The single phrase that’s probably heard more this time of the year than any other, aside from “Cold enough for ya?”, is “the flu.” “Jimmy’s come down with the flu.” “I won’t be in today, I’ve got a touch of the flu.” “Hey, have you caught the flu that’s going around?”
Although we tend to call many different illnesses “the flu,” the flu is a very specific disease–and a very common one, the last disease (one hopes) that year after year infects so much of the human race it can only be called “pandemic.”
Its commonness is reflected in its shortened name, “the flu,” derived from its proper name, “influenza.” For reasons still not clearly understood, there is a very definite “flu season,” generally beginning late in December and ending in late March. Even 400 years ago people had noticed this. They thought it was due to the “influence” of the moon and planets–hence, “influenza.”
Influenza is caused by a specific virus of the genus Orthomyxovirus. As most of us know only too well, it’s characterized by fever, cough, considerable muscle aching and sometimes a seriously upset stomach, all of which typically last from three to seven days and may be followed by several more days of fatigue and depression.
Although we tend to think of it as more an annoyance than a serious illness, influenza carries with it the danger of pneumonia, which is what usually kills those that influenza strikes down.
In Stephen King’s novel The Stand, a genetically engineered biological weapon escapes a laboratory and kills most of the human race. Even the oridnary flu virus can be scary enough. In 1918, influenza killed an estimated 20 million people world-wide, including hundreds of thousands in North America. (In the third week of October, 1918, alone, 4,600 people died in Philadelphia.) Every year, one percent of the millions of people who come down with the flu end up in hospital, and of that one percent, eight percent die; thousands worldwide. Those at highest risk include senior citizens, health care workers, and those with heart or lung problems or a weakened immune system–although the 1918 strain was so virulent it even struck down and killed many young, otherwise healthy people.
As with many diseases, once you’ve been exposed to influenza, you develop immunity to it. Unfortunately, you only develop immunity to the specific type of influenza you’ve been exposed to, and that immunity lasts less than a year. Worse, influenza comes in more flavors than Baskin-Robbins has ice cream, and new flavors are appearing all the time.
There are three types of influenza viruses, called A, B, and C; A and B are those responsible for disease epidemics. Within these types, there are two main “antigens,” hemagglutinin, known as H, and neuraminidase, known as N, which create a distinct virus, and which also come in various types. Scientists believe that only three hemagglutinin and two neuraminidase types are capable of causing infection, but that still leaves lot of possible combinations. So far this season, the most common flu in North America is A/H1N1, also known as the Texas Flu. (I’m from Texas, but please don’t blame me!)
Entirely new strains, never seen before, occasionally appear. Some are animal viruses that have somehow made the jump to humans: the Swine Flu of 1918 is believed to have originated in pigs, and the Asian flu, which killed more than 100,000 people in the U.S. alone in 1957-58, and the Hong Kong flu, which showed up in 1968, are hybrids of human viruses and bird viruses, which may have formed in pigs simultaneously infected with both viruses. It’s thought that many new flu strains seem to originate from Asia because farmers there tend to have pigs and ducks in the same farmyard.
A worldwide network of people constantly monitors influenza, so that vaccines can be prepared quickly as new strains appear. The vaccines are only about 70 to 90 percent effective, but that’s much better than nothing. People in the high-risk groups mentioned earlier should get vaccinated every year.
AIDS has a higher profile, and Ebola’s gotten lots more attention from Hollywood, but the fact is, the most widespread–and one of the most deadly–epidemics that continues to rage around the world year after year is the lowly flu.
And here I am, about to embark on my annual adventure touring the province’s schools with Prairie Opera, to be exposed to the various illnesses of some 20,000 small children.
I wonder if I could sing through a surgical mask…
