The Contribution of Legionella anisa to Legionella Contamination of Water in the Built Environment
Year: 2024
Type: article
Abstract: Legionella bacteria can proliferate in poorly maintained water systems, posing risks to users. All Legionella species are potentially pathogenic but Legionella pneumophila (L. pneumophila) is usually the primary focus of testing. However, Legionella anisa (L. anisa) also colonises water distribution systems, is frequently found with L. pneumophila and could be a good indicator for increased risk of nosocomial infection. Anonymized data from three commercial Legionella testing laboratories afforded analysis of 565,750 water samples. Data covered July 2019 to August 2021, including the COVID-19 pandemic. Results confirmed L. anisa commonly colonises water distribution systems, being the most frequently identified non-L. pneumophila species. Proportions of L. anisa and L. pneumophila generally remained similar but increases in L. pneumophila during COVID-19 lockdown suggests static water supplies might favour its growth. Disinfection of hospital water systems was effective but re-colonization did occur, appearing to favour L. pneumophila, although L. anisa colony numbers also increased as a proportion of the total. While L. pneumophila remains the main species of concern as a risk to human health, L. anisa’s role should not be under-estimated, either as a potential infection risk or as an indicator of the need to intervene to control Legionella colonization of water supplies.
Authors: Brian Crook, Charlotte Young, Ceri Ridout, Duncan Smith
Institutions: HSE Science and Research Centre, Health and Safety Executive
Language: English
Subfield: Endocrinology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,842
Funder: Health and Safety Executive
Award: G8497081579
OpenAlex ID: W4401766951