Clinical Pearls & Morning Reports

Posted by Carla Rothaus, MD

Published February 7, 2024


How is uncomplicated Plasmodium falciparum malaria usually treated?

Most cases of malaria diagnosed in the United States occur during the U.S. summer months among patients who have traveled to sub-Saharan Africa. The majority of cases are diagnosed in patients who did not receive chemoprophylaxis. Read the NEJM Case Records of the Massachusetts General Hospital here.

Clinical Pearls

Q: Which species of malaria is most often acquired in travelers who are infected in Africa?

A: Five species of malaria can infect humans, although most travelers infected in Africa acquire Plasmodium falciparum. Most patients infected with P. falciparum present with a nonspecific febrile illness with headache, chills, and myalgias, symptoms that usually develop within 4 to 12 weeks after the infectious mosquito bite.

Q: Do mosquitos capable of transmitting malaria exist in the United States?

A: In 2023, cases of malaria caused by P. vivax were diagnosed in patients residing in Florida and Texas who had not traveled, which indicated local acquisition. These cases show that mosquitoes capable of transmitting malaria exist in the United States and that limited local or ongoing transmission can occur after the importation of malaria into home communities.

Morning Report Questions

Q: How is uncomplicated P. falciparum malaria usually treated?

A: The mainstay of treatment for patients with uncomplicated P. falciparum malaria usually involves the oral administration of artemisinin-based combination therapy, although other options can be used in specific situations. As compared with other options, the use of artemisinin derivatives is associated with increased survival. In the United States, one oral preparation of artemisinin-based combination therapy, artemether–lumefantrine, is commercially available.

Q: What is the first-line treatment for severe malaria in the United States?

A: Severe disease can include altered consciousness or coma, severe anemia (defined as a hemoglobin level of <7 g per deciliter), acute kidney failure, acute respiratory distress syndrome, shock, persistent acidosis, jaundice (in the presence of other signs of severe malaria), disseminated intravascular coagulation, and a parasitemia level of at least 5%. Intravenous artesunate has been approved by the Food and Drug Administration, is commercially available in the United States, and is the first-line therapy for severe malaria in the United States. Medical institutions that care for patients at risk for malaria should have intravenous artesunate readily accessible by either stocking it or establishing protocols that facilitate the rapid acquisition of the agent or the rapid transfer of patients to a facility with treatment capacity. It is important to note that if a patient has an infection with either P. vivax or P. ovale, treatment will need to include a second agent (typically primaquine) that targets the dormant liver-stage form of these plasmodium species, known as the hypnozoite, in addition to including the first agent, which targets the blood-stage form.

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