Q Fever Outbreak Investigated in Scotland
Local public health authorities in Scotland are investigating an outbreak of Q fever in workers in a meat processing plant. The investigation was launched after almost a quarter of the plant’s staff fell ill mostly with two or more of the following symptoms: fever, headache, muscle pain, dry cough and joint pain. As of 4th August 2006, 51 cases had been identified and nine patients were admitted to hospital.
As Q fever can be contracted by airborne spread, enhanced surveillance was undertaken to identify cases in the community living in the vicinity of the meat processing plant. So far no cases have been identified in individuals who do not work at the plant.
Q fever is an uncommon zoonotic infection caused by an organism called Coxiella burnetii. The organism is most commonly found in infected farm animals, especially sheep, cattle and goats, it may also be found in cats and wild animal species such as birds, rodents or bats; in some countries it is also carried by ticks. Transmission of C. burnetii to humans occurs primarily through inhalation of aerosols or dust contaminated with faeces or urine, or from direct contact with infected animals or their products of conception, or at slaughter. It may also be acquired from drinking unpasteurised milk. It is extremely rare for the infection to be passed from person to person and does not typically occur. The infective dose can be as low as one organism, and so large outbreaks can be caused by a small source. C. burnetii can survive for many years as a spore-like form before being inhaled and causing infection.
The human form of Q fever is divided into acute and chronic Q fever. Usually the symptoms of Q fever occur two or three weeks after exposure and illness is typically self limiting and influenza-like. Symptoms include:
· Fever (high temperature)
· Muscle pains
· Fatigue (tiredness)
· Dry cough
Q fever is diagnosed by a blood test but a positive result is obtained two to four weeks after onset of the illness.
Full recovery usually occurs, even without treatment, but in some cases symptoms can be serious or prolonged, especially with pneumonia or pre-existing heart disease, and may require hospital admission. Acute Q fever is treatable with antibiotics. The chronic Q fever form, particularly endocarditis (inflammation of the inner lining of the heart), is a more serious complication which occurs in about 10% of cases and may not appear until several years later.
Outbreaks are frequently reported worldwide, but sources of infection in sporadic cases are often difficult to pinpoint. There were 10 cases of Q fever reported in Ireland in 2005.
For more detailed information on this outbreak go to:
Eurosurveillance, Volume 11, Issue 8
HPS Weekly Report, Volume 40, Issue 2006/29
For further information on Q Fever go to:
CDC, US: Q Fever
HPA, UK: Q Fever