Mosquito-borne diseases transmitted by parasites
Malaria
Malaria does not regularly occur or spread in the U.S., however there are cases reported. In a typical year, the U.S. reports about 2,000 cases of malaria. Most of these cases are in people who contract malaria while traveling to another country where malaria spreads and return to the U.S. On rare occasions, local transmission occurs because of an imported case of malaria (local mosquitos bite persons infected with malaria and then transfer it to the next person they bite).
Malaria symptoms may be very mild but can also be severe or fatal. Early symptoms can include fever and flu-like illness, chills, headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur. If not treated quickly, the infection can become severe and result in kidney failure, seizures, mental confusion, or coma.
A confirmed diagnosis of malaria requires a blood test. Prescription drugs can treat and cure malaria. Types of drugs and length of treatment depends on the type and severity of malaria.
Malaria can be prevented with prophylactic medication that is started prior to travel and continues after return from a high threat area. CDC recommends these safe and effective preventive medications for those travelling to an area where malaria is common. The military primarily uses a medication commercially known as Malarone to prevent malaria
.
Filariasis
Lymphatic filariasis, sometimes called LF, is caused by microscopic worms transmitted into a person by a mosquito (acquired when it ingested blood from an infected person).
Most people infected with the worms that cause filariasis never show symptoms. Others may not develop symptoms until many months or even years after initial infection with the parasite. Symptoms, if they occur, can include:
- Lymphedema (a swelling of the legs, arms, breasts, or genitalia)
- Swelling in the scrotal sac, usually of adult men
- Hardening or thickening of skin
- Persistent coughing, wheezing, or shortness of breath
- Bacterial infections of the skin or lymph system
Diagnosis of filariasis requires blood tests to identify the microscopic worms and look for antibodies. Healthcare providers typically prescribe a drug treatment for this disease.
Mosquito-borne diseases transmitted by viruses
Viruses carried by mosquitoes can cause some of the
Arboviruses such as JEV, Chikungunya, Dengue, Yellow Fever, West Nile Virus, and Zika.
Threat locations
According to the CDC and the World Health Organization, most mosquito-borne diseases are found in tropical and sub-tropical areas of the world, but malaria was once endemic in the United States as far north as Maryland, and
recent (2023) locally acquired malaria cases have occurred in the U.S. Mosquito-borne disease risk is higher where there is poor sanitation of water (bathing or drinking) or food sources. Most urban areas have low risk for malaria, but there are exceptions.
Military health surveillance data has found that
malaria and dengue are currently the most commonly reported mosquito-borne VBDs.
Be aware of different types of mosquito threats
Different species of mosquitos are vectors for different diseases. Examples:
-
Anopheles mosquitos are the primary carrier of the parasites for Malaria and Filariasis.
-
Aedes mosquitos known for transmitting Yellow Fever and Dengue.
Different mosquito species can also have different exposure threats. For example, dengue-bearing
Aedes mosquitos tend to bite during the day, while malaria-bearing
Anopheles mosquitos bite mostly at night.
Additional sources
