The World Health Organisation has six (6) phases of preparedness for swine flu ((or Influenza A(H1N1)):
Phase 1 – No new reports of animal viruses infecting humans
Phase 2 – Animal virus known to have infected humans
Phase 3 – Sporadic outbreaks in people. But no sustained community level human-to-human infection
Phase 4 – Community-level human-to-human outbreaks. “Significant increase [...]