Monday, April 27, 2009

Swine Flu: Getting the Facts Right

Is it me—or has there been more uninformed reporting than usual over the past few days about the developing outbreak of human swine flu? Could it be the wholesale exodus of experienced health reporters from many newspapers and magazines is having an effect on the quality of coverage? Flu is not a topic that general assignment reporters can easily get up to speed on overnight.

I have read news reports cautioning people not to get near pigs for fear of contracting swine flu.

Not true. The new human swine flu is transmitted from person to person. So you minimize your risk of getting it by keeping your distance from other people, washing hands, reminding folks to cover their nose and mouth when they sneeze.

A number of news articles ominously report that the new human swine flu is H1N1—the same subtype as was responsible for the 1918 pandemic. The implication—that a terrifying type of flu has come back after more than 90 years.

Yes, the 1918 flu was caused by an H1N1 strain. But the H1N1 subtype is now very common. Indeed, it has caused many seasonal flu outbreaks over the past 90 years. The current vaccine even includes a strain of H1N1, first identified in Brisbane in 2007.

So if the new flu is H1N1 and H1N1 subtypes have been around for years, why are health officials so worried? Because the arrangement of genetic components of the new flu have never been seen before—whether in pigs or people. And they are different enough from the recent strains that the body’s immune system may not be able to mount a quickly effective response.

Many news sites are also reporting as fact that the flu is killing more people under the age of 60 than the usual seasonal flu. We don’t actually know this for sure.

Yes, there have been lots of reports of middle-aged people dying from the flu in Mexico. That’s worrisome because it’s the same pattern of fatalities that was seen in the 1918 pandemic. But that is only part of the story. There are other possible explanations for the pattern of middle-aged deaths: maybe those were the folks who went to the hospital first. Maybe health officials haven’t paid as close attention to deaths among the elderly because they are so much more common. It could still be a true cluster of middle-aged deaths but we probably won’t know that for at least another couple of weeks.

Lots of headlines are also proclaiming that countries are racing to “prevent the pandemic.” Sorry, that horse is out of the barn. This flu has already been confirmed in Mexico, the U.S., Canada and cases are suspected in New Zealand, Israel and Western Europe. If there is going to be a pandemic, there will be a pandemic. That will depend on how virulent the virus is—something that we don’t know yet.

What people can do is mitigate the damage. Sort of like a hurricane. You can’t stop it from coming ashore but you can try to protect as many people as possible from drowning.

In addition to newsfeeds at the Centers for Disease Control and the World Health Organization, here are some of the folks I have come to trust for information on the current flu outbreak:

Anything written by Helen Branswell, Canadian medical reporter. Her coverage of flu and the potential for pandemic flu over the past several years has been stellar. She is also @diseasegeek on Twitter.

Tara Smith at Aetiology. Tara is an assistant professor of epidemiology, whose research focuses on pathogens that jump from animals to humans. Very readable and very smart.

The Reveres at Effect Measure. Anonymous, opinionated but well-informed, from public health professionals.

Crof at H5N1. Crof has been a smart aggregator about avian flu and potential pandemic news for years but is now including human swine flu.

The pandemic flu section of the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota.

Good, if technical overview on swineflu, also at CIDRAP.

And here are some web resources to understand flu and potential flu pandemics better. I’m chasing down links to some other tools and will add them as I learn them.

One-stop access to US government information on pandemic flu

The Nieman Reports special issue on preparing to cover pandemic flu

Association of Health Care Journalists ($60 per year). Members have access on the website to excellent content created specifically for journalists covering flu. (Update: AHCJ has now made its flu resources freely available.)

The basic science section of the Flu Wiki

WHO's excellent guide to risk communications in a pandemic

General overview on pandemic flu, with history, by US government's Health and Human Services.

Related blog post: Swine Flu: Stocking Up On Soup, Just In Case
(Updated April 30, 2009)


P said...

I've spent a half hour online trying to find facts (or at least an article addressing what facts are still unknown) to get a sense if this really is a cause for concern or if this is another media-driven overblown story. Thanks for the smart post and the links.

MarketBlogic said...

I still haven't seen any evidence that this is very far statistically out of line with past flu experience in Mexico.

According to the CDC, the US has 36,000 flu-related deaths per year with a population of 300+ million. Interpolate that over to Mexico's 110 million population and you get very crudely 1,000 flu deaths per month in Mexico in a tyical year.

What has happened with this flu that's notably out of line with that, I'd like to know?

f said...

Just that it's a springtime flu, a new variant, and seems (SEEMS) to be affecting young adults disproportionately. These are hallmarks of a virulent flu. however, I think a lot of information is unknown at this point. I'm beginning to suspect that there are a lot more mild infections in mexico than we know about. That fact would certainly make these deaths much more normal.

MarketBlogic said...

Since f and I pretty much agree, let me add a couple of things:

1. I'm 90% convinced that this is a big panic over almost nothing -- because there are unfortunately lots of health fatalities every month in countries as big as Mexico with 110 million people. I HAVE YET TO SEE a single solid analysis anywhere comparing health related fatalities in Mexico this year with last year - and I bet when it's done we'll find out that statistically you can't find any significant evidence of this flu on that severity level.

2. I had a bad case of the flu last week and tested positive on the QuickVue test for one of the Type A variants. Two days later, I called Quidel to find out what result the Mexican Swine flu was giving when run thru the QuickVue and unfortunately as of last Friday they still didn't know. [Note: A positive Type A still wouldn't confirm the presence of Mexican flu, BUT a negative Type A result might]. The flu I had and several friends have now had was unusual - it kicked like a country mule as they say back home - and the GI symptoms were very unpleasant, but it was just the flu. Worse than average, but just the flu. And I got an Rx for Relenza and it seemed to help.

Stefanie said...

Great post, thanks. Continuing uncertainty is what flu is all about -- and what people fear the most, I guess. So we need to keep focussing on the facts, and lack of facts; and help us all endure the uncertainty without panicking. Yes, I'm equally disappointed by the lack of info on the Mexico deaths cases.

And talking about misinformation, my favourite confusing term today is in the NYT's story about the "ground zero" boy: "[...] what might become a global epidemic." GLOBAL EPIDEMIC? What, then, is a pandemic? What could be the motivation to avoid the term, or come up with a new one?

Christine Gorman said...

Thanks for all your comments.

I realize I should go a little deeper on one point. Even if this is a mild flu--it is a mild flu that almost no one has any immunity to.

The current seasonal flu leads to 36,000 deaths in the US and that's with most of the adult population already having partial protection (because the viruses have been around so long.)

A mild flu to which no one has immunity means a lot more people get sick. A lot more people getting sick strains our resources even if not that many people die.

We are in a fluid situation, here.

We need to be keeping an eye on this--neither dismissing it out of hand, nor cowering under the bed.