People working in rural areas of Queensland were recently warned to take steps to guard against Q fever as drought conditions persist and dust and high winds increase the risk of the disease spreading.
Q fever is a serious bacterial disease which infects livestock, especially cattle, sheep and goats, while other animals, including kangaroos and wallabies, can also be infected.
Infected animals generally do not get sick but can shed the bacteria in urine, faeces and milk, and in especially high numbers in birth products, according to Workplace Health & Safety Queensland (WHSQ).
People can become infected by inhaling the bacteria in dust and aerosols, and WHSQ said the current dry and dusty conditions in parts of Queensland increase the Q fever risk.
Most infections (20-80 percent) are asymptomatic but when acute illness does occur the symptoms are non-specific, ranging from a self-limiting influenza-like illness, to more severe symptoms of pneumonia, hepatitis, heart and bone conditions.
Chronic Q fever, which may occur years after infection, is most often characterised by endocarditis but may also include osteomyelitis and hepatitis. Approximately 10-15 percent of cases experience a protracted post Q fever fatigue syndrome.
In the past five years (2013-2018) there have been on average 517 cases reported annually.
Studies indicate 40-50 percent of notified cases were hospitalised for a median of 4-6 days each, and it is likely these figures are underestimated due to the asymptomatic and non-specific nature of acute infection.
People who work with farm animals, wildlife and some domestic pets are particularly at risk, said WHSQ.
This includes cattle, sheep and goat farmers, dairy industry workers, shearers, wool classers, kangaroo shooters, livestock transporters, feedlot workers, staff and students of agricultural education programs and veterinarians and their staff.
The warning comes off the back of recent University of Sydney research which found that rural residents are at increased risk of catching Q fever, including those residents who are not currently in high risk groups recommended for vaccination.
The study, published in the Medical Journal of Australia, found that only 40 percent of people in groups recommended for vaccination knew about the Q fever vaccine, and only 10 percent of people in these high risk groups were vaccinated.
The researchers sampled 2740 blood donors in metropolitan Sydney and Brisbane, and in non-metropolitan regions with high Q fever notification rates (Hunter New England in New South Wales, and Toowoomba in Queensland).
“As expected, evidence of past exposure through Q fever antibodies was higher in non-metropolitan than metropolitan regions in both NSW and Queensland,” said Lead Author Associate Professor Heather Gidding from University of Sydney.
“One in 20 rural Queensland donors showed evidence of past exposure, however one in 36 Sydney residents also had antibodies, indicating that exposure to Q fever is more common than expected.”
However, having lived in a rural area with no or rare contact with sheep, cattle or goats was itself associated with exposure, even after accounting for other exposures, said Gidding: “which means you are highly likely to be exposed to Q fever, not because you work with animals, but just because you live in a regional or rural area.”
She also estimated that 29 to 39 percent of people with symptomatic Q fever were not actually diagnosed with the disease.
NSW Health also urged people in regional and rural NSW, particularly parents, to take extra precautions against Q fever in the past as drought and windy conditions may raise the risk of the disease in these areas.
“In these current dry, windy conditions, we’re reminding people, particularly parents, to take steps to protect themselves and their children if they are out with mum and dad helping to feed stock,” said Vicky Sheppeard, Director of Communicable Diseases for NSW Health.
“It is important people wear personal protective equipment, such as a properly fitting face mask which can be purchased from hardwares or pharmacies, and that they thoroughly wash their hands.”
In addition to vaccination, the following steps can protect against Q fever: