The World Health Organization (WHO) does not recommend border closures to fight the spreading infections of swine flu, a WHO spokesman said Tuesday.

"Border controls don't work. Screening doesn't work," Gregory Hartl told a news briefing in Geneva.

He said not all infected people show symptoms, so screening measures at airports and border crossings may not be effective.

The spokesman also reiterated that the WHO is not recommending travel restrictions, but it is considered prudent for people who feel ill to delay any travels.

So far most people confirmed with the new swine flu virus known as H1N1 were infected in Mexico, including cases in the United States, Canada, etc, Hartl said.

But the WHO does not rule out sources of infections in other countries than Mexico itself, he added.

(Xinhua News Agency April 28, 2009)