Malaria Making a Comeback in America?

Malaria was eliminated as an ongoing public-health problem in the continental United States in the early 1950s, but imported infections continue to occur. Locally acquired cases remain uncommon, yet they demonstrate that the country is still susceptible when an infected traveler and a capable mosquito population are present in the same area.

Can malaria spread locally in the United States?

Yes. The Centers for Disease Control and Prevention reported ten locally acquired mosquito-transmitted malaria cases across four states in 2023 after approximately two decades without reported local transmission. Read the CDC’s 2026 operational guidance for locally acquired malaria.

How can an international traveler lead to local malaria transmission?

A person can acquire malaria abroad and return to the United States while carrying the parasite. If a local Anopheles mosquito bites that person, becomes infected, and later bites someone else, limited local transmission can occur. The CDC identifies an imported or travel-associated infection as a likely starting point for this type of event.

Are most malaria cases in the United States locally acquired?

No. Most U.S. cases are associated with international travel. Local transmission is unusual, but the combination of imported cases and mosquito species capable of carrying malaria means health departments must remain prepared to investigate quickly.

What symptoms should travelers recognize after returning home?

Possible symptoms include fever, chills, headache, fatigue, nausea, and other flu-like symptoms. Malaria can become severe if diagnosis and treatment are delayed. A person who becomes ill after travel to an area where malaria occurs should promptly tell a healthcare professional about the travel history.

How can travelers reduce the risk of malaria?

Depending on the destination, a healthcare professional may recommend preventive medication before, during, and after travel. Travelers may also reduce mosquito exposure by using an appropriate repellent, wearing protective clothing, sleeping in screened or air-conditioned spaces, and following destination-specific public-health guidance.

How do health departments respond to a locally acquired malaria case?

Public-health agencies investigate the likely source, arrange diagnostic testing and treatment, identify other possible cases, increase mosquito surveillance, and use targeted mosquito-control measures when appropriate. Rapid reporting is important because early action can prevent a limited transmission event from expanding.

Is malaria making a widespread comeback in America?

Current evidence does not show widespread continuous transmission across the United States. The more accurate conclusion is that malaria can be reintroduced and that surveillance, travel awareness, mosquito control, and timely diagnosis remain necessary.

For a related discussion of prevention and health-system costs, read how better health habits may lower healthcare spending.

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