|
|
| Line 1: |
Line 1: |
| ''Not to be confused with [[typhoid fever]], a distinct disease caused by a different genera of bacteria'' | | ''Not to be confused with [[typhoid fever]], a distinct disease caused by a different genera of bacteria'' |
| ==Background==
| |
| *Also known as murine typhus, endemic typhus, and fleaborne typhus
| |
| *Caused by Rickettsia typhi
| |
| **Gram negative, obligate, intracellular bacterium
| |
| **Replicates in epithelial cells of flea's midgut
| |
|
| |
| {{Typhus types chart}} | | {{Typhus types chart}} |
|
| |
| ===Vector===
| |
| *Infection is transmitted by fleas
| |
| **Typically rat fleas
| |
| **Also Rickettsia felis (indistinguishable from R. typhi) carried by fleas on opossum and cats
| |
| *Feces containing R. typhi are deposited into wound made by flea bites
| |
|
| |
| *Found in areas with large populations of urban rats
| |
| **United States
| |
| ***Southern Texas
| |
| ***Southern California
| |
| **Internationally: Tropical/Subtropical urban seaboard regions
| |
|
| |
| *Seasonal predilection for summer months
| |
| **Texas: Spring to summer
| |
| **California: Summer to fall
| |
|
| |
| ==Clinical Features==
| |
| [[File:Epidemic_typhus_Burundi.jpg|thumbnail|Epidemic typhus]]
| |
| *[[Fever]], [[headache]], myalgias<ref>CDC. Typhus and related diseases. http://wwwnc.cdc.gov/travel/yellowbook/2016/infectious-diseases-related-to-travel/rickettsial-spotted-typhus-fevers-related-infections-anaplasmosis-ehrlichiosis</ref>
| |
| *Transmitted by arthropods/ ticks
| |
| *Painless eschar at inoculation site imp clue
| |
| *Camping, hiking in grassy/ scrub area
| |
| *Regional lymphadenopathy, rash
| |
|
| |
|
| |
| ==Clinical Features==
| |
| *Incubation period: 7-14 days
| |
| [[File:Murine_Typhus.png|thumb|Rash of Murine Typhus]]
| |
| ===Symptoms===
| |
| *Variable and non-specific
| |
| *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>
| |
| ;Most Common Symptoms
| |
| *Fever- can last ~1 week
| |
| *Rash
| |
| **Macular or maculopapular, blanching, non-pruritic
| |
| **Starts centrally and moves to the extremities
| |
| **Can involve palms/soles but usually sparing
| |
| **Starts 6-7 days after symptom onset (fever onset)
| |
| *Headache
| |
| *Arthralgias
| |
|
| |
| ;Other Symptoms
| |
| *Hepatomegally
| |
| *Splenomegally
| |
| *Cough
| |
| *[[Diarrhea]]
| |
| *Nausea/Vomiting
| |
| *Abdominal pain
| |
| *Confusion
| |
|
| |
|
| |
|
| |
|
| |
| ==Differential Diagnosis==
| |
| {{Template:Fever in Traveler DDX}}
| |
|
| |
| ==Evaluation==
| |
| *leukopenia, thrombocytopenia
| |
| *Usually clinically
| |
|
| |
| ==Management==
| |
| *[[Tetracycline]]
| |
| *[[Chloramphenicol]] may be an alternative, though associated with higher morbidity
| |
| *Confirm serologically, not useful in acute phase
| |
|
| |
| ==Disposition==
| |
|
| |
| ==See Also==
| |
| *[[Travel Medicine]]
| |
|
| |
| ==References==
| |
| <references/>
| |
| [[Category:Tropical Medicine]]
| |
| [[Category:ID]]
| |
|
| |
|
| |
|
| |
| ==Differential Diagnosis==
| |
| *Non-specific viral illness
| |
| *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>
| |
| {{Tick borne illnesses DDX}}
| |
| {{Template:Fever in Traveler DDX}}
| |
|
| |
| ==Evaluation==
| |
|
| |
| ===Work up===
| |
| *Infectious work up
| |
| **Not sensitive or specific
| |
| **CBC- can show anemia and thrombocytopenia
| |
| **LFTs- often elevated 3-5x normal
| |
| **Lumbar Puncture- resembles aseptic meningitis
| |
| ===Diagnostic labs===
| |
| *Immunofluorescent assay is the gold standard
| |
| **Becomes diagnostic with time. Rarely positive at onset of illness.
| |
| *PCR
| |
|
| |
| ==Management==
| |
| *[[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>
| |
| **Children - 2.2mg/kg BID
| |
| *[[Chloramphenicol]] 50-100mg/kg/day div Q6hr (Max dose = 4g/day)
| |
|
| |
| ==See Also==
| |
|
| |
| ==External Links==
| |
|
| |
| ==References==
| |
| <references/>
| |
|
| |
|
| [[Category:ID]] | | [[Category:ID]] |
