Rickettsial Diseases

Rickettsioses are a group of acute infections caused by Rickettsiales organisms, worldwide/endemic, ranging in severity. Vectors: arthropods (ticks/lice/fleas/mites); also cat/dog scratches/bites. Most present as fever-headache-rash triad in spring/summer with tick/camping/occupational exposure. Some have neuro/CNS and visceral involvement.

Common Symptoms

Fever with rash; triad

Causes and Pathogenesis

Vectors: ticks/lice/fleas/mites; cat/dog bites. Molecular taxonomy (16S rRNA/DNA-DNA hybridization) splits Rickettsiales into α subgroup (Rickettsia, Ehrlichia, Afibia, Cowdria, Bartonella) and γ subgroup (Coxiella, Wolbachia). New species: R. japonica, E. chaffeensis, E. sennetsu, Bartonella henselae; Rochalimaea renamed Bartonella (trench fever = B. quintana).

Treatment

Drug therapy, supportive therapy

Preventive Measures

Vectors are mostly arthropods; rickettsiae live symbiotically in them; transovarial transmission in ticks/mites; feces contain organisms; ticks/mites also inoculate via saliva. C. burnetii enters by respiratory route. Universal susceptibility; post-infection immunity is solid with some cross-protection within groups. Relapse (Brill-Zinsser) months-years after epidemic typhus. Epidemic/endemic typhus/Q fever worldwide; tick-borne spotted febs are endemic. Common in China: epidemic/endemic typhus, scrub typhus, Q fever, North Asian tick typhus.

Department to Visit

It is recommended to visit the Dermatology 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.