Nephros SequaPath^® and Broad Pathogen Detection in Stagnant Water

Buildings Unoccupied During the Pandemic at Risk for Greater Microbial Presence

From our facility in northern New Jersey, we had a front row seat to the devastation of COVID-19. Under directives from governmental agencies, thousands of buildings across New Jersey and the nation were suddenly unoccupied. As water people, we knew the shutdown would be accompanied by a dramatic reduction in water usage, resulting in stagnant water in thousands of buildings. And we know that stagnation supports bacterial colonization of water systems.

We recognized that there was an unmet need for a fast, reliable means to screen water for multiple families of pathogens that might grow in the pipes of unoccupied and under-occupied buildings. So, as the pandemic was building momentum, we revised our research and design plan and re-allocated resources to fast-track the development of practical tools that could be used to help assess the risks associated with the significant, widespread stagnation of water in buildings.

We accelerated the development of our SequaPath^® system, which provides a mechanism to screen water for the entire spectrum of bacterial genera (families), including bacterial pathogens in any given water sample. Under the leadership of Dr. Kimothy Smith, VP of Pathogen Detection Systems, and with guidance from some of the country’s leading scientists, we designed and implemented studies using our new SequaPath platform to compare bacterial populations in water samples from buildings that were occupied throughout the pandemic with water samples from buildings that were unoccupied during the same time period. We gathered 88 samples from various types of buildings located in four different states.

The potential verdict, the implications, and what it means for you

Since COVID-19 related containment measures were first initiated, dozens of guidance documents addressing water issues related to the re-occupancy of buildings have been produced by regulatory and public health agencies, as well as by private-sector organizations. To the extent these documents addressed microbial analysis, most focused solely on testing for Legionella to determine when it is safe to re-occupy a building. From our experience and that of thought leaders with whom we consulted; we knew that Legionella might not be the only pathogen of concern. But we did not have sufficient data to understand the relative abundance of Legionella vs. other bacteria (including pathogens) that might be in the stagnant water.

As we reviewed available data and talked to experts, we became increasingly concerned that the building re-occupation guidance focused on Legionella might be insufficient and, where Legionella is not detected, even put people in harm’s way by creating a false sense of security. Our research, made practical by the use of our SequaPath platform, produced results with important practical public health implications:

• Total bacterial populations in unoccupied building samples were at least 40% greater than in occupied building samples, with some samples showing as much as a 1,400-fold difference.
• About 50 families of bacteria with at least some pathogenic members – including but not limited to Legionella – were found in approximately 60% of unoccupied building samples, compared with approximately 35% of water samples from occupied building samples.
• Legionella was found in only about 15% of the unoccupied building samples and in less than about  5% of the occupied building samples. Even in samples where Legionella was detected, Legionella was not the dominant species.

Development of our SequaPath system is ongoing, as we continue to gather additional data to expand our understanding of the dynamics of bacterial diversity of water in buildings over time. There is a lot we still don’t know, but we believe we have shown that consideration only of Legionella to the exclusion of other pathogenic bacteria is not supported by the data. With the advent of SequaPath, it is now practical to screen the entire microbial community for families of pathogens. The water found to have bacterial genera with known pathogenic members can be further analyzed for pathogenic species by robust qPCR technology, such as our PluraPath^® platform.