Q (or "query") fever generally affects sheep, cattle, and other farm animals.
The disease agent, the rickettsial bacterium Coxiella burnetti, builds
up in placental tissues, so veterinarians and farmers aiding animal births are
at risk. But natural human cases are rare.
In the 1960s, bioweapons developers in the U.S. considered Q fever an excellent
"incapacitating" agent. The disease is debilitating, but rarely lethal. The
U.S. military envisioned using Q fever to cripple enemy forces and drain them
The Soviets, and possibly Iraq, have developed and tested Q fever. And the cult
Aum Shinrikyo obtained the microbe and toyed unsuccessfully with its use. Q
fever may appeal less to bioterrorists than to militaries, however, because it
is an inherently survivable disease.