Malaria

Malaria is a Plasmodium infection transmitted by Anopheles bite or transfusion. Vivax/quartan/falciparum/ovale. Periodic chills/fever/sweating; chronic anemia/splenomegaly. Endemic in 102 countries; 2 billion at risk; falciparum high mortality (Africa/SE Asia/Central-South America).

Common Symptoms

Diarrhea; blood marrow/sputum smear; intermittent chills; abdominal pain; low fever; cyanosis; nausea

Causes and Pathogenesis

Epidemiology: source = patients/carriers; vector = Anopheles (sinensis in plains, minimus in mountains, anthropophagus in hills, dirts in Hainan forest). Universal susceptibility; partial non-durable type-specific immunity. Tropics/subtropics; vivax most widespread, falciparum most severe. Etiology: 4 Plasmodium species (vivax/falciparum/malariae/ovale in China; mainly vivax/falciparum). Stages: trophozoite (signet ring) → schizont → merozoites → gametocytes. Life cycle: exo-erythrocytic (liver) → erythrocytic (RBC schizogony) → sporogony in mosquito. Pathogenesis: erythrocytic stage causes all symptoms; exo-erythrocytic relates to incubation/relapse. (1) Incubation; (2) attack = chills/fever/sweating 8-10 h; recrudescence vs relapse (hypnozoite); (3) anemia/hepatosplenomegaly; malarial nephrotic syndrome (type III hypersensitivity); cerebral malaria (>5% parasitemia, coma >6 h, Hb <71 g/L, jaundice, electrolyte/acid-base disturbance, renal failure, hyperpyrexia). Cerebral > hyperpyretic > algid > gastrointesinal forms.

Treatment

Drug therapy, supportive therapy

Preventive Measures

Report/cure cases; kill Anopheles; bed nets/repellents. Vaccine (subunit/gene) in trials. Chemoprophylaxis: chloroquine 0.3 g weekly; mefloquine 0.25 g weekly in resistant areas; pyrimethamine 25 mg; doxycycline 0.2 g weekly. Tafenoquine 25/50/100/200 mg weekly: 32/84/87/86% protective for falciparum. Artemether used for treatment not prophylaxis (resistance).

Department to Visit

It is recommended to visit the Infectious Diseases department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.