Effect Measure

Breathing easier, may be an apt phrase for an almost audible collective sigh of relief. So far, the incipient swine flu pandemic is not extremely nasty. Is this perhaps premature? The world’s premier scientific journal, Nature, and many flu scientists, suggest it is:

Complacency, not overreaction, is the greatest danger posed by the flu pandemic. That’s a message scientists would do well to help get across.


There is ample reason for concern: a new flu virus has emerged to which humans have no immunity, and it is spreading from person to person. That has happened only three times in the past century.


Yet at this early stage, the consequences of the pandemic are so uncertain that communicating the risks is a delicate matter. Influenza viruses evolve rapidly, making it extremely difficult to predict what this strain might look like a few months from now.


The risk is not hyping the pandemic threat, but underplaying it. (Editorial, Nature)

No one on the public health side has over reacted. When an outbreak or pandemic is unfolding, you get only one chance. The window is a narrow one. CDC (and WHO) have acquitted themselves well, so far. CDC’s daily briefings have been straightforward and informative. The public, understandably, has bounced back and forth from fear to relief and back again. I don’t think either pole is avoidable. If the scientists are baffled and uncertain, the public has a right to be, too. But CDC has been steady and consistent in their approach (more so than HHS or Homeland Security, in my view) and they clearly understand the most important thing: this outbreak is still evolving and it is premature to write it off.

The idea this is “mild” flu virus is so far true, but mild is a relative term, as we have pointed out here. And “so far” is another important qualifier. This virus is spreading relatively quickly, but it isn’t everywhere and not much time has passed. With exceedingly virulent strains like the 1918 virus many people died relatively quickly but with flu death usually comes weeks after the onset of infection. Not that many people have been infected as yet. If the pace of new cases accelerates, we will likely seem many more hospitalizations (currently there are only 35 in the US) and more deaths (currently there are two):

“My own personal view is that it is too early to say what the severity is,” says [Marc Lipsitch of the Harvard School of Public Health], who works with the CDC as part of a ‘Team B’ made up of academic researchers and other outside advisers. One reason the disease appears mild is that in the United States there has been only one reported death among 286 cases. But such case-fatality rates, reported one week after a case is confirmed, can underestimate actual mortality rates, because they can overlook patients who remain ill and subsequently die. This was demonstrated in 2003, when the reported case-fatality rate of severe acute respiratory syndrome (SARS) in Asia was initially put at a few per cent ? only to be found to be closer to 20% in studies that followed up cases. (Declan Butler, Nature)

So the question remains. Are we like the man who jumps from the Empire State Building and says as he passes the 14th floor, “So far, so good”?

Let’s hope not, but with influenza one cannot be sure of anything. In the coming months we will be watching the southern hemisphere closely to see what happens as they enter their flu season. That may give us a clue as to what to expect in the fall.

. . . or it may not.


  1. #1 James Unland
    May 7, 2009

    I interviewed Dr. Eric Toner of the Center for Biosecurity yesterday, who indicated among other things that: (a) we are in a ‘pandemic’ (b) he expects this flu to come back in the fall/winter (c) our health care system remains largely unprepared for even a modest increase in regular ‘seasonal’ flu much less something more deadly and (d) faster ‘outbreak-to-confirmation’ testing in foreign nations would be helpful in setting up better likelihood of containment or at least slowing spread while vaccines are developed. Complete unedited audio of the interview can be found at: http://www.healthbusinessandpolicy.com/TonerInterview.htm

    In a separate interview Dr. Carolyn Bridges of the CDC indicated that she is amazed at how rapidly this strain of flu has spread. Among other things she strongly recommends more and better monitoring of pigs worldwide, and area that she maintains has been sorely neglected.

  2. #2 Snowy Owl
    May 7, 2009

    Salutation Reveres here is what is coming out in Canada since yesterday in some networks.

    Second Strain Might Have Caused Some Severe Cases In Mexico, Investigators Say

    Via NPR at

    A new discovery from Canada raises the question — has a new mutation in an ordinary flu virus been causing some of the recent respiratory disease hospitalizations and deaths in Mexico?

    It’s too soon to tell, but scientists in Vancouver are wondering. They’ve found two mutations in H3N2, a regular seasonal flu virus that’s been circulating in North America since last fall. (The swine flu virus is a type of H1N1.)


    The new version of H3N2 has shown up in a number of nursing home patients in British Columbia, though not yet in the general community there. And this week the Canadian researchers spotted it when they did a complete genetic analysis of a flu virus that sickened a Canadian traveler who had just returned from Mexico.

    This raises the possibility that the traveler became infected in Mexico, says Dr. Robert Brunham, chief of the British Columbia Centre for Disease Control. If so, the H3N2 virus circulating in Mexico may have the same two mutations as those being found in British Columbia patients who haven’t been to Mexico .

    “In British Columbia, the H3N2 virus causes more severe cases of flu than H1N1 does,” Brunham says. “So we wonder if some of the severe cases in Mexico may have been caused by the variant H3N2 virus.”

    There’s another potential implication of the Canadian finding.

    Public health officials watch flu viruses closely for mutations that might make new variants of viruses less susceptible to flu vaccines. A strain called H3N2/Brisbane is one of the three components in this year’s seasonal flu vaccine — and it’s also in the vaccine now being made for next winter’s flu season.

    So far the new variation of H3N2 hasn’t crossed the threshold of concern for scientists about the effectiveness of next season’s vaccine. But, “it only takes one more mutation” to cross that threshold, Brunham says.

    But nobody can say yet whether the new H3N2 mutant has been circulating widely in Mexico. That’s something researchers really want to find out ASAP.

    British Columbian health officials have tested a number of people who have returned from Mexico recently suffering from cold or flu symptoms, along with hundreds of non-travelers. Most didn’t have any sort of flu. Among the 10 percent who did test positive for flu, they were split 50-50 between H1N1 and H3N2 types.

    However, health officials have so far only done close genetic analysis on one Mexico traveler. So they can’t say how many of the others have the new version of H3N2.

  3. #3 GeorgeT
    May 7, 2009

    Well, I know that Complacency is what we are going to get now. Closing the schools and then suddenly backing off of it has made everybody relax too much. The media is already turning away from the story as has the public. Many members of the public who thought the closures were the wrong decision are saying “I told you so” not realizing this is a long-haul issue not a couple of weeks.

    It’s going to be hard to get the fire lit under people a second time unless a large wave of deaths appear.

  4. #4 revere
    May 7, 2009

    Snowy: I have been watching this since being alerted to it by a reader yesterday. There is a description up at ProMed. Just to be clear, this is not the h1N1 virus but the co-circulating seasonal H3N2. It already had one change in the antigenic site and this was a second. Cox’s rule of thumb for antigenic drift from a seasonal flu strain is three changes in the antigenic site, although this isn’t hard and fast since it is difficult to predict what changes will make a difference. So far this is something that seems independent of the swine flu and of more significance for the seasonal flu component (A/Brisbane) of the current vaccine strain used this year and planned for next year.

  5. #5 floormaster squeeze
    May 7, 2009

    I don’t know if overreacted is quite the right word but I would say plenty of public health decisions were inappropriate and inconsistent. I would not be patting everyone on the back. This is not purely Monday morning quarterbacking, I understand that there were real possibilities that greater risks might come.

    To use one concrete example (and seeing how a HSPH figure is quoted above)the HSPH cancelled classes when a nearby school had some unconfirmed cases. A bit aggressive but possibly a necessary strong signal–yet teaching and classes are a small part of the HSPH “business”. The buildings were not closed, staff still had to got work (is the message that staff are expendable?), students and faculty still interacted in their jobs and social lives in the very same buildings. Anyone close to the situation would realize that while some interaction was curtailed, closing this school in this context was largely theater. And this is some jewel of Public Health school.

    I am not saying the actions were unreasonable but in any decision there are trade-offs and I think the public has rightfully become a tad more jaded about the risks of flu pandemic in some contexts. Sure, most of the problem may come from the media, but even then part of public health strategy has to recognize the echo chamber of a for-profit media.

    Ideally, we would reform the media but in this country letting moneyed interests frame things is more important than the public’s well-being.

    Fundamentally, there should have been a better infrastructure in place to confirm flu cases (it was clear that Canada confirmed their cases a lot faster than the US and Mexico). Then, decisions made to get the appropriate levels of attention can be rooted in informed, clearer choice. But we have other priorities, even within public health.

  6. #6 revere
    May 7, 2009

    floormaster: Without getting into the weeds on HSPH, that was a decision that wasn’t connected with CDC. A nearby dental school at Boston University did just the opposite: closed only the clinic floor where a dental resident worked. IMO, that was too little.

    CDC’s Besser has said, and I agree with him, that the variation and “inconsistency” of local responses is a feature, not a bug. It allows everyone a chance (but not a certainty) to see what works and what doesn’t.

    If you listen to CDC’s responses to the media, it is hard to see where they could have done better. They have chosen the optimum strategy: being straightforward. As for “reforming the media,” we can’t do that, any more than we can prevent rumors.

    If you do not think the actions were unreasonable, then you and I are on the same page. I agree there are trade-offs. It’s the real world. This could have been done so much worse and I am hard pressed to think of how it could have been done better, even though what was done was imperfect.

    I have been very critical of CDC, here. But credit where credit is due.

  7. #7 Snowy Owl
    May 7, 2009

    Thanks Revere for the above statement

    floormaster squeeze

    There is a Concensus that in a pandemic one of the First Priorities is to maintain Civil Order, locally and Regionally. This can only be efficiently done by adapting to the cultures.

    BTW, the same apply in maintaining Scientific Orders, and it is normal that without Full datas, there are confusing and even sometimes conflicting Statements from the Science Tribune.

    But we are getting there day after day.

    SO, while the Owl Train bullied the Fog, I pondered about Keijii..

    I’ve been around the globe so much that I am aware that Cultures generates reflexes.
    The Scientific Culture needs facts, corroborated facts.
    The various Cultures needs an Understanding and Clear Ones as TruthFull as possible.

    BTW, in the north pole you go around the World in 4 steps.

  8. #8 MLM
    May 7, 2009

    I’ve been tracking the CDC’s confirmed cases numbers and fit them to a simple exponential. I realize that there are multiple factors leading to the reported numbers (lab throughputs, general awareness, etc.), but they nevertheless fit an exponential curve pretty well, with an increase by a factor of 1.35 per day.

    Am I missing something, or is it reasonable to expect a lot of sick people here in the U.S., and some kind of replay of what just happened in Mexico, in about a month?

  9. #9 revere
    May 7, 2009

    MLM; Flu is unpredictable. It is also a highly seasonal disease, for reasons we don’t understand (we’ve posted on it the seasonality puzzle multiple times here), so the dynamics of this outbreak are still uncertain. So we are all missing something.

  10. #10 paiwan
    May 7, 2009

    MLM: “an exponential curve pretty well, with an increase by a factor of 1.35 per day.”

    I roughly calculate based on 1.35 daily exponential curve of the infected patients of 500 on day 1.
    Mortality rate 0.0004 (indicated by D).
    Day1 500 1.35 =675
    Day2 675 1.35 =911
    3 =1,230
    4 =1,660
    5 =2,242
    10 =10,053 D:4
    20 =205,325 D:82
    30 =4,128,390 D:1,651

    In a month about 4 millions infected patients, 1,651 died.
    This is a hypothetical model by simple Mathematics Biology.

    My question is, “Which day will be the turning point?”

  11. #11 MLM
    May 7, 2009

    Thanks revere. To tie this back into your post, it’s a little surprising to me that the MSM spin cycle has already moved on, when we still could very well be seeing a major surge in demand for hospital beds in a few weeks.

    I’ll keep my fingers crossed that seasonality will take effect, and that we’ll dodge any replay of 1918 this fall/winter.

    BTW, this blog is an island of sanity in an otherwise somewhat crazy flu world. Thanks.

  12. #12 glock
    May 7, 2009

    Being a a bit of a pessimist, (which I loosely define as an optimist with experience) we really need to treat this as our “spring training” and get our collective shit together. It could be much worse, and may be

    We’re stuck with the media that we have for now, but it’s a great point floormaster made about our “if it bleeds it leads” model. In public health as in the banking sector people can make their own decisions if there is a transparency the helps bolster trust. If you don’t know something you say you don’t know, and give your best guess if requested.

    I’ve made a point of talking to a lot of people and most are informed, and not panicked, or complacent nor about to sit around waiting for sufficient confirmation by health officials
    to protect their health or that of children.

  13. #13 chris
    May 7, 2009

    MLM: The numbers don’t scale well going backwards. Whilst the small number of recent data points do fit the 1.35 number that you suggest …if you trace back then it suggests that the initial outbreak was early april. Clearly it wasn’t as the Mexican authorities reported the issue as early as the 18th March – and that must have been on the basis of a good number of cases.

    The problem is with the unreliability of the early Mexican numbers… as I have said before, you don’t close down a country on the basis of only a few hundred cases. I suspect the numbers were much higher.

  14. #14 tendrel
    May 7, 2009

    I am hoping that the whole thing helps some people become less ignorant. I am amazed by how many people seem to have slept through or forgotten basic high school biology. =)

  15. #15 Snowy Owl
    May 7, 2009

    Keiji Fukuda: said it was “quite likely” the WHO would declare a pandemic in the near future

    Official says H1N1 could infect third of world

    May 7, 2009

    third of the world’s population could be infected by the H1N1 flu virus in the next year, a top UN health official said today, urging Asian governments to stay alert for a potentially wider pandemic.

    Keiji Fukuda, acting assistant director-general for the World Health Organization (WHO), also said it was “quite likely” the WHO would declare a pandemic in the near future but a final decision had not been made.

    “This is a disease that could potentially infect a third or more of the world’s population in the next several months, in the next year,” Mr. Fukuda told Asian health officials meeting in Bangkok by conference call from Geneva.

    He added that “even if the illnesses appear relatively mild on a global level, the global population level adds up to enormous numbers.”


    But David Nabarro, the UN influenza co-ordinator, worried governments might get complacent because many people in harder-hit countries had experienced only mild symptoms from the flu and recovered without medicine.

    He said the most serious flu pandemic of modern times, which killed some 40 million people in 1918-19, started with a milder early wave of infections. “We have to maintain vigilance and understand that the virus we are dealing with could easily change and become much more ferocious. We cannot let down our guard, regardless of what we are seeing at the moment,” Mr. Nabarro told the conference.

    Mr. Fukuda said there was no decision yet on whether to revise the WHO’s pandemic alert, now at 5. He said it could drop to 4 or rise to the top of its 6-point scale, which would activate emergency response plans to fight the virus.

    “I think all these possibilities are open right now, although again it’s quite likely we could go to Phase 6 in the near future,” he said.



  16. #16 Don Williams
    May 7, 2009

    1) Like MLM, I roughly curve-fitted the US cases reported by CDC to an exponential function (3 day cycle, RO=2.27) and noticed that the numbers get quite high 4-6 weeks out. (Assuming R0 is not reduced by onset of summer, CDC measures,etc.)

    2) I went to 14 drug stores to pick up some N95 masks (I’m diabetic) and found they were all sold out. I did finally find some at Home Depot, although they are not the model approved for medical use by the FDA.

    3) In these early days, why are N95 respirators in such short supply and suddenly so expensive? I understand that they are not foolproof, but shouldn’t the government be ensuring that most households have a supply of 100 or so?

    4) Also, does anyone know if there is any real difference in protection afforded by the FDA’s N95 model vice the ones used in building construction?

    I get the impression from some reports that both models would only be good for 2 or 3 hours because exhaled moisture building up in the mask would eventually make it permeable to the flu virus and continued use risky. Anyone know anything about this?

  17. #17 Don Williams
    May 7, 2009

    1) Also, does anyone see signs of the news being managed because of fear that measures needed to contain the flu would greatly deepen the current recession? (e.g., we close K12 schools but not businesses.)

    2) The widely reported “worst case” estimate from Northwestern of only 1700 US flu cases by May 28 seemed to me to be optimistic, although I hope CDC pulls it off.
    See http://news.yahoo.com/s/livescience/20090501/sc_livescience/worstcasescenarioforfluestimated

  18. #18 veebee
    May 7, 2009

    Speaking as a journalist, but not one who does breaking news (magazines, rather), I think the media may be backing off a bit because there are still only 2 deaths – reported, that is — in the US, and because there appears to be so much variation in what the public health community says that uncertainty is huge. We don’t know what to tell people besides wash your hands and sneeze into your sleeve. And keep up on the news.

    And most reporters assume that the information being released by governments at all levels is the best reflection of reality – a big assumption. There may be an uptick in media interest when it’s clear the trajectory of the story/event has changed for the worse or there is some major development outside the US – like a flareup of cases in Central & South America. Does anyone know whether figures cited by Veratect & WHO are accurate for those regions? Because they are very low.


  19. #19 Farmer
    May 7, 2009

    My understanding of the difference between N95 respirators is that the medical versions are fluid resistant (for splash protection).

  20. #20 Don Williams
    May 7, 2009

    Re veebee’s comment “I think the media may be backing off a bit because there are still only 2 deaths – reported, that is — in the US ”
    1) I’m not qualified to have an opinion on how this flu will develop — my background is engineering, not medicine. I will make some comments in the hope that people here who are far more qualified will correct me.

    2) I put the death of the Mexican child aside — I’ve wondered if there might be some genetic weakness in the Mexican population to this flu. Similar to the vulnerability of Native Americans to smallpox — because their ancestors did not sleep with the livestock for 4000 years, unlike those of European ancestry.

    3) That leaves the single death of the woman. But just that one death is significant, given she was within the first 200-victim cohort. If you extrapolate that rate to 100 million Americans, you would get 500,000 deaths.

    4) But will 100 million Americans contract this flu? Don’t know –but here is the worse case model I’m using. If the flu continues to spread at the current exponential rate, you get the following:

    Projection as of May 5: (Rt= total number of flu cases to date)
    i= 0, Rt (total ) = 20 (April 26 )
    i=1, Rt = 65 (April 29)
    i=2, Rt= 168 (May 2)
    i=3, Rt = 402 (May5)
    i=4: Rt= 933 (May 8)
    i=5: Rt = 2139 (May 11)
    i=6: Rt = 4875 (May 14)
    i=7: Rt = 11087 (May 17)
    i=8: Rt = 25187 (May 20 )
    i=9: Rt = 57196 (May 23)
    i=10: Rt = 129855 (May 26)
    i=11: Rt = 294790 (May 29)
    i=12: Rt = 669,194 (June 1)
    i=13: Rt = 1,519,090 (June 4)
    i=14: Rt = 3,448,356 (June 7)
    i=15: Rt = 7,827,789 (June 10)
    i=16: Rt = 17,769,101 (June 13)
    i=17: Rt = 40,335,880 (June 16)
    i=18: Rt = 91,562,467 (June 19)
    i=19: Rt = 207,846,820 (June 22)

    5) There are many reasons to think that the above will not happen — CDC measures, onset of summer,etc. But what I am watching for is when the daily number of cases drops below the above curve — when the growth shows signs of leveling off.

    6) Where I think the media has fallen down is in not explaining the dangerous nature of exponential growth — of how little time it gives our healthcare workers to stock up on supplies to deal with a wave of victims. Also, in not giving the public a model to use by which they can evaluate ongoing developments. News reports seems more like the caller at a Bingo tournment — “B10”. “G5. They lack context.

  21. #21 MLM
    May 7, 2009

    chris – I didn’t do anything more than look at the CDC’s numbers. Adding Mexico in leads to a lot of complications and unknowns (ranging from the frequency of contacts intra-Mexico, intra-U.S., and inter the two, to the definition of a confirmed case, to the relative propensity of a resident of one or the other to visit a doctor/hospital if they have symptoms). I assume that in either country there are a lot of cases that are mild enough that they never have a chance to be counted.

    My only point was that using two weeks of CDC data could lead one to think that the first week or two of June could be more “interesting” than most people seem to currently expect. Hospitals might get crowded, and you might end up thinking it was better to hang around home for a week or so.

  22. #22 Snowy Owl
    May 7, 2009


    IMHO there are few sites where you will find corroborated datas on all this.

    Of course, this site.
    There is Crofsblog at http://crofsblogs.typepad.com/h5n1/

    Then there is Flu Wiki at http://newfluwiki2.com/

    There is Flu Trackers at http://www.flutrackers.com/forum/index.php

    Theres the World of Micro-Organisms at

    The government sites

    But mostly (Being a free-lance reporters since 20 years please take knowledge of Peter Sandman and Jody Lanard website on Risk Communications at http://www.psandman.com/

    This site is very important if you want to grab the Communications Phases and Wordings in Timely Matters.

    Hope this Help

    Snowy Owl

  23. #23 chris
    May 7, 2009

    MLM: Ok. I was looking at the cases numbers reported by the BBC here http://news.bbc.co.uk/1/hi/world/americas/8021547.stm

    You can’t really separate Mexico out because a good number of the early cases in both the US and UK originated from folk who picked up the virus whilst in Mexico.

    Irrespective of the specific data, I concur that there is a good chance that June will be difficult.

    I presume that the CDC and other national authorities have their own mathematicsl models and that they are well aware of the potential outlook.

  24. #24 S.o.G.
    May 7, 2009

    all this curve-fitting fails to take into account there was a ramp-up in the ability/inclination to identify cases. This probably accounts for a great deal of the apparent R0.

  25. #25 MLM
    May 7, 2009

    S.o.G – You’re right, one would expect this to be a significant factor. I will say that it isn’t particularly evident yet in CA or TX, which have the longest data sets. Another week’s data should make things quite a bit clearer.

  26. #26 Kelly
    May 7, 2009

    One doc I spoke to said the biggest benefit from wearing the masks is that it keeps you from touching your face, thus cutting off a major virus transmission route. Virus on your skin therefore won’t get ingested before washing your hands. In which case, the right ‘model’ mask might be better, but the ‘wrong’ model mask will still provide significant impediment to most of the germ uptake, when used correctly.

  27. #27 Chirp
    May 8, 2009


    First, thanks for making the effort to track this evolving situation.

    Second, there are good community service and juicy investigative reporting opportunities aplenty … and the clock’s ticking on the timeliness. Specifically, (a) there is so much that needs to be done in risk communications to prepare the public for a potential pandemic and (b) virtually all public leaders have failed in this fundamental communications/leadership duty.

    If we get even a mild pandemic (low virulence), the sheer numbers of affected people (absent employees) could so impact productivity as to have a bewildering economic impact. The general public is not thinking this through … mainly because national and local “leaders” and, by extension, the media, are not delivering the message.

    I know of no better place to get and understand the critical messages than a couple of articles by Peter Sandman and Jody Lanard, a husband-wife team of risk consultants who have worked with governments, agencies and companies. At your very earliest opportunity, read their April 29th article “The Swine Flu Crisis: The Government Is Preparing for the Worst While Hoping for the Best – It Needs to Tell the Public to Do the Same Thing! and their March 2007 “What to Say When a Pandemic Looks Imminent: Messaging for WHO Phases Four and Five.”

    In my opinion, risk communications guidance just doesn’t get any better than this. (I have some perspective, having spent five years in radio news and 17 year in corporate public relations.) Please tell your colleagues in the Fourth Estate to pounce on this opportunity ASAP. Mix these messages into your daily coverage and editorials, and ask pointed questions of leaders re: why they haven’t been including proper risk communications in their pandemic preparation activities.

    While I’m writing, I’ll also suggest a post I did in December 2006, “You’re right, it’s not 1918. Is that good or bad?” Too many people mistakenly think that in today’s modern world with modern medicine and knowledge, a pandemic is not possible. In this post, I drew attention to how different the world is today than in 1918 … and how some of those differences will work against us.

    The news media doesn’t need to focus on what has happened already – two people have died in the U.S. – as much as on what very well may happen (some day, WILL happen) – a flu pandemic. At this stage of the game – when we’re still PRE-pandemic – helping people understand and adjust and prepare is how you can best serve the public. There will be ample time after the next pandemic to talk about what happened.

    Again, thanks for your involvement.


  28. #28 Don Williams
    May 8, 2009

    1) I’m kinda worried about the political calculus involved. And potential signs of how that calculation is shaking out.

    2)The problem with flu containment measures is that they hit GDP –and we have some Major campaign donors ..er.. financial service firms in the Intensive Care Unit at the moment. Robust Quarantine measures may push the feeble economy off the cliff.

    So you see attempts being made to instill confidence in the stock market. A Northwestern study being puffed on May 1 saying our “worst case” number of victims by May 28 will only be around 1700 — which I think would strike anyone familiar with exponential growth as absurd.

    3) But if you take it easy and let the flu spread, you are killing 30,000 or High Risk people (asthma, diabetics,etc.) Maybe more. Maybe a lot more.

    4) Which would nicely revive the Republican Party. After all, only 4500 lives were lost grabbing those oil deposits for the boys in Houston. You could lose that many in one day if this flu turns bads.

    5) Gee, I know. Let’s promote an urban legend about “swine flu parties” and blame the stupid soccer moms. The ones who aren’t Republican are Hillary supporters.

    Full disclosure: I worked several weeks as a volunteer in the Obama campaign — and I very much hope I’m wrong re where this is heading.

  29. #29 Jody Lanard M.D.
    May 9, 2009

    Kelly wrote:

    One doc I spoke to said the biggest benefit from wearing the masks is that it keeps you from touching your face, thus cutting off a major virus transmission route.

    I can’t find the data, Kelly — the data that hand-to-face contact is even a slightly significant proven route of influenza transmission.

    I can find LOTS of great data that hand washing kills flu viruses. I just can’t find documentation that flu transmission via hands is much of a problem. And I can find small amounts of data that suggest it makes up a negligible percentage of flu transmission.

    (Admittedly: every little bit of reduced transmission helps, which is why I continue to have contempt for officials who are disdainful about masks — given that the officials seem to believe that droplet transmission between close contacts is the main route.)

    So it looks like hand washing kills flu viruses, but hands rarely transmit flu.

    And it looks like droplet spread is the main transmission route, but we don’t have good evidence that masks reduce transmission a bit.

    If those two “it looks likes” are indeed correct, and if you were designing a flu precaution campaign, what would be your main focus (remembering in all cases to acknowledge uncertainty and evolving knowledge):hand washing or masks?

    p.s. If any of you have peer-reviewed citations about hand to face transmission of influenza, I would love to see the references. I am NOT, however, interested in more articles about how hand washing kills flu virus. That is already very impressively documented.

    p.s. Thanks for the kind words, Snowy and Chirp!