64 confirmed cases in US
over 1600 confirmed cases in Mexico
Considering the rapidly increasing number of confirmed Swine Flu cases. WHO officials have decided to raise the pandemic Alert Level to level 5.
The Committee also considered reports of possible spread to additional countries. On the advice of the Committee, the WHO Director-General has raised the level of influenza pandemic alert from the current phase 3 to phase 4.

GENEVA (Reuters) - The World Health Organization said on Tuesday it awaited formal confirmation from U.S. authorities that the new swine flu virus has spread significantly between people, a sign that could indicate an "imminent" influenza pandemic.
"We're still awaiting for a final confirmation from the U.S. authorities, but it appears that there's a number of cases in New York which appear to be human-to-human transmission," WHO spokesman Gregory Hartl told a news briefing.
28 April 2009--The situation continues to evolve rapidly. As of 19:15 GMT, 28 April 2009, seven countries have officially reported cases of swine influenza A/H1N1 infection. The United States Government has reported 64 laboratory confirmed human cases, with no deaths. Mexico has reported 26 confirmed human cases of infection including seven deaths.
"The WHO has called an emergency meeting and may declare a pandemic emergency"