Five species of malaria can infect and be transmitted by humans. Severe disease is largely caused by Plasmodium falciparum while the disease caused byPlasmodium vivax, Plasmodium ovale, and Plasmodium malariae is generally a milder disease that is rarely fatal. Plasmodium knowlesi is a zoonosis that causes malaria in macaques but can also infecthumans.
Malaria transmission can be reduced by preventing mosquito bites by distribution of mosquito nets and insect repellents, or by mosquito-control measures such as spraying insecticides anddraining standing water (where mosquitoes breed). Despite a clear need, no vaccine offering a high level of protection currently exists. Efforts to develop one are ongoing. A number of medicationsare also available to prevent malaria in travelers to malaria-endemic countries (prophylaxis).
A variety of antimalarial medications are available. Severe malaria is treated with intravenous orintramuscular quinine or, since the mid-2000s, the artemisinin derivative artesunate, which is superior to quinine in both children and adults. Resistance has developed to several antimalarial drugs,most notably chloroquine.
There were an estimated 225 million cases of malaria worldwide in 2009. An estimated 655,000 people died from malaria in 2010, a decrease from the 781,000 who diedin 2009 according to the World Health Organization's 2011 World Malaria Report, accounting for 2.23% of deaths worldwide. However, a 2012 meta-study from the University of Washington and...