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. It can survive standard disinfectants, and is resistant to many other environmental changes. "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" & "The organisms are resistant to heat, drying, and many common disinfectants."

Pathogenesis

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The ID₅₀ (the dose need 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 respiratoy symptoms, and an insidious chronic stage.

While most infections clear up spontaneously, treatment with tetracycline appears to reduce the symptomatic duration and reduce the likelihood of chronic infection.

References

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Proteobacteria