Jun 27, 2023 - Health

U.S. malaria cases reported for first time since 2003

Female Aedes aegypti mosquito in the process of seeking out a penetrable site on the skin surface of the human host, 2006.

A mosquito seeking out a penetrable site on a person's skin surface. Photo: Centers for Disease Control/James Gathany via Smith Collection/Gado/Getty Images

Malaria has been spread by mosquitos locally in the U.S. for the first time in 20 years, per a Centers for Disease Control and Prevention alert issued Monday.

Driving the news: Four people in Sarasota County, Florida, and a person in Cameron County, Texas, contracted the potentially deadly disease over a period from late May to late June through local transmission, according to the CDC. "All patients have received treatment and are improving," per a CDC statement.

  • The Florida Department of Health in a statement Monday urged residents throughout the state to "take precautions by applying bug spray, avoiding areas with high mosquito populations, and wearing long pants and shirts when possible — especially during sunrise and sunset when mosquitos are most active."

The big picture: Some 2,000 malaria cases are typically diagnosed in the U.S. every year, but the CDC noted these infections were contracted in other countries.

  • People can contract the disease if they're bitten by a mosquito carrying malaria parasites.
  • The last U.S. outbreak occurred in 2003 in Palm Beach County, Florida, when eight malaria infections were confirmed.

What they're saying: "It's not panic time," said Brian Grimberg, an associate professor of pathology and international health at Case Western Reserve University, per the Washington Post.

  • "I think the message is to be aware," Grimberg added. "Americans never think about malaria unless they travel abroad."

Go deeper: "Mosquito days" are getting more common nearly nationwide

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