Infectious diseases involving animals, such as SARS, Avian flu and AIDS are likely to grow as people travel more and have increased contact with wild life, says a scientist.
Of the pathogens causing infectious diseases, 75 percent are zoonotic that are able to transmit from animals to humans, writes Andrew Cunningham of the Institute of Zoology at the Zoological Society of London in an article in the British Medical Journal, reports science portal EurekAlert.
One of the major drivers for these diseases is closer human contact with wildlife, primarily caused by human encroachment into, and modification of, wildlife habitat, he writes.
For example, Ebola virus outbreaks often are linked to hunting for "bushmeat" or to mining development, while the AIDS pandemic originated from human encroachment into African forests for food.
He cites the rise in international trade and travel as major contributor. The researcher said the emergence of West Nile virus in North America, and AIDS and SARS globally was because of the increase in travel and trade.
"This globalisation of people and products is difficult to control and is largely related to increasing air transportation. With world air travel expected to grow at about 5 percent a year for at least the next 20 years, the problem of emerging infectious diseases will continue to grow," he warns.
Emerging infectious diseases are also a major threat to animal welfare and to species conservation. Some emerging infectious diseases also threaten domesticated species.
The problem is not small and tackling it will not be easy, but recognising a common problem is, at least a start, he concludes.