- 1 Bacillus anthracis - Anthrax
- 1.1 Hosts
- 1.2 Transmission/Exposure Routes
- 1.3 Case fatality ratio
- 1.4 Incubation Times
- 1.5 Burden of Disease
- 1.6 Microbiology
- 1.7 Envrionmental Survival
- 1.8 Recommended Dose Response model
- 1.9 References
Bacillus anthracis - Anthrax
This bacterium infects multiple types of hosts including herbivorous mammals such as livestock and is considered zoonotic however humans are a dead end host and do not become infectious.
Cutaneous: skin contact with spores from infected animals (95% of Cases; Most in Africa, Asia, and eastern Europe).
Gastrointestinal: eating poorly cooked meat/dairy from infected animal.
Inhalation: Inhalation of spores
Injectional: soft tissue infection associated with injection drug use
(Int Care Med)
Anthrax is not contagious and cannot be transmitted from person-to-person. 
Case fatality ratio
|Case Fatality Ratio||Pathway/conditions||Population||References|
|1%||Cutaneous with treatment||General US Population|||
|20%||Cutaneous without treatment||General US population|||
|75%||Inhalation despite treatment||Not Reported|||
|45%||2001 US Attack||Adult US|||
|14% (5 of 37)||Cutaneous||Children 1900-2005|||
|65% (13 of 20)||Gastrointestinal||Children 1900-2005|||
|100% (6 of 6)||primary meningoencephalitis||Children 1900-2005|||
|1.5% (of 132)||Not reported||Hospitalized adults and children, Turkey 1986 to 2000|||
|1-7 days|| Inhalation
|60 (max)|| Inhalation
|10 Days (SD: 8.67)||Inhalation||Sverdlovsk 1979 outbreak (70 cases)|||
Burden of Disease
Duration of infectiousness and disease
- Primary skin lesion 3-5 days after infection is painless puriritic papule.
- Lesion forms a necrotic vesicle leaving a black eschar surrounded by edma.
- Eschar dries and sloughs in next 1-2 weeks.
- Oral-pharyngeal form: oral or esophageal ulcer with regional lymphadenopathy edema and sepsis
- Lower GI form: primary intestinal lesions predominantly in terminal ileum or cecum. Nausea, vomiting, malaise, bloody diarrhea, acute abdomen, and sepsis are common symptoms of the Lower GI form.
Flu-like symptoms including: Fever (temperature greater than 100 degrees F). The fever may be accompanied by chills or night sweats. Cough, usually a non-productive cough, chest discomfort, shortness of breath, fatigue, muscle aches Sore throat, followed by difficulty swallowing, enlarged lymph nodes, headache, nausea, loss of appetite, abdominal distress, vomiting, or diarrhea
Excretion Rates (see Exposure)
Spores are cleared from the lung at a rate between 8-14% per day. 
Anthrax vaccination consists of 5 total intramuscular injections, followed by recommended annual boosters to maintain immunity. 
Gram +, aerobic, encapsulated, nonmotile. Exists in a dormant spore or an actively replicating vegetative rod form Extremely hardy spores can persist for years, even decades. (Int Care Med)
Recommended Dose Response model
- Brookmeyer, R., Johnson, E., & Barry, S. (2005). Modelling the incubation period of anthrax. Statistics in Medicine, 24(4), 531–542. doi:10.1002/sim. Full Text
- Holty J, Bravata D, Liu H, Olshen R, Mcdonald K, and Owens D. (2006) Systematic Review: A Century of Inhalational Anthrax Cases from 1900 to 2005. Annals of Internal Medicine. 144, 4. 270-280. Full Text
- Bravata D, Holty J, Wang E, Lewis R, Wise P, McDonald K, and Owen D. (2007) Inhalational, Gastrointestinal, and Cutaneous Anthrax in Children. Arch Pediatr Adolesc Med. 161 (9): 896-905. Full Text
- Kaya A, Tasyaran M, Erol S, Ozkurt Z, and Ozkan B. (2002) Anthrax in Adults and Children: A Review of 132 Cases in Turkey. Eur J Clin Microbiol Infect Dis. 21: 258-261. Full Text