Should you do Routine Legionella Testing?
CDC does not recommend legionella testing unless there are 2 or more legionellosis cases associated with a specific time and place. ASHRAE also avoids routine testing in their standard 188 (only mentioned in a normative appendix. The CDC policy of no routine environmental testing may not be appropriate.
Many building managers do routine testing of cooling towers and water-containing mechanical equipment. They send water samples to labs that use either a monoclonal antibody modified CDC direct fluorescent antibody (DFA) method or culture. Some labs that use the culture method join the voluntary program directed toward health care facilities sponsored by The Wisconsin State Laboratory of Hygiene (Elite).
Some Elite labs incorrectly report high numbers of legionella to their clients, resulting in costly emergency decontamination procedures that aren't needed.
A recent report from a Veterans Affairs Medical Center found spurious legionella environmental test results from Elite labs.
The scientific community needs to be more involved in outcome research of what happens in the real world when building managers follow guidelines that recommend no routine legionella testing. Without legionella testing, they have no way to determine whether their legionella control procedures are working.