Phase five is marked by human-to-human spread of the virus into at least two countries in the same area of the world.

VOA: special.2009.05.06

The World Health Organization says it needs to see clear evidence of sustained community transmission of the swine flu virus from person-to-person in at least two regions of the world before it raises its alert to the phase six pandemic level.

VOA: standard.2009.05.14