My understanding of the threat comes by comparing seasonal flu with this current virus, which is swine flu and now designated "Influenza A(H1N1)" by the World Health Organization.
Seasonal flu is a common respiratory illness that is spread from person to person. A healthy person might contract it, but usually their immune system is strong enough to fight off serious complications. Vaccinations also can protect us from seasonal flu.
In contrast, we have no natural immunity to Influenza A(H1N1). It too is spread from person to person, but there is no vaccine for it.
CDC statistics for the U.S. indicate seasonal flu-related causes most often kill the elderly and children under five years old. See: http://www.cdc.gov/flu/protect/preventing.htm
In comparison, WHO said many of the Influenza A(H1N1) deaths "have occurred in otherwise healthy young adults". See: http://www.who.int/csr/don/2009_04_24/en/index.html
Medical professionals are familiar with diagnosing and treating seasonal flu. On the other hand, no one really knows how severe or mild Influenza A(H1N1) will be.
"Let me remind you. New diseases are, by definition, poorly understood. Influenza viruses are notorious for their rapid mutation and unpredictable behaviour," said Dr. Margaret Chan, WHO Director-General, in her April 29 press statement.
See:
http://www.who.int/mediacentre/news/.../en/index.html
We do know that in recent days Influenza A(H1N1) is spreading rapidly. This fact, plus our lack of immunity and lack of a vaccine, are sources of anxiety and give us reasons to practice risk prevention.
The Center for Disease Control's web site says, "In the past, CDC received reports of approximately one human swine influenza virus infection every one to two years in the U.S., but from December 2005 through February 2009, 12 cases of human infection with swine influenza have been reported." See:
http://www.cdc.gov/swineflu/key_facts.htm
As of April 30, swine flu Influenza A(H1N1) numbers for 2009 in the U.S. have grown to 109 laboratory confirmed human cases, including one death. Mexico had 97 human cases of infection and seven deaths . See:
http://www.who.int/csr/don/2009_04_30_a/en/index.html
These numbers show the spread of Influenza A(H1N1) is much more rapid than swine flu has been in recent times.
When the World Health Organization upped their alert status for a pandemic, i.e. global outbreak, of Influenza A(H1N1) to Phase 5 yesterday, they were signaling a high probablity of worldwide swine flu outbreak. See:
http://www.who.int/csr/disease/avian.../en/index.html
Right now the World Health Organization doesn't know how debilitating or deadly this outbreak of swine flu might be. CDC doesn't know. The media doesn't know.
Yes, maybe Influenza A(H1N1) will turn out to be a mild disease that most people will recover from quickly, but it can't hurt to:
* Stock up on food, health items, sanitation and comfort items
* Avoid contact with people in public places
* Wash your hands more often

