Guest essay by Eric Worrall
Remember back when Legionnaires’ Disease outbreaks were believed to be mostly associated with poorly maintained, unhygienic building air conditioners? According to Dr David Fisman of the Dalla Lana School of Public Health, the real culprit might be climate change.
As reported cases of Legionnaires’ disease climb in the United States — there have been three major outbreaks in the news this summer — researchers say the increase could be partly a result of climate change.
More than three times as many cases of legionellosis, of which Legionnaires’ disease is one form, were reported in 2009 than 2000 — 3,522 up from 1,110, according to a 2011 report from the Centers for Disease Control and Prevention.
This year the disease has broken out at a western Illinois veterans home, at San Quentin State Prison near San Francisco and in New York City, which has seen a similar rise in the disease. Its incidence of cases increased 230 percent from 2002 to 2009, with the greatest number in high-poverty neighborhoods, according to an October study in the CDC journal Emerging Infectious Diseases.
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Dr. David N. Fisman, a professor at the Dalla Lana School of Public Health at the University of Toronto, said in an email that he doubted the increase was the result solely of improved testing. The rise is linear and across all regions of the United States, he said.
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“Give that we know climate change is going to make for hotter, stormier summers (and already is doing so) it doesn’t seem like a huge leap to suggest that the ongoing rise in legionellosis in the US could be at least partly due to climate change,” he wrote.
Obviously Dr Fisman is not insisting that climate change is the sole contributing factor to Legionella outbreaks. But given that there has been no change in global temperature for over 18 years, in my opinion it is implausible that anthropogenic global warming could be contributing significantly to the dramatic rise in the detection of Legionella cases since 2002.
I would suggest it is more prudent to launch an informational drive to educate those who operate the systems at risk, just like the one which followed the original outbreak of legionella, than to throw up ones hands and say “must be climate change”.
There is a new generation of people in the field now, and in order to cut costs, less people are maintaining more systems than ever, with less qualifications and licensing than the previous workers, who had to be paid more. This in itself is capable of explaining the increases.
There is nothing happening here that education and proactive maintenance cannot cure.
Because correlation (rise in the disease correlated to my perception about average temperature un the U.S., despite the fact actual data does not support my perception) implies causation.
A dear friend of mine (yes, I actually do have some and they are actually humanoids) retired last year. Since I quasi-retired some time ago neither of us now have anything to do. Years ago, whilst working, we’d meet at bars after work. Now, due to restricted retirement income, and bodies that have matured (although to have matured is a polite way to describe decrepitude) we meet in the morning for coffee.
A few days ago I texted him: ‘Coffee 8:00?’ He returned the text stating he wasn’t feeling well. (See, I’m finally weaving this story into a post on disease.) Anyway, he texts me the following morning asking about meeting me for coffee.
So, I meet him. He clearly looks under the weather. (See, climate is now being woven in.) He told me he had to get out of the house. You see, his 90 year mother in law lives with them. Now, this is where it gets interesting.
First, I have to say that I’m 61 years old. That means that people who actually admit to being friends with me tend to be the same age. And, this particular friend of mine is also 61 years old.
So, he’s 61 years old, he’s sick, his 90 year old mother in law lives with them, and he’s met me because he has to get out of the house. Why?
His mother in law wants to take his temperature.
Needless to say, he won’t let her. Pride is a powerful thing. But, she’s persistent. She negotiates; “Well, just let me feel your forehead.”
“No.”
Now, I’m a nice guy. But, I’m really toying with the idea of going over there and suggesting to his mother in law (who I know and get along with) that the only way to get a true reading (whether I’m right on this or not) of body temperature is rectally.
Yes, it’s taking incredible willpower not to promote the ultimate joke of all time: encouraging a mother in law to take a rectal temperature sample from her sick 61 year old son in law.
But, I won’t do it. You see, that’s what separates me from Dr. Fisman. Let’s look at it this way. My friend has helped me out many times in the past. He’s paid for things and lent me money. Consider him to be representative of the good citizen and a taxpayer. Consider his mother in law as the government (that should not be hard to do). Now, consider me as the good doctor; ready to take that mother in law and have her stick it up the taxpayer’s …
I love pictures taken with electron microscopes. You can describe anything you like, and nobody will ever know the difference. Consider the picture above, and alternate captions.
Radial dendritic growth in cyanobacteria. the dendrite formation is clearly visible.
The rapid production of chloroplasts in a typical C4 plant under intense lighting conditions.
The smooth surface of slaked lime after heat treatment. This hard, smooth surface is responsible for the reduced kinetics of slaked lime vs. quicklime.
How do you know what you are really looking at?
Global Warming has ruined my mind forever.
Hasn’t the temperature in the contiguous US actually declined slightly in recent years?
Off topic, but I have just seen on the BBC News website that the UK spends £11bn p.a. on overseas aid. Incredibly, it says ‘Globally, on schemes aimed at immunising children, providing girls and women with better education and preventing climate change in developing countries’.
Mustn’t forget the Bogeyman.
The good Dr Fisman could just be suffering from a bad case of Climatosis, or perhaps Jumpingtoconclusions Disease, which are seemingly rampant among those in the Climate Industry. He might want to get that checked out.
The title of the epidemiological study Fisman references is “It’s Not the Heat, It’s the Humidity: Wet Weather Increases Legionellosis Risk in the Greater Philadelphia Metropolitan Area” it can be found at
http://jid.oxfordjournals.org/content/192/12/2066.full
Not a promising title if one wants to link it to warming alone. The biological literature is mixed on the link between legionella infection and temperature. Fields at al. summarize “L. pneumophila multiplies at temperatures between 25 and 42°C, with an optimal growth temperature of 35°C. Most cases of legionellosis can be traced to human-made aquatic environments where the water temperature is higher than ambient temperature.” (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC118082/)
But it is not that simple. Early studies on growth rate of legionella found at Ratkowsky et. al. http://jb.asm.org/content/149/1/1.full.pdf indicating a general behavior of growth rate for bacteria of sqrt ( r ) = b(T-T0) where r is the exponential growth rate in time, b is a constant and T is temperature.
But growth rate is not the whole story. Edelstein et. al. found that legionella virulence is decreased by higher growth temperatures (they compared 25C and 41C) at http://iai.asm.org/content/55/11/2701.full.pdf .
As usual with microbiology, the reality is somewhat more complicated than first glance. The huge leap comment may have been a Freudian slip.
So because I’m a retired veteran, I’m a carrier of this disease, and should be sequestered? 🙂
No, sequestered because you are a veteran and the US Gov’t has decreed that veterans pose a risk of becoming domestic terrorists against the government. Dept. of Homeland Security has thus classified you and me et al, as being likely to team up with Right Wing terrorist groups.
Don’t know how they could come to that conclusion.
Get your kicks on Route .30-06
You see. Legionnaires increases even with a very small temperature increase, so think what would happen when the temperature increases as predicted. !!
Climate change causes poor maintenance. Wait . . . what?
When are some “scientists” going to release a study showing that deaths from freezing and cases of frostbite are decreasing because of global warming?
Wrong Louis. Global warming causes more cold weather. That’s why it’s now called climate change, so we can blame CO2 emissions when (or if) the climate starts to cool. Yes, believe it or not, making the earth warmer will make it colder. Hard to believe unless you’ve studied climate science where things are not what they seem.
I’m a guessin’ they aint nuffin bad in the whole univeworst what aint made worser by climate change.
Given the fact that temperatures have actually been falling in the continental US in recent years, it’s quite a stretch to claim that global warming has anything to do with the increase in legionnaires disease. Unless you want to include the fact that the costs associated with climate taxes and regulations have left businesses with less money to properly maintain their AC systems.
I hear Yeti sightings are up. It would not be a huge leap to suggest it’s due in part to climate change.
a professor at the Dalla Lana School of Public Health at the University of Toronto,
Can someone tell what the qualifications are to become a professor, are there any?
Yes. All you need to do is profess that you know something.
Legionairs disease can also exist in hot water systems. People who have solar heaters often do not switch on the geyser element to save money and use the hot water when it is warm – not hot. Water below 55 degrees celsius can be a breeding ground for legionairs. Perhaps the proliferation of solar water heaters is playing a part? Thermostats on geysers should be set at just above 55 degrees centigrade to ensure the bacteria are killed.
Reminds me of another Eco-friendly good intentions-bad results project. A community in New England decided they were going to use recycled materials when building a 10 mile long beautiful bike path. They used asphalt made from recycled glass.
Wonderful until after a year or so of wear the glass in the asphalt was damaging bicycle tires. Wasn’t too good for skinned knees either. They had to dig up the bike path and repaved with traditional asphalt. To add insult to injury traditional asphalt would have been cheaper than the recycled stuff.
My experience of this matter, is it could just be that the incidence is increasing because building service engineers have taken their eye off the ball!
Just before I retired I pointed out to my professional colleagues, that a new engineering fashion for “energy efficient” evaporative water cooling, of various types, would require high standards of engineering design and a rigid expensive maintenance regime to ensure safety. There appeared to be a standards gap, these new systems were not listed or detailed in existing Safety Guidance, I suggested the Guidance should be updated to include these new designs.
To my knowledge no such updating has taken place.
personally, i blame #JadeHelm & George Bush, not climate change.
I am still waiting for the paper to be published that claims that climate change increases the risk of heat rash.
What the heck, let’s just call it what it is:
Given there’s been no change in global temperature for over 18 years, Dalla Lana School of Public Health at the University of Toronto’s Dr Fisman is living proof that lack of anthropogenic global warming (or any other kind) has turned a significant portion of the world’s academics into stupid blithering fools who cravenly prostitute their “academic research” for “climate change” dollars (euros, rupies, whatever).
I’ve been watching this con game for almost 10 years and am amazed it’s still profitable.
I predicted this was coming when I saw LD in the news. Well, you can’t really call such things predictions anymore, since now *everything* bad is always linked to Climate Change.
The only thing “Climate Change “might” have caused is delusional paranoia where almost every observed event is caused by Climate Change. A variation on must be “Satans work”.
Or more likely laziness. Why work harder to figure out what is causing an observed behavior or event when you can just claim Climate Change and collect a bigger check .
I’ve done original research on the pathogen Legionella pneumophila and its environmental transmission with a major US medical school, allow me to provide a bit more information:
a) When the first widely recognized outbreak of Legionnaire’s Disease occurred in 1976, public health scientists were baffled and presumed that this was a new, previously unseen organism.
b) It was, in fact, an old pathogen that had infected and killed many people throughout history, but was not recognized as the cause of death. L. pneumophila is notoriously difficult to culture, and was proven to grow only on a very selective growth medium (“charcoal + yeast extract agar”).
c) Once it became possible to culture the bacterium, we found that many frozen tissue samples from patients who had died from “pneumonia, cause not specified” had, in fact, died of Legionnaire’s Disease. It is a rather common cause of pneumonia in the community, and the organism can be cultured from fountains, shower heads, ponds, wastewater treatment plants etc.
That being said, it is not being spread by household air conditioners, but by large, roof-top cooling towers that generate substantial aerosols. Owners of cooling towers are supposed to maintain them and add antimicrobial chemicals to prevent these types of outbreaks, but we had a breakdown of the regulatory system in NYC. Also, the susceptible population probably had many risk factors including poor health, older age etc.
Here’s a rather tragic story about a case that occurred in Chicago due to a decorative lobby fountain in a hotel: http://articles.chicagotribune.com/2012-08-31/news/chi-3rd-death-tied-to-chicago-legionnaires-outbreak-20120831_1_legionella-3rd-death-disease
IF the climate is growing warmer, then increased transmission of Legionella pneumophila is possible since water temperatures would increase, more cooling towers would be needed, etc. It all depends upon the big “if.”
CRS, DrPH
So, Legionaries Disease is a “real phenomena” breeding in the wet, kept-warm waters of roof top AC units, but it does not get transmitted by being blown through the interior cooled air ducts, but by being blown/uplifted from the outside water in and under the cooling fins of the next building over. Right?
Correct, the environmental transmission of Legionnaire’s Disease (two “n”s) is a real phenomena, and the cooling tower trade has long recognized this. Companies such as Ecolab/Nalco sell antibacterial treatment chemicals and monitoring equipment/test kits so that owners can reduce this threat. However, if there are no real regulations, then these type of outbreaks occur.
It get transmitted in the water aerosol, period. Wherever the aerosol goes, the bacteria also go. Very fine mist or even dried bacterial gels become “bioaerosols,” much hated in hospitals due to risk to immune compromised patients.
What happened in NYC is that a “perfect storm” developed. Weather was warm enough to spur the growth of L. pneumophila, commercial HVAC units were pushed, and there was probably a weather inversion that trapped the aerosol close to the ground. A + B + C, and throw in a generally unhealthy population (older, smoking etc.) and this stuff happens. Epidemiology 101.
For what it is worth, the CDC believes that the climate is changing (growing warmer) and this will have deleterious health effects. http://www.cdc.gov/climateandhealth/brace.htm
CRS, DrPH , thanks for your informative posts here. You say,
“It was, in fact, an old pathogen that had infected and killed many people throughout history”,
Obviously, there are other potential reservoirs of L. pneumophila, as you note. Wikipedia sez this bacterium maintains symbiotic relationship with aquatic amoebae. I gather that any airborne mist or aerosol is a potentially dangerous when arising from reservoirs where water temperatures are in the range 25- 42 ° C (77 and 117 °F.)
I’m wondering now if there is any relationship between L. pneumophilia, amoebae in symbiotic relationship with same, and pigeon droppings. Can you comment?