Difference between revisions of "Coxiella burnetii"

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==''Coxiella burnetii''==
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=Hosts=
 
 
===Hosts===
 
 
Animal and human
 
Animal and human
  
===Transmission/Exposure Routes===
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=Transmission/Exposure Routes=
 
Infection of humans usually occurs by inhalation of these organisms from air that contains airborne barnyard dust contaminated by dried placental material, birth fluids, and excreta of infected animals
 
Infection of humans usually occurs by inhalation of these organisms from air that contains airborne barnyard dust contaminated by dried placental material, birth fluids, and excreta of infected animals
  
===Case Fatality Ratio===
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=Case Fatality Ratio=
 
The estimated case fatality rate is low,  at 1-2% of hospitalized patients.<ref name=Parker>Parker, N. R., Barralet, J. H., & Bell, A. M. (25 February). Q fever. The Lancet, 367(9511), 679–688. doi:10.1016/S0140-6736(06)68266-4 [Http//:www.sciencedirect.com/science/article/pii/S0140673606682664 Full Text]</ref>
 
The estimated case fatality rate is low,  at 1-2% of hospitalized patients.<ref name=Parker>Parker, N. R., Barralet, J. H., & Bell, A. M. (25 February). Q fever. The Lancet, 367(9511), 679–688. doi:10.1016/S0140-6736(06)68266-4 [Http//:www.sciencedirect.com/science/article/pii/S0140673606682664 Full Text]</ref>
  
===Incubation periods===
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=Incubation periods=
The acute symptoms usually develop within 2-3 weeks of exposure, although as many as half of humans infected do not show symptoms ([http://www.cdc.gov/qfever CDC])
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The acute symptoms usually develop within 2-3 weeks of exposure, although as many as half of humans infected do not show symptoms<ref name=CDC>[http://www.cdc.gov/qfever CDC Page]</ref>
  
===Burden of Disease===
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=Burden of Disease=
 
Q Fever became a reportable disease in the United States in 1999.  Between 2000 and 2004, the US saw an average of 51 cases every year.  In 2005, 136 cases were reported to the CDC, and 169 in 2006.<ref name=McQuiston>McQUISTON, J. H., Holman, R. C., McCALL, C. L., Childs, J. E., Swerdlow, D. L., & Thompson, H. A. (2006). National Surveillance and the Epidemiology of Human Q Fever in the United States, 1978–2004. The American Journal of Tropical Medicine and Hygiene, 75(1), 36–40. [http://www.ajtmh.org/content/75/1/36.full Full Text]</ref> <br/>
 
Q Fever became a reportable disease in the United States in 1999.  Between 2000 and 2004, the US saw an average of 51 cases every year.  In 2005, 136 cases were reported to the CDC, and 169 in 2006.<ref name=McQuiston>McQUISTON, J. H., Holman, R. C., McCALL, C. L., Childs, J. E., Swerdlow, D. L., & Thompson, H. A. (2006). National Surveillance and the Epidemiology of Human Q Fever in the United States, 1978–2004. The American Journal of Tropical Medicine and Hygiene, 75(1), 36–40. [http://www.ajtmh.org/content/75/1/36.full Full Text]</ref> <br/>
 
The annual has been reported as 0.28 cases per million persons<ref name=McQuiston></ref><br/>
 
The annual has been reported as 0.28 cases per million persons<ref name=McQuiston></ref><br/>
Internationally, prevelance is estimated from 5% in urban areas to 30% in rural areas.  This is likely an underestimate due to asymptomatic infections.  Results of serological testing of blood donors revealed a prevalence of 18% to 37% in Africa.  The United Kingdom sees approximately 100 cases of Q Fever a year ([http://emedicine.medscape.com/article/227156-overview#a0156 Struble, K. 2012]).
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Internationally, prevelance is estimated from 5% in urban areas to 30% in rural areas.  This is likely an underestimate due to asymptomatic infections.  Results of serological testing of blood donors revealed a prevalence of 18% to 37% in Africa.  The United Kingdom sees approximately 100 cases of Q Fever a year<ref name=Struble>Struble, K. Cunha, B. (2012) "Q Fever" Medscape Reference. http://emedicine.medscape.com/article/227156-overview#a0156</ref>
  
 
====Duration of infectiousness and disease====
 
====Duration of infectiousness and disease====
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Q fever is rarely contagious between humans.<ref name=Parker></ref><br/>
 +
Acute illness responds well to antibiotic treatment, and fevers usually resolve in an average of 4.3 days<ref name=Parker></ref><br/>
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Chronic illness is less common, but can develop if an acute illness is not treated quickly. Endocartitis accounts for 60-70% of chronic Q fever and is the most common cause of fatality of the illness.<ref name=Parker></ref>
 +
 
====Symptomology====
 
====Symptomology====
 
Most patients (50-60%) infected with Q fever are asymptomatic. Those who do show symptoms present flu-like symptoms including fevers, coughs, sweats, myalgias, and arthralgias. Other possible symptoms are pneumonia and hepatitis.<ref name=Hartzell>Hartzell, J. D., Wood-Morris, R. N., Martinez, L. J., & Trotta, R. F. (2008). Q Fever: Epidemiology, Diagnosis, and Treatment. Mayo Clinic Proceedings, 83(5), 574–579. doi:10.4065/83.5.574 [http://download.journals.elsevierhealth.com/pdfs/journals/0025-6196/PIIS0025619611607337.pdf Full Text]</ref>
 
Most patients (50-60%) infected with Q fever are asymptomatic. Those who do show symptoms present flu-like symptoms including fevers, coughs, sweats, myalgias, and arthralgias. Other possible symptoms are pneumonia and hepatitis.<ref name=Hartzell>Hartzell, J. D., Wood-Morris, R. N., Martinez, L. J., & Trotta, R. F. (2008). Q Fever: Epidemiology, Diagnosis, and Treatment. Mayo Clinic Proceedings, 83(5), 574–579. doi:10.4065/83.5.574 [http://download.journals.elsevierhealth.com/pdfs/journals/0025-6196/PIIS0025619611607337.pdf Full Text]</ref>
  
====Latency====
 
====Asymptomatic Rates====
 
 
====Excretion Rates  (see Exposure) ====
 
====Excretion Rates  (see Exposure) ====
 
====Immunity====
 
====Immunity====
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Live, whole-cell, and acellular vaccines have been developed for Q fever.<ref name=Parker></ref>
  
===Microbiology===
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=Microbiology=
 
Obligate intracellular small Gram-negative bacteria  
 
Obligate intracellular small Gram-negative bacteria  
  
===Environmental Survival===
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=Environmental Survival=
 
The organism is extremely hardy and resistant to heat, drying, and many common disinfectants which enable the bacteria to survive for long periods in the environment
 
The organism is extremely hardy and resistant to heat, drying, and many common disinfectants which enable the bacteria to survive for long periods in the environment
  
===Recommended Dose Response Model===
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=Recommended Dose Response Model=
<br />[[has DR model::Dose response models for Coxiella burnetii]] <br />Beta-Poisson: α is 0.36, N<sub>50</sub> is 4.93E+08 <br /> [[File:Betapoisson_model.jpg|thumb|left|300px]]
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<br />[[Coxiella burnetii: Dose Response Models]] <br />Beta-Poisson: α is 0.36, N<sub>50</sub> is 4.93E+08 <br /> [[File:Betapoisson_model.jpg|thumb|left|300px]]<br /><br /><br /><br />
 
 
 
 
 
 
 
 
 
 
 
 
  
  
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<headertabs />
  
 
===References===  
 
===References===  
Struble, K. Cunha, B. (2012) "Q Fever" Medscape Reference. Retrieved on 2-1-2012 from http://emedicine.medscape.com/article/227156-overview#a0156 <br />
 
http://www.cdc.gov/qfever/ <br />
 
 
http://en.wikipedia.org/wiki/Coxiella_burnetii <br />
 
http://en.wikipedia.org/wiki/Coxiella_burnetii <br />
 
<references/>
 
<references/>
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<br>
 
<br>
[[Category:PSDS]]
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[[Category:Agent Overview]][[Category:Bacterium]]
[[Category:Agent]][[Category:Bacterium]]
 

Latest revision as of 13:33, 25 September 2012

[edit]

Animal and human

Infection of humans usually occurs by inhalation of these organisms from air that contains airborne barnyard dust contaminated by dried placental material, birth fluids, and excreta of infected animals

The estimated case fatality rate is low, at 1-2% of hospitalized patients.[1]

The acute symptoms usually develop within 2-3 weeks of exposure, although as many as half of humans infected do not show symptoms[2]

Q Fever became a reportable disease in the United States in 1999. Between 2000 and 2004, the US saw an average of 51 cases every year. In 2005, 136 cases were reported to the CDC, and 169 in 2006.[3]
The annual has been reported as 0.28 cases per million persons[3]
Internationally, prevelance is estimated from 5% in urban areas to 30% in rural areas. This is likely an underestimate due to asymptomatic infections. Results of serological testing of blood donors revealed a prevalence of 18% to 37% in Africa. The United Kingdom sees approximately 100 cases of Q Fever a year[4]

Duration of infectiousness and disease

Q fever is rarely contagious between humans.[1]
Acute illness responds well to antibiotic treatment, and fevers usually resolve in an average of 4.3 days[1]
Chronic illness is less common, but can develop if an acute illness is not treated quickly. Endocartitis accounts for 60-70% of chronic Q fever and is the most common cause of fatality of the illness.[1]

Symptomology

Most patients (50-60%) infected with Q fever are asymptomatic. Those who do show symptoms present flu-like symptoms including fevers, coughs, sweats, myalgias, and arthralgias. Other possible symptoms are pneumonia and hepatitis.[5]

Excretion Rates (see Exposure)

Immunity

Live, whole-cell, and acellular vaccines have been developed for Q fever.[1]

Obligate intracellular small Gram-negative bacteria

The organism is extremely hardy and resistant to heat, drying, and many common disinfectants which enable the bacteria to survive for long periods in the environment

References

http://en.wikipedia.org/wiki/Coxiella_burnetii

  1. 1.0 1.1 1.2 1.3 1.4 Parker, N. R., Barralet, J. H., & Bell, A. M. (25 February). Q fever. The Lancet, 367(9511), 679–688. doi:10.1016/S0140-6736(06)68266-4 [Http//:www.sciencedirect.com/science/article/pii/S0140673606682664 Full Text]
  2. CDC Page
  3. 3.0 3.1 McQUISTON, J. H., Holman, R. C., McCALL, C. L., Childs, J. E., Swerdlow, D. L., & Thompson, H. A. (2006). National Surveillance and the Epidemiology of Human Q Fever in the United States, 1978–2004. The American Journal of Tropical Medicine and Hygiene, 75(1), 36–40. Full Text
  4. Struble, K. Cunha, B. (2012) "Q Fever" Medscape Reference. http://emedicine.medscape.com/article/227156-overview#a0156
  5. Hartzell, J. D., Wood-Morris, R. N., Martinez, L. J., & Trotta, R. F. (2008). Q Fever: Epidemiology, Diagnosis, and Treatment. Mayo Clinic Proceedings, 83(5), 574–579. doi:10.4065/83.5.574 Full Text