Query fever, commonly known as ‘Q fever’, is an infectious disease that is typically transmitted to humans from infected farm animals (eg cattle, sheep or goats), infected domestic animals (eg cats or dogs) or infected wild animals (eg kangaroos).
It is caused by the bacteria coxielia burnetii, which is found in high concentrations in the tissues of infected animals and can survive in contaminated dust or soil for many months.
Between 2002 and 2012, there were 177 workers compensation claims for Q fever in NSW with costs totaling more than $3.5 million.
Spread of Q fever to humans
People at risk of contracting Q fever include:
- abattoir workers
- agricultural, farm and dairy workers
- stockyard workers
- livestock transporters
- sheep shearers, wool classers, pelt and hide processors
- people exposed to cattle, camels, sheep, goats and kangaroos or their products
- veterinary and aboratory personnel, and others who work with veterinary specimens
- dog and cat breeders
- agricultural college staff and students
- wildlife workers and volunteers, and those working outside who may handle animals such as injured fauna
- zoo workers involved with high-risk animals
- workers involved in rendering
- council/road workers who collect dead animals from the roadside
- administration and maintenance workers, and contractors who visit the above workplaces.
People usually get infected with Q fever by breathing in aerosols or dust when working with or handling infected animals, animal tissues or animal products. Infected animals often have no symptoms and can shed the bacteria into their urine, faeces or milk.
Q fever is also contracted by:
- inhaling dust from infected wool, hides, straw or grass
- handling the placenta or birth fluids of infected animals
- drinking unpasteurised milk from infected cows and goats
Contaminated work clothing is also a potential source of infection.
Q fever symptoms
Symptoms may be similar to influenza and can include sudden onset of fever, chills, profuse sweating, coughing, severe headaches, muscle pain and fatigue.
If untreated, the illness will typically last one to six weeks, with most patients gaining a life-long immunity to further infection. Occasionally, infection can persist for more than six months and this so-called 'chronic Q fever' can lead to complications such as endocarditis (inflammation of the interior of the heart) and post-Q fever fatigue syndrome . Other complications include inflammation of the liver (hepatitis) and infections of the bone (osteitis).
If your workplace is at risk of Q fever, risk control measures must be made available for your workers, contractors and others who may be exposed to the disease.
A vaccine is available to protect people against Q fever and is recommended for all those working in, or intending to work in, a high-risk occupation (unless they have prior immunity).
You must implement a pre-screening and vaccination program, utilise a particular workplace design, and use safe work practices.
Also, to control the risk of transmitting Q fever, ensure that everyone – workers, contractors, visitors, sales representatives, buyers, council workers, essential service workers and members of the public – shows proof of their immunity status before being allowed into your workplace. The risk control measures outlined below must be applied for those who are not immune or, ideally, they should be denied entry to the workplace.
A person's immune status may be reflected in the Australian Q fever register, which is accessible to registered organisations.
Pre-screening and vaccination
SafeWork NSW regards Q fever vaccination as a high order risk control measure.
A pre-screening and vaccination program might include:
- screening new workers during induction
- ensuring they are vaccinated before starting at the workplace (if they are eligible)
- allowing access to high risk work areas after immunity is established – ie 15 days after the vaccination (not after the initial skin ‘prick’ test during screening), .
In NSW, vaccinations can be done by a general practitioner.
The Australian Q Fever Register’s forms and templates should be used for all stages of the Q fever vaccination process to ensure consistency.
If a worker is not immune to Q fever and either declines or is otherwise ineligible to be vaccinated following medical advice, you should refuse entry to the workplace or provide respiratory protection (P2 respirator) and personal protective clothing (eg overalls/coat and rubber boots). Also, encourage appropriate personal hygiene procedures and only allow access to low-risk Q fever work areas.
Q fever vaccine is not recommended for children under the age of 15 years, nor for pregnant or breastfeeding women.
Identify high risk work areas where workers are more likely to be exposed to Q fever, such as:
- kill floors
- livestock transport vehicles
- yards and pens
- offal rooms
- skin sheds
- rendering areas
- handling foetal calves (eg slink rooms).
Install appropriate ventilation and dust suppression systems in these areas, to help reduce dust and other airborne particles from spreading. Ventilation systems should have the intake and exhaust vents separated to prevent recirculation of contaminated air. Also, to avoid cross-contamination, provide appropriate washing and changing facilities near these areas.
Safe work practices
To help eliminate or reduce the risk of Q fever transmission, implement the following safe work practices:
- Provide necessary information, instruction, training and supervision about Q fever to enable your workers to perform their work in a way that is safe and without risks to health.
- Arrange for personal clothing to be stored away from any work clothing that may be contaminated – work clothing should not be taken out of the workplace.
- Prohibit eating, drinking, smoking and nail-biting in animal holding or processing areas.
- Insist workers thoroughly wash their hands before eating, drinking, smoking in designated areas, before going to the toilet, and at the end of each shift .
- Wash animal urine, faeces, blood and other body fluids from the work area and equipment, and disinfect equipment and surfaces where practicable. Ensure drainage is adequate.
- Decompose (soda ash) and bury animal by-products that are not suitable for processing.
- Minimise dust in slaughter and animal housing areas.
- Pasteurise or boil milk.
- Implement an appropriate first aid program, to ensure workers with open wounds are treated quickly.
- Muzzle dogs that are used to move livestock, to prevent cross contamination.
- Implement an ongoing maintenance program – eg routine inspection of ventilation and drainage systems and wash facilities.
- Wear a mask when slashing in areas where there are livestock or native animals.
- Those who aren't immunised should not be allowed to visit high-risk work areas, such as abattoirs.
In the meat industry, the risk of Q fever transmission can be further minimised by:
- teaching appropriate knife skills, to minimize damage to the udder and the rectum and reduce potentially contaminated airborne particles from the release of milk and faeces
- maintaining the integrity of the animal organs, such as the bladder, intestines and uterus, when they are removed and lowered to the eviscerating table
- washing stock entering the kill floor with low pressure hoses, to reduce the release of potentially contaminated airborne particles
- keeping yard facilities for sheep and cattle well away from domestic living areas.