Medicines for Q fever

What it is

Q fever is an infection caused by a bacterium called Coxiella burnetii. It is usually caught from animals — particularly farm animals such as sheep, cattle, and goats, which can carry the bacteria (often without appearing ill). People usually become infected by breathing in the bacteria from dust or air contaminated by the birth products, faeces, urine, or milk of infected animals — so it is more of a risk for people who work with or are around farm animals (such as farmers, vets, abattoir workers, and others), particularly around animals giving birth. It can also, less commonly, be caught from consuming unpasteurised milk or dairy products from infected animals. It is not usually spread from person to person. Many people who are infected with Q fever have no symptoms at all, or only a mild illness. When it does cause symptoms (acute Q fever), it typically causes a flu-like illness, which can include: a high temperature (fever), which can be prominent; headache (often severe); muscle pains; tiredness; and, in some cases, a cough or chest symptoms (as it can cause a form of pneumonia), or effects on the liver (hepatitis); a rash can occur but is less common. The acute illness often gets better on its own over a couple of weeks, or is treated with antibiotics, and most people recover fully. However, there is a less common but important long-term form, chronic Q fever, which can develop months or years after the initial infection in some people (particularly those with certain underlying conditions, such as heart valve problems or a weakened immune system); this can cause more serious problems, notably an infection of the heart valves (endocarditis), and needs prolonged treatment and specialist care. Because Q fever can cause a flu-like illness and is often related to animal contact, and because it responds to specific antibiotics, it is worth considering and mentioning relevant exposure (such as contact with farm animals, or relevant occupation) to a doctor if unwell with a suggestive illness. Diagnosis is confirmed with blood tests. The key messages are that Q fever is a bacterial infection usually caught from farm animals (often causing a flu-like illness or no symptoms), that it usually resolves or is treatable with antibiotics, and that there is a rare but serious long-term form.

How it is treated

Q fever is managed by treating the acute illness with antibiotics where needed (many mild cases resolve on their own), and by recognising and treating the rare chronic form with prolonged treatment and specialist care; recognising it depends on considering relevant animal exposure. Because Q fever is often related to contact with farm animals, and its symptoms (a flu-like illness) are non-specific, it is worth considering in someone with a suggestive illness and relevant exposure (such as working with or being around farm animals — particularly around animals giving birth — or a relevant occupation, or consuming unpasteurised dairy products), and mentioning this exposure to the doctor helps point to the diagnosis; it is confirmed with blood tests (which detect the body’s response to the infection, sometimes needing repeat testing). For acute Q fever (the flu-like illness), treatment is with a specific antibiotic (typically doxycycline) to which the bacteria are sensitive, given as a course, which treats the infection and helps recovery; some mild cases may resolve on their own, but antibiotic treatment is generally used for symptomatic infection, and prompt treatment can reduce the illness and complications. Supportive care (rest and fluids) helps, and most people recover fully from the acute illness. A key part of care is being aware of, and, where relevant, monitoring for, the rare but serious chronic form (chronic Q fever), which can develop months to years after infection, particularly in people with risk factors such as heart valve problems, blood vessel abnormalities, a weakened immune system, or in pregnancy; chronic Q fever can cause serious problems, notably endocarditis (infection of the heart valves), and needs prolonged antibiotic treatment (often for a long period) and specialist care, with monitoring — so people at higher risk, or those diagnosed with Q fever, may be assessed and followed up with this in mind. Preventing Q fever is relevant particularly for people with occupational or other animal exposure: good hygiene and precautions around farm animals (especially around birthing animals and their products), appropriate protective measures for relevant occupations, avoiding unpasteurised milk and dairy products, and following any occupational guidance, help reduce the risk. The reassuring messages are that Q fever often causes no symptoms or a mild flu-like illness that resolves or is treated with antibiotics, with most people recovering fully, that recognising it (by considering relevant animal exposure) allows appropriate treatment, and that the rare but serious chronic form is treated with prolonged antibiotics and specialist care; so mentioning relevant exposure to the doctor when unwell, appropriate antibiotic treatment, awareness of the chronic form, and prevention through hygiene and precautions around animals are the keys to managing Q fever.