Malaria is a serious illness caused by parasites spread to people through mosquito bites. This disease poses a substantial public health challenge globally, particularly in tropical and subtropical regions. In 2022, there were an estimated 249 million cases of malaria worldwide, resulting in approximately 608,000 deaths. The disease also has significant economic impacts, especially in low-income countries where it is most prevalent.
How Malaria Spreads
Malaria transmission occurs when an infected female Anopheles mosquito bites a human. These mosquitoes become infected with Plasmodium parasites by feeding on the blood of a person who has malaria. The parasites then develop inside the mosquito and are transmitted to another human when the mosquito bites again.
Five Plasmodium species commonly cause malaria in humans: Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, and Plasmodium knowlesi. Plasmodium falciparum is the most prevalent and causes the majority of severe cases and deaths, especially in sub-Saharan Africa. Malaria is not spread directly from person to person, unlike common illnesses such as colds or the flu.
Recognizing Malaria
Symptoms of malaria appear 10 to 15 days after an infected mosquito bite. The initial signs can be mild and resemble a flu-like illness, making them difficult to recognize. Common symptoms include fever, chills, sweating, headaches, muscle aches, fatigue, nausea, vomiting, and diarrhea.
These symptoms occur in cycles, corresponding to the parasite’s life cycle within the human body. Severe malaria can develop rapidly, often within 24 hours if not treated, and presents with serious signs such as impaired consciousness, seizures, severe anemia, and respiratory distress. Immediate medical attention is necessary if these severe symptoms appear, as they can lead to multi-organ failure and death.
Identifying Malaria
A diagnosis of malaria requires laboratory testing, as self-diagnosis is not possible. The primary method involves examining a blood sample under a microscope to detect malaria parasites; this is known as a blood smear. This method allows for identification of the specific Plasmodium species and the parasite density.
Rapid diagnostic tests (RDTs) offer another way to quickly confirm a malaria infection by detecting specific malaria antigens in a person’s blood. RDTs are particularly useful in areas where microscopic examination is not readily available. While RDTs can quickly indicate malaria, microscopic confirmation is considered the gold standard for diagnosis.
Treating Malaria
Malaria is a treatable disease, with treatment protocols varying based on the parasite species, infection severity, and patient factors like age or pregnancy status. Antimalarial drugs are the main form of treatment. Artemisinin-based combination therapies (ACTs) are recommended for Plasmodium falciparum malaria, especially in cases resistant to older drugs like chloroquine.
Other antimalarial medications include chloroquine, mefloquine, atovaquone-proguanil, quinine sulfate, and primaquine phosphate. Individuals must complete the entire course of prescribed medication, even if symptoms improve, to ensure all parasites are eliminated and to prevent recurrence or drug resistance. Supportive care, such as managing fever and hydration, is also provided for severe cases.
Preventing Malaria
Preventing malaria involves a combination of personal protective measures and broader public health interventions. Personal strategies include using insect repellent containing DEET, IR3535, or Icaridin, wearing long-sleeved clothing and pants, and sleeping under insecticide-treated bed nets (ITNs). For individuals traveling to areas where malaria is common, taking antimalarial prophylaxis (preventive medication) as prescribed by a healthcare provider is also an option.
Vector control methods, such as indoor residual spraying (IRS) with insecticides and environmental management to reduce mosquito breeding sites, play a role in community-level prevention. The development of malaria vaccines is an advancement. The RTS,S/AS01 and R21/Matrix-M vaccines are recommended by the World Health Organization (WHO) for use in children living in moderate to high Plasmodium falciparum malaria transmission areas. These vaccines, administered in a schedule of four doses, aim to reduce malaria illness and deaths in young children.