Background

The World Health Organization (WHO) raised its pandemic alert for Influenza A(H1N1) to the second highest level Wednesday, meaning that it believes a global outbreak of the disease is imminent. Phase 5 is characterized by human-to-human spread of the virus into at least two countries in one WHO region. While most countries will not be affected at this stage, the declaration of Phase 5 is a strong signal that a pandemic is imminent and that the time to finalize the organization, communication, and implementation of the planned mitigation measures is short.