Malaria must be diagnosed and treated promptly with a recommended antimalarial drug to keep the illness from progressing and to help prevent further spread of infection in the community.

In the malaria-endemic world, diagnosis of malaria can be difficult for several reasons:

• Malaria’s clinical symptoms are shared with other diseases and conditions, and many malaria-endemic countries lack resources, such as microscopes and rapid diagnostic tests, to make a definitive diagnosis.
• Health personnel in these areas are often undertrained, underequipped and underpaid.
• Health personnel in the malaria-endemic world often face excessive patient loads, and must divide their attention between malaria and other equally severe infectious diseases such as pneumonia, diarrhea, tuberculosis, and HIV/AIDS.

Malaria may be "uncomplicated" or "severe."

• Uncomplicated malaria: Symptoms may include fever, chills, sweats, headaches, muscle pains, nausea and vomiting.
• Severe malaria: Symptoms may include confusion, coma, focal neurologic signs, severe anemia, and respiratory difficulties. A patient with symptoms of severe malaria should be assessed quickly and treated immediately. Severe malaria is most often caused by the most dangerous parasite, Plasmodium falciparum.

Diagnosis Based on Symptoms: Clinical Diagnosis

When a patient with fever is brought to a health facility in the malaria-endemic world, a health worker may suspect that the patient has malaria based on the patient's symptoms, although these symptoms are not specific to malaria. For a definitive diagnosis to be made, however, a laboratory test must be conducted.

More on: Malaria Symptoms – Uncomplicated Malaria.

Diagnosis Based on Laboratory Methods

Ideally, microscopy and/or rapid diagnostic tests will be used to make a definitive diagnosis of malaria.

Microscopy

Malaria parasites can be identified by examining a drop of the patient’s blood under the microscope. This drop is spread out as a "blood smear" on a microscope slide. Before the slide is examined, the blood specimen is stained (most often with the Giemsa stain) to give the parasites a distinctive appearance. This technique is the gold standard for laboratory confirmation of malaria. However, it depends on the quality of the reagents, of the microscope, and on the experience of the laboratorian.

More on: Malaria Microscopy

Rapid Diagnostic Tests

In the last few years, test kits have become available that can detect antigens derived from malaria parasites in a person’s blood. These immunologic ("immunochromatographic") tests are referred to as rapid diagnostic tests (RDTs) and provide results quickly---depending on the test, in about 20 minutes.

RDTs offer a useful alternative to microscopy in situations where reliable microscopic diagnosis is not available. Malaria RDTs are currently used in many clinical settings and programs in countries where malaria is transmitted. CDC and others are conducting operational research to help optimize their use. The World Health Organization's Regional Office for the Western Pacific (WHO/WPRO) provides technical information, including a list of commercially available malaria RDTs, at http://www.wpro.who.int/rdt/.

More on: Rapid Diagnostic Tests

Treatment

The World Health Organization recommends that patients in malaria-endemic areas be treated within 24 hours after their first symptoms appear.

Treatment of a patient with malaria depends on the country’s national guidelines, which typically take the following into consideration:

• Type (species) of the infecting parasite
• Clinical status of the patient
• Any accompanying illness or condition
• Pregnancy
• Drug allergies, or other medications taken by the patient

Uncomplicated Malaria

Patients who have uncomplicated malaria can be treated on an outpatient basis; however, patients with severe malaria should be hospitalized.

Most drugs recommended for treatment of uncomplicated malaria cases in the malaria-endemic world are active against the parasite forms in the blood (the form that causes disease). Listed below are some of the drugs approved by the World Health Organization and those most commonly recommended by national malaria control programs in the malaria-endemic world:

• artemesinin-containing combination treatments, (e.g, artemether-lumefantrine, artesunate-amodiaquine)
• atovaquone-proguanil
• chloroquine*
• doxycycline
• mefloquine*
• quinine
• sulfadoxine-pyrimethamine*
• artemisinin monotherapies**

*Some of these drugs, for example, chloroquine, mefloquine, and sulfadoxine-pyrimethamine, are no longer effective in some or many parts of the world.

**These monotherapies are not recommended due to concerns about drug resistance.

More on: Treatment in the United States

Another drug, primaquine, is used as an adjunct for certain species of malaria (e.g., P. falciparum, P. vivax, and P. ovale). It is active against the dormant parasite liver forms (hypnozoites ) and can prevent relapses of P. vivax and P. ovale. Primaquine should not be taken by pregnant women or by people who are deficient in G6PD (glucose-6-phosphate dehydrogenase).Patients should not take primaquine until a screening test has excluded G6PD deficiency or unless the risk of deficiency in the surrounding population is known to be low, because primaquine given to people with G6PD deficiency can cause hemolytic anemia. In some countries, primaquine is also used in a single dose to prevent secondary transmission.

Counterfeit and substandard drugs are sold in some areas and should be avoided.

Severe Malaria

Severe malaria occurs when infections are complicated by serious organ failures or abnormalities in the patient's blood or metabolism.

More on: Malaria Symptoms – Severe Malaria

Patients who have severe P. falciparum malaria or who cannot take oral medications should be given treatment by continuous intravenous infusion in a hospital. Some malaria-endemic countries recommend pre-referral drugs be given by suppository or injection whenever a severely ill patient is referred to a hospital for definitive care.

Several antimalarial drugs are available for treatment by continuous intravenous infusion.