Issue 29 / 30 July 2012

THERE must be improved collaboration between veterinarians, doctors, public health officials and environmental scientists to address the growing threat of zoonotic diseases to the human, animal and the economic health of Australia, a conference in Sydney was told this weekend.

In an Australian first, veterinarians and infectious diseases doctors from across the country met at the Zoonoses Conference 2012, from 27–28 July at the University of Sydney, to discuss the growing emergence of zoonoses as a major threat to human health.

Professor John Mackenzie, professor of tropical diseases at Curtin University, WA, told the conference that zoonoses — diseases that can spread from animals to humans — account for more than 70% of emerging infectious diseases around the world.

Zoonoses have had an enormous economic impact, he said, with the Pandemic (H1N1) 2009 influenza alone estimated to have cost $45–55 billion dollars globally.

Reasons for the emergence of zoonoses include changed farming practices, including intensified farming in poor countries, and deforestation, with the associated impingement of humans on animal habitats, Professor Mackenzie said.

Bats, rodents and birds had become the most common animal sources of new diseases, he told the conference.

Dr Stephen Graves, director of the Australian Rickettsial Reference Laboratory, said the recent 2007‒2009 Q fever epidemic in the Netherlands illustrated the importance of close communication between veterinarians and doctors.

In 2005, Dutch veterinarians had failed to tell public health officials and doctors about a Q fever outbreak in milking goats, which meant the subsequent human outbreak of 4000 cases was neither anticipated nor prevented, he said.

“Vet authorities were aware that it was Q fever, but the public health authorities were unaware … and they were therefore unaware of the risk to the human population”, Dr Graves told the conference.

While speakers at the conference applauded collaboration between veterinarians and doctors in managing and preventing Hendra virus infections in Australia, both veterinarians and doctors believed the widespread use of antimicrobials and the associated development of resistance was a concern.

To help address this issue, the Australian Commission on Safety and Quality in Health Care will introduce new health care standards in January 2013.

Under these standards, all Australian hospitals will need to demonstrate antimicrobial stewardship to become accredited.

However, veterinarians’ use of antimicrobials is less restricted, due to the significant number of largely unregulated compounding pharmacies and veterinarians’ ability to use antimicrobials off label. Conference speakers called for increased scrutiny of veterinarians’ use of antimicrobials and for more data about antimicrobial resistance prevalence, particularly in food-producing animals.

Professor Mary Barton, emeritus professor at the University of SA and a veterinary microbiologist, expressed concern about the lack of data available on antimicrobial use and resistance patterns in Australia’s aquaculture industry.

She said there were no antimicrobials registered specifically for use in aquaculture where there had clearly been off-label use for many years.

Professor Tom Riley, from the University of WA, expressed grave concern that the use of third-generation cephalosporins in humans and food-producing animals may be driving the unprecedented rise in community-acquired Clostridium difficile infection (CDI), previously a disease associated with hospitals. He called for all GPs to test for CDI routinely in patients presenting with diarrhoea.

In opening the conference, Australia’s Chief Medical Officer, Professor Chris Baggoley, said recognition of the importance of communication across medical and veterinary disciplines was not new. He said the man who coined the term “zoonosis”, German physician–scientist Rudolf Virchow, said in 1855, “Between animal and human medicine there is no dividing line, nor should there be”.

Speakers at the conference, which the Australasian Society for Infectious Diseases hosted, believed it had allowed new links and collaborations to be forged between those at the forefront of zoonotic disease management in Australia.

There was great optimism that this collaborative momentum would develop further at the next Zoonoses Conference in 2014.

– Dr Susan Maddocks

Posted 30 July 2012

One thought on “Doctors and vets unite against zoonoses

  1. Ben Wadham says:

    1.Control of the use of prophylactic antimicrobials in commercial animals is long overdue, in my opinion.
    2. I suspect that present-day new medical graduates have little appreciation of community-acquired zoonoses: the curriculum is too packed for “relative rarities”. In my practising days, the reported incidence of brucellosis in Victoria was highest in those commumities served by a G.P. who had encountered it (and, often, had served a resident term at Fairfield I don’t have any idea as to how this lack of awareness canbe overcome: maybe, medical correspondents writing in the daily press could play a role?

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