Tuesday, April 28, 2009

What is a pandemic?

The outbreak of Swine Flu has the news outlets abuzz with rumors. Again and again, the newscasts refer to a possible "pandemic." Hopefully, someone out there in authority knows what this term really means. Additionally, it would be nice if someone had read a little history about the last great flu epidemic in 1918.

Unfortunately, there is no specific definition of the term "pandemic." A pandemic (from Greek παν pan all + δήμος demos people) is an epidemic of infectious disease that spreads through populations across a large region; for instance a continent, or even worldwide.Widkipedia That seems really helpful. Think of all the diseases that are already pandemic by that definition: cholera, typhus, HIV and AIDS, measles, tuberculosis, malaria, yellow fever, and many, many others.

Just to give a little bit of perspective to the term pandemic, according to the Centers for Disease Control and Prevention, each year 350–500 million cases of malaria occur worldwide, and over one million people die, most of them young children in sub-Saharan Africa. In areas of Africa with high malaria transmission, an estimated 990,000 people died of malaria in 1995 – over 2700 deaths per day, or 2 deaths per minute. Apparently, unless people are dying in New York, a disease is not our problem.

Let's get another interesting perspective, again from the Centers for Disease Control and Prevention, the number of alcohol-induced deaths in the U.S., excluding accidents and homicides, in 2005 was 21,634. Here's another statistic, the number of Lyme Disease infections in the U.S. for 2005 were 23,305.

Maybe we ought to be a little more circumspect before throwing around the word pandemic.


  1. ccording to the folks over at Effect Measure,
    "...An epidemic is an increase in the number of new cases beyond what you would expect. Four or five cases of human rabies in an area in the US would be an outbreak or even an epidemic. Hundreds of colds or even serious pneumonias in an urban area is normal. It's not an epidemic. What makes the swine flu an outbreak is that it is an infection with a virus we haven't seen before and which we believe may be new. Hence these cases are not what we expect and it is an outbreak."

    The other consideration here is that for all we know about the flu virus (this or any other) there is much we still do not know.

    While I agree that it helps to keep some perpective (and of course the press has done its usual job of firing up the hysteria) it is also important to keep an eye on things. As the CDC accurately stated "the influenza virus is highly unpredictable and our certain knowledge of it very scant. If you've seen one flu pandemic, you've seen one flu pandemic."

    You can't catch a murder or an automobile accident from a door knob and Lyme disease doesn't pose a threat to the economy like a flu pandemic has the potential to do.

  2. So far, people aren't even dying in New York. What about Dengue Fever, spread by mosquito like Malaria, but with only a 1% fatality rate? With CDC estimates at about 100,000,000 cases a year, that's 100,000 dying people worldwide. (It might be higher, because the fatality rate in developing countries is about 5%). In Puerto Rico, about 2-3 people a week die from Dengue. I guess it's not New York or California.

  3. Thank you! I agree completely.

  4. Pandemic declaration apparently deals more with how widespread the virus is rather than it's lethality. And should it become more lethal (either in the short term or perhaps this fall) then we could be talking millions of deaths.
    Vaccines against dengue and malaria are under development - they have not been as straightforward to devise as an influenza vaccine. And a vaccine against Lyme disease was licensed but recently removed from the US market. Unfortunately no vaccines are possible for alcohol related deaths and homicides. :-)