*Dr. Greger's Pandemic Update: January 2007*
Michael Greger, M.D.
Dr. Greger's Pandemic Update: January 2007
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Happy New Year and my apologies for the delay in sending out this
update. December was an especially busy month for me on the road
(speaking schedule updated weekly at http://birdflubook.com/events.php
), and I was just unable to stay on top of this rapidly mutating field.
I don't know how all the flu bloggers are able to keep up!
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CONTENTS
I. Help New Bird Flu Video Go "Viral"
Exploring primary pandemic prevention
II. Sixty-Two Million Lives at Stake?
New study estimates potential human toll
III. Flu Year's Eve?
Why has bird flu been off the news radar?
IV. Stockpile Weeks of Essential Supplies
How much food and water should we squirrel away?
V. It's Alive!
Up to citation 3,172: http://BirdFluBook.org as a living document
*******************************************************
I. Help New Bird Flu Video Go "Viral"
More than 20 years ago, Imperial Chemical Industries invented National
Breast Cancer Awareness Month to encourage women to get mammograms with
the mantra, "Early Detection Is Your Best Prevention." Mammograms, of
course, don't really prevent breast cancer. They may mediate the impact
of the cancer (what we call in medicine "secondary prevention"), but
mammograms don't prevent the disease in the first place ("primary
prevention"). Getting at the root causes may not be something in which
Imperial Chemical Industries (a leading manufacturer of petrochemicals
and pesticides) is particularly interested.
Similarly, with the unprecedented spread of a truly unprecedented
virus, H5N1, current pandemic preparedness efforts are understandably
focused on secondary prevention, mediating the impact of the next
pandemic, with less public emphasis on trying to understand and prevent
the emergence of hypervirulent flu viruses in the first place.
I did my postgraduate medical work at a Boston public health hospital
awash with victims of AIDS. When most of us were growing up, there was
no such thing as AIDS, and now, 25 million people are dead. I began
thinking to myself, where did this virus come from? In light of the
threat of H5N1, I wrote BIRD FLU to try to answer that question. From
where do emerging diseases emerge?
Our new bird flu video, online at http://birdflubook.org/g.php?id=6 ,
attempts to encapsulate in four minutes the central thesis of my book:
The intensification of the global industrial poultry industry may be to
blame for the dramatic escalation of outbreaks in recent decades of a
variety of concerning bird flu viruses, including H5N1. I'm hoping the
video will spark interest and discussion, and encourage people to dig
deeper. For an exploration of the various lines of evidence used to
support the argument, the entire book is available free full-text
online at http://BirdFluBook.org .
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II. Sixty-Two Million Lives at Stake?
The December 23-January 5 issue of the medical journal "Lancet"
featured a study predicting that a 1918-like pandemic today could kill
between 51 and 81 million people, with a median estimate of 62 million
dead.[1] This result surprised the lead Harvard researcher: "We
expected to end up with a number between 15 and 20 million," he said.
"It turns out we were wrong."[2]
The estimate was based on the lethality of the 1918 virus, which had a
human case mortality rate of around 2%. Quoting from the study: "In
most discussions of influenza, the 1918-20 pandemic sets the upper
limit, in terms of mortality, on what might occur in future pandemics.
However, there is no logical or biological reason why that
pandemic--albeit very severe--should represent the maximum possible
mortality in a future pandemic."[3] Indeed the current case mortality
rate of H5N1 is more than 20 times that of the 1918 virus, officially
killing about 60% of confirmed cases. People don't even seem to get a
coin toss as to whether or not they live through the disease.
It's hard to believe a flu virus could be that deadly, though. The 60%
figure is calculated by taking the number of people who have died and
dividing by the total number of cases. But what if we're missing a
large number of cases? What if there are people who have gotten
infected, but were missed because they showed few or no symptoms? In
that case, the 60% mortality could be a gross overestimate. The results
of an investigation to help answer this question were recently
published by the CDC.[4]
In the Cambodian province of Kampot, dozens of chicken flocks were
dying from H5N1, but there was only one reported human case, a young
farmer who subsequently died. This was the signal for researchers to
swoop in and try to take blood from every family in the area to
determine the actual human infection rate. How many cases were we
missing? They analyzed blood work from 351 area villagers. Not a single
person showed evidence of present or past infection.[5]
There are two tentative conclusions we can draw from this study. First,
H5N1 remains at present almost exclusively a bird virus. In the ten
years since it was discovered, though it's led to the deaths of
hundreds of millions of birds, only a handful of people seem to have
even become infected. The concern, of course, is that the virus will
mutate into a human form, easily transmitted from one person to the
next, thereby triggering the next pandemic. This leads us to conclusion
number two. If this study is an accurate reflection of what's happening
on the ground, then the human case mortality rate may really be on the
order of 60%. Based on this study, we don't seem to be missing many
cases.
Even if H5N1 does indeed currently have Ebola-like human lethality, for
it to be able to mutate into an easily transmissible human form, many
assumed the virus would necessarily have to ratchet down its ferocity.
A panel of experts recently convened by the World Health Organization
(WHO), however, has brought that assumption into question.[6] Pandemic
influenza has the potential to infect billions of people. If H5N1
retained its ability to kill half of its victims, "it could be more
lethal than anything we've ever seen in history," said one WHO
scientist.[7] Or as another flu expert remarked, "All bets would be
off."[8]
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III. Flu Year's Eve?
One of the most common questions I get asked on the road is what ever
happened to bird flu? To quote my favorite public health blogger,
"[A]sk the people in Vietnam, South Korea and Nigeria. The virus
doesn't care if you know where it is or not."[9] (For my pick of the
flu-blogger litter, see the Resources section at
http://birdflubook.com/links.php ). Whether or not H5N1 ever arrives on
U.S. soil as a bird virus, should it mutate into a pandemic virus,
geographic borders would be essentially meaningless. Indeed, in the
just-released "Global Risks 2007," the World Economic Forum lists
pandemic flu as one of the greatest risks of global "major systemic
disruption" for the new year.[10]
If anything, the risk may be growing. According to the World Health
Organization, more people died in 2006 from bird flu than did in the
three prior years combined--most under 20 years old.[11] "It's still
smoldering," said Dr. Anthony Fauci, who heads U.S. scientific efforts
to combat bird flu.[12] "The danger of a pandemic is as profound now as
it was a few years ago," reiterated David Nabarro, flu czar for the
United Nations.[13] In regards to the threat of pandemic flu, the new
Director-General of the WHO who just took office said, "Complacency is
our biggest enemy."[14]
2007 marks the ten-year anniversary of the first human death from H5N1.
If H5N1 were able to trigger a human pandemic, wouldn't it have done so
by now? Some evidence suggests that the 1918 flu virus--which triggered
the greatest medical disaster in history--was "smouldering" for at
least 11 years before it went pandemic.[15] We simply don't know enough
about the biology of these viruses to accurately estimate a timeline.
H3N8, for example, circulated in horses in North America for nearly 40
years before jumping into dog populations and triggering the canine flu
that grabbed headlines in 2005.[16] With regard to H5N1, a World Health
Organization and USDA research team has concluded, "It is probably
dangerous to rely on the 'if it were going to happen it already would
have' argument."[17]
John Oxford wrote the book on influenza--literally, co-authoring the
standard textbook, "Influenza: The Viruses and the Disease" (along with
the more general textbook "Human Virology"). In his generous review of
BIRD FLU in the December 21 issue of the prestigious science journal
"Nature," he answered why we should concern ourselves with the 150 or
so human deaths to date:
"Well, go back to 1916, to Etaples in northern France, where a form of
flu causing heliotrope cyanosis (a characteristic lavender coloration
of the face) with a case fatality of 60% was beginning to spread. There
were 145 cases. At some point in the next two years it mutated to
become more infectious and 30 times less virulent. Then it killed 50
million people. Doesn't this ring a nasty bell?"[18]
According to the director of the National Center for Disaster
Preparedness at Columbia University, most scientists remain convinced
that "we most certainly will encounter a deadly H5N1 global pandemic at
some time in the future."[19] Why then the loss in media interest?
One intriguing possibility is that reporters have intentionally been
trying to downplay the pandemic threat. On behalf of Trust for
America's Health and Columbia University's School of Public Health,
researchers conducted one-on-one interviews with TV, radio, and print
journalists who cover public health issues. Numerous respondents said
that they have purposefully toned down their coverage or passed on
pandemic flu stories altogether so as "to present the news without
inducing panic." The study suggested that the reporters were very
knowledgeable but "fear that passing along too much of this knowledge
to their readers will lead to panic."[20]
Public complacency, according to the Dean of the Harvard School of
Public Health, is the biggest roadblock to pandemic preparedness.[21]
The American public wants to see more in depth reporting on the
subject.[22] This patronizing attitude revealed in the study suggests
that some journalists may be holding back instead of providing the full
story that might otherwise motivate people to action.
One media participant in the study explained their dilemma:
"I don't want to panic anyone, but I do want to prepare my audience. I
have personally told my family to get 90 days worth of supplies
together, in case they need to stay away from other people for a while.
I don't tell my readers that, because our editors think that may be
ineffective and will cause panic. But the world is a scary place.
People need to understand what could happen so that they can be
ready."[23]
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IV. Stockpile Weeks of Essential Supplies
Whichever estimate one uses, 62 million deaths,[25] 150 million
deaths,[26] or 360 million deaths,[27] WHO flu coordinator Keiji Fukuda
hit the nail: "Speculating about the possible numbers is an interesting
exercise, but the really important thing is, what do we do about it?"
The advice on the CDC website http://www.pandemicflu.gov focuses on
stockpiling weeks of essential supplies so that we can effectively
"shelter-in-place" during a pandemic. Like a snow emergency where we're
told not to go out unless it's an emergency, we may be asked to
self-isolate ourselves and our families in our homes until the danger
passes. Although globally a pandemic might last 12 to 18 months, it is
expected to come in waves, and in any particular locale, the wave may
only last a few weeks, hence the CDC's recommendations. If we have to
go out to the corner store to buy toilet paper or something during a
pandemic, we may be bringing back more than just groceries to our
families.
For how many weeks should we prepare, though? The U.S. State Department
recently sent a cable out "to all diplomatic and consular posts"
explaining that "current guidance notes that families should be
prepared to 'shelter-in-place' for up to twelve weeks, and maintain
sufficient food and water supplies to accommodate that entire
period."[28] After flu bloggers pointed out the discrepancy between
this three-month stockpiling recommendation and the two weeks cited by
the Department of Health and Human Services,[29] the two month
guideline inexplicably vanished from U.S. consulate websites.[30]
Robert Webster, arguably the world's leading bird flu expert, also
recommends three months. In a recent interview, he was asked what
people could do to protect themselves before a vaccine were available.
"If they have a house in the hills, then go for it--and stay there for
three months. And have enough food there already so you can stay as far
away from your neighbors as possible."[31]
To follow the State Department's advice to stockpile a gallon of fresh
water per person per day in case of "complete infrastructure
breakdown,"[32] for a family of three that would involved storing a ton
of water--literally. Webster has a better suggestion: "One bottle of
Chlorox is enough to purify all the water you need out of the local
river."[33]
The recipe for water purification I give in my "Be Prepared" section (
http://birdflubook.com/a.php?id=103 ) recommends 10 drops of unscented
liquid household chlorine bleach per quart (liter) of water. This
admittedly is an oversimplification. Most "regular" chlorine bleach on
the market is so concentrated (around 5% sodium hypochlorite), a mere 2
drops of fresh bleach should be sufficient for a quart of clear (and
not overly cold) water. But there are 1% chlorine products on the
market as well, requiring 10 drops. So instead of recommending everyone
read the small print on the bottle and advise 1 drop per quart for 7 to
10% bleach, 2 drops for 4 to 6%, and 10 drops for 1%, I just tried to
simplify with one number, erring on the side of caution. One purpose I
see of these monthly updates, though, is to expand beyond the basics,
particularly when it comes to concrete, practical measures families can
take to prepare. Next update, I'll cover the ethics and particulars of
obtaining and maintaining personal stashes of antiviral drugs such as
Tamiflu.
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V. It's Alive!
Not only is the entire text of BIRD FLU online free, but the electronic
format allows for easy updating so I don't have to wait for the next
edition to add new material (softcover expected in fall 2007). It also
allows for an informal global peer review to make the work as robust as
possible. Graeme Laver, for example, whose landmark experimental work
(along with Webster) established the very origin of influenza in the
avian world, kindly corrected my mischaracterization of the H spike on
the virus as an enzyme, and Jan de Jong of the Dutch National Influenza
Centre clarified his lab's role in the identification of the first
human isolate of H5N1 in 1997.
The most important change so far, though, is the rethinking of Dr.
Woodson's "Tamiflu Re-Administration Strategy." Tamiflu is normally
given as a ten-pill course, two pills a day for five days. In the
section "Stretching the Stockpile" ( http://birdflubook.com/a.php?id=9
), I posed a question: If a family of five is privileged enough to have
a single pack of ten pills, how could one possibly make such a Sophie's
Choice? Enter Woodson's creative (though erroneous) "Tamiflu
Re-Administration Strategy." Assuming that Tamiflu was excreted
unchanged by the kidneys, he figured that if each family member were to
take two pills and then drink his or her own urine for five days, the
entire family could, in theory, be saved. Do try this at home, said
Woodson, but only under medical supervision to ensure proper hydration.
Woodson listed in his book ways to improve palatability--chilled,
preferably, and flavored with citrus.
Unfortunately (or, perhaps, fortunately), this strategy won't work.
Tamiflu is altered by the liver such that urinated Tamiflu would not be
readily re-absorbed by the intestine. Dr. Woodson has since stripped
this recommendation from the latest edition of his work, "Good Home
Treatment of Influenza," generously available free for download at
http://BirdFluManual.com
Please do keep questions, comments, and corrections coming:
mh...@cornell.edu; (206) 312-8640.
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REFERENCES
[1] Murray CJ, Lopez AD, Chin B, Feehan D, and Hill KH. 2007.
Estimation of potential global pandemic influenza mortality on the
basis of vital registry data from the 1918-20 pandemic: a quantitative
analysis. Lancet 368(9554):2211-8.
[2] Cheng M. 2006. Flu pandemic could kill up to 81 million people.
Associated Press, December 21.
[3] Murray CJ, Lopez AD, Chin B, Feehan D, and KH Hill, op. cit.
[4] Vong S, Coghlan B, Mardy S, et al. 2006. Low frequency of
poultry-to-human H5N1 virus transmission, southern Cambodia, 2005.
Emerging Infectious Disease 12(10).
http://www.cdc.gov/ncidod/EID/vol12no10/06-0424.htm
[5] Ibid.
[6] Branswell H. 2006. If bird flu virus becomes pandemic, high death
rates possible: WHO report. Canadian Press, November 2.
[7] Ibid.
[8] Cheng M. 2006. Flu pandemic could kill up to 81 million people.
Associated Press, December 21.
[9] "Revere." 2006. What happened to bird flu? (partial answer, here).
Effect Measure, December 22.
http://scienceblogs.com/effectmeasure/2006/12/what_happened_to_bird_flu_answ.php
[10] World Economic Forum. 2007. Global Risks 2007.
http://www.weforum.org/pdf/CSI/Global_Risks_2007.pdf
[11] World Health Organization. 2007. Avian Influenza Update Number 76.
January 2.
http://www.wpro.who.int/NR/rdonlyres/AF22747B-5AB5-4CBE-99E2-B770DBD6B76F/0/AIWeekly76WPRO.pdf
[12] Hellerman C. 2006. Bird flu virus 'still smoldering,' U.S. expert
says. CNN. December 11.
[13] Gale J and Lauerman J. 2006. Bird Flu Cases Decline, Raising New
Risk: Complacency (Update1). Bloomberg, December 29.
[14] Altman LK. 2207. New UN health chief sets her priorities. New York
Times, January 5.
[15] Shortridge K. 2006. H5N1 "bird flu"-some insight. New Zealand
Pharmacy, April, pp. 23-7.
[16] Branswell H. 2006. Decade after H5N1 virus emerged, experts ponder
best-before-date question. Canadian Press, April 15.
cnews.canoe.ca/CNEWS/Canada/2006/04/15/1535656-cp.html.
[17] Perdue ML and Swayne DE. 2005. Public health risk from avian
influenza viruses. Avian Diseases 49(3):317-27.
[18] Oxford J. 2006. The Next Pandemic? Nature 444:1007-8.
[19] Redlener 2006. Americans at Risk (New York: Alfred A Knopf).
[20] Peter D. Hart Research Associated, Inc. 2006. Gauging the Threat:
Media Coverage of Pandemic and Avian Flu. April 26.
http://healthyamericans.org/reports/flumedia/GaugingReport.pdf
[21] Editorial. 2006. Shrugging at a pandemic. Boston Globe, November
5.
[22] Southwell BG, Hwang Y, and Torres A. 2006. Avian influenza and US
TV news. Emerging Infectious Diseases 12(11)
http://www.cdc.gov/ncidod/EID/vol12no11/06-0672.htm
[23] Peter D. Hart Research Associated, Inc., op. cit.
[24] Ibid.
[25] Murray CJ, Lopez AD, Chin B, Feehan D, and Hill KH, op. cit.
[26] Associated Press. 2005. WHO: Mutated bird flu could kill up to 150
million people. September 29.
[27] Center for Infectious Disease Research and Policy. 2005. Foreign
Affairs focuses on pandemic threat. CIDRAP News, June 10.
[28] Screenshot of google cache archived at
http://ryanschultz.vox.com/library/post/us-consulate-in-hong-kong-backtracks-on-bird-flu-warning-why.html
[29] Department of Health and Human Services. 2006. Pandemic Flu
Planning Checklist for Individuals and Families. January.
http://pandemicflu.gov/plan/pdf/individuals.pdf
[30] Baum D. 2006. State Department simply offers good advice.
Greenhammer. November 11 http://www.greenhammer.net/2006/week45.htm
[31] Dreifus C. 2006. Bird Flu and You. AARP Magazine,
November-December. 34-5.
[32] Deutsche Presse-Agentur. 2006. Stockpiling suggested for possible
bird flu. Bangkok Post Breaking News, November 7.
http://www.bangkokpost.net/breaking_news/breakingnews.php?id=114048
[33] Dreifus C, op. cit.