To help you understand how the WHO assesses the potential for a global influenza outbreak, we have listed:

• Phase 1. No viruses circulating among animals have caused infections in humans.

• Phase 2. Virus among animals have caused infections in humans; considered a threat.

• Phase 3. Animal virus/animal-human virus causes some cases or small clusters of flu; doesn’t spread easily.

• Phase 4. Human-to-human transmission of flu causes sustained outbreaks in community.

• Phase 5. Flu spreads to at least two countries, causing bigger outbreaks.

• Phase 6. More outbreaks in at least two world regions; pandemic underway.

This latest declaration of Phase 5 by the World Health Organization indicates that a pandemic could be imminent.  New cases and deaths finally seem to be leveling off in Mexico, but the threat is serious enough to step up all efforts to produce a vaccine for this type of influenza.

An unknown factor also playing out is the economic impact this will have.  Mexico, in addition to dealing with the illness, is also seeing a decline in tourism and having to close many of their gyms, restaurants, swimming pools, and other places.  Companies such as Honda, Caterpillar, and Xerox have restricted their expatriate workers from traveling south of the border at this time.

Many economic analysts feel that the economic fallout for the U.S. will be limited.  If the swine flu threat is contained, hopefully, it will have only short-term effects.  Knowing that the disease has not been terribly virulent outside of Mexico adds to the idea that it will not be a major epidemic.  Better advances in medicine and public health policies enhance the ability to monitor emergency illnesses, thereby preventing the world from being advanced to Phase 6.