Tularemia
Basics
Description
Description
- Tularemia is an acute febrile illness caused by the small aerobic gram-negative pleiomorphic intracellular coccobacillus Francisella tularensis:
- Organism is highly infectious
- Person-to-person transmission has not been reported
- Humans become infected through different environmental exposures:
- Bites from infected tick, deer fly, mosquito, or other infected insect
- Direct contact with infectious animal tissue or fluid
- Contact with or ingestion of contaminated food, water, or soil
- Inhalation of infected aerosols (e.g., cutting grass with power mowers, which may aerosolize the organism)
- Prevention should focus on insect repellents, avoiding untreated surface water, using gloves when handling animals such as rabbits, prairie dogs, rodents, and cooking meat thoroughly
- The 4 major strains of the bacterium have different virulence and geographic location:
- Two subspecies cause human infection in North America: F. tularensis subspecies tularensis (type A, more virulent) and F. tularensis subspecies holartica (type B, less virulent). In Europe, type B predominates
- Natural hosts:
- Lagomorphs and other rodents
- Found in species of wild animals (rabbits, hares, ticks, muskrats, beavers, mice), domestic animals (sheep, cattle, cats), ticks, and water and soil contaminated by infected animals
- Natural vectors:
- Ticks
- Biting flies
- Mosquitoes
- Wild rabbits
- Rodents
- Weaponization of tularemia was accomplished during the Cold War:
- Because of its virulence and ability to be aerosolized, it remains a potential biological agent for mass destruction
- Laboratory technicians handling culture specimens are at high risk:
- F. tularensis cultures should be manipulated only in a biosafety level 3 facility
Etiology
Etiology
- Individuals who spend time outdoors in endemic areas are at higher risk:
- Farmers
- Hunters
- Forest workers
- Lawnmowers/landscapers
- Those who handle animal carcasses are at highest risk (taxidermists and butchers)
- Those in contact with polluted waters
- Two-thirds of cases occur in males
- Although tularemia can occur worldwide, it is endemic in the Northern Hemisphere:
- Reported nationwide except in Hawaii
- States with the highest incidence include Missouri, Arkansas, Kansas, South Dakota, and Oklahoma
- Increased incidence in Colorado, Nebraska, South Dakota, and Wyoming
- Few hundred cases annually in the U.S., although probably underreported
- Peak season is June–October
- Mortality is 5–15%. Appropriately treated patients have mortality as low as 1%.
Pediatric Considerations
- 25% of cases occur in children 1–14 yr of age
- Children who spend time outdoors in endemic rural areas are at risk
There's more to see -- the rest of this topic is available only to subscribers.
Citation
Schaider, Jeffrey J., et al., editors. "Tularemia." 5-Minute Emergency Consult, 6th ed., Lippincott Williams & Wilkins, 2020. Emergency Central, emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307139/1.2/Tularemia.
Tularemia. In: Schaider JJJ, Barkin RMR, Hayden SRS, et al, eds. 5-Minute Emergency Consult. Lippincott Williams & Wilkins; 2020. https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307139/1.2/Tularemia. Accessed December 9, 2024.
Tularemia. (2020). In Schaider, J. J., Barkin, R. M., Hayden, S. R., Wolfe, R. E., Barkin, A. Z., Shayne, P., & Rosen, P. (Eds.), 5-Minute Emergency Consult (6th ed.). Lippincott Williams & Wilkins. https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307139/1.2/Tularemia
Tularemia [Internet]. In: Schaider JJJ, Barkin RMR, Hayden SRS, Wolfe RER, Barkin AZA, Shayne PP, Rosen PP, editors. 5-Minute Emergency Consult. Lippincott Williams & Wilkins; 2020. [cited 2024 December 09]. Available from: https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307139/1.2/Tularemia.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC
T1 - Tularemia
ID - 307139
ED - Barkin,Adam Z,
ED - Shayne,Philip,
ED - Rosen,Peter,
ED - Schaider,Jeffrey J,
ED - Barkin,Roger M,
ED - Hayden,Stephen R,
ED - Wolfe,Richard E,
BT - 5-Minute Emergency Consult
UR - https://emergency.unboundmedicine.com/emergency/view/5-Minute_Emergency_Consult/307139/1.2/Tularemia
PB - Lippincott Williams & Wilkins
ET - 6
DB - Emergency Central
DP - Unbound Medicine
ER -