Shoe leather epidemiology

Here's the way you hope it would work :

Last week, a British Midlands flight from London to Dublin was quarantined after eight passengers, who flew to London on a chartered flight from the Chinese capital, became severely ill.

Two of the passengers developed flu-like symptoms and began vomiting at London’s Heathrow airport and later boarded a flight to Dublin. The pilot, who knew 40 of his 188 passengers and eight crew had travelled together from Beijing, quarantined the plane and called ahead for medical assistance. He suspected they had contracted the deadly bird flu. (via Sunday Times Online (Dublin); hat tip, Pathogen Alert).

And here's how it actually did work:

However, when he landed in Dublin no public health experts were available because of a strike. The passengers were allowed to leave the plane after being diagnosed with food poisoning by an airport GP and were only checked by public health officials several days later, when they were given the all clear.

[snip]

“We could have found ourselves in the middle of a serious international outbreak,” said Catherine Hayes, a public health doctor and the chair of the public health committee of the Irish Medical Organisation.

“We could have been dealing with avian bird flu or Sars. We have now traced the victims, who suffered from a norovirus (gastroenteritis), but we were two days behind in our investigation. . . .”

We can take comfort in the fact that if folks come through a US airport we would check their shoes before they disperse around the country.