Malaria is a serious disease caused by a parasite that spreads to humans primarily through the bites of infected female Anopheles mosquitoes. It is mostly found in tropical and subtropical regions. Globally, there were an estimated 263 million malaria cases and 597,000 deaths in 2023, impacting half of the world’s population. The majority of these cases and deaths occur in the African Region, with children under five years old being particularly susceptible. Addressing and eliminating this disease involves recognizing its signs, pursuing effective medical care, and implementing personal and large-scale protective measures.
Identifying Malaria: The First Step
Recognizing malaria symptoms is the first step. Common early symptoms often resemble the flu, including fever, chills, headache, muscle aches, and fatigue. Individuals may also experience nausea and vomiting. Symptoms can appear anywhere from 7 to 30 days after an infected mosquito bite, though in some instances, they might take up to a year to manifest.
Seeking immediate medical attention is important, especially after recent travel to malaria-prone areas. A healthcare provider will review medical history, conduct a physical examination, and perform blood tests to detect malaria parasites.
Two types of blood tests are used for diagnosis: microscopic examination of blood smears and rapid diagnostic tests (RDTs). Blood smears involve examining a drop of blood under a microscope to identify parasites and distinguish Plasmodium species. RDTs detect specific proteins produced by malaria parasites, providing results in under 15 minutes. While RDTs offer quick results, a blood smear is still needed to confirm the parasite type and quantify the infection, which guides treatment decisions.
Treating an Active Malaria Infection
Antimalarial medications eliminate the parasite from the body. The choice of drugs depends on several factors, including the specific Plasmodium parasite causing the infection, illness severity, patient age, and pregnancy status. Five Plasmodium species can infect humans: P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi. P. falciparum is the deadliest and most common in Africa, while P. vivax is prevalent outside sub-Saharan Africa.
Artemisinin-based combination therapies (ACTs) are the standard treatment for uncomplicated P. falciparum malaria, especially where chloroquine resistance is present. ACTs combine two or more drugs that target the malaria parasite through different mechanisms, such as artemether-lumefantrine or atovaquone-proguanil. These combinations prevent or delay drug resistance. For P. malariae and P. knowlesi infections, chloroquine can still be effective in many areas, or regimens for chloroquine-resistant P. falciparum can be applied.
P. vivax and P. ovale infections require additional treatment to address dormant forms of the parasite, known as hypnozoites, which can remain in the liver and cause relapses. Medications like primaquine phosphate or tafenoquine are used to eradicate these liver-stage parasites. It is important to complete the full course of treatment, even if symptoms improve, to ensure all parasites are cleared and to prevent the development of drug resistance.
Supportive care plays a role in managing malaria, particularly in severe cases. This includes managing fever, addressing dehydration, and monitoring for complications such as severe anemia or respiratory issues. Hospitalization may be necessary for close monitoring of clinical response and parasite levels, especially for P. knowlesi infections due to their potential for severe outcomes.
Individual Measures to Avoid Re-infection
Preventing future malaria infections is an important personal health goal. Individuals can significantly reduce their exposure to infected mosquitoes through several protective measures. Consistent use of insecticide-treated bed nets (ITNs) is an effective strategy, especially during sleeping hours when Anopheles mosquitoes are most active. These nets create a physical barrier and kill mosquitoes that come into contact with the insecticide.
Applying insect repellents to exposed skin is another layer of protection. Repellents containing active ingredients like DEET, picaridin, or IR3535 are recommended for effective mosquito deterrence. It is important to apply these products according to label instructions, covering all exposed skin but avoiding over-application, and washing them off after returning indoors. Wearing protective clothing, such as long-sleeved shirts and long pants, further minimizes skin exposure to mosquito bites.
Protecting living spaces can reduce the risk of bites, including using screens on windows and doors to prevent mosquitoes from entering homes. For individuals traveling to high-risk malaria areas or for those in endemic regions, chemoprophylaxis may be recommended. This involves taking preventive medication before, during, and after potential exposure to suppress the malaria parasite and prevent disease development. While effective, these preventive medications do not offer complete protection, underscoring the importance of combining them with bite avoidance measures.
Community and Global Efforts to Eradicate Malaria
Beyond individual actions, community and global strategies aim to reduce and eliminate malaria. Large-scale vector control programs are fundamental to these efforts, controlling mosquito populations that transmit the disease. Two key interventions are widely deployed: indoor residual spraying (IRS) and the distribution of insecticide-treated bed nets (ITNs). IRS involves applying insecticide to the internal surfaces of homes, killing mosquitoes that rest on treated walls. ITNs have significantly contributed to reducing global malaria incidence, with billions distributed to endemic countries.
Supplementary vector control measures, such as larval source management, target mosquito larvae in their breeding habitats. This can involve eliminating standing water or applying larvicides to water bodies where mosquitoes lay eggs. These efforts are particularly useful in areas where larval habitats are limited and identifiable, complementing adult mosquito control. Surveillance and response systems are also implemented to track malaria cases, identify outbreaks, and quickly deploy interventions to contain transmission.
The development and deployment of new tools, including malaria vaccines, significantly advance global eradication efforts. Since 2021, the RTS,S/AS01 malaria vaccine has been recommended for broad use among children in regions with moderate to high P. falciparum malaria transmission. This vaccine has demonstrated significant reduction in malaria cases and severe disease in young children. These collaborative efforts, involving health organizations, governments, and communities, aim to continuously reduce the burden of malaria and move towards a future free from the disease.