A system developed by Canadian researchers to rapidly evaluate the world's air traffic patterns accurately predicted how the H1N1 virus would spread around the world.
Infectious disease physicians at Toronto's St. Michael's Hospital say that by evaluating air traffic patterns around the world, they were able to predict how the virus would spread globally.
Dr. Kamran Khan and colleagues analyzed flight itineraries of more than 2.3 million passengers who left Mexico on commercial flights in March and April. The team found that countries that received more travellers from Mexico were more likely to import cases of the H1N1 flu virus.
As well, the cities that received the largest number of travellers from Mexico were more likely to have imported H1N1 flu cases. The researchers found that welcoming 1,400 travellers from Mexico put a country at high risk of imported cases of the virus.
"It's intuitive that where people are travelling, infectious diseases are likely to follow in tandem," Khan told CTV Toronto on Monday.
"What makes the system different or valuable, I think, is that for the first time we are able to do this on a moment's notice."
According to Khan, the research team conducted its analysis less than 24 hours after the H1N1 virus appeared. The results are published in the New England Journal of Medicine.
Khan said he hopes the team will fine tune the system to such a degree that it will be able to conduct the analysis in less than an hour and even from anywhere in the world using a mobile device, such as a Blackberry.
"If there's one thing that travels faster than infectious diseases, it's news about infectious diseases, and this system allows us to catch up with the fact that news travels very quickly, situations on the ground change very quickly, and we want to be able to respond to it in an intelligent and measured way," Khan said.
The new system is called the BIO.DIASPORA Project and began in 2003 after the SARS crisis to study the relationship between air travel and the spread of new infectious diseases.
Just before the H1N1 epidemic broke out in this spring, Khan and his colleagues presented a 122-page report to the Public Health Agency of Canada entitled: "The BIO.DIASPORA Project: An Analysis of Canada's Vulnerability to Emerging Infectious Disease Threats via the Global Airline Transportation Network."
Key findings from the report include:
- Toronto, Montreal and Vancouver, in that order, are Canada's most vulnerable cities to global infectious disease threats. More than 13 million international passengers travel to these cities each year.
- Sixty per cent of travellers to Canada from developing countries use multiple flights to reach their destination. Half of these travellers board connecting flights to Canada in London, Hong Kong, Tokyo, Frankfurt, Paris, Miami, Amsterdam, New York and Chicago, where they could be screened for infectious diseases before travelling to Canada.
- Four developing countries -- China, Mexico, India and the Philippines -- and nine industrialized countries (the U.S., the U.K., France, Germany, Italy, the Netherlands, Japan, South Korea and Taiwan) are the source of 80 per cent of Canada's international air traffic. Canadian authorities should consider collaborating with these countries to deal with infectious disease risks.
