Screening air passengers as they arrive at British airports is unlikely to prevent importation of either SARS or influenza, researchers in London report.

The research, published online by the British Medical Journal, suggests in case of a new SARS or influenza epidemic, air travel would represent the principal route of international spread.

Although airport entry screening has been advocated, its benefit is currently unknown.

Using the incubation periods for influenza and SARS, researchers at Britain's Health Protection Agency estimated the proportion of passengers with latent infection who would develop symptoms during any flight to England.

For SARS, they found the incubation period was too long to allow more than a small proportion of infected individuals to develop symptoms during a flight. Although influenza has a much shorter incubation period than SARS, the average predicted proportion of people infected with influenza and progressing during any flight was less than 10 percent.

Copyright 2005 by United Press International