Coxiella burnetii
| Coxiella burnetii | ||||||||||||||
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| C. burnetii, the causative agent of Q fever C. burnetii, the causative agent of Q fever
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| Scientific classification | ||||||||||||||
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| Binomial name | ||||||||||||||
| Coxiella burnetii (Derrick 1939) Philip 1948 |
Coxiella burnetii is a species of intracellular, pathogenic bacteria, and is the causative agent of Q fever. The genus Coxiella is morphologically similar to the rickettsia, but with a variety of genetic and physiological differences. C. burnetii are small Gram negative bacteria with two growth phases, as well as a spore form which lies idle in soil.[1] It can survive standard disinfectants, and is resistant to many other environmental changes.[2]
Pathogenesis
The ID50 (the dose needed to infect 50% of experimental subjects) is one via inhalation— i.e. inhalation of one organism will yield disease in 50% of the population. Disease occurs in two states: An acute state presents with headaches, chills, and respiratory symptoms, and an insidious chronic stage.
While most infections clear up spontaneously, treatment with tetracycline or doxycycline appears to reduce the symptomatic duration and reduce the likelihood of chronic infection. A combination of erythromycin and rifampin is highly effective in curing and prevention of disease and so is vaccination with Q-vax vaccine (CSL).
Treatment
- Acute Q fever†
- Adults:
- Preferred Regimen: Doxycycline100 mg bid for 14 days
- Preferred regimen
- Alternative regimen
References
- ↑ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed. ed.). McGraw Hill. ISBN 0-8385-8529-9.
- ↑ Sankaran, Neeraja (2000). "Coxiella burnetii". Microbes and people : an A-Z of microorganisms in our lives. Phoenix, Arizona: The Oryx Press. p. 72. ISBN 1-57356-217-3. "In contrast to other rickettsiae, which are highly sensitive and easily killed by chemical disinfectants and changes in their surroundings, C. burnetii is highly resistant" & "Q fever". Centers for Disease Control and Prevention; National Center for Infectious Diseases; Division of Viral and Rickettsial Diseases; Viral and Rickettsial Zoonoses Branch. 2003-02013. Retrieved 2006-05-24. Check date values in:
|date=(help) "The organisms are resistant to heat, drying, and many common disinfectants."