Canadian researchers have designed a system using air travel patterns to predict how infectious diseases will spread around the world, offering a means of halting transmission by taking preventive measures as soon as an outbreak occurs, local media reported Monday.

The system, developed by infectious disease physician Dr. Kamran Khan of St. Michael's Hospital in Toronto and colleagues, accurately predicted how the A/H1N1 flu virus would circulate worldwide after arising in Mexico earlier this year, the Canadian Press said.

Using their BIO.DIASPORA system, the team analyzed the flight itineraries of more than 2.3 million passengers who departed Mexico on commercial flights during March and April 2008 to predict the spread of the H1N1 flu.

The findings show the international destinations of air travelers leaving Mexico were strongly associated with confirmed importations of the virus around the world.

"We know that infectious diseases don't respect national boundaries, but if there is one thing they have to respect as they're spreading around the globe, it's the architecture of the airline transportation system," said Khan.

"This is their mechanism for spreading around the globe."

Khan said he came up with the idea of using the air traffic grid to better understand the global transmission of infectious disease after the 2003 SARS crisis. That outbreak killed more than770 people, including 44 Canadians.

"It just became so obvious how the airline transportation network was a major conduit of the spread of infectious diseases," he said.

Days before Khan and his team were to deliver a report on BIO.DIASPORA to the Public Health Agency of Canada, news began trickling out about a new flu virus in Mexico. Their system allowed them to track its spread as it quickly infiltrated populations in one country after another.

"The movement of passengers out of Mexico aligned very nicely with the observed spread of H1N1," said Khan, principal author of a paper on the initiative published this week in the New England Journal of Medicine.

"I see this publication as being an important point now where we can say: OK, this is proof of principle that where people move, infectious disease of people will follow, that that principle now is validated in this A/H1N1 outbreak."

Co-author Dr. Michael Gardam, director of infectious diseases prevention and control for the Ontario Agency for Health Protection and Promotion, said the system provides for the first time an accurate picture of not only where diseases will travel, but how often and when.

"This work provides the world with a potent early-warning system for emerging infectious diseases," he said.

Source: Xinhua