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| ''Also known as "endemic typhus" and "fleaborne typhus"''
| | #REDIRECT[[Typhus]] |
| ==Background==
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| *Caused by Rickettsia typhi
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| **Gram negative, obligate, intracellular bacterium
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| **Replicates in epithelial cells of flea's midgut
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| ===Vector===
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| *Infection is transmitted by fleas
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| **Typically rat fleas
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| **Also Rickettsia felis (indistinguishable from R. typhi) carried by fleas on opossum and cats
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| *Feces containing R. typhi are deposited into wound made by flea bites
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| *Found in areas with large populations of urban rats
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| **United States
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| ***Southern Texas
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| ***Southern California
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| **Internationally: Tropical/Subtropical urban seaboard regions
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| *Seasonal predilection for summer months
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| **Texas: Spring to summer
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| **California: Summer to fall
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| ==Clinical Features==
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| *Incubation period: 7-14 days
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| [[File:Murine_Typhus.png|thumb|Rash of Murine Typhus]] | |
| ===Symptoms===
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| *Variable and non-specific
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| *Often presents as acute, self-limited illness, with no complications<ref>Civen R, Ngo V, 2008. Murine typhus: an unrecognized suburban vectorborne disease. Clin Infect Dis 46: 913–918.</ref>
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| ;Most Common Symptoms
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| *Fever- can last ~1 week
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| *Rash
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| **Macular or maculopapular, blanching, non-pruritic
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| **Starts centrally and moves to the extremities
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| **Can involve palms/soles but usually sparing
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| **Starts 6-7 days after symptom onset (fever onset)
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| *Headache
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| *Arthralgias
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| ;Other Symptoms
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| *Hepatomegally
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| *Splenomegally
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| *Cough
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| *[[Diarrhea]]
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| *Nausea/Vomiting
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| *Abdominal pain
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| *Confusion
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| ==Differential Diagnosis==
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| *Non-specific viral illness
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| *Most common admitting diagnosis in one case study was "fever of unknown origin"<ref>Civen R, Ngo V, 2008. Murine typhus: an unrecognized suburban vectorborne disease. Clin Infect Dis 46: 913–918.</ref>
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| {{Tick borne illnesses DDX}}
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| {{Template:Fever in Traveler DDX}}
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| ==Evaluation==
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| ===Work up===
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| *Infectious work up
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| **Not sensitive or specific
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| **CBC- can show anemia and thrombocytopenia
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| **LFTs- often elevated 3-5x normal
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| **Lumbar Puncture- resembles aseptic meningitis
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| ===Diagnostic labs===
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| *Immunofluorescent assay is the gold standard
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| **Becomes diagnostic with time. Rarely positive at onset of illness.
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| *PCR
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| ==Management==
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| *[[Doxycycline]] 100mg BID continue for 3 days after resolution of symptoms<ref>Civen R, Ngo V, 2008. Murine typhus: an unrecognized suburban vectorborne disease. Clin Infect Dis 46: 913–918.</ref>
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| **Children - 2.2mg/kg BID
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| *[[Chloramphenicol]] 50-100mg/kg/day div Q6hr (Max dose = 4g/day)
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| ==See Also==
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| ==External Links==
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| ==References==
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| <references/>
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| [[Category:ID]]
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