Is there a ‘query’ over Q fever in your herd?

Q fever, caused by the

bacterium Coxiella burnetti, is endemic in GB dairy farms with studies show-ing positive bulk milk samples ranging from 70 per cent PCR positive in south-west England to 80 per cent ELIZA positive results across 255 UK herds.

Recently Q fever has become reportable in the UK and climate change is changing the future risk profile as the disease has the potential to have a significant impact on livestock health and production. However, the disease is frequently overlooked as other infert-ility causes are often investigated first, which can lead to economic losses for farmers.

To help capture farmers’ experiences of Q fever, Ceva Animal Health has launched a national Q fever survey to assess the scale and on-farm awareness of the condition and the important role of vaccination in helping to prevent the disease. The grassroots survey, which is approximately three minutes long, can be carried out by visiting www.smartsurvey.co.uk/s/Y5EWLO/

A prize draw will be carried out after the survey closes with 10 lucky participants winning a Q fever snood.

Renzo Di Florio, veterinary advisor at Ceva Animal Health, commented: “Despite Q fever being endemic in GB dairy herds, we believe that awareness amongst the farming industry is low.

“Our National Q Fever Survey will help us ascertain how we can support farmers and vets when it comes to diagnostic challenges, treatment options and pre-vention through vaccination to help protect farmers, farming families and the related professions from the

disease and reduce the impact of Q fever on farms.”

Jonathan Statham, MA VetMB DCHP FRCVS, a RCVS registered specialist in cattle health, co-author of the ‘Dairy Herd Health’ textbook and chief executive of RAFT Solutions, added: “Multiple surveys in the UK support Q fever prevalence ranging from 60 to 80 per cent in our national dairy herd, including recent work

carried out by RAFT Sol-utions in NE England and SW England (2021).

“Reproductive issues are, of course, multifactorial and it is important therefore not to associate a Q fever positive diagnostic result as a single cause of infertility.

“However, increased level of metritis and endometritis, abortion and pregnancy loss or extended calving-conception intervals merit further investigation with Q fever as part of a herd health discussion that should of

course address other infect-ious disease such as BVD, IBR or leptospirosis.

“Q fever is of further significance as a zoonosis and also as a potentially emerging disease in the context of climate change and changing vector patt-erns.”

Coxiella burnetii is zoo-notic and can infect humans, cattle, goats, sheep and many other mammals, as well as reptiles, ticks and birds; the disease was orig-inally known as ‘query fever’ until its true cause was first identified in Australia in 1935 after an outbreak of disease in abattoir workers.

The disease has the pot-ential to cost farmers over £7,000 a year in a 100-cow dairy herd and infection is generally through inhalation of the bacterium, which can be spread through a number of ways, including ingestion, via blood from tick bites, birth fluids and foetal materials.

Q fever is usually described as mainly asymptomatic, as in humans.

When clinical signs occur, Q fever primarily affects reproductive performance in cattle and presents a serious threat to productivity.

Clinical signs in cattle include abortion, infertility (poor conception or incr-eased calving interval), metritis (inflammation of the

uterus), retained placenta, stillbirth and weak new-borns.

Indeed, a cow that has been exposed to the bacteria is 2.5 times more likely to have an abortion, 1.5 times more likely to have retained foetal membranes and 2.5 times more likely to have a high incidence of metritis/clinical endometritis.

Infection may cause an

increased calving to con-ception interval as well as increased early pregnancy loss.

Clinical signs in goats and sheep also include abortion.

Presenting a health threat to farmers, farming families and related professions such

as vets, veterinary tech-nicians and abattoir workers, the bacterium is particularly resilient and can survive for extended periods of time in the environment.

For example, up to five months in soil and up to two years at minus 20oC.

It is also resistant to many commonly used dis-infectants.

Alongside environmental persistence, Coxiella burnetii can be spread on the wind. An outbreak seen in the Netherlands (2007-2010) was linked to a 75-fold increase in goat numbers seen in the preceding 25 years.

The bacterium thrives in dry environments and rain has a negative impact on the distribution.