The National Academies of Sciences, Engineering, and Medicine released a new report August 14 titled Management of Legionella in Water Systems. The report reviews Legionella occurrence in water systems and provides recommendations for managing the growth of the bacterium within water distribution systems in order to reduce the incidence of Legionnaires’ disease.
The Water Science and Technology Board of the National Academies convened a committee of 13 experts to address this issue. According to the report, the committee held six meetings where they heard from experts involved in “characterizing, monitoring, and remediating Legionella as well as from those knowledgeable about Legionella control policies from Australia, Canada, and Europe.”
A four-page summary states that Legionnaire’s disease is highly underreported at a factor of up to eight- to ten-fold and estimates the number of individuals with Legionnaires’ disease in the United States ranges from 52,000 to 70,000 each year (a rate of 20.5 to 27.4/100,000).
The report includes a number of recommendations, such as:
- Register and monitor cooling towers (to allow for rapid public health response including timely remediation of possible sources of infection).
- Require water management plans in all public buildings such as hotels, businesses, schools, apartments, and government buildings.
- Require a temperature of 60°C for hot-water heaters and 55°C for distal points.
- Require a minimum disinfectant residual throughout public water systems and concomitant monitoring for Legionella.