Legionella is in the water supply of our hospital?

We have documented colonization with Legionella in the hospital water supply of our small hospital. We have not observed cases of Legionnaires’ disease at this time (but underdiagnosis is probable), and after a successful trial of superheat and flush, colonization recurred. It is technically impossible to resume that disinfection method (old distribution system). Thus, we cannot disinfect the water supply and we cannot shut down the hospital. Is it reasonable to withhold drinking water from our patients and to institute systematic laboratory testing for all patients with hospital acquired pneumonia in an attempt to treat with anti-Legionella antibiotics with minimal delay?

Yes, your approach is very reasonable. We would not recommend disinfection of your water supply since your patients are not high risk. We would recommend that your clinical microbiology lab adopt the urinary antigen test if the Legionella in your water supply is serogroup 1. Physicians should order it for patients who have contracted hospital-acquired pneumonia.

If your patients contract hospital-acquired pneumonia of uncertain etiology, we recommend adding a quinolone (e.g., levofloxacin) as part of empiric therapy.

Please download the Allegheny County Guidelines on the Guidelines page. These guidelines, which are simple and cost-effective, will protect your patients from Legionnaires’ disease. Your suggested approach is in concordance with the guidelines. Knowledge of colonization can eliminate mortality without tremendous expense by adopting laboratory testing and using effective antibiotics.