Q FEVER awareness and vaccine access needs to increase for all people living in rural and regional areas, new research from University of Sydney has shown.
The study published in the Medical Journal of Australia found rural residents in Australia were highly likely to be exposed to the infectious bacterial infection, even if they were not working with animals.
Researchers also estimated that 29-39 percent of people with symptomatic Q Fever were not actually diagnosed with the disease.
Q Fever is a highly infectious bacterial disease that can cause a severe flu-like illness. It is commonly found in rural and regional areas with the bacteria spread to humans from animals, mainly cattle, sheep and goats. Most cases are asymptomatic, but in some the infection can lead to pneumonia, bone and joint infections, chronic Q Fever, heart disease and debilitating chronic fatigue syndrome.
The study found that only 40 percent of people in groups recommended for vaccination knew about Q Fever vaccine, but only 10pc of those in the high risk groups were vaccinated.
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. It is likely these figures are underestimated due to the asymptomatic and non-specific nature of acute infection, researchers said.
The study is the first community based study in Australia designed to measure past exposure to Q Fever and identify factors associated with exposure. 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).
Lead author Associate Professor Heather Gidding from University of Sydney and the National Centre for Immunisation Research and Surveillance said as expected, evidence of past exposure through Q Fever antibodies was higher in non-metropolitan than metropolitan regions in NSW and Queensland.
Associate Professor Gidding said 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.
“Adults who have regular contact with sheep, cattle or goats, abattoir workers, and those assisting with animal births had the highest levels of exposure and these groups are recommended to receive the Q Fever vaccine.
“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,” she said.
“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.
“We also estimate that 29 to 39 percent of people with symptomatic Q Fever were not actually diagnosed with the disease.”
Co-author Associate Professor Nicholas Wood from University of Sydney and NCIRS said awareness and access to Q Fever vaccine needs to be improved.
“We need to increase vaccination rates for all people living in rural and regional areas.
“With only 40pc of people in groups recommended for vaccination knowing about the Q Fever vaccine, and only 10pc vaccinated, there are a lot of people at risk of catching the disease,” he said.
“We found that most rural donors were exposed to multiple risk factors.”
“Raising awareness about Q Fever and the vaccine in rural communities and amongst health care workers will help improve uptake of what is a highly effective vaccine.
“A new online training module for rural general practitioners has recently been developed by the Communicable Diseases Branch, Health Protection New South Wales through the Australian College of Rural and Remote Medicine and should improve awareness of the vaccine as well as improve general practitioners’ knowledge about Q Fever and how to diagnose it.
“We recommend more detailed studies in rural communities to identify reasons for their increased risk. But given we found that most rural donors were exposed to multiple risk factors, it would be a good idea for people to discuss with their GP their own need for the Q Fever vaccine,” he said.
Meanwhile, a new Q Fever research consortium has been established, with the aim of protecting the health of high-risk groups of people living and working in rural and regional areas.
The Q Fever Research Consortium comprises personnel from the University of New England, James Cook University and University of Queensland; public health practitioners including NSW Health, Hunter New England Health and QLD Health; as well as the Australian Rickettsial Reference Laboratory (ARRL) located in Victoria.
QRC members have expert knowledge in public health, microbiology, clinical immunology, computational science, economics and primary health care practice. Together they will gather data through a range of projects that will inform robust vaccination processes and future best practice in managing Q fever.
Professor Geetha Ranmuthugala, head of the school of rural medicine at UNE, said a priority for the consortium was to create awareness of the mechanism of the disease and make vaccinations more accessible for high-risk groups.
Rural northern NSW is regarded as a Q fever hotspot, accounting for the vast majority of the 1653 cases notified in NSW between 2005 and 2015, with notifications steadily increasing since 2009.
“The current vaccination, Q-VAX, is very effective but tests have to be carried out before the vaccine is provided to those requiring the vaccine, which results in higher costs,” Prof Ranmuthugala said.
“Developing a study to survey and track the immune cells to determine how Q-VAX provides protection is important, as it will allow us to develop more cost effective alternatives, which is a top priority for the consortium.”
Fellow consortium member, Prof Natkunam Ketheesan, who has a special interest in the interactions between bacterial pathogens and immune cells, will lead the UNE arm of the study in collaboration with Prof Robert Norton, director and clinical microbiologist at Townsville Hospital, QLD and Professor Stephen Graves, medical microbiologist and founder of the Australian Rickettsial Reference Laboratory.
Prof Norton has a special research interest in Q fever and has seen the impact the disease has had on communities in North Queensland in the course of his clinical work. He believes it is largely due to non-occupational exposure.
“The consortium will help to inform the public and encourage research into this very relevant infectious disease to our regional and rural communities,” Prof Norton said.
“Q fever is a major problem in regional and rural Australia. We are currently working on the development of a goat vaccine for coxiellosis and a new human vaccine for Q Fever to reduce notifications,” Prof Graves said.
Other projects that the consortium will undertake include mapping livestock numbers and movement, current climate conditions and Q fever notifications to better understand the mechanics of the relationship, and to determine the cost of the disease to producers and the community.
Q Fever is caused by the highly infectious bacterium Coxiella burnetii, which has an almost world-wide distribution. C burnetiiinfects both wild and domestic animals and their ticks, and humans are exposed via the inhalation of infected droplets or dust.
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.