Typhus Fevers

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Basics

An infectious disease syndrome caused by several rickettsial bacterial organisms resulting in acute, chronic, and recurrent disease (1)[C]

Description

  • Acute infection caused by three species of Rickettsia
    • Epidemic typhus: human-to-human transmission by body louse; primarily in setting of refugee camps, war, famine, and disaster. Recurrent disease occurs years after initial infection and can be a source of human outbreak. Flying squirrels are a reservoir.
    • Endemic (murine) typhus: spread to humans by rat flea bite
    • Scrub typhus: infection and infestation of chiggers and of rodents to humans by the chigger; primarily in Asia and western Pacific areas
  • System(s) affected: endocrine/metabolic; hematologic/lymphatic/immunologic; pulmonary; skin/exocrine
  • Synonym(s): louse-borne typhus; Brill-Zinsser disease; murine typhus

Epidemiology

  • Epidemic and endemic typhus: rare in the United States (outside of South Texas)
  • Scrub typhus: travelers returning from endemic areas

Incidence
Endemic typhus: <100 cases annually, primarily in states around the Gulf of Mexico, especially South Texas; underreporting suspected

Etiology and Pathophysiology

  • Epidemic typhus by Rickettsia prowazekii
  • Endemic typhus by Rickettsia typhi (2)[A]
  • Scrub typhus by Rickettsia tsutsugamushi

Risk Factors

  • Vector exposure
  • Travel to endemic countries

Geriatric Considerations
Elderly may have more severe disease.

General Prevention

Vector control:

  • Scrub typhus: protective clothing and insect repellents
  • Endemic typhus: ectoparasite and rodent control
  • Epidemic typhus: delousing and cleaning of clothing; vaccine for those at high risk of exposure (typhus vaccine production discontinued in the United States)

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Basics

An infectious disease syndrome caused by several rickettsial bacterial organisms resulting in acute, chronic, and recurrent disease (1)[C]

Description

  • Acute infection caused by three species of Rickettsia
    • Epidemic typhus: human-to-human transmission by body louse; primarily in setting of refugee camps, war, famine, and disaster. Recurrent disease occurs years after initial infection and can be a source of human outbreak. Flying squirrels are a reservoir.
    • Endemic (murine) typhus: spread to humans by rat flea bite
    • Scrub typhus: infection and infestation of chiggers and of rodents to humans by the chigger; primarily in Asia and western Pacific areas
  • System(s) affected: endocrine/metabolic; hematologic/lymphatic/immunologic; pulmonary; skin/exocrine
  • Synonym(s): louse-borne typhus; Brill-Zinsser disease; murine typhus

Epidemiology

  • Epidemic and endemic typhus: rare in the United States (outside of South Texas)
  • Scrub typhus: travelers returning from endemic areas

Incidence
Endemic typhus: <100 cases annually, primarily in states around the Gulf of Mexico, especially South Texas; underreporting suspected

Etiology and Pathophysiology

  • Epidemic typhus by Rickettsia prowazekii
  • Endemic typhus by Rickettsia typhi (2)[A]
  • Scrub typhus by Rickettsia tsutsugamushi

Risk Factors

  • Vector exposure
  • Travel to endemic countries

Geriatric Considerations
Elderly may have more severe disease.

General Prevention

Vector control:

  • Scrub typhus: protective clothing and insect repellents
  • Endemic typhus: ectoparasite and rodent control
  • Epidemic typhus: delousing and cleaning of clothing; vaccine for those at high risk of exposure (typhus vaccine production discontinued in the United States)

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