Viral Fear

With the school year upon us, it is probably time for another installment of Swine Flu 101. My kids have already had the flu, or some sort of viral bug, this year, and I cough and sputter as I write this. Feels like I have had this bug for a month or more already.

This year’s flu season is looking to be pretty rough. On a day when I called my son in sick from school, 7 other kids were absent from his class, and 5 from from my daughter’s including the teacher. Does this mean I should panic? No. But, should I use some common sense? Yes. Sick kids need to stay home. Because sick kids get other kids sick, and then they all miss school, and that is no good for anyone’s education.

Is this a challenge in that I have to miss work when I am home with a sick kid? You bet. Two working parents on furlough and with no local family who can help makes sick kid days tough. Are my kids ever sick on furlough days? Of course not. Are they sick on a day when I have meetings scheduled back to back and incredibly important, career-limiting deadlines, of course. But, a sick kid is a sick kid and they have to stay home.

If you don’t already have a plan for how you are going to handle your child’s illness this year, it is a good idea to make one. Chances are you are going to have a sick kid. Chances are that when your kid is sick, you are carrying the germs and just not showing the symptoms, making you a prime vector for whatever the disease of the moment is. Viruses are typically most transmissible (ie contagious), before you show symptoms. That is the evolution at work. A successful virus is really good at spreading itself before you know it is there, and can fight it. That is how it ensures its survival. Having you home too, with your kid, is just not a bad idea.

In the meantime, should we panic? Definitely not. H1N1 is out there, in our population, right now. It has pretty much made it into the mainstream at this point. Doctors appear to be just assuming their patients have it now, and not sending every patient out to be tested. You should view this as a good thing. If doctors are not so panicked that they feel they need to test every suspect case, then the cases are mild, and the flu is doing what it is supposed to do in an evolutionary biology sense. It is becoming less virulent. Another hallmark of a successful virus is that it does not kill its host, as a live host means it can be spread to more and more people.

Dr. Marc Lipsitch of Harvard University estimates that we are now down to a Stage 1 pandemic. Stage 1 is the lowest level. Yes, people are going to contract this. Category 1 is equivalent to a moderate (not mild, but not severe) seasonal flu. Like seasonal flu, he predicts this is going to tend to affect the elderly and the immune compromised the worst. Because this effect is being added to the usual seasonal flu effect, it is going to be noticed. But, it is predictable.

What to do in the meantime? Cover your mouth when you cough or sneeze, stay home when you are ill, and do the same for your kids. What to do about all the others around you coughing and sneezing and not following this advice? A little hand-washing goes a long way. Do help yourself to the Purell and other sources provided to you to clean those items you touch that are out there being touched by everyone. But also remember, viruses are not biotic. Antibiotic wipes and gels won’t work against viruses, and there is lots of evidence that these contribute to the breeding of antibiotic-resistant bacterial strains. Antibiotic soaps and the like are not allowed in my home. Alcohol-based products like the hand-sanitizers are antiseptic, meaning they kill just about everything and kill it good. These, so far, are not linked to generating antibiotic resistance, are recommended by my personal doctor, and are allowed in my home.

The tiny world around us

In the wake of the Influena A-H1N1 chaos, you must have known I’d get around to writing about germs eventually. Hopefully most of us have calmed down now, and been able to put the H1N1 threat into the proper context and realized that, like seasonal flu, it tends not to affect healthy individuals all that severely, and it is best prevented with the same old remedies Mom taught you of good hand-washing and covering your mouth when you cough or sneeze. And, if you are sick, with any ailment, stay home and don’t spread it. But, it gets me around to the concept of germs, or more specifically, viruses, bacteria, and other tiny micro-organisms (oh my!).

Viruses, like H1N1, are just tiny packages of genetic material wrapped in a cozy protein coat. They reproduce inside host cells (i.e., you) using the hosts’ genetic machinery (i.e., yours). They make thousands of copies of themselves and then spread, implementing their little genetic programmes. Viruses do not always cause disease, but they usually cause an immune response, and once your body has produced that response you often have lifetime immunity to the virus (notable exceptions would be the herpes virus, hepatitis B, etc which elicit an incomplete immune response and remain with the host for life). Vaccines typically contain killed virus in order to cause the body to produce the desired immune response, when then protects the host from future invasions by this particular viral agent. Viruses are not killed by antibiotics, specifically because they are not “biotic.” Viruses lack the components of living cells that make them susceptible to antibiotics. Viruses, however, are the most abundant “life” form on the planet.

Bacteria are living cells. They live everywhere on earth, and we are able to culture only a tiny fraction of them. The vast majority are completely harmless, many are quite helpful, and a special few can be devastating. Most are easily dispatched by our immune system, and those that aren’t can sometimes be killed by antibiotics (but, not every harmful bacteria has a known antibiotic, and many are evolving resistance to known antibiotics). There are perhaps ten times more bacterial cells in your body than human cells. You are your own walking bacterial ecosystem.

A recent study [Science, 23 May 2008, p. 1001] looked to quantify the numbers of different types of bacteria living on the human body, and where. They swabbed all the places you might normally think of as well as some you probably don’t want to think of (mostly external), and the big winner? Not what you might think…it was our forearms; 500 to 1000 species of bacteria live on our skin.

Other tiny biological structures include prions, which are proteins that re-fold themselves to adopt a shape that causes them to interfere with normal protein function. And, fungi, which come in many forms, ranging from microscopic to the size just right for veggie pizza and portobello burgers. Mold is in this group, which is good for cheese, bad for heating and ventilation ducts, and pretty useful as a class of antibiotics.

When it comes to these tiny organisms, we humans are greatly outnumbered. Just a little humbling, isn’t it?