Editor’ s comment
The Legionella Action Group has just released a report on the outbreak of legionnaires’ disease in South Africa, which we will publish in the next issue. The point is that a disease that we thought was long gone has returned. Let us hope that the authorities, designers, planners, legislators, and installers do not wait for an epidemic to occur before applying two simple rules:( 1) Ensure that standards are applied; and( 2) Forget any shortcutting in favour of profit and at the expense of the public, which we all purport to protect, except for unqualified professionals, plumbers and unscrupulous suppliers.
The US Environmental Protection Agency( EPA) developed this document because it recognises that many species of the genus legionella are a public health threat. The EPA recognises that many facility managers are choosing to install treatment systems to prevent or mitigate legionella growth in their premise plumbing systems. The target audience for this document includes, but is not limited to, primacy agencies, facility operators, facility owners, technology developers, and vendors.
This document summarises peer-reviewed scientific literature, reports from nationally and / or internationally recognised research organisations, and guidelines and standards from nationally and / or internationally recognised organisations. The reviewed literature characterises the effectiveness of different technologies that may be used to control legionella growth in premise plumbing systems. Particularly, it focuses on premise plumbing systems of large buildings, such as hotels, hospitals, schools, and other buildings with complex plumbing infrastructure.
The EPA expects this document will improve public health protection by helping the target audience make better informed, science based risk management decisions to control legionella growth in buildings.
Background
Legionella is a bacterium that can be found throughout the world, mostly in aquatic and moist environments, such as lakes, rivers, groundwater and soil. The infection caused by legionella is known as legionellosis and occurs primarily in two forms:
• Legionnaires’ disease, which is a type of pneumonia( Fraser et al., 1977).
• Pontiac fever, which is a milder flu-like illness without pneumonia( Kaufmann et al., 1981; Glick et al., 1978).
The disease can be acquired by inhaling or aspirating aerosolised water or soil( potting soil, compost soil) contaminated with legionella( Travis et al., 2012). No infection associated with animalto-person contact, consumption of contaminated food, or ingestion of contaminated water has been reported. Only one probable case of person-to-
28 Water Sewage & Effluent January / February 2017