Thread by @j_g_allen

"Mysterious outbreak in Argentina solved"

Newly interested in #Legionella? Here's an excerpt from my book, #HealthyBuildings (in the opening chapter, after my FBI story...)

And...good time to mention...new edition comes out October 18. First look at the new cover!

1/n

It was during one of my first forensic investigations of a “sick building” that I first saw the power and potential of this burgeoning Healthy Buildings movement. This was no ordinary case of sick building syndrome...

It wasn’t a stuffy cubicle farm where people sometimes report symptoms like headaches, eye irritation, dizziness, or allergic reactions. I don’t mean to diminish those types of sick buildings in any way, but this was a hospital and the lives of four people were in jeopardy.

It was Grady Hospital in Atlanta in 2009. Four patients on the same two floors had developed Legionnaires’ disease within the same month: a classic disease outbreak scenario.

Before we go any further with how the Grady Hospital outbreak unfolded, let me give you some quick background on Legionnaires’ disease, a disease that to this day continues to impact many thousands of Americans every year, in and around buildings.

Legionnaires’ disease is pretty common—7,500 cases are reported each year, but this is a gross underestimate of the actual number of cases. Legionnaires’ disease is underdiagnosed and underreported. It’s also a deadly disease—1 in 10 people who get it die.

Legionnaires’ disease was first “discovered” after the infamous outbreak at the convention of the American Legion at the Bellevue-Stratford Hotel in 1976.

Over the course of a few days, 2,000 people became sick with a severe, life-threatening type of pneumonia. 29 of those people died. The scariest part? No one knew the cause. The other 10,000 people who attended the convention were, rightfully, in a panic about their own health.

This was front-page-of-Newsweek-type stuff. (In the age before the rise of internet news, making
the cover of Newsweek was a big deal.)

The disease was dubbed “Legionnaires’ disease” because of the location of this outbreak—at the American Legion meeting, where members call themselves Legionnaires.

After several months of investigation, the US CDC identified the cause of the outbreak: a bacterium in the building air-conditioning system that they named—you guessed it—Legionella.

Legionella are naturally occurring waterborne bacteria that can cause a pneumonia-like illness. Out in the natural world, where they are everywhere, their numbers stay small. But given an environment where water stagnates and where temperatures stay lukewarm, they proliferate.

That makes a few places in a building a nice home for Legionella.They like to live, and grow, inside the biofilm in water pipes, inside cooling towers on the roof of a building, or, in the case of the infamous American Legion outbreak, in the condensate drains of air conditioners

Within a building (a hospital, for example), Legionella are also commonly found in “dead legs” of a building’s plumbing system. Dead legs are sections of the plumbing system areas where an old line was cut off, say, during a renovation in which a water fountain was removed.

Sometimes, for reasons of efficiency, cost, laziness, or shortsightedness, rather than cutting the water line all the way back to its joint in the plumbing system, the building owner just caps the pipe where the fountain used to be and patches up the wall.

Thus, a dead leg is created.

The dead leg of the system is that extension of pipe that is no longer part of the normal circulating water flow, so the water stagnates and stays luke-warm. These are the perfect conditions for Legionella to grow.

And importantly, they grow in an area where they can’t be easily “attacked” by residual disinfectant in the building’s water supply (traditionally chlorine), and therefore they act as a source that continually feeds bacteria into the main line of the water system.

But simply having Legionella in water doesn’t mean you’ll get sick from it. The way we can get Legionnaires’ disease is by breathing in the bacteria.

So the mere presence of Legionella in a building doesn’t mean there’s a problem; the bacteria must also be aerosolized, or released into the air in tiny droplets.

In the case of the American Legion outbreak, the bacteria were aerosolized and distributed around the convention through the air-conditioning system.

Since that time, we have done a much better job of controlling Legionella in our cooling systems.

(For the most part, anyway...

Outbreaks still frequently occur, like the outbreak in Disneyland in 2017 that impacted 22 people, or the outbreak in Portugal in 2014 that sickened 336 and killed 10.)

And in most commercial buildings, there really aren’t many opportunities indoors to aerosolize the water in any meaningful way, other than through spray from the sink or postflush spray from the
toilet. (Yes, you read that right.)

Hospitals, on the other hand, have a lot of opportunities for aerosolizing water that other types of buildings don’t always have—showers. (Hotels fall into this category, too, and there have been many high-profile outbreaks in hotels.)

Now that you’re armed with the basics of Legionella, let’s go back to Grady Hospital in Atlanta."

[Want to know what happened next?? #HealthyBuildings👇]

amazon.com/dp/0674278364/…