The international trade in exotic pets such as monkeys, crocodiles and rats must be stopped if human beings are to be protected from global pandemics, a leading microbiologist has cautioned.

Dorothy Crawford, Professor of Medical Microbiology at the University of Edinburgh, said that the risk to people from zoonoses – animal-borne microbes – had never been greater, and that there was a need to reexamine our relationship with wild and domestic animals.

Professor Crawford also predicted that global travel would need to be restricted in the event of an avian flu pandemic.

Most emerging infections, including HIV, severe acute respiratory syndrome (Sars) and bird flu had been acquired from animals and no one could say how many other devastating diseases could yet mutate to human beings, Professor Crawford said. “Who knows what could be hiding around the corner? We really have to think about what we are doing,” she said.

Professor Crawford highlighted the example of a consignment of giant Gambian rats, which were flown from Ghana into the US as exotic pets. The rats carried monkeypox virus, which transferred to prairie dogs that were sold in the same pet shop. The prairie dogs then passed the disease to their human buyers. The chain of infection was only terminated after the microbe had infected 71 people. In another instance, crocodiles being farmed in Papua New Guinea to provide luxury items for the West had been infected by a virus from wild pig meat, which crossed to their keeper.

Professor Crawford, whose new book Deadly Companions was published last week, said that it was “only a matter of time” before the growing tourist demand for bush meat in Africa led to a new epidemic from microbes jumping from their primate host. She said that common sense could be as helpful as scientific advancement in preventing pandemics. “Microbes are always going to be one step ahead of us. Their generation time is 24 hours, ours is 30 years. They mutate, they change, they will find a way. They are amazing opportunists,” she said.

“We just don’t treat microbes with enough respect. Is it really necessary to have a horrible, ugly giant Gambian rat as a pet? Is it sensible to fly carcasses from South America? Do we need to travel to Spain or even South Africa for the weekend? We really need to think. We could start chipping away those things which are completely unecessary.”

Professor Crawford, who is a Fellow of the Academy of Medical Sciences and Assistant Principal of the Public Understanding of Medicine at University of Edinburgh, said that an avian flu outbreak would be likely to restrict flying. “When that comes, we are going to have to change our lifestyles and cooperate globally,” she said.

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