Yellow Fever

Yellow fever is an acute flavivirus disease transmitted mainly by Aedes. Severe cases: fever, jaundice, albuminuria, relative bradycardia, bleeding. Endemic in tropical/subtropical Africa and South America; not reported in Asia. WHO-listed quarantinable disease.

Common Symptoms

Gum bleeding; anorexia; myalgia; body pain; restlessness; fatigue; constipation; nausea

Causes and Pathogenesis

(1) Etiology: Flavivirus group B, Togaviridae, 22-38 nm enveloped +ssRNA; heat/disinfectant/ether/deoxycholate-sensitive; stable 1 month at 4°C in blood, months in 50% glycerol at 0°C, years at -70°C/lyophilized. Asibi strain attenuated to 17D vaccine. (2) Pathogenesis: local node replication 3-4 days → viremia → liver/spleen/kidney/heart/bone marrow/lymph. Pathology: midzonal hepatic necrosis with cloudy swelling, microvesicular steatosis, coagulative necrosis, Councilman bodies, minimal inflammation; renal tubular degeneration to necrosis; myocardial degeneration/fatty infiltration involving SA node/His bundle; cerebral edema/petechiae.

Treatment

Drug therapy, symptomatic, supportive therapy

Preventive Measures

Isolate patients; mosquito-proof rooms; border quarantine requiring vaccination certificate. Mosquito control. 17D live vaccine 0.5-1.0 mL SC, immunity 7-9 days, lasts ≥10 years; caution egg allergy; 18 encephalitis cases (15 in infants <4 months) since 1945. Co-administration with HepB/polio/Ty21e safe.

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.