Legionella pneumophila serogroup 1 in a birthing pool.

This report describes a risk assessment and subsequent actions following isolation of Legionella pneumophila serogroup 1 in the water supply to a birthing pool during a planned maintenance programme. A literature search for cases of neonatal legionellosis identified 24 reports of cases among babies aged <2 months, two of which were associated with water births. On this basis, the pool was closed until Legionella spp. were undetectable. Control proved difficult as hyperchlorination failed, and a filter fitted to the thermostatic mixer tap supplying the pool slowed filling so much that additional taps were required to achieve a satisfactory flow rate.