Malaria is an acute febrile illness caused by Plasmodium parasites, which are spread to people through the bites of infected female Anopheles mosquitoes.
There are 5 parasite species that cause malaria in humans, and 2 of these species - P.
falciparum and P.
vivax - pose the greatest threat.
is the deadliest malaria parasite and the most prevalent on the African continent.
vivax is the dominant malaria parasite in most countries outside of sub-Saharan Africa.
The first symptoms - fever, headache and chills - usually appear 1015 days after the infective mosquito bite and may be mild and difficult to recognize as malaria.
Left untreated, P.
falciparum malaria can progress to severe illness and death within a period of 24 hours.
In 2020, nearly half of the world's population was at risk of malaria.
Some population groups are at considerably higher risk of contracting malaria and developing severe disease: infants, children under 5 years of age, pregnant women and patients with HIV/AIDS, as well as people with low immunity moving to areas with intense
malaria transmission such as migrant workers, mobile populations and travellers.
According to the latest World malaria report, there were 241 million cases of malaria in 2020 compared to 227 million cases in 2019.
The estimated number of malaria deaths stood at 627 000 in 2020 - an increase of 69 000 deaths over the previous year.
While about two thirds of these deaths (47 000) were due to disruptions during the COVID-19 pandemic, the remaining one third of deaths (22 000) reflect a recent change in WHO's methodology for calculating malaria mortality (irrespective of COVID-19 disruptions).
The new cause-of-death methodology was applied to 32 countries in sub-Saharan Africa that shoulder about 93% of all malaria deaths globally.
Applying the methodology revealed that malaria has taken a considerably higher toll on African children every year since 2000 than previously thought.
The WHO African Region continues to carry a disproportionately high share of the global malaria burden.
In 2020 the Region was home to 95% of all malaria cases and 96% of deaths.
Children under 5 years of age accounted for about 80% of all malaria deaths in the Region.
Four African countries accounted for just over half of all malaria deaths worldwide: Nigeria (31.9%), the Democratic Republic of the Congo (13.2%), United Republic of Tanzania (4.1%) and Mozambique (3.8%).
Over the last 2 decades, expanded access to WHO-recommended malaria prevention tools and strategies - including effective vector control and the use of preventive antimalarial drugs - has had a major impact in reducing the global burden of this disease.
Vector control is a vital component of malaria control and elimination strategies as it is highly effective in preventing infection and reducing disease transmission.
The 2 core interventions are insecticide-treated nets (ITNs) and indoor residual spraying (IRS).
Progress in global malaria control is threatened by emerging resistance to insecticides among Anopheles mosquitoes.
According to the latest World malaria report, 78 countries reported mosquito resistance to at least 1 of the 4 commonly-used insecticide classes in the period 20102019.
In 29 countries, mosquito resistance was reported to all main insecticide classes.
Preventive chemotherapy is the use of medicines, either alone or in combination, to prevent malaria infections and their consequences.
It includes chemoprophylaxis, intermittent preventive treatment of infants (IPTi) and pregnant women (IPTp), seasonal malaria chemoprevention (SMC) and mass drug administration (MDA).
These safe and cost-effective strategies are intended to complement ongoing malaria control activities, including vector control measures, prompt diagnosis of suspected malaria, and treatment of confirmed cases with antimalarial medicines.
Since October 2021, WHO also recommends broad use of the RTS,S/AS01 malaria vaccine among children living in regions with moderate to high P.
falciparum malaria transmission.
The vaccine has been shown to significantly reduce malaria, and deadly severe malaria, among young children.