Swine Flu Likely to be Spread During Flights

Swine Flu Likely to be Spread During FlightsA new study says that there is a diminutive but reckonable risk of contracting the Influenza A H1N1 virus or swine flu during long-haul flights.

This research is the first scientifically documented outbreak of flu on a plane in recent times and has attracted international interest. It was led by public health epidemiologist Michael Baker and Craig Thornley of Auckland Regional Public Health Service.

The research was based on New Zealand's first brush with swine flu in April 2009, when a flight arrived in Auckland with an infected secondary school group returning from a trip to Mexico.

Nine passengers were confirmed with swine flu and were unwell during the flight. Two other passengers became sick after the flight, and were also confirmed with swine flu.

"The pandemic gave us a unique opportunity to investigate the risk of influenza transmission on a flight. Because this was an entirely new virus to New Zealand, we know that the only place it could come from was from other passengers on this flight", says Baker.

This suggests transmission by small droplets produced by coughing and sneezing rather than via fine aerosols carried through the plane's air-conditioning system.

The study also looked at practical issues about how we manage the risk of introduced infections in airline passengers.

It shows that most passengers on the flight were located and followed up by public health authorities, but only 52 percent were reached within three days of landing.

Baker will present this study at the International Conference on Emerging Infectious Diseases in Atlanta, US, in July.