The World Health Organization raised its global alert level Monday, signaling the swine flu virus was spreading from human to human in community outbreaks, but it stopped short of declaring a full-blown pandemic.
The WHO announcement in Geneva followed a decision by the top EU health official urging Europeans to postpone nonessential travel to parts of the United States and Mexico because of the virus.
Mexico health department spokesman Carlos Olmos confirmed the move by the WHO to raise the alert level from Phase 3 to Phase 4.
Putting an alert at Phases 4 or 5 signals that the swine flu virus is becoming increasingly adept at spreading among humans. That move could lead governments to set trade, travel and other restrictions aimed at limiting the disease's spread.
The WHO's Phase 6 is the pandemic phase, characterized by outbreaks in at least two regions of the world.