Sydney University investigators are investigating occupational health and safety risks presented by Coxiella burnetii following an outbreak of Q-fever in a western Sydney veterinary hospital.
In July 2010, testing revealed that nine staff members of a veterinary clinic, along with a cat breeder and her cat, were infected with C. burnetii, following a caesarean section on the cat.
Seven of the nine staff members became clinically ill, with two female staff members requiring three weeks of hospitalisation and the remainder suffering from mild to moderate flu-like signs. An investigation coordinated by Central Sydney Public Health Unit found that the two most severely affected staff members had received the newly delivered kittens during the caesarean and had the greatest contact with reproductive fluids.
However, as the organism is highly resilient, staff members who had no direct contact with the cat – some who were not even at the practice on the day of the procedure – also fell ill.
According to researchers Jacqui Norris and Kate Bosward, while this cluster of cases is not the first report of transmission of Q-fever from cats to humans, its occurrence in a veterinary clinical context has huge implications for future occupational health and safety requirements in companion animal practice. They are collaborating on a major project with veterinarian and PhD candidate Amanda Shapiro, who hopes to find some answers.
“We are unsure of the likelihood of exposure to Q fever in Australian vets, hence the urgent need for research,” Shapiro said. “But the severity of the 2010 outbreak following a single cat caesarean, and our results to date, suggest that we are only at the tip of the iceberg and the risk that infected dogs and cats pose to veterinary personnel requires elucidation to protect the veterinary as well as the dog and cat owning community.”
One of the biggest challenges is that signs of infection and disease associated with C. burnetii are only vaguely described in the literature and the role of the organism in the pathogenesis of companion animal disease is largely unexplored. In other words, very little is known about how a dog or cat with Q fever might present to a veterinarian.
“It is likely that Q fever is associated with reproductive failure, still-births and neonatal mortality in cats and dogs but there may be other disease associations,” Shapiro said.
Shapiro is calling for assistance from veterinarians who can submit serum samples from dogs and cats. As little as 0.5ml is sufficient for the study. Samples may be submitted where veterinarians have any suspicions whatsoever that a patient is infected with C. burnetii, or from animals with particular disease syndromes including reproductive, cardiac or hepatic disease, or fever of unknown origin.
Investigators are particularly interested in samples from dogs and cats associated with confirmed human cases of Q-fever, for example in veterinarians, nurses or clients.
Shapiro hopes to complete her development of a serological test for detecting antibodies to C. burnetii in cats and dogs, determine the prevalence of infection in Australian cats and dogs, identify risk factors for transmission of C. burnetii from companion animals to humans and to investigate the potential role of C. burnetii in the pathogenesis of feline and canine diseases – especially fever of unknown origin and reproductive failure.
Veterinarians able to submit samples should email Shapiro at Amanda.shapiro@sydney.edu.au copying in both Norris (jnorris@sydney.edu.au) and Bosward (Katrina.bosward@sydney.edu.au).
ANNE FAWCETT
References
Maywood, P., 2011. Outbreak investigation: Q Fever in a small animal hospital. In: Australian College of Veterinary Scientists
Marrie, T.J., Langille, D., Papukna, V., Yates, L., 1989a, Truckin’ pneumonia – an outbreak of Q fever in a truck repair plant probably due to aerosols from clothing contaminated by contact with newborn kittens. Epidemiology and Infection 102, 119-127
Langley, J.M., Marrie, T.J., Covert, A., Waag, D.M., Williams, J.C., 1988, Poker players’ pneumonia: an urban outbreak of Q fever following exposure to a parturient cat. New England Journal of Medicine 319, 354-356.