<prompt> Which of the following characterizes Q fever?Has an incubation period of four to six weeksis an acute febrile illness caused by Coxiella BurnetiiIs an illness confined to the upper respiratory tractIs most commonly found in tropical region  <response>: Q fever is an acute, flulike illness caused by C. burnetii. It is the one rickettsial disease not transmitted by the bite of a tick. C. burnetii is found in high concentrations in the urine, feces, and placental tissueamniotic fluid of cattle, goats, and sheep. Transmission to humans is by aerosol inhalation of those specimens. 