Thursday, February 9, 2017

A Thought Experiment on Herd Immunity

You may have heard of the concept of “herd immunity.” I am not referring to anything having to do with groups of large, hoofed animals, although I suspect the concepts would apply to them as well. What this refers to is the resistance of a population to a disease.

Let’s consider a highly-contagious, fictional disease by the name of Sauderosis. Assume we have a vaccine for Sauderosis which is effective in preventing the disease in 90% of the people who are vaccinated and subsequently exposed to the disease.

Imagine a school with one hundred students who have all been vaccinated against Sauderosis. Since the vaccine is 90% effective, ten of the students in the school will be susceptible to Sauderosis if they are exposed. If there are 20 students in each class, that means two students in each class who are susceptible, so there is not likely to be a widespread problem with the illness in the school, even if someone comes to school sick with the disease.

Now consider that same school if only 50% of the students are immunized against Sauderosis. There are now 55 unprotected students in the school, all 50 who were not vaccinated and five who were (10% of the 50 immunized students). That would mean there are, on average, 11 students in each class who are susceptible so there is a significant chance of a large outbreak if the illness is introduced to the school.

Now imagine your child has an underlying medical condition which makes him more likely to have complications of Sauderosis. If he gets this illness, he is likely to end up in the hospital and may even have life-threatening complications. Which school population would you want him to be in?

Wednesday, February 1, 2017

Random Thoughts While Running


This is another blog post that really doesn’t have anything to do with pediatrics but for some reason was what I was thinking about while running today.

A few months ago, one of our vehicles had a flat tire. For a variety of reasons that I won’t bore you with (in part because I can’t remember them), the only time I had to change the tire was late on a Saturday afternoon. But when I went to take off the flat tire, one of the lug nuts was stripped and the wrench just kept slipping off. I really couldn’t figure out what to do and knew we needed to have the vehicle available Monday morning.

I texted a friend for advice and called around until I found one tire place in town which was open for another 30 minutes. I pumped up the tire with the bicycle tire pump, threw the pump in the back, and headed to town hoping for the best.

After I arrived safely, it took them about ten minutes to remove a nail, patch the tire, and get it pumped up again for me. We chatted about college football while they were doing it and I was ready to leave in no time. When I went to pay, the charge was $10. Forty-five minutes earlier I had been in a panic trying to figure out what to do and these guys saved me. I told them to charge me more but they insisted $10 was the charge.

That made me think about how we determine the value of things. The guys who fixed my tire possess equipment and knowledge to know how to patch a tire. That is a valuable thing to a guy like me who does not know how to do it himself.

We all have our own niche and expertise and need to value that in each other. When I have a patient who needs more help than I can provide, I refer them to a doctor who specializes in the problem they have. When an oak tree fell on our garage roof, I called guys who could remove it safely. If I want to understand a scientific issue, I read things written by the scientists who work on it. If I have a problem with the house, I call a contractor. When my snowblower quit working, I called folks who know how to fix snowblowers. If I don’t know which E&M code to use for a visit, I ask our office manager.

We all depend on each other for different things. I know some really handy and talented people but I don’t know anyone who can get through life all on their own. At the risk of sounding preachy, it reminds me of I Corinthians 12:14 and following which talks about the need for every part of the body to do its job for the body to function properly.

So look for the value in others and acknowledge it. It will make their day and it will help you appreciate them more.