Malaria

Symptoms

• Fever
• Chills
• Sweats
• Headache
• Nausea and vomiting
• Body aches (muscle and joint pain)
• General feeling of unwellness (malaise)
• Diarrhea (less common)
• Abdominal pain (less common)
• Cough (less common)
• Impaired consciousness (sign of severe malaria)
• Extreme weakness or inability to stand/sit (prostration) (sign of severe malaria)
• Seizures (sign of severe malaria)
• Coma (cerebral malaria) (sign of severe malaria)
• Difficulty breathing or fast breathing (respiratory distress) (sign of severe malaria)
• Acute kidney injury (sign of severe malaria)
• Dark urine ('blackwater fever') (sign of severe malaria)
• Severe anemia (low red blood cell count) (sign of severe malaria)
• Unusual bleeding (sign of severe malaria)
• Low blood sugar (hypoglycemia) (sign of severe malaria)
• Yellowing of the skin or eyes (jaundice) (sign of severe malaria)
• Circulatory collapse or shock (sign of severe malaria)

Causes & Risk Factors

• Infection with protozoan parasites of the genus Plasmodium (e.g., Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, Plasmodium knowlesi)
• Bite of an infected female Anopheles mosquito
• Congenital transmission (from mother to fetus, rare)
• Blood transfusion (rare)
• Organ transplantation (rare)
• Use of contaminated needles or syringes (rare)
• Residing in or traveling to areas where malaria is common (endemic areas), especially sub-Saharan Africa and parts of South Asia
• Being a young child under 5 years of age in endemic areas, as they may not have developed partial immunity
• Pregnancy, which can reduce immunity and increase the risk of severe disease, maternal anemia, and adverse birth outcomes
• Having a weakened immune system, such as individuals with HIV/AIDS or other immunosuppressive conditions
• Being a non-immune migrant, mobile population, or traveler from non-endemic areas
• Absence of the spleen (splenectomy)
• Lack of personal protective measures (e.g., not using insecticide-treated nets, repellents, or protective clothing)
• Not taking recommended preventive medication (chemoprophylaxis) when traveling to endemic areas
• Poor housing quality (e.g., lack of screens on windows and doors)

Diagnosis

• Review of recent travel history (within the last year) to a malaria-endemic country
• Discussion of symptoms, especially if fever is cyclical
• Inquiry about previous malaria infections
• Review of malaria preventive medication use and adherence
• Physical examination to check for fever, paleness (anemia), yellowing of skin/eyes (jaundice), enlarged spleen (splenomegaly), or enlarged liver (hepatomegaly)
• Physical examination to identify signs of severe malaria, such as altered mental status or respiratory distress
• Light microscopy: Examination of thick and thin blood smears, considered the gold standard, to detect and identify parasite species, quantify parasite density, and monitor treatment response
• Rapid Diagnostic Tests (RDTs): Immuno-chromatographic tests that detect parasite-specific antigens in blood, useful when quality microscopy is unavailable
• Molecular Tests (PCR): Highly sensitive and specific tests for confirming species, identifying mixed infections, and detecting low parasite levels, though not typically for initial acute diagnosis due to turnaround time
• Ancillary tests: Complete blood count (to check for anemia, low platelet count), liver function tests, renal function tests, and blood glucose levels
• A definitive parasitological diagnosis (blood test) is required for all suspected cases before starting treatment

Treatment Options

• For uncomplicated P. falciparum malaria (or unknown species): Artemisinin-based combination therapy (ACT), such as artemether-lumefantrine, artesunate-amodiaquine, dihydroartemisinin-piperaquine, or artesunate-mefloquine
• For uncomplicated P. vivax or P. ovale malaria: Chloroquine (if effective in the area) or an ACT, followed by a 'radical cure' treatment (primaquine for 14 days or a single dose of tafenoquine) to eradicate dormant liver-stage parasites and prevent relapses. G6PD deficiency testing is mandatory before primaquine or tafenoquine due to the risk of severe red blood cell destruction.
• For uncomplicated P. malariae malaria: Chloroquine
• For uncomplicated P. knowlesi malaria: ACT
• For severe malaria (all age groups): Intravenous (IV) artesunate as first-line treatment
• If IV artesunate is not immediately available for severe malaria: Intramuscular (IM) artesunate or IM artemether can be used as a pre-referral intervention
• Supportive care for severe malaria: Management of complications including fluid and electrolyte balance, treatment of low blood sugar, management of seizures, and blood transfusions for severe anemia
• For uncomplicated malaria in the first trimester of pregnancy: Quinine plus clindamycin for 7 days
• For uncomplicated malaria in the second and third trimesters of pregnancy: ACT is recommended
• For severe malaria in all trimesters of pregnancy: IV artesunate
• For P. vivax or P. ovale in pregnancy: Chloroquine for the acute infection; radical cure with primaquine or tafenoquine is delayed until after delivery due to potential risks to the fetus
• Follow-up: Re-evaluation if symptoms do not resolve or recur, and repeat blood smears to confirm parasite clearance, especially for P. falciparum
• Referral: Urgent referral to a facility capable of providing IV antimalarials and supportive care (ideally an intensive care unit) for all patients with signs of severe malaria or those unable to tolerate oral medications

Frequently Asked Questions