0521779407-20 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:22
Typhus Fevers 1475■Epidemic Typhus: Indirect immunofluorescent antibody (IFA) titer
≥1:128
■Endemic Typhus: IFA 4-fold rise to >1:64 or single titer of≥1:128,
usually 15 days after onset. Immunohistology of skin biopsy.
■Scrub Typhus: IFA titer >1:320 or 4-fold rise in titer. Early treatment
may blunt antibody response.Other Tests
■CXR in endemic typhus may be abnormal.
■CSF in scrub typhus may have 0–110 WBC/mm^3 , and mildly incr-
eased protein.differential diagnosis
■Rocky mountain spotted fever, brucellosis, meningococcemia, bac-
terial and viral meningitis, measles, rubella, toxoplasmosis, lep-
tospirosis, typhoid fever, Dengue fever, flavivirus infection, relapsing
fever, secondary syphilis, infectious mononucleosis, gastroenteritis,
ehrlichiosis, Kawasaki’s disease, toxic shock syndrome.
management
What to Do First
■Consider rickettsial infections in patients with abrupt onset of fever,
headache and myalgias with appropriate exposures. Examine care-
fully for rashes. Begin antirickettsial therapy.General Measures
■General supportive measures as needed.
■10% of patients with endemic typhus will require ICU hospita-
lization; these have a 4% mortality.
■Can give corticosteroids in patients with severe CNS disease.specific therapy
Indications
■Treat all suspected rickettsial infections.Treatment Options
■Treat severely ill patients intravenously with the same drugs and
dosages as oral regimens.
■Epidemic Typhus: Louse-borne typhus – Doxycycline. Indigenously
acquired epidemic typhus or Brill-Zinsser disease – until patient
afebrile 2–3 days.
■Endemic Typhus: Doxycycline or chloramphenicol 7–15 days.