The Coming Influenza Pandemic?

1 Comments:

At 3:49 PM,  Wulfgang said...

Orange;

Nice set of diverse articles today – I will say one thing, you believe in diversity. However, I really don’t wish to comment on the usual standing debate subjects: NPI’s or whether migratory birds or cross-border trade and smuggling, spreads the virus most. I really don’t care.

I’d like to comment on what seems like Dr. Nabarro’s one thousandth warning and message: the pandemic is still out there. And I’d like to express my disagreement with the following statements made by Dr. Pascal James Imperato, Public Health Director of SUNY-Downtown Medical Center, who made the following two statements in the article:

“… we have a wider margin of comfort, because this virus has not been able to commingle its genetic material with that of a human influenza virus, and in so doing, acquire the ability to be transmitted from person-to-person.”

“ Sporadic human-to-human transmission of the H5N1 strain has been reported in Hong Kong, Vietnam and Indonesia but none of the cases has been proven and officials determined there was no epidemiological significance because the spread was not sustained”.

These kind of benign and placating statements are what confuses people, and the media, and lulls everyone unfamiliar with the subject, into complacency.

Earlier this week, Dr. C.A. Nidom, an Indoesian molecular biologist, reported that the H5N1 virus has in fact mutated into 5 distinct subgroups in Indonesia, unknown to the outside world. Here’s the link: http://www.tempointeraktif.com/hg/nasional/2007/11/26/brk,20071126-112317,id.html . In addition to this, coincidentally, some very well founded unusual and unsubstantiated rumors have also begun circulating on the flu blog sites, about the situation there rapidly “getting out of hand”. And as I always say, there usually is a kernel of truth in rumors.

If this weren’t alarming enough, several other avian viruses have infected humans in recent years, some of them resulting in deaths, and these should not be ignored as other pandemic sources: H7N2, H7N3, H7N7, H9N2 and H10N7. In fact, the H2 influenza virus has not been in human circulation for many years, and it seem people would be high susceptible to it, as well, and have little resistance.

So what is my point? My point is that we are not out of the woods and in fact, we still face an increasing probability of a pandemic as time passes. But the problem is the relative probability of any pandemic originating from the high pathogenic H5N1 virus, rather than from any of the other avian viruses I mentioned, cannot be quantified because no comprehensive comparative data is available, and there is very poor comprehension of viral evolution processes and risk factors. The fact that clusters have no had sustained human-to-human spread, and the viruses have not had effective demonstrated commingling with human genetic material or common seasonal influenza strains – is zoonotic and viral deception. What we have now occurring, in my opinion, is significant genetic variation in circulating avian viruses (as demonstrated in Indonesia) as a result of extremely high rates of genetic drift, and an ever-increasing unknown range of hosts.

Here is the bottom line that should be recognized and communicated: only two small proteins produced enough change in the 1918 virus (H1) to alter its transmissibility and cause millions of deaths worldwide. Not only would it take a similar small change to alter the H5N1 virus to enable it to become similarly pandemic capable – but I believe the same phenomenon could well happen (or be happening) within all the other avian virus family of viruses also.

The next pandemic will be a random event, according to science and statistics. But just like the throwing of the dice… sooner or later the “snake eye’s” pop up, given enough time and tosses.

Wulfgang

 

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