A disease due to the organism Coxiella burneti. It is characterised by fever, severe headache and often PNEUMONIA. It was first described in 1937 amongst abattoir workers in Brisbane. The disease was given the name ‘Q’ fever, the Q (as in question mark) referring to the unknown cause of the condition when first described.

The principal reservoir of human infection in Britain is probably cattle and sheep, in which the infection is usually sub-clinical – that is, it does not cause any symptoms. The diagnosis is confirmed by the detection of serum antibodies to Coxiella burneti. The organism is sensitive to the antibiotic tetracycline.