Trying for a perspective on the swine flu epidemic

BBC has a story today that the estimate of the number of deaths from swine flu in Mexico has gone down (from 176 to 101). The article goes on to imply (although the authors don't say so explicitly) that there is more than one strain of flu causing the Mexican epidemic. It also suggests that the Mexican swine flu is not as easily communicated nor as lethal as had originally been feared. All of which is of course good news.

We are moving toward the end of the "normal" annual flu epidemic. Flu is a serious disease, killing some 35,000 people a year in the United States. Unfortunately, people don't take it sufficiently seriously. It is suggested each year that people who would be likely to be very sick if infected, and the contacts of those people, have immunizations to protect against the likely agents of that year's epidemic, but the levels of immunizations are never as high as one would wish.

On the other hand, schools are closing in my and a lot of local areas because a kid may have caught a case of the flu that may have been the swine flu. This is happening even when the communicability and lethality of the disease are not known, when it is more probable that a case of flu that actually occurs here is not swine flu, and even though most cases of respiratory illness are not influenza. The media have clearly done a disservice in raising too much fear in the public about swine flu.

On the other hand, there are a lot of protection measures that are very low cost, which may have other benefits, and which people should be using. Certainly washing ones hands and taking measures to avoid spreading germs by sneezing and coughing are prudent. So too might be avoiding crowds, at least when there is no good reason to join them. The benefits of a couple of weeks of schooling are probably great enough to justify the risks of attending a school where a kid came down with a respiratory illness without further evidence of the seriousness of that illness.

The issue is how appropriately weigh the risks of a new strain of flu against the benefits of the activities one is asked to give up or the costs of the protective measures one is asked to undertake.

I mentioned above that not only do we ask the elderly to be immunized against flu, but we ask that those who might give them the disease also to be immunized. We do so because the benefits of protection to the family members and care givers of the elderly are not only those which the individual receives, but in the protection of those who might be secondary infections. More generally, public health has to take into account the social benefits of public health measures. We ought to be especially vigilant against flu now because we don't want to help spread a new disease that might be especially serious. On the other hand, let us not overstate the risk and over react to the problem.

The Bush administration hugely overstated the threat from international terrorists, and gained some short term political advantage by doing so. The Ford administration allowed the risk of swine flu to be overstates and reaped political disaster when the costs of unnecessary immunizations were counted (probably over-counted due to a misperception of the risks of complications from the immunizations). I certainly hope that the Obama administration handles the public perception of risks of this epidemic well.