Zoonoses: Q-fever

Q-Fever is a disease of animals and man arising from infection with the organism Coxiella burnetii. which live within the cells of the infected individual. is. Although it has now been classified as a bacterial infection (closely related to Legionella pneumophila) it is still commonly referred to as a rickettsia in much of the literature.

Q-Fever is not a notifiable disease in animals in Great Britain. However, farmers should be aware of legislation requiring notification of human cases under the Health and Safety at Work Act which can be found on the Health and Safety Executive website.

Infection in animals

The infection has been found in various wild and domestic animals. It has also been found in birds and in some arthropods, such as ticks.

Animal infection is most commonly reported in ruminants (cattle, sheep and goats). Infection is generally considered to cause little disease in livestock so specific studies have to be conducted to assess its presence. Each year a small number of infections have been associated with abortion in cattle and sheep. It is an uncommon diagnosis of the cause of abortion in cattle and sheep in Great Britain. In 2008, there were five diagnoses of Q fever in UK farm livestock specimens submitted to VLA and SAC laboratories (two in cattle, two in sheep and one in goats). No cases had been diagnosed in 2009 up until the end of September.

Often the organism does not cause any disease in animals, but occasionally infections have been recorded as causing placentitis (inflammation of the placenta) and abortion in cattle, sheep and goats.

Transmission in animals

The organism may be present in reproductive fluids of infected animals, e.g. sheep at lambing. Infection of other animals occurs through inhalation of aerosols or ingestion of infected contaminated material. There is also the possibility that ticks carrying the infection may infect animals. The organism may also be present in raw milk, urine and faeces from infected animals. The organism may survive in a resistant spore-like form in the environment for variable periods of time and be a source of infection. It is not susceptible to common disinfectants.

Presence in the UK

The organism is distributed worldwide and is present in the UK. A small number of cases of Q fever associated with abortion in cattle, sheep or goats are diagnosed each year. In 2008, there were five diagnoses of Q fever in UK farm livestock specimens submitted to the Veterinary Laboratories Agency and Scottish Agricultural Council laboratories (two in cattle, two in sheep and one in goats). No cases had been diagnosed in 2009 up until the end of September.

Advice to farmers

Defra recommends that famers take care to check the health status of their own animals and those purchased as part of their normal biosecurity protocols. Further advice on biosecurity is available.

Infection in humans

In humans, Q-Fever is generally a self-limiting illness and many people who become infected suffer no symptoms. Some individuals become ill: their symptoms will usually be similar to a flu-like illness or pneumonia. In a small number of cases there may be serious complications. Medical advice should be sought if there is concern.

Transmission to humans

In the UK most Q fever cases are thought to be associated with exposure to farm animals or farm environments (including aerosol transmission or windborne infection), however the source and route of transmission for most sporadic cases is not determined. There were outbreaks of Q fever in humans in 2006 and 2007. A small number of cases are diagnosed each year. There were 41 confirmed cases of Q fever in humans in the UK in 2008.

Prevention in humans

Prevention in humans is primarily through good hygiene and use of protective clothing when working with farm animals, especially when handling potentially infected material, and by not drinking unpasteurised milk. Pregnant women should avoid contact with sheep and lambs during the lambing season. They should also avoid contact with other animal species if these animals are due to give birth or have recently done so.

Control measures

Q-Fever does not normally cause disease in animals. There have been cases of abortion in sheep and in cattle associated with the organism. Control of the infection where required would concentrate on management practices such as separation of animals, and hygiene measures such as appropriate disposal of placentas. If a farmer is concerned that Q-Fever infection is causing disease in the livestock, the private veterinary surgeon should be consulted for advice.

Situation in the Netherlands and the implications on the UK

In 2007 there were 168 reported human cases of Q-Fever in the Netherlands. This figure rose to 1000 in 2008 and approaching 2300 cases in 2009.  Six individuals with underlying health issues who contracted the disease have subsequently died.

There is currently no definite evidence to suggest the Dutch Q fever differs from that already found endemically in the UK. Defra requested that the Dutch Q fever outbreak be considered by the Human Animal Infections and Risk Surveillance (HAIRS) Group at its meeting in January. The meeting considered the one published paper suggesting the possibility that the organism responsible for the Dutch Q fever outbreak may be of a different strain, but considered this to be inconclusive and will await further evidence.

The Dutch government has announced that it would carry out a cull of sheep and goats in the Netherlands in response to the sharp rise in cases in both the animal and human population. It is thought that up to 40,000 sheep and goats may be culled.

The Dutch authorities are now stepping up their surveillance measures on dairy sheep and goat farms, imposing stricter movement controls on infected premises and have introduced a ban on the breeding of milking sheep or goats on farms with over 50 animals that will be applied until 1st July 2010. In addition there are rules on manure handling. The ban on farm visitors implemented in June 2008 is to continue. 

Further information can be found on the Eurosurveillance website, which is a European scientific journal devoted to the epidemiology, surveillance, prevention and control of communicable diseases.

Imports and exports

As there is no evidence to suggest the Dutch Q fever differs from that already found endemically in the UK, the VLA’s small ruminants experts group has concluded there are no reasons to stop imports. There are only a few consignments of sheep and goats imported from the Netherlands annually (14 in 2008).

Is it likely that a similar outbreak could occur in Great Britain?

We currently have no reason to expect any significant change in the UK situation, as the disease has been endemic here for many years.  However, we are not complacent and will remain vigilant, both of the Dutch situation and through our ongoing scanning surveillance and a research project. In December 2009 the European Centre for Disease Prevention and Control (ECDC) undertook a threat assessment in response to the Q fever situation in the Netherlands. As the January edition of the HPA’s Zoonoses Network Newsletter makes clear, ECDC have suggested that other Member States (including the UK) are not likely to have similar outbreaks. This is because in the Netherlands farms are often in the proximity of densely populated areas and goats are kept differently to the way they are generally managed in other countries.

Why is it called Q-Fever?

In August 1935, E H Derrick, the Director of the Laboratory of Microbiology and Pathology at the Queensland Health Department at Brisbane, Australia was asked to investigate an outbreak of undiagnosed febrile illness among abattoir workers in Brisbane. He named the illness Q for ‘query fever’.

Further information

Page last modified: 17 November, 2010