Difference between revisions of "Bacillus anthracis"
From QMRAwiki
m |
|||
| Line 1: | Line 1: | ||
==''Bacillus anthracis'' - Anthrax== | ==''Bacillus anthracis'' - Anthrax== | ||
| − | + | =Hosts= | |
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. | 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. | ||
| − | + | =Transmission/Exposure Routes= | |
Cutaneous: skin contact with spores from infected animals (95% of Cases; Most in Africa, Asia, and eastern Europe).<br /> | Cutaneous: skin contact with spores from infected animals (95% of Cases; Most in Africa, Asia, and eastern Europe).<br /> | ||
Gastrointestinal: eating poorly cooked meat/dairy from infected animal. <br /> | Gastrointestinal: eating poorly cooked meat/dairy from infected animal. <br /> | ||
| Line 11: | Line 11: | ||
Anthrax is not contagious and cannot be transmitted from person-to-person. <ref name=Brookmeyer></ref> | Anthrax is not contagious and cannot be transmitted from person-to-person. <ref name=Brookmeyer></ref> | ||
| − | + | =Case fatality ratio = | |
{| | {| | ||
{| border = "1" | {| border = "1" | ||
| Line 90: | Line 90: | ||
|} | |} | ||
| − | + | =Incubation Times= | |
{| | {| | ||
{| border = "1" | {| border = "1" | ||
| Line 124: | Line 124: | ||
|} | |} | ||
| − | + | =Burden of Disease= | |
| Line 154: | Line 154: | ||
Anthrax vaccination consists of 5 total intramuscular injections, followed by recommended annual boosters to maintain immunity. <ref name=CDC></ref> | Anthrax vaccination consists of 5 total intramuscular injections, followed by recommended annual boosters to maintain immunity. <ref name=CDC></ref> | ||
| − | + | =Microbiology= | |
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.<ref name=IntCareMed></ref> | 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.<ref name=IntCareMed></ref> | ||
| − | + | =Envrionmental Survival= | |
| − | + | =Recommended Dose Response model= | |
[[has DR model::Dose response models for Bacillus anthracis]] | [[has DR model::Dose response models for Bacillus anthracis]] | ||
<br /> | <br /> | ||
Revision as of 11:53, 2 August 2012
Contents
Bacillus anthracis - Anthrax
Hosts
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.
Transmission/Exposure Routes
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
[1]
Anthrax is not contagious and cannot be transmitted from person-to-person. [2]
Case fatality ratio
| Case Fatality Ratio | Pathway/conditions | Population | References |
| 1% | Cutaneous with treatment | General US Population | [3] |
| 20% | Cutaneous without treatment | General US population | [3] |
| 75% | Inhalation despite treatment | Not Reported | [3] |
| 89% | Inhalation | Occupationally Acquired: 20th century untreated | [1] |
| 45% | 2001 US Attack | Adult US | [4] |
| 14% (5 of 37) | Cutaneous | Children 1900-2005 | [5] |
| 60% | Inhalation | Children 1900-2005 | [5] |
| 65% (13 of 20) | Gastrointestinal | Children 1900-2005 | [5] |
| 100% | Gastrointestinal | Unreported | [1] |
| 100% (6 of 6) | primary meningoencephalitis | Children 1900-2005 | [5] |
| 100% (6 of 6) | primary meningoencephalitis | Children 1900-2005 | [5] |
| 1.5% (of 132) | Not reported | Hospitalized adults and children, Turkey 1986 to 2000 | [6] |
| 30% (3 of 10) | Injectional | Adults aged 23-53, UK | [1] |
Incubation Times
| Days | Pathway | Population | Reference |
| 0-1 | Cutaneous | Not Reported | [3] |
| 1-7 days | Inhalation
Ingestion |
Not Reported | [3] |
| 60 (max) | Inhalation
Ingestion |
Not Reported | [3] |
| 10 Days (SD: 8.67) | Inhalation | Sverdlovsk 1979 outbreak (70 cases) | [2] |
Burden of Disease
Duration of infectiousness and disease
Gastrointestinal: 10-14 days[1]
Symptomology
Cutaneous:
- 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.
Gastrointestinal:
- 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.
Inhalational:
Two-stages
- 1: Flu-like symptoms including cough fever, fatigue that last from hours to a few days
- 2: Rising fever, dyspnea, diaphoresis, shock. In advanced form, cyanosis and hypotension progress rapidly and death can occur within hours
Injectional:
- Tissue swelling around the injection site
- Abdominal symptoms[1]
Excretion Rates (see Exposure)
Spores are cleared from the lung at a rate between 8-14% per day. [2]
Immunity
Anthrax vaccination consists of 5 total intramuscular injections, followed by recommended annual boosters to maintain immunity. [3]
Microbiology
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.[1]
Envrionmental Survival
Recommended Dose Response model
Dose response models for Bacillus anthracis
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Int Care Med
- ↑ 2.0 2.1 2.2 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
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 CDC
- ↑ 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
- ↑ 5.0 5.1 5.2 5.3 5.4 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
http://en.wikipedia.org/wiki/Anthrax
