Fully Automatic Early Warning System to Detect and Quantify Legionella in water

Legionnaires' disease (LD) is a pneumonia acquired by inhaling legionella bacteria found in building water systems. It is rising at an alarming rate in the U.S. and other countries, killing 1 in 10 patients who contract it (U.S. Centers for Disease Control and Prevention). Hospitalization annual cost is over $433,000,000 in U.S. and $1,359,000,000 in Europe, exceeding $24,000–$34,000 per patient. Both the aging population and global warming exacerbate the problem. The more effective way to address LD is to reduce exposure to harmful bacteria by scrutinizing the building's water systems, but current method provides no preventative value due to long time to confirm results (2-28 days are required). Legionnaires’ disease (LD) is one of the deadliest waterborne diseases in U.S. Recent outbreaks have led us to help building owners and managers know Legionella level sooner and better maintain water systems.

Most people could think the water problems are correctly addressed and water isn’t something they need to worry about anymore. If anything, the recent water crisis in Flint, Michigan, and frequent Legionnaires’ disease outbreaks across the world have demonstrated that’s not the case. There’s even more of a push to worry about Legionella in buildings because once water reaches your house from the treatment plant, the authorities stops regulating it. That’s why it’s more important than ever to make sure people aren’t being exposed to harmful Legionella in water, in the presence of a growing number of older people.

To protect people from Legionella infections, we first need to understand the Legionella level in water. If we can rapidly determine how much Legionella is in the water, we can more efficiently target resources and prevent disease outbreaks. The goal is to give better tool for monitoring Legionella in building´s waters. Fast Legionella results can be used to inform water safety plans to reduce risks.

A fully automated system able to produce reliable on-site results within 2 hours, based on a certified rapid test (AOAC-RI). It eliminates human error, supporting timely steps on the risk facility before the bacterium spread.

Quantitative data presented by the analyzer could form the basis for remedial action, if any, according to different published guidelines used to manage the risk of contracting Legionella in risk facilities in the cities, thereby protecting public health. It can take less than 2 hours for the full diagnosis and report to become available using the automated method, thereby reducing the likelihood of exposure to Legionella in contaminated installations following delays in taking preventative actions (surveillance, cleaning and disinfection). The need of sampling protocol involving preservation procedures and transport conditions is avoided because the actual sample is taken on-site to be immediately analyzed, from sample collection through sample analysis to result obtention.

Reliable quantifying of Legionella could be achieved in comparison with other techniques. Culture enumeration can underestimate the risk of Legionella due to, among other issues, slow growth rate of Legionella in a plate, overgrowing of accompanying organisms, inability to count viable but non-culturable (VBNC) organisms, presence of vesicles containing Legionella expelled from protozoa, or loss of cultivability during sample holding time prior culturing. For some samples containing PCR inhibitors, high quantification limits do not allow the quantification of the target by this technique in complex waters. Automated analyzer provided repetitive measurements without any processes involving human manipulation. Data could be hosted in the cloud, remaining available for further studies.

As an example, we refer the results that have been achieved in a public swimming pool, and how they have been used to improve the health conditions of the users. Water from this facility was monitored at different dates between August and November 2018 (132 water samples, S). Negative (N) and positive (P) controls were also tested. In August, this concentration was occasionally high during the maintenance work. Two weeks before the subsequent opening of the facility in mid-September, the Legionella sp. was no longer detected. However, after only 7 days, the concentration increased to 12,600 UFCeq/L, also in October (159 UFCeq/L) and November (630 UFCeq/L), always on Monday. The facility is closed on Sundays. The events were never longer than two days, but people were exposed. Using these results, otherwise not available, this risk situation was rectified by changing operation rule. Infrequent Legionella testing cannot be the basis of a reliable assessment of health risks. The solution constructs health scenarios.

The system has also been used to monitor the efficiency of disinfection and cleaning procedures in hospitals or to control the performance of a cooling tower in a private company.

Current development status

Working prototypes

Desired business relationship

Joint ventures

Adaptation of technology to other markets

Other: Commercialization

Current development status

Commercially available technologies