Q Fever General Information

[sharon sanders]

Vet Microbiol. 2009 Aug 8. [Epub ahead of print]
Q fever.

Angelakis E, Raoult D.
Unit? des Rickettsies, CNRS UMR 6020, IFR 48, Facult? de M?decine, Universit? de la M?diterran?e, 27 Bd Jean Moulin, 13385 Marseille Cedex 05, France.
Q fever is a zoonotic disease caused by the ubiquitous pathogen Coxiella burnetii responsible for acute and chronic clinical manifestations. Farm animals and pets are the main reservoirs of infection, and transmission to human beings is mainly accomplished through inhalation of contaminated aerosols.



This illness is associated with a wide clinical spectrum, from asymptomatic or mildly symptomatic seroconversion to fatal disease. In humans Q fever can manifest as an acute disease (mainly as a self-limited febrile illness, pneumonia, or hepatitis) or as a chronic disease (mainly endocarditis), especially in patients with previous valvulopathy and to a lesser extent in immunocompromised hosts and in pregnant women.



In contrast in animals, Q fever is in most cases, strikingly asymptomatic. The definite diagnosis of Q fever is made based on a significant increase in serum antibody titers, the determination of which often requires considerable time, and therefore patients must be monitored for a certain period.

The treatment is effective and well tolerated, but must be adapted to the acute or chronic pattern with the tetracyclines to be considered the mainstay of antibiotic therapy.



Several actions have been proposed to prevent and reduce the animal and environmental contamination. Vaccination of animals in infected flocks, as well as in uninfected ones close to them, with an efficient vaccine can prevent abortions and shedding of the bacteria.

PMID: 19875249 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/pubmed/19875249?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=14

[Gert van der Hoek]

Re: Q Fever General Information

Very informative article, lots of references


Q fever

M. Maurin and D. Raoult*

Clinical Microbiology Reviews, October 1999, p. 518-553, Vol. 12, No. 4

Q fever is a zoonosis with a worldwide distribution with the exception of New Zealand. The disease is caused by Coxiella burnetii, a strictly intracellular, gram-negative bacterium.

Many species of mammals, birds, and ticks are reservoirs of C. burnetii in nature. C. burnetii infection is most often latent in animals, with persistent shedding of bacteria into the environment.

However, in females intermittent high-level shedding occurs at the time of parturition, with millions of bacteria being released per gram of placenta.

Humans are usually infected by contaminated aerosols from domestic animals, particularly after contact with parturient females and their birth products.

Although often asymptomatic, Q fever may manifest in humans as an acute disease (mainly as a self-limited febrile illness, pneumonia, or hepatitis) or as a chronic disease (mainly endocarditis), especially in patients with previous valvulopathy and to a lesser extent in immunocompromised hosts and in pregnant women. Specific diagnosis of Q fever remains based upon serology.

Immunoglobulin M (IgM) and IgG antiphase II antibodies are detected 2 to 3 weeks after infection with C. burnetii, whereas the presence of IgG antiphase I C. burnetii antibodies at titers of 1:800 by microimmunofluorescence is indicative of chronic Q fever.

The tetracyclines are still considered the mainstay of antibiotic therapy of acute Q fever, whereas antibiotic combinations administered over prolonged periods are necessary to prevent relapses in Q fever endocarditis patients.

Although the protective role of Q fever vaccination with whole-cell extracts has been established, the population which should be primarily vaccinated remains to be clearly identified. Vaccination should probably be considered in the population at high risk for Q fever endocarditis.


INTRODUCTION


Because Q fever is rarely a notifiable disease, the incidence of human Q fever cannot be assessed in most countries. Current epidemiological studies indicate, however, that Q fever should be considered a public health problem in many countries, including France, the United Kingdom, Italy, Spain, Germany, Israel, Greece, and Canada (Nova Scotia), as well as in many countries where Q fever is prevalent but unrecognized because of poor surveillance of the disease.

Q fever remains primarily an occupational hazard in persons in contact with domestic animals such as cattle, sheep and, less frequently, goats. Persons at risk from Q fever include farmers, veterinarians, abattoir workers, those in contact with dairy products, and laboratory personnel performing Coxiella burnetii culture and more importantly working with C. burnetii-infected animals.

However, there has been an increase in reports of sporadic cases in people living in urban areas after occasional contact with farm animals or after contact with infected pets such as dogs and cats.

Read everything here:

http://cmr.asm.org/cgi/content/full/12/4/518?view=full&pmid=10515901%20%20#B297

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