https://www.cdc.gov/healthywater/pdf/swimming/resources/legionella-factsheet.pdf
- How is Legionella spread in hot tubs?
Legionella is naturally found in water, especially warm water. Hot tubs (or spas) that are not cleaned and disinfected enough can become contaminated with
Legionella. A person
can get infected with Legionella when they breathe in steam or mist from a contaminated hot tub.
Legionella can also be found in cooling towers, plumbing systems, and decorative pools or fountains.
Legionella is not spread from one person to another.
- Four Questions to ask Your Hot Tub Operator
- What was the most recent health inspection score for the hot tub?
- Are disinfectant and pH levels checked at least twice per day?
- Are disinfectant and pH levels checked more often when the hot tub is being used by a lot of people?
- Are the following maintenance activities performed regularly:
- » Removal of the slime or biofilm layer by scrubbing and cleaning?
- » Replacement of the hot tub water filter according to manufacturer’s recommendations?
- » Replacement of hot tub water?
The Most Recent Legionnaires' Disease Outbreaks | HC Info
The above link shows a list of
Legionella incidents so you can search for the ones for spas.
http://www.floridahealth.gov/diseas...se/_documents/gsi-legionella-update-final.pdf
The above talks about the bacteria being in amoeba and biofilm.
The following are papers on
Legionella in biofilms:
Biofilms: The Stronghold of Legionella pneumophila
There is now evidence that some legionellosis outbreaks are correlated with the presence of biofilms.
Factors Mediating Environmental Biofilm Formation by Legionella pneumophila
L. pneumophila is able to survive and persist within multi-species biofilms that cover surfaces within water systems. Biofilm formation by
L. pneumophila is advantageous for the pathogen as it leads to persistence, spread, resistance to treatments and an increase in virulence of this bacterium. Furthermore, Legionellosis outbreaks have been associated with the presence of
L. pneumophilain biofilms, even after the extensive chemical and physical treatments. In the microbial consortium-containing
L. pneumophila among other organisms, several factors either positively or negatively regulate the presence and persistence of
L. pneumophila in this bacterial community. Biofilm-forming
L. pneumophila is of a major importance to public health and have impact on the medical and industrial sectors. Indeed, prevention and removal protocols of
L. pneumophila as well as diagnosis and hospitalization of patients infected with this bacteria cost governments billions of dollars.