Falciparum Malaria

Falciparum malaria is infection by Plasmodium falciparum, the species responsible for most malaria deaths and for nearly all severe disease in Africa. It multiplies every 48 hours with sequestration of infected red cells in capillaries.

• Kenyan transmission zones are the lake region and coast (endemic), the western highlands (epidemic prone) and the arid north (seasonal).
• Challenges: partial artemisinin resistance (kelch13 mutations reported in East Africa), pfhrp2 and pfhrp3 gene deletions causing false negative rapid tests, and lumefantrine partner drug failure.
• Immunity develops slowly and wanes after leaving endemic areas.

Fever, chills, headache, malaise, myalgia, vomiting, diarrhoea; hepatosplenomegaly; severe forms with coma, convulsions, anaemia, respiratory distress, jaundice and shock.

• Non specific in children and pregnancy; placental malaria causes maternal anaemia and low birth weight.
• Differential diagnosis: other febrile illnesses (viral, typhoid, bacterial sepsis), dengue, meningitis, hepatitis, leptospirosis, relapsing fever, brucellosis, other Plasmodium species.
• Complications: cerebral malaria, severe malarial anaemia, hypoglycaemia, acidosis, pulmonary oedema, acute kidney injury, blackwater fever, spontaneous splenic rupture, secondary sepsis, congenital malaria, death.

Parasitological confirmation.

• Rapid antigen test (pfHRP2) and microscopy with species and parasite density (parasites per microlitre or percent of red cells infected); if pfhrp2 deletion suspected use pLDH based test or PCR.
• Haemoglobin, glucose, creatinine, lactate and bicarbonate in suspected severe disease; HIV test as indicated.
• Repeat blood films every 12 to 24 hours if still symptomatic; day 3, 7, 28 follow-up films in treatment failure.

Uncomplicated: oral artemisinin combination; severe: IV artesunate.

• Supportive: antipyretic (paracetamol 15 mg/kg or 1 g every 6 hours), fluids, nutrition, nets, correction of hypoglycaemia and anaemia, monitoring in children.
• Pharmacological, uncomplicated: artemether lumefantrine (20 mg/120 mg) twice daily for 3 days with fatty food: 5 to under 15 kg 1 tablet; 15 to under 25 kg 2; 25 to under 35 kg 3; 35 kg and over 4 tablets per dose, at 0, 8, 24, 36, 48 and 60 hours. Alternative dihydroartemisinin piperaquine (adults 36 to under 60 kg 2 tablets, 60 to under 80 kg 3 tablets, 80 kg and over 4 tablets of 40 mg/320 mg) once daily for 3 days. First trimester: quinine 10 mg/kg three times daily plus clindamycin 10 mg/kg twice daily for 7 days. Severe: artesunate 2.4 mg/kg IV (children under 20 kg 3 mg/kg) at 0, 12, 24 hours then daily, then complete with a full oral artemisinin combination; quinine 20 mg/kg loading then 10 mg/kg every 8 hours if artesunate is unavailable. Treatment failure within 28 days: give a different artemisinin combination and confirm adherence and absorption. Prevention in pregnancy: sulfadoxine 500 mg with pyrimethamine 25 mg, 3 tablets as a single directly observed dose from 13 weeks, repeated at least 4 weeks apart. Perennial malaria chemoprevention for infants and seasonal chemoprevention for children where applicable.
• Procedures: exchange transfusion is not recommended; dialysis and ventilation for severe complications.
• Special groups: pregnancy, treat promptly in all trimesters, insecticide treated nets and intermittent preventive treatment; infants, weight based dosing; HIV, cotrimoxazole prophylaxis (which provides some malaria protection) and checks for drug interactions; sickle cell disease, daily chemoprophylaxis.
• Red flags: drowsiness, convulsions, shock, respiratory distress, severe anaemia, jaundice, hypoglycaemia, parasitaemia over 10 percent, vomiting all doses.
• Follow-up: clinical review at day 3 and day 28; haemoglobin at 2 to 4 weeks; vector control and nets; malaria rapid diagnostic test only for symptomatic patients.