You may have noticed that winter is here, and with it, influenza. The name of this disease comes from the Italian word for influence because the reemergence of the flu infection on a yearly basis seemed to the ancients to have been influenced by the planets.
We now believe that the reason influenza comes in the winter in temperate climates is the crowding indoors that occurs in that season. In the tropics, influenza tends to peak in the summer, which is the rainy season—again leading to crowding indoors. (See a CDC tracker that shows where flu has spread in the U.S.)
An Unwelcome Return
This year, the predominant strain of influenza virus is the so-called pandemic H1N1 virus that recently made its return engagement in 2009. I’m calling it a return engagement because it is similar to the swine influenza virus that caused the catastrophic pandemic of 1918, often referred to (by everyone but the Spaniards) as Spanish flu.
In the years 1918 to 1921, this pandemic resulted in an estimated 40 million deaths worldwide. During the pandemic, young adults were particularly prone to severe infection leading to death. More young people were killed by influenza during those few years than lost their lives in all the battles of World War I.
Recently, researchers apparently have discovered the reason for this unusual mortality curve. This particular strain of the virus causes the immune system to launch into overdrive. In an attempt to fight the infection forcefully, it actually overshoots, leading to severe disease and death.
H1N1: Who Is Most at Risk?
While not nearly so devastating as the 1918 influenza strain, this season’s H1N1 virus is also causing severe infection predominantly in young adults and middle-aged people. More than 40 states have reported outbreaks. Severity in some states is high, especially in Texas and other portions of the south central U.S.
The good news is that this virus strain is included in the currently available influenza vaccines, meaning that they offer protection. Some of the new vaccines available are not grown in eggs, thereby eliminating allergy risks—one of the few previous reasons for not getting vaccinated.
This year, there is a vaccine preparation suitable for all ages, with little toxicity and an effectiveness rate of about 70 percent. Everyone over 6 months old should be vaccinated. Since this is a health-related blog, it is certainly important to point out that healthcare workers, including medical students, should be vaccinated for the benefit of their patients and themselves.
If all that isn’t enough to convince you, consider that a recent study in the Journal of the American Medical Association found that getting a flu shot can help lower the risk of heart attack or other major cardiac events by roughly a third over the previous year.
If You Get Flu: What to Do?
If you do get sick with a flu-like illness, it may not always be flu, but you should visit a healthcare facility at the onset of symptoms and have a rapid test to see if it is influenza. There are drugs available that can help curtail infection, but optimally, these should be received within the first 48 hours after you start feeling sick.
Don’t rely on treatment after exposure. Get vaccinated now!