Coxiella burnetii, the agent of Q fever, can be transmitted by ticks.

• A. False
• B. Only by inhalation
• C. Only by direct contact with animals
• D. True

Answer: (D)

Coxiella burnetii is most commonly transmitted to people by inhaling contaminated aerosols from infected animal birth products, urine, feces, or placental tissue. In addition, ticks can harbor the organism and participate in its cycle among animals, and there are rare instances where tick exposure has been implicated in transmission to humans. However, ticks are not the main or typical route of human infection; the inhalation pathway is far more important for outbreaks. So stating that transmission by ticks can occur is accurate in a broader ecological sense, even though it is not the primary mode of human transmission.