One flu over the cuckoo's nest
Or, failing to prepare for the predictable
A post on Bobharris.com inspired me to write this. Bob Harris' blog entry included a link to an article describing recent developments with the H5N1 bird flu virus. The classic "good news, bad news" runs like this: The good news is that the H5N1 virus must go through two mutations in order to produce a pandemic causing strain. The bad news is that this can happen very easily. The following comes from the explanation I e-mailed to Bob:
I want to thank you for the link to the new H5N1 flu study. Although very interesting reading, I thought you would be interested in the reasons why we are still in deep trouble.
Probability and risk are likely the most poorly understood mathematical concepts in popular culture. Here are the factors that the article in question did not mention:
1.) Large parts of the world have no health reporting at all. Others have only minimal reporting in place. As a librarian I have laughed with my colleagues over questions that people ask which, by definition, have no answer. For example, "could you tell me the number of unreported cases of child abuse in Michigan in the 1990s?" If the cases are unreported, how do we count them? Most of sub-saharan Africa does not have even the most rudimentary health reporting. Likewise parts of Asia. The low number of "reported" cases of humans with bird flu becomes meaningless when you realize we have no idea how many people in Africa have died from it. Some of the species of migratory birds coming from Asia enter Africa around Ethiopia and Somalia. Neither country has health reporting procedures in place.
2.) On this planet we have about 900 million people living in over-crowded slums that make someplace like the "inner-city" in the U.S. look like country clubs. Here's how mutations of the flu happen: a person trapping wild birds in or near a slum contracts the bird flu. Call him patient zero. The incubation period for this is about a week to 10 days or so. Before showing symptoms the person enters the slum (or lives in it already) in which people sleep 5, 10, or more to a room. Malnutrition also harms immune response (along with stress, gee how stressful can never knowing where your next meal is coming from get?). Patient zero contracts the regular human to human flu virus. The two viruses encounter each other and produce a mutation. Patient zero's wife, mistress, girlfriend contracts the new virus. Now let's say the girlfriend catches the conventional virus later as well. Those two viruses find each other in her body and form another mutation. This scenario looks highly unlikely. But play out typical human behavior through millions of iterations. Add stress, malnutrition and over-crowding.
I found the article in cidrap somewhat reassuring in the sense that the H5N1 requires two rounds of mutation instead of one to start a pandemic. In theory the intermediate strain, when detected, can give us an early warning and lead to effective countermeasures. The operative words are "when detected." How many unreported cases have happened already? Think about it. The cidrap article is good, for what it does. But non-scientists re-stating and summarizing what scientists tell them sometimes leave out significant details.
If you have read this far, thank you! It's a long message. The information above comes from an interview in Salon.com with Mike Davis, author of The Monster at our door and a 3 page article When Flu Flies The Coop: A pandemic threatens Ben Harder. (Science News. Washington: Sep 10, 2005.Vol.168, Iss. 11; pg. 171, 3 pgs) and my reading of science publications.
The current administration has not shown much indication of preparing for a flu pandemic. I suspect the recent study will supply an excuse not to bother, under the assumption that we will find the intermediate strain before the killer one. I hope so.
I just read an article from the blog Science Based Medicine which describes in very clear laymen's terms the mechanism by which the Swine Flu virus works, the level of concern that's warranted and practical precautions. It makes for good reading. And fortunately, it's now 2009 and we have an administration which, despite its flaws, will most likely take seriously any scientifically based public health concerns.