Barriers to effective Legionella control in a changing world: a practitioner’s view

Abstract

Inhalation of aerosols containing Legionella pneumophila, a water-borne bacteria commonly found in natural and manmade water systems, is the main causative agent of Legionnaires’ disease (LD). Approximately 10–15% of all reported cases of LD result in fatality, with susceptibility to the disease being higher in immunosuppressed patients, men over 45 years of age, alcoholics, smokers and individuals with underlying diseases. The World Health Organisation (WHO), European Centre for Disease Prevention and Control (ECDC) and The United Kingdom (UK) Health and Safety Executive (HSE) have implemented a strict code of practice and guidelines to minimise the risk of the public from contracting LD. This paper provides a critical review of these three published guidelines. Evidence suggests that the current detection methods for Legionella, by culture and quantitative polymerase chain reaction (qPCR), show large disparities in the detection and quantification of bacteria in water samples, raising concerns about the reliability of measures needed to safeguard public health. Moreover, a survey of 20 residential building complexes in different London boroughs highlights the need for a review of remedial action recommendations and a more inclusive risk assessment strategy that protects ‘at risk’ people in society.