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Legionnaire's Disease in NYC

Posted: Tue Aug 11, 2015 10:00 pm
by duodecima
So, no panicking allowed, this is not the beginning of the apocalypse, but as a current event that has killed 12 people in a major city and made 100+ people sick, it's on par with other current events in DICE. (Mods may of course move as they see fit.)

But, since there have indeed been 113 cases with 12 deaths (as of yesterday, according to the NYC Dept of Health http://www.nyc.gov/html/doh/html/diseases/cdlegi.shtml) in the Bronx since 7/10, and since there's just been a case diagnosed at Riker's which appears to have been caught while there so I'm guessing the public health folks in NYC are holding their breath (hah) hoping there aren't any more at Riker's, sporadic cases are actually more common than outbreaks, it seemed reasonable to review what Legionnaire's is.

Legionnaire's disease is an "atypical pneumonia" caused by a bacteria named Legionella pneumophila, so named because it was first identified as the cause of an outbreak after an American Legion convention in 1976. Once identified, it was determined that it had, in fact, caused previous outbreaks for which a cause had not been identified. (As with many things, not a new bug, just newly identified.) http://www.washingtonpost.com/news/morn ... ur-in-n-y/

It is spread by inhaling mist droplets from a contaminated water source. It is, critically NOT SPREAD PERSON-TO-PERSON. In the case of the Bronx outbreak, several cooling towers (which disperse heat from AC units by evaporative cooling, hence the mist) in the Bronx. http://www.nytimes.com/2015/08/05/nyreg ... break.html It is pretty much never fatal except in people with other medical problems (which has been the case in this outbreak as well, all 12 had other medical issues). Other sources include other causes of water mist, especially warm - hot tubs, fountains, respiratory equipment in hospitals, hot water heaters, other large plumbing systems. (http://www.cdc.gov/legionella/about/cau ... ssion.html) Given the outside temps, water-based recreation, and increased use of AC, outbreaks are more common in summer. Cruise ships have also had outbreaks.

Importantly you don't catch this by drinking the water, even from a contaminated source. However, IF a plumbing system was contaminated, showers are an issue. I read that people in the Bronx were drinking bottled water - this is utterly not needed - the water supply there isn't the source, and even if it were, just using the water for showers (and possibly pressurized toilet flushes) would be the big issues. It's actually not clear exactly how the contaminated systems get that way. There are tiny amounts of Legionella in natural freshwater sometimes, just no where near enough to cause disease. Also, individual home AC units and window units are NOT an issue.

Individuals at risk for more serious disease include >50yo, smokers, chronic lung disease, immunosuppressed, those with cancer, diabetes, and kidney failure. Symptoms start 2-14 days after exposure (most cases present by day 10), causing fever, cough and pneumonia (sometimes GI symptoms or confusion also). It is treated by the same antibiotics as the other atypical pneumonias (macrolides, quinolones, tetracyclines, aka azithromycin, levoquin (but NOT cipro, guys) and doxycycline.) http://www.cdc.gov/legionella/clinicians.html

There's a form of Legionella disease called Pontiac Fever, miserable but milder, which causes fever and illness without pneumonia, happens between 2-3 days after exposure, and simply does not kill. That one you just ride out and get better in about a week, no antibiotics needed. http://www.cdc.gov/legionella/clinicians.html

Fun links I found while reviewing all this - directions for cleaning your hot tub if it tested + for Legionella! Note, this is not going to be a normal cleaning procedure for your home tub!!! Just scrub it so it's not slimy (this matters) and keep it properly chlorinated! http://www.cdc.gov/legionella/downloads ... ection.pdf There's a guideline for preventing/minimizing the risk of Legionella in building water systems, but they want $ for that. (Tho, might be good investement for one's building maintenance staff, if one owns a building with such a system.) The CDC Vessel Sanitation program manuals which include are on the CDC website tho they're quite technical.

Things that struck me as interesting about this -

-People switching to bottled water, which was completley unneccessary.
-sand filters used with hot tubs had been associated with outbreaks (for those of us with an interest in sand filters tho I wouldn't worry about filtering cold water...)
-No particular PPE precautions for cleaning a legionella-contaminated hot tub, tho they said you could use an N-95 if you wanted to be super paranoid.

Anyway, hope that's interesting for you all.

Re: Legionnaire's Disease in NYC

Posted: Mon Aug 24, 2015 6:24 am
by Valarius
>No particular PPE precautions for cleaning a legionella-contaminated hot tub, tho they said you could use an N-95 (face mask) if you wanted to be super paranoid.

Oh, yes I would. And goggles and gloves. Having Personal Protective Equipment never hurt anyone yet. Thanks for posting this, I hadn't heard anything about it.