HIV and ID Observations

The town of Braintree, just south of Boston, has cancelled Friday night high school football games until the first frost of the year due to concerns about West Nile.  Apparently the campus has a lake and wetlands,  good breeding grounds for mosquitoes.  “This is all in the name of safety,” says the school headmaster.

(If someone were doing a presentation on “How Massachusetts Differs from Texas”, this move is Exhibit 1.)

When West Nile encephalitis first appeared in Boston in the Summer of 2000, there were newspaper articles about how parents would rush their children from house to car on summer evenings to avoid mosquito bites; lots of debate over the relative safety of various chemical repellents; people scrutinized their neighbors’ yards for suspicious bird baths or, worse, old tires with stagnant water.

This all seemed to me a variant on a commonly-observed inability for us humans to figure out relative risk.  Which was more dangerous, a few mosquito bites on a summer evening, or the drive in the car?  We fear what we can’t control — especially creepy microbes, bugs, germs, yuck — and if anything can be done to reduce this risk further, even if it’s from a 1 in a million to a 1 in 10 million chance, let’s do it.  (See rabies prevention, for another example.)

By contrast, we have the illusion of control over things like car safety, when in fact most car accidents happen suddenly —  no warning –- and we have no control at all over the driver trying to find his sunglasses while talking on the cellphone after having a few too many. People are more concerned with feeling safe than being safe — just try to convince the driver of a large SUV otherwise.

This is not to diminish the potential seriousness of West Nile disease — a colleague of mine’s father died of it in California several years ago — but the reality is that so far this year in Massachusetts there have been zero human cases; last year there were 6 (3 encephalitis, 3 fever).  Less than 1% of people who become infected with West Nile virus will develop severe illness.  Most people who get infected with West Nile do not develop any disease at all, and the elderly — not high school football players — are at the greatest risk for encephalitis.

As a 140-pounder when wet, I can think of lots of good safety reasons reasons not to play high school tackle football on Friday nights — but the risk of West Nile isn’t one of them.