Feeling under the weather this winter? You're not alone. This year's flu season in the United States is particularly harsh, leaving many of us wondering: is it just a bad cold, or something more serious, like the dreaded 'super flu'? Let's dive in and clear up the confusion.
Colds vs. Flu: Knowing the Difference
Respiratory illnesses are caused by a variety of germs, but most are viruses. The common cold is caused by a vast collection of over 200 different viruses, each capable of causing a respiratory infection. The flu, however, is caused solely by the influenza virus, although different types of influenza viruses circulate globally at any given time, including those that affect animals like birds.
While colds and flus share some similarities, they have distinct characteristics. Colds are typically upper respiratory infections, affecting your nose, throat, and sinuses. Symptoms include a runny or stuffy nose, sore throat, coughing, and sneezing. These symptoms tend to develop gradually, are relatively mild, and usually disappear within a week.
Flus often start as upper respiratory infections, but they can hit you much harder and more suddenly than a cold. Expect a severely sore throat. The flu also commonly brings systemic symptoms like fever, body aches, and fatigue. It lasts longer, sometimes up to two weeks. Furthermore, the flu is more likely to spread deeper into your lower respiratory tract, potentially leading to severe complications like pneumonia and bronchitis.
But here's where it gets controversial... There are nuances to consider. Some germs, like the respiratory syncytial virus (RSV), typically cause a cold in most people but can cause severe illness in vulnerable groups, like young children. Even mild cold viruses can occasionally cause lower respiratory infections. However, as a general rule, if your illness isn't completely debilitating, it's likely not the flu.
What About the 'Super Flu'?
This flu season is dominated by a specific variant of the H3N2 flu, known as subclade K. H3N2 flus are known to cause more misery than other seasonal flu viruses. Subclade K is particularly concerning because it emerged unexpectedly last year and is genetically different from the strains scientists predicted. This means the seasonal flu vaccine is less effective against it.
And this is the part most people miss... The good news is that subclade K doesn't appear to cause more severe illness than other H3N2 viruses. However, its arrival has triggered unusual waves of flu worldwide. In some countries, like Australia, it prolonged the flu season, while in others, like the UK, it started the season earlier. In the U.S., it has contributed to record-high flu levels this winter.
Data from the Centers for Disease Control and Prevention (CDC) shows that doctor visits for flu-like illnesses last week reached the highest level in nearly 30 years. The CDC estimates that the flu has sickened 11 million people, hospitalized 120,000, and caused 5,000 deaths this season. Flu activity is expected to remain high for several more weeks.
Many flu diagnostic tests can identify the broad type of influenza you have (A or B), and some can even identify the strain, such as H3N2. Scientists conduct further testing to diagnose specific variants, but these results are used by health officials to track flu trends and aren't widely available to the public.
Given this, and the fact that subclade K isn't worse than the average flu, you likely won't know for sure if K is to blame for your infection. That said, the chances are high that it is. According to the CDC, nearly all tested samples reported last week by public health labs came back positive for H3N2 (91%). Of all H3N2 samples further tested by the CDC since last September, about 90% were identified as subclade K.
Despite the mismatch with subclade K, the flu vaccine still offers some protection against seasonal flu, so it's still worth getting your shot. Other precautions, like regular handwashing and wearing masks, can also lower your risk of catching the flu.
What are your thoughts? Do you think the flu vaccine is worth it, even with the current strain? Share your experiences and opinions in the comments below!
