Department of Health reports travel-related malaria case in Hawai‘i

The Hawai‘i Department of Health has received one report of a travel-related malaria case in Honolulu County.

The individual diagnosed with malaria had recent travel to a country where malaria is commonly found. The case was investigated by the Disease Outbreak Control Division and is pending a site assessment by the Vector Control Branch.

There is generally no risk of transmission in Hawai‘i, as the type of mosquito that is capable of transmitting malaria to humans is not known to be present within the state.

Separately, the Center for Disease Control reported a single case of locally acquired malaria in the National Capital Region in August 2023. This is in addition to reports in June of locally acquired malaria cases in Sarasota County, Florida. and Cameron County, Texas.

Prior to these cases, the last locally acquired mosquito-borne malaria case in the United States was in 2003. There is no evidence that cases in the affected counties or in Hawai‘i are connected. These cases do not raise the risk of local transmission in the state or to other areas outside the reported counties.

Malaria is a unique mosquito-borne disease caused by a parasite and is transmitted through female anopheles mosquitoes often found in tropical and subtropical areas such as in Africa south of the Sahara and parts of Oceania such as Papua New Guinea. Anopheles mosquitoes are not found in Hawai‘i. Malaria is not spread from person to person and is not sexually transmitted. The incubation period is typically from seven to 30 days.

Symptoms of malaria may include fever, chills, headache, myalgias, and fatigue. Nausea, vomiting, and diarrhea may also occur. For most people, symptoms begin 10 days to four weeks after infection, although a person may feel ill as early as seven days or as late as one year after infection. If not treated promptly, malaria may progress to severe, life-threatening disease. Antimalarial drugs are available and can be taken for treatment.

If you have traveled to any location experiencing local malarial transmission, and you have symptoms of malaria, you are advised to seek medical attention immediately to be evaluated for the disease. Be sure to advise your medical provider of your travel history. The disease is diagnosed with a laboratory test which can be ordered by your medical provider.

Avoiding mosquito bites is the best practice to prevent mosquito-borne illnesses. Mosquito bite prevention includes wearing light-colored, long-sleeved tops and long pants, using insect repellent, keeping windows or doors closed or covered with screens to keep mosquitos out of your living quarters. Prevent standing water from collecting around the home and workplace to prevent mosquitos from laying eggs.