the opposite.

“I’ve had times where I don’t even finish disc golfing,” one of them said about getting pestered by mosquitoes.

The bites are annoying, but the diseases they carry can be concerning. For the first time in 20 years, the CDC confirmed malaria has spread within the U.S. Four cases were in Florida and one in Texas.

Normally when someone in the U.S. has malaria, they caught it while traveling to a continent or country where the disease is present, such as parts of South America, Africa and Southeast Asia.

“In this case in Florida and Texas where there’s been some transmission, it’s a situation where someone has come in with the malaria infection, the parasite’s active within their system and then being fed upon by a local mosquito,” said Kirk Johnson, a vector ecologist with the Metro Mosquito Control District. 

Malaria confirmed in Florida mosquitoes after several human cases

The mosquito then carries the malaria parasite, transferring it to anyone else it bites.

Should people be concerned about malaria spreading in the U.S.?

“Usually if there’s a mosquito-borne illness active in an area, there’s a pretty immediate mosquito control response, public health response to inform citizens,” Johnson said. “So, the likelihood of this continuing to spread is fairly low, even in warm Florida.”

Getting sick with malaria feels like the flu. Mild symptoms include headache, fever, and muscle aches.

Severe symptoms include changes in mental status, lung and kidney failure. It can be deadly if not treated.

According to the CDC, about 2,000 cases of malaria are diagnosed in the U.S. each year, with the vast majority being travelers or immigrants coming from a country where the disease is endemic.  

The World Health Organization estimates that in 2020, there were 241 million cases of malaria worldwide. About 627,000 people died from it, most of them children in Africa.

When was the last time, if ever, there were malaria cases in Minnesota? 

“There were cases documented up through the 1880s, but it was eradicated from the northern part of the U.S. around the turn of the century and in the rest of the U.S. between 1930 and 1950,” Johnson said.

There are mosquito species across the country still capable of carrying the disease, including in Minnesota. But Johnson doesn’t want people to worry.

“We do have introduced malaria cases in Minnesota nearly every year and we still haven’t seen local transmission. That’s how rare it would be in Minnesota,” he said.

Science-backed tricks to keep mosquitoes out of your yard

However, if you are traveling to Texas, Florida, or a country where malaria is present, the key is protecting yourself.

“Any common sense mosquito prevention efforts will go a long way towards reducing malaria risk,” Johnson said. 

Insect repellent that includes DEET, wearing pants and long sleeves, and closing windows to keep bugs out can help limit mosquito bites.

It takes between 10 days and four weeks for symptoms to start after getting malaria. The five people who caught disease within the U.S. have received treatment and are improving.