What is Pandemic Flu?
What are “ordinary seasonal” and “pandemic” flu?
When pandemic flu happens, it’s a new or mutated strain of influenza virus we haven’t seen before. We are now in the midst of an influenza pandemic. A new strain of influenza virus, called 2009 H1N1, first appeared in April 2009 and within months has spread around the world.
There are hundreds of different respiratory viruses that can cause colds, with coughing, sniffing, sneezing and feeling generally lousy. Most of these flare up in the wintertime. One of the worst of these is influenza. Its symptoms are much the same as the other winter viruses, but it is more likely to come on very suddenly and to cause higher fevers and body aches. It commonly spreads between family members in a matter of days. This is seasonal flu, caused by influenza viruses that plague us year after year. For most people the illness is over within a week.
Even these “ordinary” seasonal flu strains typically infect a fourth of the population, hospitalizing a quarter of a million people and causing an average of 36,000 deaths almost every winter.
Both seasonal and 2009 H1N1 influenza strains spread from person to person mainly through coughing or sneezing. Sometimes people may become infected by touching something with the flu virus on it and then touching their mouths or noses.
How does a pandemic flu differ from seasonal flu?
The main difference is that pandemic flu is a new or mutated strain of influenza virus that most of the world’s people haven’t seen before. Therefore, it can spread easily because people completely lack the proper immunity. This is why new viruses can become pandemic, or widespread. Symptoms may or may not be more severe than those of seasonal flu.
The worst example of pandemic flu came in 1918-1919 with the Spanish flu, which not only spread easily but was also often lethal, killing tens of millions of people worldwide. Other pandemic strains appeared in 1957 and 1968, but these caused far fewer deaths.
You may have heard of avian flu, or “bird flu,” which is epidemic in birds but, fortunately, does not spread from person to person. Avian influenza is carried by wild birds throughout Asia, spreading westward into Europe and Africa. Sometimes it spreads to domestic chickens and ducks and, rarely, from domestic birds to humans. In the rare times it does affect humans, it is deadly in about half of those cases. The situation has remained this way since 2004, and so far a feared lethal pandemic strain has not appeared, giving time for production of medications and development of vaccines to stop it in case it ever does come. Scientists are monitoring these strains very carefully for any change in the virus that allows it to be contagious from person to person, a situation that could produce a highly lethal and pandemic strain and cause widespread severe illness and death.
Where does 2009 H1N1 flu fit in?
We now have a pandemic 2009 H1N1 virus, a new influenza virus that was not expected. This virus has been spreading from person to person worldwide, so much more effectively than seasonal flu that it has spread even during the summertime, when seasonal flu doesn’t spread. The first case in the United States appeared in April 2009. By June, the virus had spread around the world, and the World Health Organization therefore signaled that a pandemic of 2009 H1N1 was under way.
Fortunately this strain of the virus, while spreading easily, has turned out to be no more severe than ordinary seasonal flu. H1N1 spreads mainly from person to person through coughing or sneezing. Sometimes people may become infected by touching objects with the flu virus on them and then touching their mouths or noses. The vast majority of cases seen both nationally and at University of Missouri Health Care have been generally mild. In fact, 2009 H1N1 may prove to be less lethal than seasonal flu because many adults over age 65 are immune to it, and this age group usually has, by far, the most hospitalizations and deaths from flu.
The keys to minimizing potential damage from pandemic flu are proper planning and prevention.