C burnetii infection in livestock often goes unnoticed. In humans, acute C burnetii infection is often asymptomatic or mistaken for an influenza like illness or a typical pneumonia . In rare cases, C burnetii infection becomes chronic, with devastating results, especially in patients with pre excisting valvular heart disease.
There are several aspects of Q fever that make it challenging for healthcare providers to diagnose and treat. Symptoms may vary from patient to patient and can be difficult to distinguish from other diseases. Treatment is more likely to be effective if started in the first three days of symptoms. Diagnostic tests based on the detection of antibodies will frequently appear negative in the first 7-10 days of illness.
In June 2006, the UK experienced its largest outbreak of Q fever with 138 cases associated with a slaughterhouse near Stirling in Scotland. The slaughterhouse had been processing post-parturition ewes which were thought to be the likely source. Mortality of acute Q fever is <2% but hospitalisation is commonly required. Hence proper health conditions should be maintained.