The World Health Organization (WHO) has defined criteria for recognizing severe falciparum malaria.
Severe falciparum malaria is defined as:
(1) one or more of the defining criteria below
(2) asexual parasitemia with Plasmodium falciparum (although smear-negative cerebral malaria may occur)
Defining Criteria |
Finding |
---|---|
cerebral malaria (unrousable coma) |
unrousable coma not attributable to any other cause in a patient with falciparum malaria. Coma should persist at least 30 minutes after a generalized convulsion to make the distinction from transient post-ictal coma. |
severe normocytic anemia |
normocytic anemia with hematocrit < 15% or hemoglobin < 5 g/dL in the presence of parasitemia > 10,000 parasites per µL. If microcytic indices seen, need to consider iron deficiency anemia, thalassemia and hemoglobinopathy. |
renal failure |
urine output < 400 mL in 24 hours in adults, or 12 mL per kg in children, failing to improve after rehydration, and with serum creatinine > 265 µmol/L (3 mg/dL) |
pulmonary edema, ARDS |
|
hypoglycemia |
whole blood glucose < 2.2 mmol/L (< 40 mg/dL) |
circulatory collapse, shock |
hypotension (systolic blood pressure < 50 mm Hg in children 1-5 years old; < 70 mm Hg in adults) with cold, clammy skin or a core-to-skin temperature difference > 10 °C |
spontaneous bleeding. DIC |
spontaneous bleeding from gums, nose, GI tract or other sites, with laboratory evidence of DIC |
repeated generalized seizures |
more than 2 observed seizures (>=3) within 24 hours despite cooling |
acidemia or acidosis |
arterial pH < 7.25, plasma bicarbonate < 15 mmol/L |
malarial hemoglobinuria |
need to exclude hemoglobinuria due to antimalarial medications and to G6PD deficiency |
Additional Criteria |
Finding |
---|---|
impaired consciousness but rousable |
impaired consciousness less marked than unrousable coma, can localize a painful stimulus |
prostration and extreme weakness |
patient unable to sit or walk, with no other obvious neurological explanation |
hyperparasitemia |
very high parasite densities are associated with increased risk of severe disease but is affected by the immune status (more than 5% parasitemia in non-immune is serious, but may be well tolerated in semi-immune children); > 500,000 per µL |
jaundice |
total bilirubin > 50 µmol/L (> 3 mg/dL) |
hyperpyrexia |
rectal temperature > 40 °C |
post-mortem evidence of severe malaria |
neuropathologic evidence of venules and capillaries packed with erythrocytes containing malarial parasites |
Risk factors for development of severe falciparum malaria:
(1) splenectomy
(2) pregnancy, especially primigravid
(3) immunosuppression
(4) low immunity states: non-immune (lack of previous exposure), especially in small children, or lapsed immunity (due to living away from malarious area for several years)
Purpose: To identify patients with falciparum malaria who have severe disease based on clinical and laboratory findings.
Specialty: Infectious Diseases
Objective: criteria for diagnosis
ICD-10: B50,