Scott McPherson's Web Presence

This week, an elderly Central Florida woman named Catherine "Cay" Thompson died of swine (H1N1/2009) influenza.

The news report, a capsule of which can be found here, says the Lake County (just north of Orlando) woman had recently traveled to California.  the new report also says local health officials are "shocked" that a flu case should come so early in the season.

A more detailed Orlando Sentinel account can be found here.

There are a few takeaways to these articles that just jump out at me.

First, are we surprised that a (previously) pandemic virus would still be circulating in the United States outside of flu season?  Pandemic viruses do not follow the seasonal pattern.  When do we determine that a pandemic virus loses its characteristic ability to infect people outside of "flu" season?  We all know the WHO said "stand down, please" to the H1N1/2009 pandemic, declaring it over well before now.  But when exactly does a virus lose its ability to infect outside of flu season?  I would imagine that occurs when the virus burns through the population enough to establish more of a seasonal-looking infection pattern.  I would also imagine that occurs due to natural mutations in the virus itself.  But since the WHO declared the 2010 vaccine formula would be used again in 2011, it would seem that any evolution in the virus, to this point, and based on surveillance, was very minor.

The Sentinel article states the woman and her church group traveled to California, and she fell ill while there.  She then returned early back to Florida.  It does not state how long she was in California before she fell ill, but we all know that influenza takes several days to manifest symptoms.  She died on August 25th, and I cannot find a church calendar that would shed light on when she might have first been exposed to the virus.

Even with these gaps in the travel calendar, I think we can draw up a theory.  The answer to how this unfortunate woman contracted influenza may be found, not from the visit to California, but much, much closer to home.  Orlando, as everyone knows, is a massive tourist destination.  South Americans love Disney just as much as the Brits and the Europeans and the Chinese and the Japanese.  And, indeed, India is struggling with swine flu right now.  But it is amazing how we fail to look south and, instead, default to looking to our left and right for answers.  It's flu season right now in the Southern Hemisphere.  And it is officially Hot as &@%%$ in Florida right now.  Well, actually, pretty much everywhere.  So the chances of a flu virus circulating in 90-degree-plus temperatures is remote.

In my opinion, it is far more likely that this woman actually contracted influenza at the Orlando International Airport, rather than being infected in California.  One sneeze from a Chilean or Argentine would have done the trick.

The other takeaway from this story is the woman's apparent lack of immunity to H1N1.  We all know that pandemic viruses disproportionately attack the young, sparing the elderly, who -- hypothetically -- have been previously exposed to a similar strain of the returning pandemic virus.

But this was not the case with Mrs. Thompson.  There are references in the stories to her immune system, and how the virus overtook it.  But Mrs. Thompson, being 80 years of age, would have had to have lived through the transformation of the Spanish Flu (1918 A/H1N1) and its many mutations.  She would have lived through the near-pandemic 1943, 1947 and 1951 attacks of H1N1.  She would have lived through the transition from H1N1 to H2N2 in 1957.  And she would have gone through two waves of the swine flu, which attacked Orlando pretty hard, precisely because of its status as a global vacation destination. She also appeared to be in relatively good health, based on her levels of activity within the church.

Where I am going with this blog entry is that we should take a closer look at the virus that felled Mrs. Thompson.  It would be wise for public health experts and scientists to tke a look at Mrs. Thompson's killer through an electron microscope, because the death of an otherwise-healthy 80-year old woman from swine H1N1 should not be simply relegated to statistic status.

It has been a long time since I blogged anything about the flu.  For starters, I am busier than ever at work, which cuts severely into my blogging time.  But also because I just have not felt the muse.  The swine flu pandemic was blessedly mild overall, although there are thousands of families still coping with the loss of a loved one due to H1N1/2009 who would harshly disagree with my assessment. But it wasn't 1918, so we breathed a sigh of relief.

There are many seemingly divergent storylines currently out there, which I will just list at random.  I am not so sure they are not somehow interconnected, however.

First has to be the continued number of human bird flu infections and deaths in Egypt.  Overlaying this ongoing problem is the sudden departure of Mubarak, the takeover by the Egyptian military, and what this portends for both transparency and NAMRU's operations within the nation. 

Second is the realization that this year's seasonal flu vaccine was way off the mark.  I began to notice last month that my employees were getting sick from flu, and I knew they had received their vaccinations in the late fall.  My deputy, in fact, was tested type A-positive last month.  That's pretty specific.  Here in Tallahassee, doc-in-the-box and emergency rooms were positively overrun with flu cases.  Things are looking better, but the WHUMP! of flu cases in January was much more severe than at the same time last year.  And last year was the dang pandemic!  Almost everyone who got flu this year who I am personally acquainted with, had, in fact, received the vaccine months prior.

Third is the ongoing Siege of Japan by H5N1 in poultry.  We all have read the articles about the culling of hundreds of thousands of birds in Japanese poultry farms.  this has spread to the mainland, especially South Korea.

What is clear to me is that the H1N1/2009 pandemic was not sufficient to push the other subtypes off the radar.  This runs contrary to previous pandemics where a dominant substrain was capable of, and able to, sufficiently supplant  the previous Big Dog of Flu.  H1N1 was replaced by H2N2, which was replaced by H3N2, and so on.  Swine flu was not able to eradicate H3N2, nor was it able to eradicate B.  for that matter, I do not know what research existed prior to the mid-1950s to actually track Influenza B.  for all I know, Influenza B has been around since the Chinese domesticated ducks some 4,000 years ago. 

Or, since B mutates more slowly than A, and is therefore not capable of producing pandemics (so says Wikipedia), it is not subject to the King of the Mountain game like Influenza A.

But someone apparently blew the call on the vaccine this season.  I get the feeling the only strain they got right was, in fact, the pandemic strain! 

The other strain that H1N1/2009 did not push off the radar is H5N1.  In fact, so far this year, bird flu activity seems to be much more intense than at the same time last year.  Human cases and deaths in Egypt seem to be at the same levels as last year, but H5N1's overrunning of the Japanese poultry industry is disconcerting.

Finally, there seems to be some concern that this year's flu outbreaks are more severe than last year's.  Again, this is not scientific, but my people got hit and hit hard by the virus.  Their symptoms were severe, with one person requiring hospitalization.  In one case Tamiflu did nothing, although there is a chance it was not administered in time.

H1N1 had a comeback in the late 1940s and early 1950s, with several epidemics (the Liverpool Flu of 1951, for instance) that were considered equal to, or more severe than, the 1918 pandemic, depending on location.  Shortly afterward, H2N2 (re)appeared, seemingly wiping H1N1 off the face of the Earth.

I openly wonder if the appearance of swine flu in 2009 was, in fact, the Beginning of the End of H1N1 as it was in the 1950s, and we are at the brink of the introduction of a different substrain of flu.

Over at Flutrackers, there is a thread regarding the prevalence of avian influenza in American birds. 

Avian influenza virus (AIV) is an important public health issue because pandemic influenza viruses in people have contained genes from viruses that infect birds. The H5 and H7 AIV subtypes have periodically mutated from low pathogenicity to high pathogenicity form. Analysis of the geographic distribution of AIV can identify areas where reassortment events might occur and how high pathogenicity influenza might travel if it enters wild bird populations in the US. Modelling the number of AIV cases is important because the rate of co-infection with multiple AIV subtypes increases with the number of cases and co-infection is the source of reassortment events that give rise to new strains of influenza, which occurred before the 1968 pandemic. Aquatic birds in the orders Anseriformes and Charadriiformes have been recognized as reservoirs of AIV since the 1970s. However, little is known about influenza prevalence in terrestrial birds in the order Passeriformes. Since passerines share the same habitat as poultry, they may be more effective transmitters of the disease to humans than aquatic birds. We analyze 152 passerine species including the American Robin (Turdus migratorius) and Swainson's Thrush (Catharus ustulatus).
Methods

We formulate a regression model to predict AIV cases throughout the US at the county scale as a function of 12 environmental variables, sampling effort, and proximity to other counties with influenza outbreaks. Our analysis did not distinguish between types of influenza, including low or highly pathogenic forms.

Results

Analysis of 13,046 cloacal samples collected from 225 bird species in 41 US states between 2005 and 2008 indicates that the average prevalence of influenza in passerines is greater than the prevalence in eight other avian orders. Our regression model identifies the Great Plains and the Pacific Northwest as high-risk areas for AIV. Highly significant predictors of AIV include the amount of harvested cropland and the first day of the year when a county is snow free.
Conclusions

Although the prevalence of influenza in waterfowl has long been appreciated, we show that 22 species of song birds and perching birds (order Passeriformes) are influenza reservoirs in the contiguous US.

OK, insightful analysis time.  We always associate bird flu with ducks, or chickens, or turkeys or geese, but rarely do we associate it with songbirds and other smaller birds.  This study makes a clear association between those birds (called "passerines") and bird flu. 

The distribution of those avian flu cases is seen in this map (thanks Laidback Al!):

Now let us look at a map of the principal migratory bird routes over North America:

There is a veritable swarm of migratory bird routes over the Great Plains and Mississippi River delta, and a very strong west coast migratory route.  So it is no coincidence, in my mind, that these migratory superhighways also contain the areas where avian flu has been most strongly detected since 2005.

Now you also notice those "down arrows" leading South of the Border.  This map helps illustrate what happens south of us:

We've got birds encroaching from the south as well as from the north.  This does not just figure into the avian flu equation:  There is this little thing called a major dengue fever epidemic that is raging in many, if not most, South American nations.  And as I mentioned recently, Key West, Florida has enough dengue in it to sicken a man this year.

This all leads into the current status of H5N1 sentinel activity.  With massive budget cuts, waning interest, and competition for attention from swine flu and other diseases, do we have as good a handle on things as we did in 2006 and 2007?  I would like to think so, but I doubt it.

Imagine the encounter:  A researcher goes into his/her supervisor's office, requesting additional funds for H5N1 monitoring.  What, the supervisor says?  You want me to divert $$ from certain necessary projects over to bird flu monitoring?  All while my departmental budget is being cut to ribbons?! No stinking way!

Or words to that effect.  I wish it were not so, but I am pretty certain I am right.

In the midst of all this, the Mexican government recently issued an alert to be watchful for an H5/H1 hybrid virus.  My first impulse was to say, What do they know?  What have they heard?  But is may have been nothing more than speculation.  Nonetheless, vigilance is important, now more than ever.  For H1N1v may not have been the pandemic everyone feared, but it was substantial in terms of its effect on the young; far worse than, say, 1977.  Yet H1N1v, being 1/3 avian, can still hang out with avian flu viruses and reassort.  It is precisely this scenario that should cause us to view this latest report with concern. 

The world press is beginning to focus on the province of Bak Kan (or Bac Can), Vietnam.  Bak Kan is in the extreme north of Vietnam, near the Chinese border.  Last week, I blogged on the potential H5N1 bird flu cluster that was threatening to emerge within that province. Just scroll down to read my previous blog.

Following my blog, a second story appeared regarding a second human infection.  It was dated at 6:01 PM, 04/09/2010.  It appears below, and the link to the VOV story is in the headline:

Another A/H5N1 infection case reported in Bac Kan