COXIELLA INFECTION : Q FEVER
Q fever is primarily a zoonosis transmitted from animals to humans by inhalation rather than by arthropod bite. Its distribution is worldwide among a wide range of mammals, of which cattle, sheep, and goats are most associated with transmission to humans. C. burnetii grows particularly well in placental tissue, attaining huge numbers (>1010 per gram), which at the time of parturition contaminate the soil and fomites, where it may survive for years. Q fever occurs in those individuals exposed to infected animals or their products, particu-larly workers involved with slaughtering. Another high-risk environment is animal research facilities that have not provided adequate protection for personnel. Infection in all of these circumstances is believed to result from inhalation, which may be at some distance from the site of generation of the infectious aerosols. Infection can also occur from ingestion of animal products such as unpasteurized milk.