Coxiella burnetii – named for Cox and Burnet – is no longer regarded as closely related to the Rickettsiae, but as similar to Legionella and Francisella, and is a Gammaproteobacterium. Society and culture
An early mention of Q fever was important in one of the early Dr. Kildare films (1939, Calling Dr. Kildare). Kildares mentor Dr. Gillespie (Lionel Barrymore) tires of his protégé working fruitlessly on "exotic diagnoses" ("I think its Q fever!") and sends him to work in a neighborhood clinic, instead.Q fever was also highlighted in an episode of the U.S. television medical drama House ("The Dig", season seven, episode 18). Biological warfare
C. burnetii has been used to develop biological weapons.The United States investigated it as a potential biological warfare agent in the 1950s, with eventual standardization as agent OU. At Fort Detrick and Dugway Proving Ground, human trials were conducted on Whitecoat volunteers to determine the median infective dose (18 MICLD50/person i.h.) and course of infection. The Deseret Test Center dispensed biological Agent OU with ships and aircraft, during Project 112 and Project SHAD. As a standardized biological, it was manufactured in large quantities at Pine Bluff Arsenal, with 5,098 gallons in the arsenal in bulk at the time of demilitarization in 1970. C. burnetii is currently ranked as a "category B" bioterrorism agent by the CDC. It can be contagious, and is very stable in aerosols in a wide range of temperatures. Q fever microorganisms may survive on surfaces up to 60 days.
Annual screening is typically recommended.In 2001, Australia introduced a national Q fever vaccination program for people working in "at risk" occupations. Vaccinated or previously exposed people may have their status recorded on the Australian Q Fever Register, which may be a condition of employment in the meat processing industry or in veterinary research. An earlier killed vaccine had been developed in the Soviet Union, but its side effects prevented its licensing abroad.Preliminary results suggest vaccination of animals may be a method of control. Published trials proved that use of a registered phase vaccine (Coxevac) on infected farms is a tool of major interest to manage or prevent early or late abortion, repeat breeding, anoestrus, silent oestrus, metritis, and decreases in milk yield when C. burnetii is the major cause of these problems. Treatment
Treatment of acute Q fever with antibiotics is very effective and should be given in consultation with an infectious diseases specialist. Commonly used antibiotics include doxycycline, tetracycline, chloramphenicol, ciprofloxacin, ofloxacin, and hydroxychloroquine. Chronic Q fever is more difficult to treat and can require up to four years of treatment with doxycycline and quinolones or doxycycline with hydroxychloroquine. If a person has Chronic Q fever, doxycycline and hydroxychloroquine will be prescribed for at least eighteen months. Q fever in pregnancy is especially difficult to treat because doxycycline and ciprofloxacin are contraindicated in pregnancy. The preferred treatment for pregnancy and children under the age of eight is co-trimoxazole. Epidemiology
The pathogenic agent is found worldwide, with the exception of New Zealand.