Epidemic typhus(European,Classic, or Louse-Borne Typhus or Jail fever)
Epidemic typhus is caused by rickettsia prowazekii.
Symptoms are prolonged high fever , intractable, and maculopapular rash.
Human are the natural reservoir for R. prowazekii , which is prevalent worldwide and transmitted by body lice when louse feces are scratched or rubbed into bite or other wounds (and sometimes the mucus membranes of the eyes or mouth).
In the US human may occasionally contract epidemic typhus after contact with flying squirrels.
Fatalities are rare in children < 10 years but mortality increases with age and may reach 60% in untreated patient > 50 years.
Symptoms and signs
After an incubation period of 7 to 14 days fever, headache and prostration suddenly occur. Temperature reaches 40 degrees centigrade in several days and remains high, with slight morning remission, for about 2 wk.
Headache is generalized and intense. Small, pink macules, which appear on the 4th to 6th day, rapidly cover the body, usually in the axillae and on the upper trunk and generally excluding the palms, soles, and face.
Later the rash becomes dark and maculopapular. In severe cases, the rash becomes petechial and hemorrhagic.
Splenomegally sometimes occurs. Hypotension occurs in most seriously ill patients.
Vascular collapse, renal insufficiency, encephalitic signs, ecchymosis with gangrene and pneumonia are poor prognostic signs.
Diagnosis,prevention and treatments
Primary treatment is doxycycline 200mg po once followed by 100mg bid until the patient improves and has been a febrile for 24 to 48 hours, but continued for at least 7 days.
Chloramphenicol 500mg po or IV qid for 7 days is a second line treatment.
Louse infestation is usually obvious and strongly suggests typhus in the proper setting.
Immunization and louse control are highly effective for prevention. However, vaccines are not available in the US,
Lice may be eliminated by dusting infested people with malathion or lindane
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