Entries in Webby (1)
H7N9 begins its turn toward mass human infection
The news today brings two more cases of human infection with H7N9 avian flu, and the confirmation of the fourth death I mentioned in yesterday's blog.
WAIT! NEWS FLASH! Now, according to Treyfish, veteran Flutrackers poster, China has reported 14 cases of human H7N9 infection. And one pigeon. Five humans are dead. The pigeon's status is uncertain.
I am only half-joking when I mention the pigeon. As I blogged yesterday, birds appear to be unaffected by this bird flu. Ordinarily, when a bird has bird flu, it gets very sick and then dies.
As ESPN celebrity and former FSU player Lee Corso would say, not so fast, my friend. This bird flu is not making birds sick. If it were, we would have seen H7N9 coming.
Now, Corso did not say that about bird flu. I said that.
At least one of the two newly-reported cases is in Zhejiang Province. This province has previously reported cases of H7N9 recently. Please refer to the map of Chinese provinces I posted in a previous H7N9 blog. The location of the second new case today is not confirmed.
There is feverish (so to speak) activity taking place among those who know the genetics of influenza. These intrepid individuals have been studying the anatomy of H7N9 and sharing that data via the Internet. The crowdsourcing of H7N9 data is most helpful and extremely important, for it allows a much greater number of qualified researchers to begin the process of dissecting this troubling new virus.
As one can imagine, samples of this new strain of H7N9 are rare. I can only imagine the frantic process of obtaining these samples and sending them via fighter jet halfway around the world to ground transports, those transports, in turn, racing these samples to facilities such as St. Jude and Drs. Webster and Webby. Well, that's how it would work in the movies. The reality is probably based around Fed Ex and UPS. "Sign here for your lethal bird flu virus, Doctor Webster."
Anyway, you have eleven positive victims, and four deaths, and only so much tissue to go around. So those lucky enough to have actually processed the samples themselves are able to post their research online.
We are a long, long way from being able to replicate things in a laboratory. We are a long, long way from growing H7N9 in quantities sufficient to conduct any real experiments, with ferrets, birds, or any other creatures. So all we have right now are the phylogenetic charts showing the antecedents of H7N9, and where we have seen their individual component parts before.
For example, GeneWurx, which posts to Flutrackers, says this about what they have seen:
Though H9N2 is regaled as the nearest relative on file for these internal gene segments of the H7N9 emerging zoonosis, note the highlighted areas including a fatal H5N1 human, pH1N1 in swine (with human homology) and sH3N2. These H7N9 sequences have developed from pedigrees not entirely disjunctive from human infection.
You will recall the (not so) little problem America had with its rural county fairs the past two summers. People were petting farm animals and then winding up with swine H3N2. I really meant to blog about those cases. Anyway, an excellent CIDRAP article from last October showed now closely related the swine H3N2 and the longtime seasonal human H3N2 were related.
The press has been running excerpts of an interview with Dr. Richard Webby, of St. Jude. For new readers: St. Jude has arguably the top influenza research facility in the world. Its director, Dr. Robert Webster, is nicknamed the "Pope of Influenza." Dr. Richard Webby works with Dr. Webster and he is also an email buddy of mine. Dr. Webby said this to the press about H7N9:
"I think that's what's concerning about this ...This thing doesn't any longer look like a poultry virus," Webby, a swine flu expert, said in an interview.
"It really looks to me like it's adapted in a mammalian host somewhere."
If the virus is spreading in mammals, finding that source is critical to try to reduce human exposure and prevent additional cases, he said.
Also weighing in is Dr. Henry Niman. Dr. Niman has composed an excellent map of the human cases so far, cases known and suspected. He also is seeing the progression that Dr. Webby has seen, but he does have a rather flamboyant writing style:
The latest cases increase concerns that the presence of D225G and Q226L represents human adaption of a lethal bird flu virus that has a greater pandemic potential than H5N1. This potention is enhanced by the presence of PB2 E627K.
Veteran readers of this Blog know that the presence of PB2 E627K signals a move away from avian proclivities and toward mammals. These are the changes that worry researchers so much. Also knowing that the birds are not dying means surveillance using conventional (and cheaper) methodology is out the window. We need a better way to detect the presence of this new flu, and we need it quickly.
There is no question that, somewhere along the line, a pig -- or a human -- was the Mixing vessel that produced this new, novel and immensely troubling virus.
Fasten your seat belt.