It's flu season again. And now, along with the barrage of helpful flu shot reminders, comes the annual outbreak of myths about the flu.
First, here are some basic facts. Influenza (also known as the "flu") is a contagious respiratory illness caused by influenza viruses, and is different from the common cold. According to the Centers for Disease Control and Prevention (CDC), each year between 5 and 20 percent of the U.S. population gets the flu. Of those, more than 200,000 people will end up in the hospital, and approximately 20,000 people will die (with up to 500,000 deaths worldwide). Symptoms come on quickly and can include fever, body aches, cough, sore throat, runny nose, and fatigue. Complications that can accompany the flu include bronchitis, pneumonia, as well as ear and sinus infections.
These complications are especially dangerous for the elderly, young children, pregnant women, and anyone with a chronic condition (e.g., heart disease, diabetes, or asthma). The CDC estimates that 90 percent of flu-related deaths occur in people over 65. The prevalence of specific strains of influenza varies from year to year, and influenza vaccines offer protection from the most likely strains for the current season. Scheduling your flu shot each year is, without a doubt, the best way to prevent getting the flu.
Those are the facts -- now let's look at the myths. My guess it that you've probably heard some or all of these at one time or another.
Myth #1: The flu vaccine can give you the flu. It can't. Period. Injected flu vaccines only contain the dead virus, which can't infect you. The nasal vaccine FluMist contains the live virus, but is engineered to remove the parts of the virus that make people sick. These weakened viruses are also cold-adapted, meaning they are designed to cause mild infection only at the cooler temperatures found within the nose. These viruses cannot infect the lungs or other areas of the body where warmer temperatures exist. The reason this myth persists is most likely because people mistake the side effects of the vaccine (which can include redness, tenderness, and swelling at the injection site, and, in some cases, muscle aches and low-grade fever) for the flu itself. Another factor is the high prevalence of colds and other respiratory illnesses during flu season. Many people get the vaccine and then, within a few days, get sick with an unrelated cold virus.
Myth #2: Antibiotics can fight the flu. Nope. Antibiotics only fight bacterial infections. Because influenza is a virus, antibiotics have absolutely no effect on it. The flu can, however, weaken your immune system, leaving you less able to fight off bacterial infections like bronchitis or pneumonia.
Myth #3: "Stomach flu" is a form of influenza. The flu is a respiratory disease, not a stomach or intestinal disease. Gastrointestinal viruses are sometimes (incorrectly) called the "stomach flu," but they have no connection to influenza. The influenza virus can sometimes cause vomiting and diarrhea, but if you have these symptoms without a fever or body ache, you probably don't have the flu.
Myth #4: Swine flu is transmitted by eating pork products. The current form of "swine flu," more correctly known as the H1N1 virus, first appeared in the U.S. in April 2009. It was nicknamed swine flu because the virus that causes the disease originally jumped to humans from the live pigs in which it evolved, not from pork products. H1N1 is a "reassortant" virus, containing a mix of genes from swine, bird, and human flu viruses. It is spread by human-to-human transmission.
Myth #5: Cold weather causes the flu. Sorry grandma and grandpa, but going outside in the winter has nothing to do with catching the flu. The flu season follows the natural life cycle of the virus, not the temperature. That's why people in sunny Florida are just as susceptible to the flu as people in freezing Alaska.
The two takeaways here are simple. First, everyone should get the flu vaccine to stop the spread of the disease and its dangerous complications. Second, everyone should inoculate themselves with facts to prevent the spread of potentially deadly misinformation.