By Philip R. Fischer, MD, DTM&H
Professor of Pediatrics, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN; Department of Pediatrics, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates
SYNOPSIS: Malaria is preventable and treatable, yet there still are hundreds of millions of cases of malaria each year. New guidelines encourage personal and community prevention. Treatment usually is with artemisinin-based combination therapy.
SOURCE: World Health Organization. Consolidated guidelines for malaria. March 31, 2022. https://www.who.int/teams/global-malaria-programme/guidelines-for-malaria
This year, the World Health Organization (WHO) released updated evidence-based guidelines for the prevention, diagnosis, and management of malaria. This article reviews key recommendations from the WHO report, supplemented with comments from the Centers for Disease Control and Prevention (CDC). The 220-page WHO paper is readily available for download, and it will be updated repeatedly at the WHO website.
Malaria is preventable and treatable. Nonetheless, 3 billion people live at risk of getting malaria, and there still are nearly 250 million cases of malaria around the world each year, with approximately 600,000 deaths.
There are more than 2,000 cases of malaria in the United States each year, and the number has been increasing during recent decades.1 More than half of U.S. cases result from exposures in West Africa, and more than two-thirds are caused by Plasmodium falciparum.1
Prevention
For individuals residing in areas where malaria is endemic, the use of pyrethroid-impregnated bednets is effective to reduce malaria transmission. Sleeping under nets is most useful, but there also is usefulness to having nets hanging in living areas during evening hours. In addition to blocking physical contact between mosquitoes and potential patients, these insecticide-laden nets also repel, disable, and/or kill mosquitoes.
Although the use of topical repellents can be effective for individuals, limited compliance with repeated applications of repellents makes community-wide use of topical repellents of dubious value.
Among residents of malaria-endemic areas of Africa, pregnant women should receive intermittent chemoprophylaxis with at least three monthly doses of sulfadoxine-pyrimethamine during the second and third trimesters of their first and second pregnancies. Children should receive sulfadoxine-pyrimethamine along with their second and third sets of routine immunizations.
In the Sahel region of Africa where there is seasonal transmission of malaria, children should receive monthly doses of amodiaquine and sulfadoxine-pyrimethamine during the malaria season for their first six years of life.
In parts of Africa with moderate to high transmission of malaria, a four-dose series of the RTS,S/AS01 malaria vaccine should be initiated for children at 5 months of age.
The WHO guidelines deal with population groups living in areas of malaria transmission. For travelers, the CDC provides detailed guidance for malaria prevention, noting the use of personal protective measures, geography-based risk, and anti-malarial selection.2
Diagnosis
Patients with suspected malaria should have testing done, either with microscopy or with a rapid diagnostic test. Quality control of testing is essential.
The CDC malaria guidelines remind clinicians working in non-malarial areas, such as the United States, that the presenting symptoms of malaria are nonspecific.3 Thus, malaria should be considered in any febrile traveler who has been in a malaria-endemic area within recent months. Blood testing is necessary.
Management
Artemisinin-based combination therapy (ACT) is the mainstay of pharmacologic management of falciparum malaria. Other than for women during the first trimester of pregnancy, treatment of uncomplicated malaria may be with one of the following combinations:
- artemether + lumefantrine;
- artesunate + amodiaquine;
- artesunate + mefloquine;
- dihydroartemisinin + piperaquine;
- artesunate + sulfadoxine-pyrimethamine;
- artesunate + pyronaridine.
The treatment should be for three days.
During the first trimester of pregnancy, uncomplicated falciparum malaria should be treated with seven days of quinine and clindamycin.
In regions of chloroquine sensitivity, non-falciparum malaria may be treated with chloroquine. If susceptibility is in doubt, artemisinin-based combination therapy should be employed. A 14-day course of primaquine may be given to prevent relapse of vivax and ovale malaria if the patient does not have glucose-6-phosphate-dehydrogenase deficiency.
The first-line treatment for anyone with severe malaria (even infants and pregnant women) is 24 hours of parenteral artesunate. When the patient can tolerate oral medication, artemisinin-based combination therapy may be used to complete a three-day course. The dose per kilogram of artesunate is higher in smaller children (specifically, those weighing less than 20 kg) than in larger children. In the United States, expert advice and access to intravenous artesunate, when not locally available, are available around-the-clock from the CDC.3
There is a rare but reported risk of post-artemisinin hemolytic anemia following the use of parenteral artesunate, possibly related to the initial degree of parasitemia.3 Thus, patients with severe malaria who receive intravenous artesunate should be monitored weekly for up to four weeks to promptly identify those who might be developing this rare complication.3
REFERENCES
- Mace KE, Lucchi NW, Tan KR. Malaria surveillance – United States, 2017. MMWR Surveill Summ 2021;70:1-35.
- Centers for Disease Control and Prevention. Choosing a drug to prevent malaria. Reviewed Nov. 15, 2018. https://www.cdc.gov/malaria/travelers/drugs.html
- Centers for Disease Control and Prevention. Treatment of malaria: Guidelines for clinicians (United States). Reviewed Nov. 2, 2020. https://www.cdc.gov/malaria/diagnosis_treatment/clinicians1.html
Malaria is preventable and treatable, yet there still are hundreds of millions of cases of malaria each year. New guidelines encourage personal and community prevention. Treatment usually is with artemisinin-based combination therapy.
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