The Centers for Disease Control and Prevention (CDC) has issued a warning that malaria has spread from mosquitoes to humans inside the US for the first time in 20 years. The CDC stated that four cases of mosquito-transmitted Plasmodium vivax malaria have been reported in Florida during the past two months, with a single case also located in Texas. However, all patients are reportedly improving following treatment. While American Anopheles mosquitoes, which are found across many US regions, can transmit malaria if they feed on an infected person, the risk of contracting malaria in the country is described as "extremely low."
Malaria symptoms can include fever, chills, headache, muscle pain, fatigue, nausea, vomiting, and diarrhoea, according to the CDC. Typically, symptoms begin between ten days and four weeks post-infection, although they can emerge up to one year later.
Transmitted primarily through the bite of an infected female mosquito, malaria affects over 240 million people annually. Although rare, the disease can occur via transmission from a mother to her unborn child, through blood transfusions, or needle-sharing.
Patients suspected of having malaria should have blood and rapid diagnostic tests according to the CDC. Treatment involves taking antimalarial drugs such as chloroquine or at ovaquone and proguanil, depending on the origin of the infection. If ignored, malaria can lead to severe complications such as kidney failure, acute respiratory distress syndrome, seizures, coma, and, ultimately, death.
The CDC recommends preventing mosquito bites to protect against malaria best. This includes wearing long-sleeved clothing and pants that are loose-fitting, using insect repellent that is environmentally-friendly and registered with the EPA, using screens on windows and doors, and removing items that allow mosquitoes to breed.
The last malaria transmission incident reported in the US dates back to 2003 in Palm Beach, Florida. Before Covid, only 2,000 malaria cases were reported each year within the US, with almost all occurring in travelers who had visited areas prone to malaria. Yearly infections result in between five to 10 fatalities annually. Despite the unfavorable news of what appears to be a new malaria transmission cycle, the CDC's reassurance that the risk of catching malaria in the US remains "extremely low" offers much-needed comfort.