Malaria

GENERAL PRINCIPLES

• Malaria is endemic to most of the tropical and subtropical world, with 229 million infections and 409,000 deaths in 2019. It is transmitted by the female Anopheles mosquito.

• Travel advice and chemoprophylaxis regimens can be found at http://www.cdc.gov/travel/.

DIAGNOSIS

Clinical Presentation

• Patients present with nonspecific symptoms, including fever, headache, and myalgias.

• P. falciparum malaria, the most severe form, is associated with high mortality. Complicated, or severe, falciparum malaria is diagnosed if there is hyperparasitemia (>5%), cerebral malaria, hypoglycemia, lactic acidosis, renal failure, acute respiratory distress syndrome, or coagulopathy.

• Paroxysmal fever every other day can be seen in P. vivax and P. ovale, and every 3 days with P. malariae.

Diagnostic Testing

• Malaria should be excluded in all persons with fever who have traveled to an endemic area.

• Diagnosis is made by visualization of parasites on Giemsa-stained thick and thin blood smears, preferably obtained during febrile episodes.

• Rapid diagnostic tests targeting antigens common to all Plasmodium species as well those specific to P. falciparum are available but should be confirmed with microscopy.

TREATMENT

• Treatment should be started as soon as possible and is dependent on the type of malaria, severity, and risk of chloroquine resistance. Updated information from the CDC can be found at http://www.cdc.gov/travel/ and http://www.cdc.gov/malaria.

• Uncomplicated malaria (P. falciparum, P. ovale, P. vivax, P. malariae, and P. knowlesi) from chloroquine-sensitive areas:

î Chloroquine 600 mg base PO single dose followed by 300 mg base PO at 6, 24, and 48 hours.

• Uncomplicated P. falciparum from chloroquine-resistant areas and P. vivax from Indonesia or Papua New Guinea:

î Artemether-lumefantrine (20 mg artemether, 120 mg lumefantrine) 4 tablets PO at 0 and 8 hours, followed by 4 tablets q12h ? 2 days.

î Quinine sulfate 542 mg base PO q8h plus doxycycline 100 mg PO q12h or clindamycin 20 mg base/kg/d divided into three daily doses for 7 days.

î Atovaquone-proguanil (250 mg atovaquone/100 mg proguanil) four tablets PO qday for 3 days.

• P. ovale or P. vivax: Add primaquine phosphate 30 mg base PO qday for 14 days to prevent relapse, after ruling out glucose-6-phosphate dehydrogenase deficiency.

• Complicated severe malaria (most commonly P. falciparum): Artesunate 3 mg/kg IV (first dose) followed by 3 mg/kg IV at 12 and 24 hours, followed by 3 mg/kg IV qday for 3 days. If IV artesunate is not available commercially, an emergency request can be made to the CDC Malaria Branch (weekdays: 770-488-7788; after-hours: 770-488-7100). While waiting for IV artesunate, start oral medication (artemether-lumefantrine, atovaquone-proguanil, or quinine plus doxycycline or clindamycin).⁵²