The science of the common cold

[madlori]

I am at work. I have told my boss that I will put forth a valiant effort, but am not likely to make it the full day. Cold has moved from my head to my chest, producing that super sexy Eartha Kitt voice we all love to get. It's not too bad. But I am tired and achey. I will be better tomorrow. My colds are always very predictable and resolve pretty fast.

I'm pretty hardy in terms of illness. I've never had a yeast infection, or a sinus infection, or a UTI. I generally get one cold/flu per year and it comes and goes within a week, although that lingering cough sometimes hangs around longer. Ninety percent of my sick days are the result of non-infectious stuff, like reactions to meds (my old glucophage prescription used to cause me no end of grief) or pouch-related issues.

In honor of my current malaise, which statistically about five percent of the country shares with me right now, here are some facts about the common cold! IT'S SCIENCE!

• The common cold is caused by a virus, one of several classes. Thirty to fifty percent are caused by rhinoviruses, of which there are about a hundred known serotypes. Adult colds are more commonly caused by coronaviruses. There are over 200 known strains of viruses which cause colds. As you probably know, you never have the same cold twice. Once you are infected with a specific virus, your body develops antibodies and immunity to it. But because there are so many cold viruses, and they're constantly mutating, you keep getting them. This is why adults are less frequently sick than children, though. According to the Wik, adults typically have between two and four colds annually but kids can have as many as six to twelve. This is also why a cold vaccine is damn near impossible. The virus is never the same.
  
• Colds are seasonal, it's a real statistical thing and not just a subjective impression (as so many things are). Traditionally, folk wisdom held that cold temperatures made you catch cold. That's why they're called "colds." There is scant, unclear evidence that cold exposure may increase susceptibility in some people, but other studies show no such correlation. The reasons they're seasonal are mostly behavioral. Cold weather means more time spent indoors in close proximity to other people, and of course kids being in school. Another reason is humidity. Cold viruses travel better in dry air, which as the makers of ChapStick know, is a winter thing.
  
• Upper respiratory infections are the most common illness among adults and children. They are the leading cause of doctor visits. Something like sixty percent of these visits leads to antibiotic prescriptions. I'm sure this isn't news to any of you, but this does nothing to alleviate the cold and is actually harmful, by encouraging antibiotic resistance and by killing the beneficial bacteria in your guts, making you more miserable. Who needs diarrhea on top of a stuffed-up head and a cough?
  
• Handwashing can reduce the transmission rate by up to 20%, however, antibacterial soap is no better than regular soap at eradicating cold-causing viruses. Alcohol-based hand sanitizers do very little.
  
• One of the best things you can do to limit your risk of getting sick is sleep. Studies have shown that those who get fewer than seven hours of sleep a night are three times more likely to develop symptoms after exposure to a rhinovirus than those who get eight hours or more.
  
• Boosting your immune system actually makes the cold symptoms worse. Those with strong immune systems exhibit more severe cold symptoms, because the symptoms arise from the immune-system response, not from the action of the virus. Getting a runny nose means your body is clearing the virus. That's what you want.
  
• Telling the difference between a cold and the flu is tricky. Most people use the presence or absence of a fever to tell, but some colds come with fever, too. Generally the biggest difference is that colds ramp up, with symptoms peaking after 2-3 days, whereas the flu has sudden onset of symptoms which remain constant until you get better. Also, the flu involves the lungs more severely.
  
• As many as one-fourth of people who are infected with a cold virus never develop symptoms. They can still pass the virus on to others, though.
  
• The common cold accounts for 40% of sick days taken in the US, between people having colds and staying home with kids who have colds.
  
• The folk wisdom that treating cold symptoms is bad for you is bogus. The activity of the virus takes place well apart from the immune system response. Treating the symptoms will not only make you feel better, but it decreases the chances of contagion by making you cough and sneeze less, and increasing your ability to sleep.
  
• Chicken soup actually is good for you! The ingredients have beneficial effects and hot liquids help loosen phlegm and all that stuff. There's no reason chicken soup is any better than, say, egg drop soup (which is what I always crave when I have a cold).
  
• Another reason that Benjamin Franklin is THE MAN...150 years before germ theory was generally accepted, Franklin made observations and concluded that colds were caused by sitting in close proximity to someone who had one and breathing their exhalations, leading him to surmise that the disease traveled through their air. Good call, Ben!
  

So. Sniffling yet? Go to bed!