The Definition of Q Fever

Definition of Q Fever

Q fever is an infection caused by the bacterium Coxiella burnetii. It is a zoonotic disease, meaning it spreads from animals to people. Cattle, sheep and goats are the most common sources. The bacteria are shed in large numbers in birth products such as placentas and birthing fluids, and also in milk, urine and feces. People usually become infected by breathing in dust or aerosols contaminated by these materials.

Q fever is an occupational disease for people who work with livestock or animal products, including farmers, shearers, veterinarians and vet staff, abattoir and meat processing workers, dairy workers and laboratory staff handling the bacteria. Very few bacteria are needed to cause infection, and contaminated dust can travel some distance on the wind.

Key Facts About Q Fever

• Many infections cause no symptoms or a flu-like illness with high fever, severe headache, fatigue and muscle pain. Some people develop pneumonia or hepatitis.
• A small proportion develop chronic Q fever, which can affect the heart valves, or long-lasting post-Q fever fatigue.
• Pregnant women and people with heart valve problems or weakened immune systems face higher risk of serious complications.
• Australia offers a Q fever vaccine for at-risk workers after pre-vaccination screening. No vaccine is commercially available in the United States.
• One of the largest recorded outbreaks occurred in the Netherlands between 2007 and 2010, with more than 4,000 human cases linked to goat farms.

Example of Q Fever Risk

During lambing season, a farmhand helps with deliveries and cleans up birthing pens without respiratory protection. Two weeks later he develops a sudden high fever and severe headache. His doctor asks about his work, tests for Q fever and confirms the diagnosis. The farm reviews how birth products are disposed of and adds respiratory protection and hygiene controls for the next season.

How to Control Q Fever Risk at Work

1. Identify roles with exposure to livestock, birth products, raw animal products or contaminated dust.
2. Where available, offer vaccination after screening, as recommended in countries such as Australia.
3. Dispose of birth products promptly and safely, and limit dust from bedding and manure.
4. Provide respiratory protection, gloves, protective clothing and washing facilities for high-risk tasks.
5. Train workers on symptoms, and make sure they mention their job when seeking medical care.

Related Terms

• Zoonotic Disease
• Biological Hazard (Biohazard)
• Respiratory Protection
• Medical Surveillance
• Industrial Hygiene

Q Fever Frequently Asked Questions

How do people catch Q fever?

Most people are infected by breathing in dust or droplets contaminated with the bacteria from infected animals, especially around birthing. Drinking unpasteurized milk and contact with contaminated materials are less common routes.

Which workers are most at risk?

Farmers, livestock handlers, shearers, abattoir and meat workers, veterinarians and their staff, dairy workers and some laboratory workers face the highest risk.

Is Q fever reportable?

In many countries, including the United States and Australia, Q fever is a notifiable disease that doctors and labs must report to public health authorities. Work-related cases may also need to be recorded as occupational illnesses.

Why is it called Q fever?

The "Q" stands for "query." The disease was first described in Australia in the 1930s, when the cause of the fever was not yet known.