Typhus

Typhus is an acute rickettsial disease. Epidemic (louse-borne, R. prowazekii, winter-spring) vs endemic (flea-borne, R. mooseri, summer-autumn); endemic is milder. Incubation 5-21 d (10-12). Acute onset with chills/high fever/severe headache/myalgia (calf tenderness)/flushed face/injected conjunctiva/CNS symptoms. Day 5: maculopapular rash becoming hemorrhagic, splenomegaly. Epidemic typhus is human-louse-human; human is the only host. Endemic typhus is zoonotic: rodents are reservoirs, Xenopsylla cheopis is vector, humans are accidental hosts.

Common Symptoms

Fever with lymphadenopathy; splenomegaly; lymphadenopathy; Yi Yupin

Causes and Pathogenesis

R. prowazekii and R. mooseri are similar, Gram-negative, heat/disinfectant-sensitive but cold/dry-resistant. Human body louse is the epidemic vector (head louse minor). Rickettsiae multiply in louse gut epithelium and are excreted in feces 5 days later; scratching inoculates into skin. Rat flea transmits endemic form. Rickettsiae multiply in small-vessel endothelium; toxins and vasculitis cause typhus nodules. Pathology: vasculitis/perivasculitis (lung/brain/heart/kidney), mononuclear/lymphocyte/plasma cell cuffing; severe cases have endothelial edema/necrosis/rupture. Rickettsiae detected in endothelium/macrophages/myocardium.

Treatment

Drug therapy, supportive therapy

Preventive Measures

(1) Rodent control. (2) Avoid chigger/flea/louse bites; tuck clothing; repellents. (3) No licensed human vaccine; 56 kDa outer-membrane protein antigen under study.

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.