Pigs possibly linked to H1N1 flu cases in B.C.

Remember when they called it “swine flu”? The first pandemic flu in 41 years was quickly renamed “H1N1” in its early days after the pig industry, in damage-control mode, proclaimed loudly that people couldn’t get sick from eating pork. And they said that it looked like the flu was spreading worldwide from person to person—not from pigs to people.

More than two months after the initial outbreak, it’s still not clear how the flu started. The most accepted explanation is that a farm worker at a massive swine operation in Mexico got the virus from a pig and carried it into the wider population, where it spread without any more involvement from pigs.

But a closer look at the data on H1N1 cases in B.C. and the rest of Canada suggests the pandemic has a much closer relationship with pig farming than suspected. That relationship is especially striking in the most serious cases of the flu that have caused hospitalization and death.

The Fraser Health Authority, the district with the largest number of pigs in the province—and one of the most intensively farmed areas in Canada—has a 39-percent-higher rate of confirmed H1N1 cases per capita (9.7 per 100,000 people) than the provincial average (7.0 per 100,000), according to data from the B.C. Centre for Disease Control as of July 6. B.C.’s first confirmed death from H1N1 flu occurred on July 13 in the region.

The rate is even higher in the Northern Health Authority, which has the highest ratio of pigs to people in the province. The northern region has a 48-percent-higher per capita H1N1 rate (10.3 per 100,000) than the B.C. average.

The data shows a near-perfect 93-percent correlation between the number of pigs in a health region and the number of confirmed H1N1 cases there. (Correlation measures the strength of the relationship between two groups of data. A correlation of 70 percent or higher is generally considered to be strong.)

Density of pigs also seems to have a relationship with H1N1 rates—especially when it comes to the most recent flu cases. There is a 95-percent correlation between new cases of H1N1 confirmed during the week of June 29 and the number of pigs per farm in a particular region.

The same high correlations exist Canada-wide, according to Statistics Canada figures on pig farms and an analysis of data on confirmed H1N1 cases from the Public Health Agency of Canada as of July 8. The data shows that the flu has been more severe in areas with intensive, large-scale hog production.

The total number of confirmed H1N1 cases in each province has a 99-percent correlation with the number of pig farms in that province.

In Quebec, the province with the highest number of pigs—4.3 million—residents were twice as likely to be hospitalized when they acquired H1N1 as the Canadian average. Quebec’s death rate from H1N1 per capita has been 60 percent higher than the national average.

The flu outbreak has been even more severe in Manitoba, which has 2.4 pigs per person, more than any other province. There, the number of H1N1 hospitalizations per capita is triple the national average. The rate of H1N1 deaths per capita in Manitoba has been more than 3.7 times higher than the Canadian average.

The high correlations surprised even long-time critics of intensive, large-scale farming. “Wow, that’s astounding,” said Peter Fricker, projects and communications director for the Vancouver Humane Society.

“If there is a possible link between pig farms and susceptibility to disease, public-health authorities should definitely be investigating. If the correlations are correct, the whole issue of factory farming has to be looked at,” he said in a phone interview.

“Wow, really. I don’t think anybody’s looked at this before,” said Bob Martin, who headed the Pew Commission on Industrial Farm Animal Production, which released a major study last year that said workers in large farms and their neighbours have high rates of asthma and other respiratory illnesses due to manure runoff and emissions like ammonia and fine-particle pollution.

Martin, speaking from Washington, D.C., said some people living near pig farms could be more susceptible to H1N1 and to more severe reactions because of such respiratory ailments.

As of mid-June, 40 percent of the people who had died of H1N1 in the U.S. had had an additional medical condition like asthma, diabetes, a compromised immune system, or heart disease, according to the U.S. Centers for Disease Control.

Dr. David Patrick, director of epidemiology at the B.C. Centre for Disease Control, said the data could mean people living in hog-producing regions have a higher predisposition to catching H1N1. But he cautioned that there could be other, unknown explanations for the high correlations, too.

“The fact that particulates can predispose people to asthma is clear. If particulates are an issue, we have to gradually improve our environment,” he said.

“If we have issues of predisposition [to catching H1N1], that’s a question for sober inquiry by people in environmental health.”

Until now, he said, public-health officials have believed H1N1 spreads randomly between people or may cluster in areas with dense human populations.

“Probably the most important message is if people with flu symptoms have asthma or chronic lung disease or anything that affects their immune system, see a doctor right away because antivirals can help avoid hospitalization,” he said.

The B.C. Pork Producers Association didn’t return a call for comment.

In the province’s agricultural heartland, the Fraser Valley, H1N1 seems to be going strong instead of dying off after the end of the usual flu season, as initially predicted. So far, the vast majority of incidents have been mild, but a flurry of 22 new H1N1 cases there was confirmed during the week of June 29. That number was the highest in any region of the province and almost twice as many per capita as the provincial average.

The high numbers coincide with a trend of relatively high incidence of recent H1N1 cases in some of the biggest hog-producing provinces. During the week after July 3, Manitoba saw the highest rate of new confirmed H1N1 cases per capita in Canada (8.4 per 100,000)—5.6 times more than the Canadian average (1.5 per 100,000).

The location of new flu cases also seems to have a close relationship with especially high concentrations of pig farming. There is an 80-percent correlation between the number of new cases in the seven days after July 3 and a province’s ratio of pigs to people. In other words, the more pigs there are per person, the higher the rate of the flu.

And no region of Canada has a higher density of farm animals by weight than the Fraser Valley, according to Hans Schreier, a soil scientist and professor emeritus at the University of British Columbia who has studied agricultural pollution in the Valley.

“We’re generating so much manure in these operations, it winds up in the soil and water,” he said in a phone interview.

Thanks in large part to massive amounts of farm waste pouring into the Fraser River watershed, the Georgia Basin is “perhaps the most threatened area in the country” for coastal eutrophication—a process that stimulates algae blooms and chokes marine life—according to a study Schreier coauthored in 2006 in the journal Biogeochemistry. The study said farm-waste discharge is poorly regulated across Canada.

An Agriculture Canada report in 2002 found factory pig farms were causing health and pollution risks to farm workers and the local community. “In B.C.’s Fraser Valley, this chemical soup [from farm emissions] is so thick it causes a visible haze and can make up 70 per cent of the airborne particles in summer,” said the report, which was quoted in a 2002 Ottawa Citizen story and was obtained under an access-to-information request.

And of all the farm animals in the region, pigs are by far the single biggest source of smog-causing fine-particle pollution, contributing 64 percent of the total fine-particulate matter from all farm-animal sources in the Fraser Valley Regional District, according to a 2004 study done for the district and Environment Canada.

That study noted that while air-quality improvement in the region had focused on reducing emissions from vehicles and industry, “emissions from agricultural operations have been relatively untouched.”

Meanwhile, levels of nitrogen—another big emission from farms—in ground water in the Central Fraser have been above the allowable limit for drinking water since 1981, according to a 1997 UBC study published in the journal Environmental Management.

George Peary, the mayor of Abbotsford, shares his community with the highest number of pigs of any agricultural district in the province—75,570, according to the 2006 census. He acknowledged that manure from pig farms has seeped into ground water in some areas and made some well water undrinkable, but he defended farming practices. “I wouldn’t tie it [H1N1] to agricultural operations,” he said in a phone interview.

“If there were an issue, the public-health people would keep me informed.”¦There would be all sorts of bells and whistles going off.”

A top health official also dismissed the higher H1N1 rates in his region and said they’re not worthy of further investigation or action. “It just doesn’t matter. It spreads from person to person.”¦We’re not looking at it from that perspective,” said Dr. Roland Guasparini, chief medical health officer with the Fraser Health Authority.

In recent years, the B.C. government has encouraged hog producers to spread far north to the fertile Peace River region, where there’s more available farmland. The policy has helped turn Peace River into the fastest-growing hog-producing region in the entire country, with a threefold expansion in pig numbers between 2001 and 2006. The region is now home to 24,000 pigs, more than double the human population of Dawson Creek, the region’s administrative centre.

And it just so happens that the Northern Health Authority, which includes the Peace River area, has the highest ratio of pigs to people in the province—and the highest rate of confirmed H1N1 flu cases per capita.

Just across the nearby Alberta border, Denis Sauvageau has all kinds of experience with pig farms moving in next door. He is a fourth-generation farmer in a tiny community called Falher.

On April 28, Canada’s first death related to H1N1 occurred at the High Prairie Health Complex, a 50-minute drive east from Sauvageau’s house. The woman had had asthma-related difficulties, though there’s no evidence they were related to farming emissions.

Sauvageau still recalls vividly how hog producers first came to town in the late 1990s with a slick promotion campaign promising a miracle of rural revitalization. “They would create jobs, keep schools open, keep our children here,” he said.

Today, the smell from a complex of large pig farms five kilometres away is often so strong, Sauvageau can’t stay outside. “The stench is gut-wrenching. It makes you want to puke. You’re done for the night.”

Sauvageau and his neighbours started a protest group, the Peace River Environmental Society, six years ago to demand improvements in farm waste management practices. They held demonstrations. The group estimated that the 50,000 swine in nearby farms produce 20 million gallons of manure per year.

Especially worrisome, he said, are the health problems in nearby areas—high rates of asthma and other respiratory illnesses.

The group finally convinced a reluctant province to study air quality in the area. “Odours do extend into surrounding areas at levels that may disrupt quality of life,” a draft version of the province’s report said in 2007. “The subgroup agreed by consensus that odour from CFOs [confined feeding operations] can have health effects.”

(The report was never published because the committee writing it, dominated by government and industry officials, couldn’t reach agreement on the document; Sauvageau’s group posted the draft on its Web site.)

The report cited other studies that had found ammonia from farms can reach levels in the surrounding area that can cause eye and throat irritation, respiratory problems, haze, and fine-particle pollution. Farm emissions of hydrogen sulphide, an eye and respiratory-tract irritant and neurotoxin at high doses, can “cause significant quality-of-human-life concern at the local scale”, according to a 2003 U.S. National Research Council study cited in the report.

The Alberta report also cited international research that found pig-farm workers have rates of chronic bronchitis that are 2.5 to 5 times higher than those in the wider population and 50- to 100-percent higher than those in dairy and poultry workers.

The possible connection between intensive hog operations and H1N1 means governments should tighten rules on farm waste, according to the humane society’s Peter Fricker. “They’re like small cities, except with no sewer system. You could understand why there would be a risk to human health.”

The Pew Commission’s Bob Martin agreed: “We have reached the point that we have to decentralize this production. It’s really a critical kind of issue.”

With 22 new flu cases confirmed just on July 13 and 14—two-thirds in the Fraser—maybe we’ll be calling it “swine flu” again soon.

Comments (21) Add New Comment
Pat Gardiner
You are right. Using entirely different measures, I long ago came to the same conclusion.

The Alberta carpenter has now been cleared of giving the pigs swine flu and a new variety of swine flu has been found in pig workers in Saskatchewan. the pigs have had flu, but the link os not firmly established.

Here is my theory:



Mutated Circovirus in pigs, the consequences treated with heavy use of antibiotics, is followed by
MRSA in pigs and then MRSA and C.Diff epidemics in humans.

Poor health in the pig herds makes them vulnerable to Swine Flu (H1N1).
Humans may be infected and Swine Flu may mutate further in infected herds.


A circovirus mutation in Britain in 1999 was covered up. The resulting epidemics spread first around the UK, then to Canada and from there, most recently, to the United States.

(Thesis formulated over nine years, first published 2007. First published here (on my site) Feb 2009. Amplified to include H1N1 May2009)

Pat Gardiner
Release the results of testing British pigs for MRSA and C.Diff now!
www.go-self-sufficient.com and http://animal-epidemics.blogspot.com/
Rating: +7
Intensive pig farming is inevitable when we consume meat at the current level. The pollutants coming from these farms are detrimental to our planet and ourselves. If we all do out part by significantly reducing or cutting out our consumption of meat, intensive farms will have to disappear. Switching to organic is not the way to stop pollution, because it does not reduce the number of animals being raised.
Rating: +11
This is a good article. Until we start to take responsibility for the extreme environmental damage that farms do, things are just going to get worse.
Rating: +6
i raise organic pigs and they are very healthy. The problem is when you put to much of anything in one place against nature, you are going to have problems. Much farming nowadays is controlled by big business.

Go see Food Inc, that will explain everything and get ready for high prices soon. No more cheap oil, no more cheap food.

Time to relocalize. . . everything
Rating: +2
The problem with the whole "organic meat" notion is that there is no way in hell that there is enough land to "grow" animals "organically" for the amount of meat people currently consume. The only way that we can rid factory farms is to actually eat less meat. The only reason they're around is to keep up with the demand. Look at Cargil meat packers in High River, AB as an example. The kill floor goes 24 hours a day as long as there isn't a break down, and that's just one slaughter house...they go through thousands of animals in a day.

Rating: -4
We have a family farm with 850 pigs, sounds like a lot to most people, but the income from 850 pigs is not enough for a family to live on. We have a healthy herd, the animals are vaccinated to prevent some diseases just like we do with our pets and kids. We do keep them in a barn to protect them from diseases(to keep rodents and birds away from their feed because they can pass on some diseases). I'm proud of the work I'm doing, I know that my animals are raised with the least stress as possible, I love seeing the young pigs play with each other and see the older ones nicely sleeping together and only open up one eye when I enter the barn and keep on resting. A bad day is when I find a pig with an injury and I have to put it down, it is in the animals best interest but it doesn't make it easier. When they are around 250 lbs they go to slaughter, I do raise them to make some money.
I feel attacked by the outside world about my way of living, they call farms like mine a factory farm, what makes it a factory? The animals are kept in a barn and we started doing that for a reason; to protect the animals from the elements, to keep a better eye on their health and to try to make a living.
The manure which some people see as waste is being used to fertilize our field so we can grow a crop without having to buy fertilizer.
The particles in the barn itself, we call it dust, is less a problem than the dust that I breath in when a truck drives a gravel road.
When I read all the comments about the influenza outbreak and people just trying to blame this on the hog industry I shake my head, we would have more influenza outbreaks if we were still having backyard pigs, it is good for everybody's health, pigs and humans, that we are living separated.
Rating: +3
Tim from Richelieu
This story about the unprofitability of raising pigs organically is a myth. Have any of you looked at the price of organic pork chops compared to CAFO raised ones? In the province of Quebec we regularly see boneless industrial chops on special for $1.50 a pound while my organic ones from our co-op group are over $4.
And using the manure as fertilizer is fine if it is composted with the straw used in the buildings but is defininitely not good if it is liquid pig waste which has been stewing in a lagoon or reservoir and then spread over the fields just before a heavy rainful so it gets washed into the wells and waterways from which we get our drinking water like they do here!.
Rating: +4
Alex Barnaby
By law, all intensive pig farms must have a waste management program in place including collection and disposal of manure that meets local bylaws. The comment by the writer that says pig farms are like small cities without sewer system is false and the writer should investigate with the local authorities responsible for approving the construction or expansion of pigs farms to cooborate.
Rating: -1
Marisa Herrera
I call this connecting the dots. Obviously, government, industry and those who profit from and support factory farming will dismiss/ignore the facts.
It's to their benefit to propagate the idea that factory farming is good for the non-human animals, good for people, good for jobs, good for farming, etc.

Why does factory farming exist? Because people want to consume non-human animal flesh and their products, and people profit from this animal exploitation.

In a "civilized" society people should have an understanding that all living creatures deserve to be free from oppression, intolerance, exploitation and cruelty. It's time we evolve to a civilized and compassionate way of thought and action and protect nature and all her creatures.

Regretably, we live in a world where non-human animals are regarded as objects for our profit, exploitation and entertainment. The supremist and patriarchial doctrines still rule and are destroying the living systems that sustain ALL life and the amazing creatures who share Earth with us.

We abuse, oppress, torture, massacre, and obliterate these innocent creatures who have as much right to live a life of freedom as we do.
Rating: -1
The article provides no evidence of a link; the fact that B.C. has pig farms and H1N1 in numbers is not evidence; it is coincidental. Alberta has swine farms in numbers; shouldn't their numbers of H1N1 cases be up there too using your hypothesis? Crappy science. Great paranoia.
Rating: +1
Thanks for your thoughts, Eloise. Alberta's number of pigs per capita is much closer to the Canadian average that, say, Manitoba's.

Alberta has a 25-percent higher number of pigs per capita than the national average - and a 20-percent higher number of confirmed H1N1 cases per capita.

Especially striking in Alberta's case is the data on more recent flu cases. In the week after July 3, Alberta had a 93-percent higher number of H1N1 cases per capita than the Canadian average.
Rating: -3
The solution is quite simple: Areas with more pigs have more cases of swine flu, so to stop swine flu we need less pigs. How do we achieve that? By eating less meat. As the demand for meat drops, the farms will breed fewer pigs and the number of swine flu cases will reduce to a point where it disappears.
Rating: +4
I am shocked that the editors of the Georgia Straight allowed this article to be printed. It is a shameful example of *Bad Science Journalism*. In fact, this story could be held up as an example in a science journalism class to teach writers how NOT to write about science. The author Alex Rosin is using jargon from the scientific world to make it sound as though there is some scientific evidence for his claims when in fact there is none. He uses a classic fallacy of coincidence as a ruse for correlation. In fact no correlation exists. I am a professional science writer and this kind of reporting brings down the quality of our craft. With the same bogus technique Rosin could just as well have compared variations in the incidence of bubble gum chewing and found correlations with H1N1 flu. The ideas in this article have no basis in reality and the piece should never have been printed. Shame on you Georgia Straight editors for allowing this junk science in your newspaper.
Rating: -9
Hi Baz,

Thanks for your feedback. You might have had a point if there was just a single, possibly coincidental high correlation in all the data. But the very high correlations I wrote about are:

(1) Present across B.C.'s five health regions and across the 10 provinces. Finding the same high correlations in these two different groups of data vastly reduces the risk of this being a mere coincidence.

(2) All statistically significant - and that at very high levels. The inter-provincial correlations have less than 0.6-percent chance of being attributable to chance, and some have less than 0.01-percent chance.

(3) Present in numerous differing sets of data for H1N1 cases (i.e. confirmed cases, hospitalization rates, death rates) and hog farming (number of pigs, number of pig farms, ratio of pigs to farm, per-capita number of pigs in various regions and provinces). This further reduces the chance of a coincidence.

(4) Not present in other types of farming used for control purposes - i.e. poultry and cattle.

(5) Made plausible by the explanations given by various experts cited in the story - including B.C.'s top epidemiological official - who said the correlations could be linked to respiratory ailments that are well known factors in both H1N1 and hog farming. (Unlike chewing gum.)

If you can correlate H1N1 to some other thing at such high levels, with so many differing sets of data and with similarly plausible explanations for the link - chewing gum included - please share. I eagerly await.

Rating: +1
You may be be a great writer Alex, but in this case you are totally wrong. I'll address your points one by one.

1. You are not comparing the same things. In one sentence you compare total number of pigs per area to number of cases of flu. In the next sentence you compare number of pigs per capita to number of cases. You find your so-called "correlations" where they are convenient, but you keep changing the rules. This is not allowed in a proper scientific report.

2. You use terms like "statistically significant" but you are not using true statistical analysis in your article. You are just taking percentages and averages. That's not statistics. Statistics requires true random samples and also must have controls. You have not done this properly.

3. This is my point. Either you have to stick to comparing one thing to one thing, or don't compare anything. You can't pick and choose. This is not allowed in science.

4. That is not what you call a control. Making a fallacious correlation of other data, does not support your initial fallacy.

5. The expert in your story, David Patrick, was published in this week's Georgia Straight saying essentially what I said in my initial comment above. i.e. that you are misrepresenting the facts. He states: "There is abundant evidence that swine are not contributing in any important way to the ongoing pandemic spread." This is from the expert and this should be the main message in your article. Instead you ignore the expert. That's bad science reporting.

From http://www.nobeliefs.com/fallacies.htm you have committed the following fallacies in this piece:
1. confusion of correlation and causation: (e.g., More men play chess than women, therefore, men make better chess players than women. Or: Children who watch violence on TV tend to act violently when they grow up.) But does television programming cause violence or do violence oriented children prefer to watch violent programs? Perhaps an entirely different reason creates violence not related to television at all. Stephen Jay Gould called the invalid assumption that correlation implies cause as "probably among the two or three most serious and common errors of human reasoning" (The Mismeasure of Man).

2. misunderstanding the nature of statistics: (e.g., the majority of people in the United States die in hospitals, therefore, stay out of them.) "Statistics show that of those who contract the habit of eating, very few survive." -- Wallace Irwin

3. observational selection (similar to confirmation bias): pointing out favorable circumstances while ignoring the unfavorable. Anyone who goes to Las Vegas gambling casinos will see people winning at the tables and slots. The casino managers make sure to install bells and whistles to announce the victors, while the losers never get mentioned. This may lead one to conclude that the chances of winning appear good while in actually just the reverse holds true.

4. post hoc, ergo propter hoc: Latin for "It happened after, so it was caused by." Similar to a non sequitur, but time dependent. (e.g. She got sick after she visited China, so something in China caused her sickness.) Perhaps her sickness derived from something entirely independent from China.

5. red herring: when the arguer diverts the attention by changing the subject.

And in fact a few others.

Alex: please apologize to your readers for corrupting science by employing these classic fallacies to promote ideas that are simply wild guesses and not true at all, according to the BC Centre For Disease Control epidemiologist David Patrick.
Rating: +4
Peter Michael
1 Hog + 1 Human = A Problem - Solution:
Multiple, Activated Charcoal Pre-Filter...
Testing for Zero Chlorine

What happens when you add municipal chlorinated water to nitrogen from hog farm manure leaching into ground water...

Chlorine + Nitrogen =http://commons.wikimedia.org/wiki/Category:Nitrogen-chlorine_compounds


add table salt = colon cancer: http://www.ncbi.nlm.nih.gov/pubmed/19389412

same effect as tear gas = asthma connection http://en.wikipedia.org/wiki/Pool_chlorine_hypothesis

De-Natures Blood...
Rating: +3
Hi again Baz,

I didn’t have room in the story to list all the statistically significant correlations between the H1N1-related data and pig data. There were far too many, and they exist across the board—both across the regions in B.C. and across all 10 Canadian provinces. And they were present in a wide variety of datasets: the number of pigs in those areas, the number of pig farms and the ratio of pigs per farm; and the number of H1N1 cases, number of H1N1 hospitalizations and number of H1N1-related deaths. I reported only a few of the more notable ones in the story.

The fact that so many statistically significant correlations exist in these various types of datasets reduces the likelihood it’s all just a big fluke. Now, in your latest comment, you seem to be saying that including these various types of datasets actually shows I am “not comparing the same things.” You can’t have it both ways.

You also suggest the story confused correlation with causation. In fact, the story never said pigs directly caused all these H1N1 cases. You are misinterpreting the story. It did cite various experts—including Dr. David Patrick of the B.C. Centre for Disease Control—who gave a reasonable explanation for the many statistically significant correlations—the undisputed fact that pig farms tend to reduce air quality, the also-undisputed fact that reduced air quality is linked with respiratory ailments and the also-undisputed fact that respiratory ailments make one more vulnerable to H1N1, especially to more severe complications.

Finally, regarding Dr. David Patrick, you are misquoting his letter. He did not say I was “misrepresenting the facts.” And you will note that he does not deny the quote I attributed to him—specifically, that fine-particle pollution (which is caused by pig farms) contributes to asthma, which in turn makes people more vulnerable to H1N1.

Yes, virtually all transmission of H1N1 has been person-to-person. That’s pretty clear. But what’s also clear is that areas with more hog farming have higher rates of H1N1 cases, more hospitalizations and more deaths.

Rating: +3
This is a good article. I am a lifelong vegetarian and animal rights advocate. Unless we start to link modern farming practises to international health panics we may never convince people to adopt a healthier, kinder system of food production. The jury may still be out when it comes to identifying the causes and sources of H1N1, but until we know for sure, a little bit of journalistic alarmism could do everyone the world of good. Thank you.
Rating: 0
Now I read the comments, it is kind of weird how the writer won't acknowledge the errors in his reasoning pointed out above and in the letters page this week. I guess he really does think that correlation equals causation. Whatever. As long as the message to eat less meat is out there, that's the important thing.
Rating: +6
I like my pork
I don't like CAFO's and I especially dislike large hog feed operations but the science writer BAZ is right. This is poor journalism. We live in SIoux County, Iowa with a human population of about 36,000 and a hog population of more than 1,000,000. The rate of H1N1 is not higher here than other parts of the country per capita.
Rating: +1


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