Health Advisory: Locally Acquired Malaria Case

The Texas Department of State Health Services (DSHS) has been notified of a case of malaria diagnosed in a Texas resident who has not traveled outside the country or state. Clinicians should consider malaria in patients with fever or other compatible symptoms and a history of mosquito bites and order testing as needed. The public should protect themselves from mosquito bites by using an EPA registered insect repellant, wearing long sleeves and pants, and draining standing water to limit mosquito breeding habitat.

A Texas resident who spent time working outdoors in Cameron County was recently diagnosed with malaria. DSHS has been working with local health departments to follow up on the case and determine whether other people may have been exposed. So far, no other locally acquired malaria cases have been identified in Texas.

Malaria is a serious and potentially fatal disease caused by a protozoan parasite from the Plasmodium genus, which can be transmitted through the bite of a mosquito of the genus Anopheles. Almost all cases of malaria in the United States are imported and occur in people who have traveled to or are coming from countries with ongoing malaria transmission. Occasional locally acquired cases occur in the United States when an Anopheles mosquito bites an infected traveler and then bites someone else. Texas averages more than 120 travel-related malaria cases a year. The last locally acquired Texas case occurred in 1994.

The most common symptoms of malaria are flu-like and include fever, shaking chills, sweats, headache, body aches, nausea, and vomiting and typically start 7 to 30 days after infection. Without treatment, severe malaria can be life-threatening and can cause disorientation, seizures and other neurological symptoms, low red blood cell counts (anemia), acute respiratory distress syndrome, and kidney damage.

• Routinely obtain a travel history to determine whether a symptomatic person spent time outdoors and got mosquito bites in an area with malaria activity.
• Promptly report suspected malaria cases to your local health department.

CDC provides consultations for healthcare providers on diagnosis and management: Contact Us | Parasites | CDC

• Protect yourself from all mosquito-borne diseases by preventing mosquito bites.
  • Wear EPA registered insect repellents whenever you go outside.
  • Cover up with long-sleeved shirts and long pants, especially at night when mosquitos are active.
  • Keep mosquitoes out by keeping doors and windows closed and/or installing window screens.
  • Prevent mosquitoes from breeding by dumping out standing water, keeping gutters clear, covering trash containers, regularly changing water in pet dishes and bird baths, and using mosquito larvicide in water that can’t be drained.
• If you are traveling, check your destination and consult your healthcare provider to see if you should take prescription malaria medication.

• Malaria (DSHS)
• Prevent mosquito-borne disease (DSHS)
• About Malaria | Malaria | CDC 
• Malaria information and prophylaxis by country (CDC): Yellow Fever Vaccine & Malaria Prevention Information, by Country | CDC Yellow Book 2024