Author: Frederik Hammes
Some thoughts on:
HACCP-Based Programs for Preventing Disease and Injury from Premise Plumbing: A Building Consensus (Pathogens 2015, 4(3), 513-528)
I spent some time today to read this nice open access paper from McCoy & Rosenblatt (2015) on the implementation of Hazard Analysis and Critical Control Point (HACCP) program implementation in premise plumbing to counter microbiological risk. HACCP is a program of the USA’s Food and Drug Administration (FDA), and the authors argue correctly that HACCP programs have worked excellently for food safety and discuss several HACCP based programs already in place for water/building management.
A first important point made is that the absence of knowledge (lack of system understanding, lack of monitoring data) is a central theme to many documented cases of Legionella outbreaks in the USA. This is a very good point: we currently have preciously little detailed data on actual temperature and hydraulic fluctuations in premise plumbing systems, and even less information about how these affect microbial behavior. Moreover, routine monitoring in premise systems is also not the norm, especially not in private homes.
The authors further argue that HACCP-based management programs should be feasible because “Building (plumbing) systems are comprised of a series of processes that operate within definable parameters that can be measured and managed in real time”. This is entirely correct. However, it is firstly clear that such programs are more easily implemented for large communal facilities (hospitals, prisons, hotels, etc.), where responsibility may be more clearly defined, and potentially trickier for private homes. The second point is the real-time monitoring, where the authors argue for real-time operational controls such as temperature, pH and disinfectant concentrations. We would need something smarter than disinfection control, because many EU countries operate anyway without disinfectant residuals. In this regard, there is a fabulous new study by the group of Michele Prevost on temperature monitoring and control. These abiotic parameters are certainly easier to measure, but I would argue that we should keep on pushing the boundaries of smarter and faster (and potentially online) microbial monitoring methods as well!
In terms of microbiology the paper is heavily focused on Legionella, which is justified by the large number of cases (estimated at 18’000 p.a.) in the USA) and deaths (estimated at 4’000 p.a.) in the USA). One would like to see the same principles developed further for a broader range of (opportunistic) pathogens. As a real pleasure to a microbiologist, the authors strongly argue against cultivation-based methodology for detection, arguing that this is slow and unreliable. An enjoyable conference series (HDiD: How Dead is Dead?) focuses on the topic of viable but not cultivable bacteria (VBNC) and this was also a central theme to several presentations at the recent IWA Drinking Water Biofilms Conference in Arosa, Switzerland.
Some final comments and ideas....
The HACCP programs discussed here focuses strongly on working with the systems that you currently have. I think there can also be a stronger push towards optimizing existing systems to reduce risk, and designing new systems with minimized risks (i.e. improved hydraulics, better materials, etc.). An excellent approach would be clear identification of the critical control points in a plumbing system, and installing dedicated sampling/monitoring sites in those locations. In this respect, it may be worthwhile to consider dedicated biofilm sampling as well, since we know that >99% of all bacteria live in the biofilms.
HACCP-Based Programs for Preventing Disease and Injury from Premise Plumbing: A Building Consensus (Pathogens 2015, 4(3), 513-528)
I spent some time today to read this nice open access paper from McCoy & Rosenblatt (2015) on the implementation of Hazard Analysis and Critical Control Point (HACCP) program implementation in premise plumbing to counter microbiological risk. HACCP is a program of the USA’s Food and Drug Administration (FDA), and the authors argue correctly that HACCP programs have worked excellently for food safety and discuss several HACCP based programs already in place for water/building management.
A first important point made is that the absence of knowledge (lack of system understanding, lack of monitoring data) is a central theme to many documented cases of Legionella outbreaks in the USA. This is a very good point: we currently have preciously little detailed data on actual temperature and hydraulic fluctuations in premise plumbing systems, and even less information about how these affect microbial behavior. Moreover, routine monitoring in premise systems is also not the norm, especially not in private homes.
The authors further argue that HACCP-based management programs should be feasible because “Building (plumbing) systems are comprised of a series of processes that operate within definable parameters that can be measured and managed in real time”. This is entirely correct. However, it is firstly clear that such programs are more easily implemented for large communal facilities (hospitals, prisons, hotels, etc.), where responsibility may be more clearly defined, and potentially trickier for private homes. The second point is the real-time monitoring, where the authors argue for real-time operational controls such as temperature, pH and disinfectant concentrations. We would need something smarter than disinfection control, because many EU countries operate anyway without disinfectant residuals. In this regard, there is a fabulous new study by the group of Michele Prevost on temperature monitoring and control. These abiotic parameters are certainly easier to measure, but I would argue that we should keep on pushing the boundaries of smarter and faster (and potentially online) microbial monitoring methods as well!
In terms of microbiology the paper is heavily focused on Legionella, which is justified by the large number of cases (estimated at 18’000 p.a.) in the USA) and deaths (estimated at 4’000 p.a.) in the USA). One would like to see the same principles developed further for a broader range of (opportunistic) pathogens. As a real pleasure to a microbiologist, the authors strongly argue against cultivation-based methodology for detection, arguing that this is slow and unreliable. An enjoyable conference series (HDiD: How Dead is Dead?) focuses on the topic of viable but not cultivable bacteria (VBNC) and this was also a central theme to several presentations at the recent IWA Drinking Water Biofilms Conference in Arosa, Switzerland.
Some final comments and ideas....
The HACCP programs discussed here focuses strongly on working with the systems that you currently have. I think there can also be a stronger push towards optimizing existing systems to reduce risk, and designing new systems with minimized risks (i.e. improved hydraulics, better materials, etc.). An excellent approach would be clear identification of the critical control points in a plumbing system, and installing dedicated sampling/monitoring sites in those locations. In this respect, it may be worthwhile to consider dedicated biofilm sampling as well, since we know that >99% of all bacteria live in the biofilms.