Air travel, climate change, population growth and rising demand for meat products from developing countries have accelerated the spread of 'zoonotic' diseases, according to a panel set up by the Institute of Medicine and the National Research Council.

Species-jumping pathogens also pose special dangers for people because the human immune system can be ill-equipped to resist them.

But health authorities have no effective system that can stamp out new diseases as they arise among animals and humans.

'At the moment, it's like a wildfire,' said Dr Gerald Keusch of Boston University, who helped lead the committee that wrote the report. 'We deal with it as an emergency. It costs huge amounts of resources. It would be a lot cheaper and cost-effective to have a system in place.'

The panel called for a sustainable, integrated surveillance system to monitor animal and human populations worldwide and for moving quickly to contain new outbreaks.

Such a system could have provided early detection for the H1N1 swine flu virus, which became a pandemic weeks after it emerged in North America in March, said the panel's other co-chair, Marguerite Pappaioanou of the Association of American Veterinary Medical Colleges.

'The swine influenza virus basically was circulating for probably about 10 years,' she said. 'There also is evidence to suggest that the first opportunity for the swine virus to jump into people was probably during the summer of 2008.'