Mitigation of opportunistic pathogens in hot water systems: a review focused on premise plumbing in South Africa

Abstract

Water reticulation systems (i.e., premise plumbing) serve as a reservoir for opportunistic premise plumbing pathogens (OPPPs) to survive within these premise systems.  OPPPs can be transmitted to individuals mainly via inhalation of aerosols from these water systems.  These OPPPs can adapt, thrive and survive under a range of different conditions, which include high temperatures and low oxygen levels during stagnation, conditions often associated with household plumbing systems, including hot water systems (HWS).  Hospitals are of specific concern as infections caused by OPPPs predominantly affect individuals who have underlying illnesses or health conditions.  The current South African National Standard (SANS) 241 for drinking water does not provide information regarding testing for the presence of OPPPs, while the SANS 893 and 893-1 standards only provide a guideline for Legionella in water systems.  The presence of OPPPs within HWS and premise plumbing is a concern, and a need exists to establish remediation and mitigation measures to control the presence of OPPPs in buildings.  This review addresses risk analysis, evaluation and measures, which include the control of geyser temperatures and training of plumbers, as well as sampling and detection of OPPPs. This should limit the number of infections amongst individuals and will thus lessen the financial burden on health care systems and the economy.