A potential source of undiagnosed Legionellosis : Legionella growth in domestic water heating systems in South Africa
Date
2018-12-02
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
ENGLISH ABSTRACT: Legionella is a genus of pathogenic bacterial mesophiles that cause a range of diseases collectively referred
to as Legionellosis, with immunocompromised individuals being particularly susceptible. Water heaters,
a potential domestic niche for these pathogens, are heavy energy consumers, causing cost-sensitive users to
employ energy-saving initiatives, such as scheduling and lower temperature set points. However, lower heated
water temperatures allow Legionella to
ourish. This paper uses computational
uid dynamics modelling
to show that the pipes downstream of a horizontal electric water heater provide an environment that is
conducive to Legionella growth, not the heater itself. The presence of Legionella in water heaters is established
through water sampled from ve in- eld water heaters, of which the temperatures and heating schedules are
known. Microbiological techniques (PCR and weight-based qRT-PCR) are used to assess Legionella and L.
pneumophila presence at point-of-use taps. A model is used to determine the potential infection rate from
these concentrations, demonstrating that undiagnosed Legionellosis infection is likely. In low- and middleincome
countries, like South Africa, misdiagnosis of Legionellosis may be common due to the shadow cast by
HIV and TB prevalence.
Description
CITATION: Stone, W., et al. 2018. A potential source of undiagnosed Legionellosis : Legionella growth in domestic water heating systems in South Africa. Energy for Sustainable Development, 48:130-138, doi:10.1016/j.esd.2018.12.001.
The original publication is available at https://www.sciencedirect.com
The original publication is available at https://www.sciencedirect.com
Keywords
Electric water heaters, Legionnaires' disease, Water heaters
Citation
Stone, W., et al. 2018. A potential source of undiagnosed Legionellosis : Legionella growth in domestic water heating systems in South Africa. Energy for Sustainable Development, 48:130-138, doi:10.1016/j.esd.2018.12.001