Malaria

Malaria is a mosquito-borne infectious disease caused by protozoan parasites belonging to the genus Plasmodium. Five species account for almost all human infections, with P falciparum being the most severe. When an infected mosquito bites a human, it can introduce the parasite from its saliva into the person's blood. The long lifespan and strong human-biting habit of the Anopheles species that carry malaria are the main reasons for the high incidence of malaria in Africa.  Malaria can be prevented by avoiding mosquito bites and with medicines. Treatments can stop mild cases from getting worse.

Malaria symptoms usually start within 10-15 days of getting bitten by an infected mosquito. Getting tested early is important as some types of malaria can cause severe illness and death. Infants, children under 5 years, pregnant women, travellers, and people with HIV or AIDS are at higher risk. Severe symptoms include extreme tiredness and fatigue, impaired consciousness, multiple convulsions, difficulty breathing, dark or bloody urine, jaundice, and abnormal bleeding.

People with severe symptoms should get emergency care right away. Malaria infection during pregnancy can also cause premature delivery, stillbirth, or delivery of a baby with low birth weight.

WHO recommends that all suspected cases of malaria be confirmed using parasite-based diagnostic testing. Malaria is a serious infection and requires treatment with multiple medicines. The most common medicines are Artemisinin-based combination therapy medicines like artemether-lumefantrine, artesunate+amodiaquine, artesunate+mefloquine, artesunate+sulfadoxine-pyrimethamine, dihydroartemisinin+piperaquine and artesunate+pyronaridine. Primaquine should be added to the main treatment to prevent relapses of infection with the P. vivax and P. ovale parasites. In case of severe disease, people need to go to a health centre or hospital for injectable medicines.

Anopheles stephensi is a major threat to the control and elimination of malaria in Africa, but large-scale surveillance of the vector is needed. An stephensi has been expanding its range over the last decade, with detections reported in Djibouti, Ethiopia, Sudan, Somalia, Nigeria and Ghana. It thrives in urban settings. Countries are encouraged to step up surveillance activities to ensure early detection of this vector.

WHO has been leading efforts to introduce the RTS, S vaccine in African countries with high malaria burden. In 2019, the vaccine was introduced in Ghana, Kenya, and Malawi as part of a pilot program to assess its effectiveness and safety in real-world settings. Following the WHO recommendation for broader use of the malaria vaccine in moderate to high Plasmodium falciparum malaria transmission areas, issued in October 2021, the WHO has supported Ghana and Malawi to expand the vaccine administration in comparator areas. By the end of March 2023, 1.5 million children with RTS, S, and more than 4.1 million doses had been administered since the initial launch in 2019. Malawi launched expansion of RTS, S on 29 November 2022. It was followed by Ghana, which launched the expansion on 20 February 2023. Kenya launched the expansion on 7 March 2023.  At least 28 countries in Africa have expressed interest in introducing the vaccine, with some additional countries to start in early 2024. The unprecedented demand for the first malaria vaccine is considered an opportunity to bring children back to clinics to catch up on missed vaccines and child health interventions – including reinforcing the need for children to sleep under ITNs every night. WHO has also been working with African countries to scale up other proven malaria control interventions, such as insecticide-treated bed nets, indoor residual spraying, intermittent preventive treatment of malaria in pregnant women, seasonal malaria chemoprevention, perennial malaria chemoprevention in young children as well as prompt diagnosis and treatment of malaria cases.

Publications

See all