Has swine flu peaked, and it if has, what does that mean?

Have you seen the movie "Speed"? Great action flick if you haven't. One of my favorite scenes in that movie is this one (apologies for vagueness ... I have not seen the movie in quite some time): There is a bus running wild on the streets being followed by emergency vehicles. A group of girl scouts are crossing the street, but the bus is coming, and the horn is blaring, so they run out of he way. The bus speeds by. The troop of girl scouts is led by their leader across the street again. But now a police car, siren blaring, comes tearing down the street. The girl scout troop jumps out of the way and the police cruiser speeds by. Now that the action is over, the girls scout troop can safely cross the street, and they start to do so. But then a fire truck with its sirens blaring comes tearing down the street.

If you are observant you've seen the same thing happen in real life where some moron pulls over for the first fire truck and then haplessly pulls out in front of the second fire truck and is almost hit. If you are NOT observant, then perhaps you are the hapless moron.

This reminds me of us, we humans, right now, with the swine flu "peak" idea. Increasingly we are hearing that the swine flu is peaking now. This is because numbers of new cases are lower than they were a week or few weeks ago (depending on your location), numbers of schools with the threshold count of students out sick has gone down for the first time since going up and up and up for a while. So it looks like were are past a peak and everything is going to be OK.

Is this true, does this matter, and what are we doing wrong with this assumption?

There are three reasons that it is not a good idea to think that since we are passing a peak we are out of the woods. They are:

1) It just may be wrong. This may be a short term fluctuation in a longer term trend. My gut feeling is that this is NOT a minor fluctuation in long term data. I'm betting on the peak theory, that we are passing a peak and that we will see a decline in swine flu cases over the next few weeks. But that may be totally wrong. This whole "peak thing" could be a minor fluctuation.

2) If there is a peak, it does not mean that it is safe to stop washing your hands and to start sneezing on each other. Two weeks ago the situation with swine flu was bad, dangerous, and icky. If the peak looks more or less like a normal curve (and such things often do) then this means that in two weeks from now the situation with the swine flu will be bad, dangerous, and icky. In other words, an imminent decline of swine flu cases does not equal zero swine flu cases. In still other words, one cop car with sirens blaring may be whizzing by as we speak. Don't just wander blissfully out into the middle of the street like it is all over, because you will be flattened by the firetruck that you illogically assume is not coming next.

3) There maybe another peak. This is the scary part, and here's how it works.

The swine flu has done a pretty good job of spreading and infecting people. But it did this during the time of the year that we don't normally see a lot of flu. The flu is normally seasonal because conditions change across the year with the seasons, and those conditions determine the quality of the environment in which the flu lives and spreads. So there is a down time and an up time. The swine flu seemed to do pretty well during the down time, during the time when the environment is not very good for the spread of flu. How did it do that? Probably by being very very very easy to catch. It is probably the ease with which the flu is transmitted from person to person that varies seasonally because of the environment, and the swine flu did just fine, thank you very much, in a suboptimal environment.

But then a lot of the people who were for one reason or another more likely to catch the flu got it, and a lot of the people between whom the flu was more likely to be passed regardless of other environmental conditions passed it back and forth already, so the spread and prevalence of the swine flu is (if the peak is really passing) diminishing.

.... BUT ....

As we enter the time of year in the Northern Hemisphere when the flu in general, including the swine flu, is relatively easily passed around ... and this transition happens over the next several weeks ... the swine flu may very well make a comeback, for an additional peak coinciding with the normal seasonal flu season.

The comeback may be less severe than the previous peak because lots of people already got the flu. Or it may be more severe than the previous peak because adding together this flu's ability to spread with improved conditions for any flu spreading may create a higher peak. Or, a variant of the swine flu that has not been around yet may show up and be really good at spreading. Or not.

An early November peak was postulated by epidemiologists over a month ago. Previously, roughly similar pandemics (such as 1918 and 1957) peaked early like this one may be doing.

Don't let your guard down. Don't panic. Do get the H1N1 shot when it is available. And a seasonal flu shot. Continue to cough/sneeze into your sleeve. Wash your hands. Wipe your feet before you come into the house and don't talk with your mouth full. Those last two may not help with the flu but they will make your mother happy.