Q fever, a rickettsial infection caused by Coxiella burnetii, has been recognized as a widely distributed zoonosis with the potential for causing both sporadic and epidemic disease. The resistance of C burnetii to heat, chemical agents, and desiccation allows the agent to survive for extended periods outside the host.
The infection is spread by the inhalation of infected material, mainly from sheep and goats. They shed the organism in feces, milk, nasal discharge, placental tissue, and amniotic fluid.
The clinical spectrum of disease ranges from unapparent to fatal. Respiratory manifestations usually predominate; endocarditis and hepatitis can be complications.

If agglutination reaction are observed the following approximate titres would be observed if a confirmatory tube test was carried out : 80 ul. = 1:20 40 ul = 1:40 20 ul = 1:80 10 ul = 1:160 5 ul = 1:320 In this way the rapid slide test provides an approximation to the expected results from a corresponding tube test Note : It is necessary to perform all dilutions in the slides test to obviate the prozone effect where higher concentrations of the serum may give a negative resukt but further dilutions may give a positive result.