Q fever pathophysiology: Difference between revisions
Jump to navigation
Jump to search
Tarek Nafee (talk | contribs) |
|||
| Line 7: | Line 7: | ||
==Pathophysiology== | ==Pathophysiology== | ||
===Transmission | ===Transmission=== | ||
The organism is transmitted through:<ref name="pmid17423643">{{cite journal |vauthors=Marrie TJ |title=Q fever - a review |journal=Can. Vet. J. |volume=31 |issue=8 |pages=555–63 |year=1990 |pmid=17423643 |pmc=1480833 |doi= |url=}}</ref> | The organism is transmitted through:<ref name="pmid17423643">{{cite journal |vauthors=Marrie TJ |title=Q fever - a review |journal=Can. Vet. J. |volume=31 |issue=8 |pages=555–63 |year=1990 |pmid=17423643 |pmc=1480833 |doi= |url=}}</ref> | ||
*Aerosoloes: Inhalation of contaminated aerosoles is the main mode of transmission. | *Aerosoloes: Inhalation of contaminated aerosoles is the main mode of transmission. | ||
| Line 15: | Line 15: | ||
*Through [[tick bites]] | *Through [[tick bites]] | ||
===Pathogenesis | ===Pathogenesis=== | ||
[[Coxiella burnetii|C. Brutenii]] has the ability to exist in 2 forms: | [[Coxiella burnetii|C. Brutenii]] has the ability to exist in 2 forms: | ||
====Small cell form | ====Small cell form<ref name="urlDiagnosis of Q Fever">{{cite web |url=http://jcm.asm.org/content/36/7/1823.short |title=Diagnosis of Q Fever |format= |work= |accessdate=}}</ref>==== | ||
Often described as the spore form of [[Coxiella burnetii|C. Brutenii]] | Often described as the spore form of [[Coxiella burnetii|C. Brutenii]] | ||
Resists the external environmental factors as heat, pressure and disinfectants for long periods. | Resists the external environmental factors as heat, pressure and disinfectants for long periods. | ||
====Large cell form | ====Large cell form==== | ||
The active form of the [[organism]] | The active form of the [[organism]] | ||
large cell form persists in the [[macrophages]] inside acidic vacuoles. | large cell form persists in the [[macrophages]] inside acidic vacuoles. | ||
| Line 33: | Line 33: | ||
**Phase II: characterized by rough [[lipopolysaccharide]] capsule and [[antibodies]] against phase II have been isolated from chronic Q fever patients. | **Phase II: characterized by rough [[lipopolysaccharide]] capsule and [[antibodies]] against phase II have been isolated from chronic Q fever patients. | ||
===Q fever as a biological weapon | ===Q fever as a biological weapon=== | ||
*Because of its route of infection it can be used as a [[biological warfare]] agent. | *Because of its route of infection it can be used as a [[biological warfare]] agent. | ||
| Line 45: | Line 45: | ||
:*Causing chronic illness in 9,000 individuals | :*Causing chronic illness in 9,000 individuals | ||
==Microscopic pathology | ==Microscopic pathology== | ||
*[[Coxiella burnetii|C. Brutenii]] is a [[gram negative]] polymorphic [[Intracellular|intracellular organism]].<ref name="urlQ Fever on JSTOR">{{cite web |url=http://www.jstor.org/stable/4458369?seq=1#page_scan_tab_contents |title=Q Fever on JSTOR |format= |work= |accessdate=}}</ref> | *[[Coxiella burnetii|C. Brutenii]] is a [[gram negative]] polymorphic [[Intracellular|intracellular organism]].<ref name="urlQ Fever on JSTOR">{{cite web |url=http://www.jstor.org/stable/4458369?seq=1#page_scan_tab_contents |title=Q Fever on JSTOR |format= |work= |accessdate=}}</ref> | ||
Revision as of 22:36, 12 July 2017
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
|
Q fever Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Q fever pathophysiology On the Web |
|
American Roentgen Ray Society Images of Q fever pathophysiology |
|
Risk calculators and risk factors for Q fever pathophysiology |
Overview
Q fever is a disease caused by C. brutenii, an intracellular gram-negative proteobacterium. The disease can have a wide range of clinical presentations and affect many organ systems due to the unique virulence factors of the organism.
Pathophysiology
Transmission
The organism is transmitted through:[1]
- 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[2]
Often described as the spore form of C. Brutenii Resists the external environmental factors as heat, pressure and disinfectants 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 analyzed 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:[3]
- Phase I: characterized by smooth lipopolysaccharide capsule. Despite being less efficient in the invasion of host cells, antibodies against phase I is always isolated from acute Q fever patients.
- Phase II: characterized by rough lipopolysaccharide capsule and antibodies against phase II have been isolated from chronic Q fever patients.
Q fever as a biological weapon
- Because of its route of infection it can be used as a biological warfare agent.
- Q-fever is category "B" agent. It is highly contagious and very stable in aerosols in a wide range of temperatures.
- Just 1-2 particles are enough to infect an individual.
- Q-fever microorganisms may survive on surfaces up to 60 days (like sporulating bacteria).
- According to WHO estimates[4], 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.[5]
- It was previously classified as a rickettsia, but now is considered a proteobacterium.
 |
 |
|---|
References
- ↑ Marrie TJ (1990). "Q fever - a review". Can. Vet. J. 31 (8): 555–63. PMC 1480833. PMID 17423643.
- ↑ "Diagnosis of Q Fever".
- ↑ Choyce DP (1992). "Anterior chamber lens exchange". J Cataract Refract Surg. 18 (5): 537. PMID 1489455.
- ↑ "apps.who.int" (PDF).
- ↑ "Q Fever on JSTOR".