Mosquitoes breed in water and they are especially plentiful during the rainy season. If the most basic prevention is to avoid bites by sleeping under insecticide-treated bed nets, the natural breeding ground of the insect needs to be eliminated. Spraying insecticide and drying sources of stagnant water are strategies used for controlling the proliferation of mosquitoes.

Diagnosing malaria is done by using either a rapid diagnostic test or a microscope with a skilled laboratory person. A rapid diagnostic test uses blood from a finger prick and is relatively cheap and easy to perform—community health workers with no previous training can quickly learn to do them. In some areas neither test is available, so health workers must diagnose sick children based on symptoms alone - leading to over-diagnosis of malaria, while the real cause of the symptoms is left untreated.

The most effective treatment for malaria is a two-drug combination called artemisinin-based combination therapy (ACT). These drugs cure most infections in three days. Early treatment is essential to avoid severe malaria, which requires hospitalisation with intravenous antimalarials. Patients with severe malaria often need blood transfusions, requiring a safe, adequately-stocked blood bank—difficult to achieve in under-resourced areas. Without treatment, or with significantly delayed treatment, severe malaria kills.

The WHO recommendation of ACT, which contains the drug artemisinin, in 2001 was a major breakthrough, replacing old, ineffective treatments such as chloroquine, or quinine. But the malaria parasite has developed resistance to artemisinin in parts of Southeast Asia, meaning that ACT may no longer be effective. If the spread of resistance cannot be stopped, it represents a major risk to public health, and would most likely lead to a resurgence of malaria, since there aren’t currently any new drugs available.

In Africa’s Sahel region, malaria is highly seasonal and most cases happen during a 4-5 month period. In 2012, MSF piloted a seasonal malaria chemoprevention (SMC) in Mali, Niger and Chad, now used in several countries. SMC involves providing antimalarial drugs to prevent infection among those most at-risk - children under five. Malaria can also be prevented by avoiding being bitten by the mosquitoes that carry the parasite, through the use of insecticide-treated mosquito nets, unavailable for many.