Geography: Sub-Saharan Africa is most at risk; cases also appear in Southeast Asia, Eastern Mediterranean, Western Pacific, and the Americas
Cases Per Year: 228 million
Fatality Rate: 0.02%
First Discovered: 1889 by Alphonse Laveran in Europe
Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitos. Transmission is most intense in places where the mosquito lifespan is longer and where it prefers to bite humans rather than other animals. In many places, transmission is seasonal, with the peak during and just after the rainy season.
In a non-immune individual, symptoms usually appear 10 to 15 days after the infective mosquito bite. The first symptoms are fever, headache, and chills. Without treatment, the infection can progress to severe illness, often leading to death. Children with severe malaria frequently develop severe anemia, respiratory distress in relation to metabolic acidosis, or cerebral malaria. In adults, multi-organ failure is frequent.
Adults in areas of moderate to intense transmission build up partial immunity, which reduces the risk that malaria infection will cause severe disease. Therefore, children under 5 years of age are the most vulnerable group affected by malaria. In 2018, they accounted for 67% (272,000) of all malaria deaths worldwide. In 2018, the African region was home to 93% of malaria cases and 94% of malaria deaths. 6 countries accounted for more than half of all malaria cases worldwide: Nigeria (25%), the Democratic Republic of the Congo (12%), Uganda (5%), Cote d’Ivoire, Mozambique, and Niger (4% each).
Insecticide-treated mosquito nets, indoor residual spraying with insecticides, and antimalarial drugs are used to prevent malaria.
Photo: Malaria Plasmodium sporozoite – Electron micrograph.