Q fever pathophysiology: Difference between revisions
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*C. Brutenii is a gram negative polymorphic intracellular organism. | *C. Brutenii is a gram negative polymorphic intracellular organism. | ||
*It was previously classified as a ricketsia, but now is considered a proteobacterium. | *It was previously classified as a ricketsia, but now is considered a proteobacterium. | ||
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![[Image:Q_fever.jpg|center|300px|thumb|Coxiella brutenii ]] | |||
![[Image:Immunohistochemical detection of Coxiella burnetii in resected cardiac valve of a 60-year-old man with Q fever endocarditis - By Mahamat A, Edouard S, Demar M, Abboud P, Patrice J-Y, La Scola B, et al. -Public domain-, via Wikime.jpg|center|300px|thumb|Immunohistochemical detection of Coxiella burnetii in resected cardiac valve of a 60-year-old man with Q fever - By Mahamat A, Edouard S, Demar M, Abboud P, Patrice J-Y, La Scola B, et al. -Public domain-, via Wikime ]] | |||
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==References== | ==References== | ||
Revision as of 16:05, 6 June 2017
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
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Q fever Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Q fever pathophysiology On the Web |
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American Roentgen Ray Society Images of Q fever pathophysiology |
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Risk calculators and risk factors for Q fever pathophysiology |
Overview
Pathophysiology
Transmission:
The organism is transmitted through:
- Aerosoloes: Inhalation of contaminated aerosoles is the main mode of transmission.
- Ingestion of raw dairy products
- Vertical (mother to fetus) transmission has been reported
- Parentral
- (Through tick bites
Pathogenesis:
C. Brutenii has the ability to exist in 2 forms:
Small cell form: Often described as the spore form of C. Brutenii Resists the external environmental factors as heat, pressure and dissinfectants for long periods
Large cell form: The active form of the organism Large cell form persists in the macrophages inside acidic vacuoles.
Small and large cell forms are antigenically different and this plays a role in the virulence of the organism. The genome of C. Brutenii has been analysed in 1995. Multiple genes encoding for Na/ ion proton exchanger have been discovered and this explains the ability of the organism to survive in low PH.
The infection has 2 phases that correlate with changes in the lipopolysaccharide of C. Brutenii.
Phase I: characterized by smooth lipopolysacharide capsule. Despite being less efficient in invasion of host cells, antibodies against phase I is always isolated from acute Q fever patients.
Phase II: characterized by rough lipopolysacharide capsule and antibodies against phase II have been isolated from chronic Q fever patients.
Q fever as a biological weapon:
C. Brutenii is an extremely virulent organism.
According to WHO estimates[1], an amount of 50 kg of C. Brutenii if spread in an area of 2 square kilometers is capable of:
- Infecting 500,000 humans
- Killing 150 individuals
- Causing acute illness in 125,000 individuals
- Causing chronic illness in 9,000 individuals
Microscopic pathology:
- C. Brutenii is a gram negative polymorphic intracellular organism.
- It was previously classified as a ricketsia, but now is considered a proteobacterium.
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References
- ↑ "apps.who.int" (PDF).