Malaria

疟疾

Evidence-backed information EN 5/7 applicable sections · ZH 5/7 applicable sections Updated Oct 23, 2026

Malaria is a life-threatening yet preventable and curable parasitic disease found mainly in tropical countries, with an estimated 282 million cases and 610,000 deaths across 80 countries in 2024 ^[1]^[2]. The WHO African Region bears the overwhelming share of this burden, accounting for about 95% of both cases and deaths ^[1]^[2]. Young children, pregnant women, travellers, and immunocompromised persons face the highest risk of severe illness ^[1]^[3].

Read the full clinical and epidemiological profile 6

Definition

Malaria is an acute febrile illness caused by Plasmodium parasites, which are transmitted to humans through the bites of infected female Anopheles mosquitoes ^[3]^[2]. It is a life-threatening but preventable and curable condition that is not contagious between people ^[1]^[3]. Five parasite species infect humans, with P. falciparum and P. vivax representing the greatest threat ^[3]^[2].

Clinical features

Initial manifestations are often mild and nonspecific, including fever, chills, and headache, which can make early recognition difficult ^[1]^[2]. Without timely treatment, especially from P. falciparum, the disease may advance to severe forms with fatigue, confusion, seizures, or breathing difficulty within 24 hours ^[1]^[2]. Severe malaria frequently involves cerebral complications, respiratory distress, or severe anaemia, with fatal outcomes reported in a substantial proportion of affected children and adults ^[4].

Epidemiology

Globally in 2024, malaria caused an estimated 282 million cases and 610,000 deaths across 80 nations ^[1]^[2]. The WHO African Region carried approximately 95% of cases (265 million) and deaths (579,000), while South-East Asia, Eastern Mediterranean, Western Pacific, and Americas also reported meaningful case counts ^[1]^[2]. Children under five accounted for roughly 75% of malaria deaths in the African Region ^[1]^[2]. Nearly half the world's population was at risk of infection in 2024 ^[2].

Transmission

The disease spreads to people principally through bites of infected female Anopheles mosquitoes, of which around 40 of over 400 species act as vectors ^[1]^[3]. It is not transmitted person-to-person, though rare routes include blood transfusion and contaminated needles ^[1]. Transmission intensity varies by locality and season, peaking during rainy periods in tropical settings ^[3].

Prevention

Avoidance of mosquito bites combined with appropriate medicines forms the basis of prevention ^[1]. Travellers to endemic areas should consult a medical professional weeks ahead of departure so that suitable chemoprophylaxis is selected, with some regimens requiring initiation two to three weeks before travel ^[1]. Prophylactic drugs must be taken for the full stay and continued for four weeks after last possible exposure, since liver-stage parasites may emerge later ^[1].

References

1 World Health Organization. Malaria [Internet]. cited 3 Sept 2026. Available from: https://www.who.int/news-room/fact-sheets/detail/malaria
2 World Health Organization. Malaria [Internet]. cited 3 Sept 2026. Available from: https://www.who.int/health-topics/malaria
3 World Health Organization. Malaria [Internet]. cited 3 Sept 2026. Available from: https://www.who.int/news-room/questions-and-answers/item/malaria
4 Omari AA et al. Malaria: severe, life-threatening. BMJ Clin Evid. 2007 Jul 1. PMID: 19454095. PubMed: https://pubmed.ncbi.nlm.nih.gov/19454095/