About the Q fever disease
Q fever occurs almost everywhere in the world. In Australia, Q fever was first recognised during the 1930’s when workers at a Brisbane meat processor became ill with a fever. Since the cause of the illness was unknown, the workers were diagnosed with ‘Query’ fever – which was eventually abbreviated to Q fever.
How do you catch Q fever?
Q fever can be acquired from the air or from animals. Domestic and wild animals can be infected, without showing any apparent signs of infection.
In Australia, cattle, sheep, and goats are the main reservoir, although bandicoots, kangaroos and dogs can also be infected. In Canada, Q fever has occurred from exposure to cats and rabbits. Humans can be infected with the germ (Coxiella Burnetii) following contact with infected animals or products from these animals, urine, faeces or milk birth products.
The Q fever germ is very tough and can survive in dust formed from contaminated animal products. Infected dust may settle on the ground, or on wool, hides, clothing, straw etc, and then be disturbed by movement or wind. Infection may also be acquired from drinking unpasteurised milk.
How important is Q fever?
Q fever rarely attracts media attention, and yet it is among the most costly and severe infectious diseases in Australia.
Every year, about 600 cases of Q fever are reported in Australia, of which about 300 are in Queensland. Yet because the symptoms are often mistaken for severe influenza – and some cases develop no symptoms – the real incidence of the disease is likely to be much greater. Unlike influenza, Q fever can cause severe complications such as extreme fatigue, or heart and liver damage.
In 1997 it was estimated that 1,700 weeks of work were lost to Q fever in Australia each year. The risk of contracting Q fever among unvaccinated Australian meat workers has been estimated at one in 300 every year.
Claims made to the Australian meat industry as a result of Q fever are at least AUD$1 million annually. The average cost of an uncomplicated case is $7,000, with two to four weeks of sick leave expected. Up to 20% of cases are complicated, leading to long term complications and up to 6 months sick leave being taken. Complicated cases leading to litigation are common, and the cost of this litigation ranges from $300,000 to $1.24million.
Q fever symptoms
Acute Q fever develops after an incubation period of about 3 weeks. The symptoms are:
- Fever, usually of abrupt onset and lasting for 5-50 (or more) days
- Chills lasting 3-4 days
- Profuse sweats
- Severe headache which usually lasts with the fever
- Muscle and joint aches and pains
- Profound fatigue and tiredness
- Eyes become sensitive to light
- Loss of weight
Because these symptoms occur with other diseases (such as influenza), Q fever is often misdiagnosed. Some people DO NOT develop symptoms and infection is only discovered when they are tested incidentally.
An uncomplicated Q fever infection lasts 2-6 weeks. If complications develop, people may be ill for up to 6 months. Some people develop a persistent low grade infection which causes headache, joint and muscle pain, tiredness and sweating attacks for up to 5 years.
Some Q fever patients also develop an infection in the heart muscle which may not become obvious for 5 years. After the primary attack, it is very rare for individuals to get Q fever a second time.