Avian Influenza – some thoughts

"Avian influenza refers to a large group of different influenza viruses that primarily affect birds. On rare occasions, these bird viruses can infect other species, including pigs and humans. The vast majority of avian influenza viruses do not infect humans. An influenza pandemic happens when a new subtype emerges that has not previously circulated in humans. . . . For this reason, avian H5N1 is a strain with pandemic potential, since it might ultimately adapt into a strain that is contagious among humans. Once this adaptation occurs, it will no longer be a bird virus–it will be a human influenza virus. Influenza pandemics are caused by new influenza viruses that have adapted to humans."  WHO statement at  http://www.who.int/csr/disease/influenza/pandemic10things/en/index.html  (14 October 2005)
 
"Human infections remain a rare event. The virus does not spread easily from birds to humans or readily from person to person."  WHO statement at http://www.who.int/csr/2006_02_20/en/index.html (20 Feb 2006)
 
"Although the virus is known to have infected 173 people, not one of these cases has been linked to the consumption of properly cooked poultry or poultry products."  WHO statement at http://www.who.int/en/ (27 Feb 2006)
 
"The public health threat of novel influenza subtypes such as influenza A (H5N1) will be greatly increased if the virus gains the ability for sustained spread from one human to another. Such transmission has not yet been observed. However, a few cases of probable person-to-person spread of H5N1 viruses have been reported, with no instances of transmission continuing beyond one person. For example, one case of probable person-to-person transmission associated with close contact between an ill child and her mother is thought to have occurred in Thailand in September 2004."  American CDC  statement at  http://www.cdc.gov/travel/other/avian_flu_ig_americans_abroad_032405.htm   (current as of 5 March 2006)
 

"Right now, there are 105,000 ventilators, and even during a regular flu season, about 100,000 are in use. In a worst-case human pandemic, according to the national preparedness plan issued by President Bush in November, the country would need as many as 742,500. To some experts, the ventilator shortage is the most glaring example of the country’s lack of readiness for a pandemic. "This is a life-or-death issue, and it reflects everything else that’s wrong about our pandemic planning," said Dr. Irwin Redlener, director of the National Center for Disaster Preparedness at Columbia University. ‘The government puts out a 400-page plan, but we don’t have any ventilators and there isn’t much chance we’re going to get them.’"  

http://www.nytimes.com/2006/03/12/national/12vent.html?pagewanted=2&th&emc=th (NY Times 12 March 2006)

__________________
 
Okay, it may have happened.  About a month ago, a sick bird fell from the sky in Hong Kong.  Then another, and another.  They tested postive for avian influenza.  I’ve been trying to educate my housekeeper on how to keep meat and poultry products separate from vegetables and fruit.  This issue of keeping meat separate from raw vegetables doesn’t seem to matter much to Guangzhou people.  Perhaps it’s due to lack of education, or perhaps it’s because they cook everything anyway, so it doesn’t matter if the vegetables are exposed to salmonella or whatever.  But since I like raw vegetables, it matters to me.  In response to my instruction, my housekeeper assured me, "there’s no bird flu HERE."  Well, the news reported last night that one person in Guangzhou became ill with a serious flu that appears to be bird flu, with test results pending. 
 
At my local market, the chickens look wonderfully healthy and clean.  They are kept in cages and slaughtered on the spot when someone purchases one.  In my previous BLOG entry of market pictures, I showed a picture of the fresh meat market where I buy not only meat but also produce, tofu, nuts, and cooking oil.  If you look closely, one of the photos shows someone’s takeout lunch in a styrofoam container, sitting in the middle of the poultry plucking / cleaning area. 
 
Avian flu is highly contagious among birds.  They have no resistance.  To date, almost every single case of avian flu in a human has resulted from close human contact with extremely sick birds, without any kind of sanitary precautions whatsoever.  Poultry workers in Viet Nam culling thousands of sick birds with no sanitary  precautions, a child in Thailand who found stacked carcases of culled birds and thought she was doing her mother a favor by plucking them, children in Turkey playing with heads of slaughtered chickens.  The virus is spread by any secretion from a sick bird:  saliva, blood, excrement, egg yolk or white.  Safe handling includes cooking all poultry products well done (including egg yolk), washing of eggs prior to handling, washing of hands, and not handling poultry when one has any cuts. 
 
I heard on the TV news that avian flu can decimate a domestic poultry flock in two hours.  While this sounds implausible, I’ve read that wild birds have developed some resistance but that domestic birds have none so the virus decimates the flock very quickly.  Wildlife biologists lament that wild birds have it just as bad, they just don’t have the same economic value to us to merit our counting them so closely. 
 
Scientists have been preparing for the next flu pandemic ever since they figured out that pandemics are a regular occurrence in human history.  Like category 5 Hurricanes, volcanoes, and earthquakes.  They may not have occurred recently enough to be in anyone’s immediate memory, but they happen.  A January 2005 Scientific American article examined the question, why was the 1918 flu epidemic so deadly?  (It was estimated to have killed 40 million people.)  After examining the forensic evidence, the researchers came to the conclusion that the body’s immune response to such an unfamiliar virus is too powerful.  In response to a newly mutated virus, the immune system goes into a haywire overdrive  — most of the patients actually died from pneumonia caused by their own bodies creating such a powerful immune response that their lungs filled with fluid which drowned them.  The people most likely to have such a strong immune response were those who generally had the strongest immune systems — the young and the healthy.  ( http://www.sciamdigital.com/index.cfm?fa=Products.ViewIssuePreview&ARTICLEID_CHAR=B5053C29-2B35-221B-65836DF15F29E88F )
 
Last spring, my doctor advised me to ponder in advance what course of action to take in the event of a pandemic causing mutation.  She said the question is not whether to evacuate from China, but when to evacuate.  Would I evacuate when there was a case of human to human transmission in Shanghai?  Hong Kong?  Viet Nam?  Because if I wait until it’s here, the city would be closed off and evacuation would be impossible.  Not only that, any potential means of transportation would already be flush to capacity.  If 20% of the population were to become ill, and another 20% staying home to take care of the ill ones, and another percentage of people staying home because they were afraid of infection, there will realistically be a breakdown in basic infrastructure.  Planners realistically envision a situation similar to what occurred in New Orleans following Hurricane Katrina. 
 
The other thing is, you can run but you can’t hide.  The pandemic (if or when it happens) is expected to move across the world like a wave.  Or, more realistically, in a group of small waves as travelers carry it with them, just as SARS leapt to Atlanta and Toronto.  Epidemiologists have assumed that the next flu would originate in South China.  That’s because traditionally, animals harboring animal viruses (pigs, ducks) have been kept in close proximity to humans.  This close contact between animal and human genes enables animal viruses to recombine with human virus to create new strains, which humans then have no immunity to.  Our denial mechanism wants to tell us that the risk comes from some jungle in Thailand where they engage in cock fighting.  However, H5N1 is being spread by migratory birds.  The spread of H5N1 into Europe (e.g. currently infecting birds and some cats in France,  and some human cases in Turkey) illustrates the fallacy of that assumption.  The threat may end up coming, figuratively speaking, in anyone’s back yard.  There have been reports of H5N1 in Canadian migratory birds.  It’s just a matter of anticipating when that one mutation will occur which makes the virus able to infect humans readily.  While that hasn’t happened yet, Americans need to be thinking the same thoughts and taking the same precautions as everyone else.  I don’t feel that my location in Guangzhou places me at any particularly greater risk, in terms of the big picture.  Except that here the numbers are bigger, so the public health challenges are bigger, say 100 million people sick at one time.  There are about as many cell phones in China as there are people in the USA! 
 
Hospital beds in the USA are already filled to 95% capacity, a very large percentage of respirators (required for life sustaining patient support) are already in use.  Even the USA does not have reserve medical capacity to manage the large numbers of people expected to become ill in a pandemic.  Power plants will be understaffed and there may be power failures, police will have high rates of absenteeism, indeed so will every industry and service.  Medical staff will be particularly hard hit because of their increased exposure.  There are debates among medical professionals about what exactly is their ethical obligation when it comes to willingness to work in such a high risk environment. 
 
But if you follow this to its logical conclusion, evacuation won’t really be an option.  By the time we learn of it, it will be too late.  Not only will airports and railways will be closed, but borders will be closed.  What country wants evacuees who may be carrying a deadly virus?  Further, resort to public transportation will increase risk of exposure, as would also the possibility of being quarantined by the receiving country along with people who do have the illness. 
 
So the current advice has changed.  We have been advised to stockpile six weeks worth of canned food and bottled water, sanitary and medical supplies, and plenty of DVD’s.  It is anticipated that the pandemic will flow across the world in waves.  The first wave of illness will last about six weeks in each place.  Over time, for some reason, the experts think the virus that remains will become less deadly.  So, we have a stockpile of six weeks worth of water, and about two weeks worth of food.  In the meantime, it seems as relevant to worry too much about it as to worry about whether the next airplane will crash.  One person may have been exposed to avian flu in this city.  There are 12 million people here.  So, my risk is one in 12 million right now?  Okay, I admit, I handled my chicken today very carefully.  But still, I see no cause for panic.  Another way of looking at is this:  if you’re gonna go, you’re gonna go.  If you have faith, I mean real faith, even that’s not such a horrible thing. 
 
So, keep advised, assess your risk, be prudent, and don’t panic! 
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