Read condition-specific symptoms and clinical context for Francisella tularensis. A rabbit-and-rodent bacterium so infectious that a handful of cells can cause illness, yet it is not passed between people.
PHAC describes F. tularensis as a Gram-negative, non-motile coccobacillus, non-sporing and aerobic, requiring cystine for growth, and distinguishes Jellison type A, which is highly virulent, from type B, which causes milder disease. Its infectious dose is extraordinarily low — PHAC gives 5 to 10 organisms by the respiratory route against 10⁶ to 10⁸ by ingestion. CDC states that people become infected through tick and deer fly bites, skin contact with infected animals, drinking contaminated water, and inhaling contaminated aerosols or agricultural and landscaping dust, and that naturally occurring infections have been reported from all states except Hawaii. Human-to-human transmission is rare.
PHAC describes the ulceroglandular form and gives an incubation period of 1 to 14 days, usually 3 to 5 days. CDC states that symptoms vary depending on how the person was infected.
Possible symptoms: A slow-healing ulcer at the site of infection; Swelling of the regional lymph nodes; Prolonged fever.
PHAC gives a 5 to 15% fatality rate for type B strains. CDC describes multiple exposure routes including tick and deer fly bites and skin contact with infected animals, so the history of exposure guides testing. Diagnosis and treatment are clinical decisions.
PHAC states that inhalation may produce pneumonic disease or a primary systemic (typhoidal) picture, and gives approximately 35% mortality from pulmonary tularemia caused by type A strains.
Possible symptoms: Chest illness after inhaling contaminated dust or aerosols; Prolonged fever; Systemic illness without a visible entry site.
PHAC gives approximately 35% mortality from pulmonary tularemia caused by type A strains, against 5 to 15% for type B strains overall. Subspecies and route both matter, so one figure does not describe all tularemia.
Outdoor or animal exposure in an area where tularemia occurs does not mean infection.
The bundled sources give no symptom list for exposure that does not lead to illness, and none is invented here. PHAC records wild animals, particularly rabbits, and birds as hosts along with some domestic animals, and states that human-to-human transmission is rare, so a person with tularemia is not a source for others. CDC notes the disease is more common in males, possibly because of a greater likelihood of exposure through hunting and landscaping — an exposure pattern rather than a biological susceptibility. This profile assigns no human carriage state.
Because the respiratory infectious dose is as low as 5 to 10 organisms, laboratory exposures are managed under formal occupational protocols. Community exposure questions are for local public-health services.
Source check: 2026-09-20. Educational content; independent scientific review remains pending.