Current Events Scrapbook

Effect Measure: Indonesian cluster: What, me worry?

Right about the time the Indonesian volcano erupted in May 2006, an interesting report came out.

It disclosed that there was a cluster of 8 people infected with avian flu. That in itself was not surprising. Lots of the poultry birds there have it and people have been getting infected from the birds.

What was interesting is that in the case of this cluster, there did not seem to be birds around these people that were carrying the virus.


Effect Measure: Indonesian cluster: What, me worry?:

One thing I've learned in many years as an epidemiologist is that disease outbreaks are rarely what they appear to be at first. Sometimes they are worse and sometimes they are better, but mostly they are different. I've spent a lot of years dealing with cancer clusters and I am a strong believer these clusters are real. But there is a school of thought that says they aren't and there is a strong argument to make there. I disagree with them, for technical reasons. The one thing I know about clusters, though, is that it is important to verify all the initial information. A large proportion of the time the cancers in a cancer cluster aren't even cancer, or they are a different kind of cancer than initially reported. Numerous other facts usually turn out to be different than originally thought .


So in the Indonesian cluster, as with other reports about bird flu that come to us from far away, filtered through media reports and machine translations, I now prefer to wait a bit and see how it shakes out. I didn't do that in the early days of the bird flu problem but I should have. I've checked the diagnoses with a source in-country and I'm satisfied it is H5N1. But the other information, like dates of onset, are always problematic, so I'm waiting to see what develops.


My personal opinion is that the Indonesian cluster looks like it is a possible instance of either increased bird to human transmission or an instance of human to human. These cases have occurred before, but the size of this cluster makes one ask if something has changed. Henry Niman derides the idea it is enhanced bird to human transmission on the grounds that bird flu is very hard to catch from a bird. True. There are millions of bird human exposures and very few human cases. On the other hand it is hard to catch from other people, too. So I'm not sure I understand Henry's point (although I am quite sure he'll tell me, in his usual gracious way).

Wait-and-see seems like a good policy. More news on the cluster will undoubtedly come out. The volcano might interfere with this a little, by drawing attention away from this subject briefly.

However, because bird flu - especially the H5N1 - has gotten so much attention from media and governments worldwide, they will not drop this story before the facts about how these people got infected come out.

posted by John Collins @ 3:17 PM