H1N1 burning out? Why?

About two or three weeks ago, H1N1 was all over the news. I even had coworkers who had serious bouts with it (yes, they were diagnosed with H1N1, not just seasonal flu, and one had to spend several days in the hospital due to respiratory problems).

But now, it seems like not only that H1N1 isn’t in the news much any more, but I came across this chart from the CDC which says that the number of doctor visits for flu-like symptoms has been cut in half in just a couple weeks.


  1. Do these data indicate that the spread of H1N1 is slowing? Or could there be another trend: decrease in news coverage has people less panicked about the spread of the disease?

  2. Could the H1N1 vaccine, even in short supply, have had this effect so rapidly?

  3. Could the number of cases spike yet again?

  4. Or has the concern about H1N1 been completely overblown?

Generally, influenza strains have “seasons” in which they are most active. We aren’t entirely sure yet of what is the case with H1N1, and in fact, it’s worse than the usual “seasonal” influenza in that it’s been active for many more months out of the year (worldwide) than the usual strains are.

From the same CDC website:

So, the simple answer is, “We don’t know.”

Maybe all the preparations we have taken are actually working:

-Hand sanitizer sales are off the chart; though we don’t necessarily know about usage thereof
-People have been asked to stay home if they have flu-like symptoms; how many cases of H1N1 have been avoided by sick kids staying at home from school?
-Millions of Americans have now received the H1N1 vaccine; vaccines have been called the second greatest public health weapon after clean drinking water

All the media hysteria has helped reinforced the above. I’m guessing we are all going to relax our precautions and we will then see a second- actually third round- early next spring.

Influenza tends to occur in waves - and it’s possible there could be resurgences of H1N1 later in the season, especially after the Xmas holiday when people have had a chance to trade germs with friends and relatives around the country.

It’s already had quite a run…it’d be nice if the worst was past, but it’s too soon to say.

Anyone who knows what will happen next just doesn’t know enough to know that they do not know.

“Waves” usually seem to come in chunks about 6 to 8 weeks to peak (although they can last longer). No one knows why they last that long.

The timing of this one was as many expected with a virus already circulating widely in the communities - starting up within a couple of weeks to a month of schools starting back up and driven by the kids.

IF there is to be another H1N1 wave (and most experts expect that there will be one) then it might reasonably be driven by the usual seasonal influenza factors. Whatever those factors are that means sometime middlish of January to mid-February and then another 6 to 8 weeks to peak.

OR there could be that enough have already had it or been vaccinated that another wave is prevented.

Separately it is also anyone’s guess whether we will have a seasonal influenza season. On its own or co-circulating with H1N1.

The media portrays the only options as OMIGOD WE ALL GAWNA DIE vs it’s all a hype. The reality is that there is lots of uncertainty and hard to define risks. The job of the WHO and the CDC is to manage that uncertainty and risk. Right now getting vaccinated is like wearing your seatbelts: odds are you’ll be okay if you don’t wear them but buckle up anyway.

Also, in that time period the vaccine has reached a lot more people.

Maybe it was overblown. Regular flu kills a lot more people. The vaccine is still not readily available around here. My wife is scheduled to get her shot in a week. I am not getting one at all.

H1N1 is a variation of Influenza A, the novelty is that H1N1 has the most severe impact on groups that are usually not severely hit by the usual A/B Influenza strains.

As is the case with the usual influenza, H1N1 is presenting a typical pattern of burning through a population at risk, attenuated to an extent by an aggressive vaccination campaign.

Living in Australia the H1N1 virus was a non event even without a vaccination campaign, some people at risk died as they always do in flu season however I’m in the at risk group and my doctor said not to worry about the free vaccine till next next year.

[li]I aint heard no fat lady sing.[/li][li]The WHO it kills is very different. Pandemic A/H1N1 has by and large spared those at highest risk of death, the elderly. But pediatric and young adult deaths are much higher than most seasonal years.[/li][li]What we had is not likely (although who knows?) in place of flu deaths in the usual time that they occur, Febuary through March; they are likely in addition to (be those from seasonal or H1N1 then).[/li][li]The RISK has not been overblown. There has been and continues to be a real risk that this could be much much worse. There is no certainty that it will be, or that it won’t be. Each day I get in my car there is a risk that I will be in an accident. Most days I do not but I wear my seatbelt each time anyway. Is wearing my seatbelt unneeded because in retrospect I didn’t have a car accident that day and I would have been just as well off without my belt on that time? [/li][/ol]

By the way, Australia had 15x their normal rate of influenza ICU admissions. A non-event for most, but for some, it was bad indeed.

Even with declining H1N1 case numbers, flu hospitalizations and deaths remain higher than normal for this time of year.

Here’s what the CDC is saying about risks and true numbers of flu cases (the figures given for laboratory-confirmed H1N1-related deaths markedly undercount actual numbers).

http://reason.com/blog/2009/10/26/swine-flu-the-mystery-epidemic I have read a lot of sources saying the swine flu is way over counted. The CDC quit testing a long time ago. As it fizzles they can declare their measures saved us and we can be grateful.

It’s certainly true that the regular flu kills thousands every year but not in October. The simplest explanation for the early deaths in unusual populations, is that all of the flu deaths are from swine flu. Any widespread flu at all is extraordinarily unusual as early as September. Once again, while they aren’t doing specific tests to see which flu is spreading, the simplest explanation is that the flu that is spreading is swine flu. We are at the beginning of the regular flu season. The idea that the extremely early peak in flu diagnosis wasn’t due to the swine flu, simply doesn’t hold up under scrutiny.

What’s tough about all this is that as “killer diseases” come and go (SARS, West Nile Virus, Swine Flu this decade), there could well be a “Boy Who Cried Wolf” effect when the real Captain Trips comes about. Public-health agencies must really struggle with how to keep their warnings relevant and heeded in the face of a lay audience that thinks in black/white.

For those of us with chronic respiratory illness and young children this is the real Captain Trips. Weekly Pediatric Deaths. I am very glad that the CDC has had the guts to warn us knowing the risk of being perceived as crying wolf. The real risk is being successful in mitigating the problem, then having people claim there was no problem.

Yeah, like all of those hurricane warnings over the years that came to nothing.

As long as you’re not scaring them with predictions that don’t come to pass, the public is quite forgiving of the occasional instance of unpreparedness. Like with New Orleans and Hurricane Katrina.

Slight hijack:

Many of them do, in fact, come to (relatively) nothing. You don’t even have to evacuate for them all the time. Your comparison is actually quite sound.

Actually it is way undercounted, which is a good thing. Studies have shown that many have antibody evidence of disease without having had notable disease. Enough of that and there may be some herd immunity sooner than later.

http://www.rep-am.com/articles/2009/12/09/news/national/453817.txt We conservatives are not buying it. The death rate is far lower than std. flu. It is making a fortune for the makers on Tamiflu though.

That effect already exists. You can see it every time someone challenges the concept of vaccination.