Swine flu: case definitions and tough decisions

Salutation Revere

CDC MMWR Dispatch at http://www.cdc.gov/mmwr/preview/mmwrhtml/mm58d0430a2.htm
Tables and Figures, can we know how's that sound?

Thank you

Snowy

Reported by: General Directorate of Epidemiology, Ministry of Health, Mexico; Pan American Health Organization; World Health Organization; Public Health Agency of Canada; CDC (United States).

They have tables and Figures

TABLE 1. Timeline of key events in detection and response to outbreak of swine-origin influenza A (H1N1) virus (S-OIV) infection --- Mexico, April 12--30, 2009

FIGURE. Number of confirmed (N = 97) and probable (N = 260)* cases of swine-origin influenza A (H1N1) virus (S-OIV) infection, by date of illness onset --- Mexico, March 15--April 26, 2009

TABLE 2. Number of patients and deaths from laboratory-confirmed infection with swine-origin influenza A (H1N1) virus (S-OIV), by age group --- Mexico, April 1--27, 2009*

Date last reviewed: 4/30/2009

Is it known, if I get the flu, can I give it to my parrot and cockatiels?
WWYD

Agreed - when collecting data points it is good science / essential to use a consistent criteria. If the details are not fully recorded at point of collection then it is nigh on impossible to retrospectively determine them.

What we need is a standardised questionaire - world-wide. Then we have a chance of building a global database of real value. The design of that database would take a little thought and debate but should not be too difficult.

Chris

the CDC should use Twitter to coordonate their actions

Comments on H1N1 from The Lancet

Swine influenza: how much of a global threat?

Free registration rquired at
http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(09)60826…

Excerps;

The public should expect further deaths from this swine influenza outbreak. The Lancet certainly expects the number of those infected to increase and the spread of infection to expand.

Therefore, all recommendations made so far should be seen as provisional.

We are passing through an unstable period in this outbreak's evolution.

Every member of the public has a part to play in limiting the risk of a full-blown pandemic. Vigilance, and not alarm, is needed, with readiness to self-isolate oneself at home if an influenza-like illness develops.

Such home isolation, combined with other measures of social distancing, are most likely to stop the spread of swine influenza.

These actions could buy the necessary time to boost stockpiles of antivirals and develop a vaccine against this virus, which will inevitably take months rather than weeks to prepare and distribute.

So far, the rapid responses by governments and international agencies have triggered effective mechanisms to protect the public.

But the vital role and responsibility of the individual should not be ignored.

Snowy Owl

Interestingly, last time I had a flu tests (several years ago), the Doctor acted like it was 100% accurate.

The schools and such are in a no win situation. If their shutdowns work, they get trashed by the people who don't know better.

@ Houston:

Last I heard, there have been NO cases of this strain of the flu in any animals at all; it's only been found in humans. I admit that testing pets probably hasn't been a high priority, but with people as alarmed as they have been I would assume that any widespread infection in pets would have been noticed by now.

Since the latest and greatest on this strain is that it's 80% swine flu... and the other 20% has actually been in pigs for a decade [1], I'd be a little surprised if we found it infecting birds in large numbers at this point. (It will mutate over time, just as it did to start infecting us, so the future is hard to predict.)

1. http://news.yahoo.com/s/ap/20090501/ap_on_he_me/med_swine_flu_name

Today's CDC list of confirmed cases doesn't include the one from GA, which the state announced as confirmed yesterday.

In other news here in Atlanta, cashiers at Walmart were wearing gloves as they rang people up today. The kids brought home a letter from school advising general precautions (wash hands, etc).

I do IT work. When all is well no-one says thanks for making it all work so good. Every so often I do a a bit of PR work, to let my valued users know what improvements we've made. This works well, I often get good feedback and it keeps me sane. Also mitigates against the backlash when we have problems, and holds the flames off my boss who is busy firefighting. Lesson?

I think the paranoia is sufficiently ramped up (and not necessarily a bad thing) but in order to lower the stress level I think we should all start referring to it as Hamthrax.

A large number of cases seem to be falling off the radar. For example, check the news from the U. of Delaware. Their PR department posted an article yesterday. That article says 4 confirmed and 12 suspected cases. But three paragraphs later it says that 400 students streamed into the student health center with flu symptoms.

So what do these students have? Does anyone know whether these students mostly had fever--not usually associated with the "worried well"? If they did, you don't have to be Dr. Kildare to diagnose what they had as flu, and very likely the new flu. If that's so, then it looks like Ro is high enough that social distancing is not going to be effective, and that the virus is going to have its way with us.

Am I wrong about this?

And Reveres, in your opinion, how many cases are likely out there, in this strange category of "less than suspected (and likely never to be tested)"?

"You also have to have been in close contact with a You also have to have been in close contact with a confirmed cases within the last 7 days (the upper range of the incubation period) or have traveled in the last 7 days (in the US or internationally) someplace where there have been confirmed cases"

Anyone with the flu, specifically with influenza A should be a suspect case. Given the time it takes to confirm a case, and the fact that influenza spreads rapidly, using similar criteria as SARS which had a minimum incubation period of 10 days (10 days contact criteria) is foolish (influenzas minimum is typically between 1 day, most within 1-4 days).

Also, you don't necessarily know where you got influenza, from someone in an elevator, passing by on the street, or from a door knob, and those who passed it on to you may not even be symptomatic, let alone known to be a confirmed case. SARS required close contact with someone who was symptomatic, influenza does not.

Why limit the number of suspect cases, especially when the disease is mild. Collect all flu samples in this period and get them tested.

The clock is ticking. Just a matter of time before we hear the call for forced vaccinations this fall. Hopefully Baxter can keep it H5N1 free.

Why limit the number of suspect cases, especially when the disease is mild. Collect all flu samples in this period and get them tested.

The reason is probably simply that the lab capacity is no longer up to the sheer volume of testing requests that are coming in. If someone has a mild case of the flu, and there is already H1N1 in that community, what more does it really tell you? At this point, spot sampling is more practical, as it will give an idea of the spread and mutation without overwhelming the test capacity.

'hamthrax'....rofl

Thanks for hosting this blog, Pauls (may I call you Pauls?) I understand that hundreds of students were ill at St. Francis Prep but new ill students were no longer being tested (sorry no cit. but I saw it in multiple sources earlier this week). I can imagine this being done to focus limited testing resources on finding new nodes. Doesn't this make CDC's box scores meaningless - except for the geographic angle of which states have cases?

In spite of my best attempts at scientific and public health education, I had a kid return to school today, coughing, after a day's absence, looking terrible and saying how sick he was with a fever. Anybody else's hands getting chapped?

Totally off topic, but - I'm a HS bio teacher. Obviously we are trying to use this as a huge teachable moment for our students, and they have a ton of really good questions. There was one that came up today that I want to check on...

H1N1 has human, avian, and swine components. (I think, anyway- correct me if I'm wrong) The students asked - if someone gets infected with it, and survives, would they potentially have at least some level of immunity against a future avian / swine flu outbreak? And if this outbreak turns out to be fairly mild but widespread, might it turn out to be a good thing for humanity?

My answer was that it was possible, but not definite, since the strains mutate so quickly, and there are lots of different strains to begin with. Obviously that's pretty simplified (I teach sophomores). Is it basically correct, and is there a better way to explain it?
Thanks in advance.

I am concerned about adequate sample collection. Usually when we (an ICU nurse here) swab the nose for MRSA or something we just swipe the inside of a nare. In order to get a proper sample to test for swine flu, you must stick the swab *way back* in the nose, pretty much until it hits the back of the throat. We need to make sure that we are consistent -- and consistently doing it right.

Elissa: The avian segment is in an internal gene, so probably wouldn't provide much protection. "Bird flu" (H5N1) is a totally different virus and its main antigenic proteins are very different than this H1N1. So, yes, it was a good question. But there is really no relation between them. The avian component is also old, having moved into the pigs at least a decade ago, so it is pig adapted. See our post on this here.

Catherine: Thanks. I'm not sure why they are not advocating pharyngeal swabs. I'll have to look into this.

Thanks for the answer and for not laughing :) I was proud of them - we went from a Monday question of "Can I get it from eating bacon?" (and yeah, they were serious) to that question today. That's a definite improvement!!

It's worth pointing out, I think, that apparently CDC is getting a 95 percent hit rate on probable cases, in terms of confirmations. I would guess this is part of the rationale of much of their current guidance re: school closing, which recommend a closure for a week based on a probable test result. In theory, no one should be waiting for confirmatory tests. I've also heard that states should be able to do their own confirmations within a week or so.

Does anyone know if the case that is confirmed in KY is the same one that is hospitalized in GA? GA DPH announced yesterday we had a confirmed case http://tinyurl.com/dm3z69 but it's not showing on the CDC map. (The GA patient traveled from KY.) This is bugging me--it's not like they'd have to send the sample far!

It is--you can visit healthalerts.ky.gov for more info on that case.

Thanks, mouse. It just was irritating me that I couldn't tie that loose end.

Given the relatively mild disease in most US cases so far, the CDC school closure recs (even more aggressive as of today) seem excessive:

"Dismissal of students from schools and closure of childcare facilities should be considered for not-yet-affected schools and childcare facilities in the same area (e.g. a feeder school network or a geographic area) if more than one school or childcare facility in that area has confirmed or non-subtypable influenza A cases among their students, faculty, or staff. This would include preemptively dismissing students from schools in that area, including schools without current laboratory-confirmed cases."

One can make the abundance of caution argument for closing schools, but given moribity to date, I predict a backlash next week if school closures increase exponentially ...instead of panicking about the presence of swine influenza in a school, parents will be arguing for a more measured response. It will be interesting to see how this will play out. The analysis of the effectiveness of community mitigation measures during the 1918 pandemic seems weak, and the models supporting these strategies are just that...and deserve a skeptical response--it was "expert" modelling that helped lead to the current financial meltdown.)

Here is a quote from DA Henderson on pandemic response:

"Think twice before taking actions driven primarily by the perceived need to demonstrate to the public that government authorities can take some definitive action to cope with the problem."

http://www.iom.edu/Object.File/Master/38/129/D.A.%20Henderson.pdf

@cooties: I'm no expert, but the revised CDC guidelines recommending closing nearby-but-not-yet-affected schools and *leave them closed for up to 14 days* don't seem excessive if you accept the premise (stated in the guidelines) that children are likely to be infectious for about 7â10 days after disease onset. We're told influenza is a highly infectious disease. Scientists have determined this week that although the 2009 H1N1 seems to cause only mild disease (at least in some locations), it also seems to transmit very well. So, social distancing is the tactic of choice. (Factoring in, of course, the fact that kids are not particularly good at hygiene - handwashing, cough etiquette, etc.)

Parents may howl over both (a) closing nearby but not affected schools/daycares and (b) leaving them closed up to 14 days. But they'd howl if their kids were sick en masse, too. (I'd rather have the first problem instead of the last.) Either way, it's an inconvenience. But one is a saner inconvenience, IMHO.

BTW, Revere et al, did anyone else notice that the CDC's revised guidelines for school and childcare closures were revised once in the morning and again in the afternoon May 1? One notable difference I noticed: In the morning version, the guidelines said that if a school or childcare facility was closed, they "should dismiss students for a minimum of 14 days." The afternoon version says the school or childcare facility "should close for up to 14 days." Not a "minimum of" 14 days but "up to" 14 days. Further, the afternoon version added the note that "additional guidance on duration of school closures will be provided no later than May 8." Curious.

"The avian component is also old, having moved into the pigs at least a decade ago, so it is pig adapted."

Sorry but there was a link on another thread provided by timtiptoes in which a chief veterinary officer from FAO clearly stated that this virus does NOT circulate among swine. According to that link, it would have been necessary to have a swine flu epidemic among swine FIRST, and the virus could then have mutated.
But that epidemic among swine never happened.

So, it appears that this virus does not originate in swine though it has a pig component.
Calling the disease swine flu doesn't make it swine flu. Who was it who called type A(H1N1) flu "swine" flu FIRST?
There's no point denying that the virus is not a pig virus, and that it wasn't produced by pig IMO.

Or is there a point denying this fact?

@3 : The CDC does have a Twitter account.

http://twitter.com/cdcemergency

Lily, swine epidemics don't happen like human epidemics. They don't use similiar transportation systems and they have different living arrangement as humans. There is no guarantee symptoms would be similiar.
The correct term is Swine Flu because I assume, the genetics of this outbreak appear to match the medical/agriculture definition of Swine Flu. Maybe it will turn out to be more Avian Flu or more humam flu and deserves a name change, but it is not being called Swine Flu because of some on-the-fly definition; the uncertainty would be how to name a pathogen with multiple genetic pieces.

An applied example is if you start calling it different things, international researchers speaking international languages will be confused. You and the media and pork lobby are fucking this one up, but the very fact this is a conversation topic is a good sign; I don't really care what they call it but it would be a shame if this had (or will yet have) a 2% mortality and people needlessly died because some researcher assumed the (as yet not happened) 2% mortality mutated version was just a new Israel/pork-lobby/Mexico name for was medical professionals are calling Swine Flu.
If you want PC definitions and you want to promote pork heart attacks and global food shortages, don't do it in the middle of an epidemic. Good thing North American researchers in this case all spoeak English.

Chirp: CDC, like everyone else, is making it up as they go along. I think that's the right way to do it. As data and reflection dictate, don't be afraid to change.

Phil,

I don't care about anybody calling this pancake flu or roastbeef flu. "Swine flu" is diverting the general public's attention to make them believe the virus originated in swine, in La Gloria, Mexico.

No, its emergence did have nothing to do with pig, pork, swine & Co. Let's call it the NEW virus, and we'll ask the right question: Where did it originate?
It's the job of scientists to understand "Mother Nature", not to withhold facts and findings because nature would be so unpredictable.

Nature follows laws that can be understood.

I'm not sure whether it's a progressive public health interest to really want to find out and share the information.

Phil,

The media were too quick to identify patient zero, Edgar Rodriguez whose image (living in La Gloria) will stick in people's minds despite local residents' assertions that he had not had the new A(H1N1) flu.

Maybe it's just the scientific community who are misleading the media and who should clarify facts before the media rush to provide the wrong images to the masses.

Of course, politics is not everything, and we have to deal with this virus now - and with what it might become.

"No, its emergence did have nothing to do with pig, pork, swine & Co."

Why do you believe this?. It isn't likely (+50%) this SWINE FLU came from La Gloria high density hog farms but it is certainly the most likely (25%?) explanation. Again, what is your vector hypothesis if not La Gloria?

Phil,

Thank you.

It may have come from La Gloria as much as it could have come from any other point on the globe because this virus did not mutate from a virus currently found in swine. There was no epidemic outbreak of any kind of swine flu in recent weeks/months in La Gloria.

So, I can confirm what it is not. I don't know what it is. But we could all get closer to finding out what it really is if "scientists" dropped their assertion that it is most likely that SWINE FLU came from La Gloria.

While I'd prefer any plausible (!) natural explanation, bioengineering looks more likely in view of the poor evidence in favour of nature.

Lily, Phil: As I understand it, no one knows where this virus came from, speculation to the contrary. Perhaps we'll find out at some point. One of the main questions is where did the unusual HA come from. It seems relatively unrelated to Eurasian and North American HA, or at least not more closely related to one or the other, but apparently still swine origin. When and where it jumped from swine is unknown at this part.

The Genomic and Epidemiological Dynamics of Human Influenza A Virus

Credit to PabloMorgan at http://www.flutrackers.com/forum/showthread.php?p=227127#post227127

Rambaut A, Pybus OG, Nelson MI, Viboud C, Taubenberger JK & Holmes EC

(2008) Nature 453, 615-619.

The evolutionary interaction between influenza A virus and the human immune system, manifest as 'antigenic drift' of the viral haemagglutinin, is one of the best described patterns in molecular evolution.

However, little is known about the genome-scale evolutionary dynamics of this important pathogen. Similarly, how genomic processes relate to global influenza epidemiology, in which the A/H3N2 and A/H1N1 subtypes co-circulate, is poorly understood.

Through an analysis of 1302 complete viral genomes sampled from temperate populations in both hemispheres, we show that the genomic evolution of influenza A virus is characterized by a complex interplay between frequent reassortment and periodic selective sweeps.

The A/H3N2 and A/H1N1 subtypes exhibit strikingly different evolutionary dynamics, with diverse lineages circulating in A/H1N1, indicative of weaker antigenic drift.

These results suggest a sink-source model of viral ecology in which new lineages are seeded from a persistent influenza reservoir, which we hypothesize to be located in the tropics, to sink populations in temperate regions.

Attached FilesRambaut et al (2008) Nature.pdf
http://www.flutrackers.com/forum/attachment.php?attachmentid=3165&d=124…

Snowy

PRIVATE

Alberta pigs said to be infected with flu
Article Video Comments (4)

The Canadian Press

May 2, 2009 at 4:32 PM EDT

OTTAWA â The Canadian Press has learned federal officials are set to announce the swine flu virus is believed to have infected pigs in Alberta.

A government source says the animals were thought to be infected by a farm worker who had recently been to Mexico and fell ill upon his return.

This may be the first time this particular swine flu virus has been found in pigs.

http://www.theglobeandmail.com/servlet/story/RTGAM.20090502.wcanflu0502…

Michel

"When and where it jumped from swine is unkown..." (revere)

It did not "jump from" swine.

"...the animals were thought to be infected by a farm worker who had recently been to Mexico and fell ill upon his return.

This may be the first time this particular swine flu virus has been found in pigs." (Snowy Owl)

So, that was the F I R S T time.
And this is what is harbouring the greatest danger.

Lily; You know this to be true? Where did it come from? This is not a rhetorical question. The segments appear to have pig lineage most recently (like the triple reassortant first seen in pigs in 1998). At some point they acquired an unusual HA, which also looks like swine, but may have come from another animal, where and when we don't know at the moment. Where humans got it from we also don't know now. So this is a virus that is currently in human beings but has the genetic components characteristic of pigs. In other words, once it was in pigs, now it is in humans. In between we need to figure out. That's what I mean when I say "when and where it jumped from swine we don't know." What do you mean when you say it did not, presumably, ever jump from pigs?

revere,

This blog's editors are insisting a tad too much on the "pig to man" theory while it lacks supporting evidence, more than most other possible explanations for the sudden occurrence of this new virus.

OTTAWA, ONTARIO -- (Marketwire) -- 05/02/09 --

The Canadian Food Inspection Agency (CFIA) indicates that it has found H1N1 flu virus in a swine herd in Alberta. The safety of the food supply is not affected and Canadian pork continues to be safe to eat.

It is highly probable that the pigs were exposed to the virus from a Canadian who had recently returned from Mexico and had been exhibiting flu-like symptoms. Signs of illness were subsequently observed in the pigs. The individual has recovered and all of the pigs are recovering or have recovered.

While further testing is needed to more fully characterize the virus, the CFIA is taking a precautionary approach.

The herd has been placed under quarantine, and the Agency is working with public health colleagues to determine the most appropriate next steps to ensure that public and animal health remain protected.

The chance that these pigs could transfer virus to a person is remote.

Influenza viruses do not affect the safety of pork, according to the World Health Organization (WHO) and the Food and Agriculture Organization of the United Nations (FAO). As with any raw meat, pork should always be properly handled and cooked to eliminate a range of food safety concerns.

Pigs in Canada are tested for influenza viruses on an ongoing basis across the country during routine investigations into respiratory illnesses. The CFIA is working with provinces, territories, the swine industry, and private sector veterinarians since April 24th to enhance monitoring of swine herds for signs of illness and to maintain enhanced biosecurity measures on farms across the country.

http://uk.sys-con.com/node/945935

Lilly: Don't you think swine origin has some substance to it? It isn't avian or human origin, right? All the segments are swine segments. So while we don't know where and when, the origin seems quite clearly swine at this point. We aren't insisting on it. We are just reporting what has been found. Of course everything in science is subject to revision.

Snowy: We'll have to see about the virus in the CFIA report. H1N1 is a normal pig subtype, or was until 1998, so this may or may not be the virus in people. It would not be unexpected if it could infect pigs, however, although so far there is no evidence any swine have this particular strain of H1N1.

Personnal translation

Canadian Food Inspection Agency (CFIA) state that the risks of transmission of this new H1N1 virus from swines to humans is low.

World Health Organisation (WHO) has indicated that there are no proof allows us to believe that swines can transmit the virus to humans or that consommation od swine meat creates a risk to humans.

It could be the first time that this specific virus of influenza is detected in swine.

http://www.radio-canada.ca/nouvelles/National/2009/05/02/003-gripe-A-po…

First of all, thank you for such an informative blog. I am a teacher w/o any medical & statistics expertise, and I was totally overwhelmed this post.

I don't understand how anyone can get remotely accurate numbers given the fact that so few will end up being tested; and even then, the test given may miss 50% of those who are positive for Type A. I guess statisticians can factor all of that into their calculations. However, I can't help but feel like we, the public (via the MSM) are only contemplating a tiny puzzle piece of this pandemic and leaping to judgments that this is overblown without considering all of the people who are carriers / contagious but who have been left out of the testing process completely, tested false negative -- and were sent back to work / school, have tests on backlog at either the state level or CDC.

Here's what I do know about: kids & schools. An article just appeared in the WaPo Swine Flu Report - What If There's No Soap? http://voices.washingtonpost.com/swine-flu-report/2009/05/what_if_there…
When I taught in a public middle school in Jacksonville, FL, the restrooms (including faculty) were FILTHY and never had soap or hot water. Even with soap, kids (and grown ups - frankly) are not the best hand washers or cough coverers; and kids cannot keep their hands away from their faces -- fingers are always in mouths, noses, and eyes. So, in my less than humble opinion, schools are cess pools of contagion and there should be no hesitation to close them if needed to keep the kiddos from passing it around and taking it home, so that their parents can then take it to work. Despite their non-compliance, I still love kids, and that is why we need to keep them at home when they are in danger of catching and spreading something potentially serious.

Lily,

What is it you do, exactly? Are you a pork lobbyist? I hope someone is paying you well to defend the poor pigs : )

We (in our jurisdiction that I care not to identify) are making sure that we carefully distinguish between "clinical case definition" and "epidemiological case definition" for A/(H1N1-2009).

Basically these subtleties, as far as I understand it, (since I'm a non-medical scientist involved in the emergency management aspects of this event) relate to the differences between the clinical presentation to a family doc and the patient's travel or contact history.

Revere, I'm sure you can explain the difference much better than I: and I welcome your input.

Is the distinction in your view important? Or is it merely a "distinction without a difference"?

Leah,

As a unique parent of youg children, I have to say, that closing Schools and Day Care without helping us will bring us down, muchos down. If we are very Down, that is, Mentally, Emotionnally, Solidaritarelly,financially and I have to Stop the Downhill here, Closing Schools will loose a lot of efficiency.

Federal Governments, all three of them must give us a hand to cope so we can keep the Pace and thus not become a burden on the system.

Snowy

Snowy Owl,

You are right about the hardships on families, and I think that has to be weighed in the decision-making process. I am very concerned about kids who rely on free/reduced breakfast/lunch as well as the care of those students who are too young to stay home alone while parent(s) work. It is very frustrating and makes me very sad that we (USA) supposedly have emergency plans for pandemics or other disasters, but we really haven't worked things all of the way through.

As far as the FREE / REDUCED Breakfast / Lunch, I think we could do something like "Meals on Wheels" - cooking the meals at schools and having teachers & other well employees deliver them to students. The child care issue is more difficult, because the whole point is to avoid groups of kids, so daycare situations are out. Maybe payment to affected parents w/ financial need similar to Jury Duty pay? And job protection similar to Jury Duty; you can't be fired for Jury Duty.

I hope we can get these issues figured out during this hopefully mild "test run" instead of concluding that this is just a "time wasting false alarm", which seems to be the message of most of the Washington Post Comments.

Alberta pigs infected with flu, CFIA says
http://www.theglobeandmail.com/servlet/story/RTGAM.20090502.wcanflu0502…

STEVE RENNIE AND HELEN BRANSWELL AND BOB WEBER
The Canadian Press
May 2, 2009 at 7:56 PM EDT

OTTAWA â Pigs at an Alberta farm caught the same swine flu strain that has sickened hundreds of humans around the world, federal officials said Saturday.

A farmhand who travelled to Mexico and fell ill upon his return apparently infected the pigs with the H1N1 influenza virus, said David Butler-Jones, Canada's chief public health officer.

âSo far, basically what we're seeing in the pig is the same strain as we see in the humans,â Mr. Butler-Jones said.

âThe concern is that if it's circulating in a pig herd, that any other humans that come onto the farm might be exposed and be at risk.â

snip

One other farm worker subsequently fell ill. It's not yet known if that person caught the swine flu.

The virus has shown no signs of mutation when passing from human to pig, Mr. Evans said.

âAt this point in time, the issue of this being a human virus, having been introduced to the pigs, and the characterization of this virus, shows it is still that virus,â he said. âThere's been no adaptation identified through the transfer from humans to pigs at this time.â

snip

âThe chance that these pigs could transfer virus to a person is remote,â Mr. Evans said.

The H1N1 virus, which is made up of swine flu genes, is believed to have jumped to humans some time back and has been passing person to person

snip

Though he emphasized that to date most cases are mild, he also urged Canadians to be cautious.

âI ask people to be extra vigilant and to take precautions around general hygiene. That means washing hands thoroughly and often, coughing and sneezing into your sleeve and disinfecting tables and worktops,â he said.

Snowy

"The Canadian Food Inspection Agency (CFIA) indicates that it has found H1N1 flu virus in a swine herd in Alberta. The safety of the food supply is not affected and Canadian pork continues to be safe to eat."

Holy crap this happened way too quick. The world's four human/animal Level 4 biolabs just attained solid platinum status (or should I say copper). I wonder if there is a way to build two more of these labs in Asia and one in Africa at least on the diagnostic end of things (so as to not increase future bioterror odds). I'd say odds of pig origin are now 100% and of La Gloria origin +40%.

I've worked out that you can measure the increase in human Swine Flu infection mutations or changes in the rate of mutations (I'm not sure if all virus genes are important or just the ones that affect transmissibility) to gauge odds of "2nd wave". Sure the mutation might happen non-linearly; suddenly, but hopefully not. But pigs as reservoirs aren't a homogenous population like we are. Almost certainly a Swine Flu mutation in a pig in one end of the globe won't sweep through the oinker world like human flus start in Asia and go global in a semi-predictable way (thus flu shot often work).
At the same time I've been in line at food banks in 3 different cities and that pork protein kept me thinking and/or working manual labour. To say nothing of how important pork calories and revenues are in developing world. I'm not a big fan of pork industry, but slaughtering pigs en masse will cause a global food shortage.
All I'll say for now is I hope surveillence can be good enough to tell where human cases of swine flu geographically overlap with pig cases of this same strain of Swine Flu. Where data isn't and won't be available, sadly you have to assume they overlap. I know Atlanta and Winnipeg will be working on the "etymology" (whatever the term is for measuring mutations of Swine Flu cases over different calender times and geographies) of oinker and human Swine Flu cases and I hope they release these ASAP.
If the genetic makeup of Swine Flu infected pigs demonstrates diverging mutations (and this is very optimistic to assume linear Swine mutations; "2nd wave" mutation might happen suddenly), this is one reservoir we can maybe do without for now, assuming more pig herds get coughed on. No rush in the next weeks (outside Chile and Argentina?!), but we don't want a winter of mutating Swine Flu working its way through pig herds.

Snowy Owl,

Thanks for your good work of translation and updating the latest news and information. It is very helpful.

From reading through the above posts, am I do understand that at one time, the virus was (probably) transmitted from pig to human? Now the virus is readily transmissable from human to human, and most recently it appears that it can transmit from humans back to pigs. But several posters above R/O the possibility that it can currently transmit from pigs back to humans. Why is that? Why has it lost that original capability?
Humbly asked, Paul.

I guess I was focused on the geographical overlap of a human-to-human Swine Flu strain working its way through a pig herd and nearby humans at the same time, because it constitutes a mutation "hot-spot". But really, any human-to-human communicable Swine Flu strain working its way through any pig herd (which necessarily exposed farmers but maybe not true of wild animal reservoirs) is unsettling. A doctor said today or yesterday a pig vaccine may be possible.
...Paul I called you stupid because you reasked a question that you claimed was already answered. Didn't mean IQ stupid but if you are and self-conscious about it; girls generally don't like guys into the books unless they use brains to get $$, so tradeoffs either way. No one understands your 11:41AM question. To me what is troubling is that yesterday's news indictaes this strain can transmit back to pigs from a farmer or slaughterhouse labourer as easily as it can trasmit P-to-P. Before yesterday, I think it was guessed this type of transmission was harder.

Phillip: To clarify my 11:41 question, which you claim "no one" can understand (I assume you're representing this entire blog audience), I quote Snowy's post above. She doesn't I.D. who "Mr. Evans" is, but she quotes him as follows: "âAt this point in time, the issue of this being a human virus, having been introduced to the pigs, and the characterization of this virus, shows it is still that virus,â he said. âThere's been no adaptation identified through the transfer from humans to pigs at this time.â

snip

âThe chance that these pigs could transfer virus to a person is remote,â Mr. Evans said.

Outside of Evans' quote, Snowy then adds: "The H1N1 virus, which is made up of swine flu genes, is believed to have jumped to humans some time back and has been passing person to person

That was the basis for my 11:41 question: re-phrased, the same virus has demonstrated that, at some time in the past, pigs *did* transmit it to humans. Currently it is readily tranmissible H2H, and even now seems to be transmissible human to pig. My question: why and when did it become a remote possibility that pigs could transfer virus back to humans (thus completing the transmission cycle), if it is assumed that at one time that was exactly what happened, and it is known to be the same virus.

Relevance of the question: If that is a misstatement, and it is *still* readily transmissible from pigs to humans, this indeed does represent a "hot spot" for a mutation situation (as you and I apparently agree).

As for girls, Phillip, they're also not interested in old men, be they stupid or not (I guess unless they have $$, even so).