A
reader asked about Avian Influenza (H5N1.) Do public health professionals
take it seriously? The answer is very much Yes. Of course we can't
predict the future with certainty, and there *is* a certain amount
of hype right now -- but, yes, the situation *could* eventually rival
the 1918-19 influenza pandemic. At the same time, I must emphasize
there is no guarantee that will happen: and we are not there, yet,
not by a long shot.
The bottom line is yes, it is *possible* the H5N1 virus could mutate
so as to efficiently jump between humans (person-to-person transmission)
and cause a Very Bad Situation indeed. Fortunately, although a few
instances of person-to-person transmission have already occurred in
northern Vietnam, it was not very "efficient" from the viral
perspective and has not been sustained.
Still, the just-starting annual influenza season in the Northern Hemisphere
will be a time for continued vigilance on H5N1, focused on Asia. Your
readers should recognize that there's a lot of attention -- public
health surveillance -- directed to this issue right now. I really expect
any new sinister abilities by the H5N1 virus will become apparent in
SE Asia first. Indonesia in particular is quite worrisome at this
moment. (I am quite mindful of the Chinese government's very poor initial
reaction to SARS in 2003, but frankly it's at the point where no government
could hide serious new developments re: human H5N1 even if they wanted
to.) My point is, don't over-react to winter respiratory
illness in the rest of the world. We call it "cold and flu season" for
a reason!
(In this regard, I must say the current hysteria in some quarters over
the Toronto nursing home deaths seems misplaced. I am prepared to be
wrong, but having investigated nursing home outbreaks for more than
a decade, I know that in respiratory outbreaks in nursing homes People
Do Die and sometimes it's not instantly apparent why. I have no inside
information -- but so far, from the press reports, the situation really
doesn't strike me as all that exceptional. Is it a bad outbreak? Obviously.
But nasty nursing home outbreaks happen somewhere every year. Labeling
it "mysterious" is true as far as it goes, but not meaningful.
The public health folks in Toronto, some of whom I know personally,
have reported it's not the most obvious nor most worrisome bugs --
not influenza A of any type, nor Legionella, nor SARS, etc etc -- so
my predictions: it's RSV, or parainfluenza, or adenovirus. Sometimes
theses things just aren't as easy to diagnose as we'd like.)
Anyhow, back to H5N1: a good technical review article was just published
in the New England Journal of Medicine and is currently free on their
website: "Current Concepts: Avian Influenza A(H5N1) Infection
in Humans," September 29, 2005, http://content.nejm.org/cgi/reprint/353/13/1374.pdf.
Also, for a doomerish perspective from a professional who has been
beating the drum loudly on this topic, read any of the editorials by
or news
stories on Michael Osterholm, a much-respected former State
Epidemiologist from Minnesota. Just "Google" his name. I
am not offering any detailed pandemic 'flu advice as requested by the
other reader because I don't have anything new or brilliant to
offer. In the very worst imaginable situation -- not likely but also
not completely impossible IMHO -- your readers *already* should be
aware that deep preparations, a chain saw for dropping trees,
and a remote location ought to be part of their extended personal options.
They
are certainly part of mine. If they don't know this already, then they
should reconsider why they are bothering to read your blog at all.
- "A.
Physician"
A. Physician's Letter Update(8 October): As a follow up to my comments: The much-watched Toronto nursing home outbreak turned out to be due to Legionella after all (according to news reports made after I wrote my initial note to you.) Nasty but far from unprecedented. The diagnosis was eventually made from autopsy specimens. I'm guessing that earlier "urine antigen" tests were negative, but those can only diagnose one type of Legionella that accounts for 80-90% of Legionella outbreaks; and Legionella bacteria are difficult to grow via sputum cultures from living patients.
