NEW YORK (GenomeWeb) – Legionnaires' disease is a bacterial infection frequently traced to cooling towers atop large buildings, and an increasing number of recent outbreaks has spurred officials at the local and federal levels to enact new regulations for cooling tower inspections.
Hoping to tap into this new market, and ultimately to reduce outbreaks, Spartan Bioscience has developed a 45-minute molecular test for Legionella bacteria that runs on the firm's point-of-use molecular platform.
Ottawa, Ontario-based Spartan manufactures the Spartan Cube, a rapid molecular diagnostics platform that purports to be the world's smallest PCR system, standing at four inches on each side.
The company has been developing a menu of molecular diagnostics for the platform, and considers there to be only a handful of similar instruments currently available, CEO Paul Lem said in an interview, including systems like the Alere i, Roche Liat, and Cepheid GeneXpert.
But environmental testing is a new domain for Spartan. The diversification of its product portfolio into non-medical molecular testing was motivated by customer demand. "A very large property management company approached us and told us about the Legionella testing application, and then in our discussions with them we realized that it was a humungous opportunity," Lem said in an interview.
Spartan plans to sell its platform and Legionella test worldwide, Lem said. It will use a subscription model that includes Cube rental and four tests per month, and will reach out to large real-estate management firms. The company maintains that weekly testing with the Spartan system can detect Legionella bacterial growth early and allow cleaning and decontamination of a cooling tower before Legionella reaches levels dangerous to human health.
Spartan appears to be the first in the space to offer point-of-use molecular Legionella testing. In terms of a dollar amount, Lem said its tests will cost between $5,000 and $10,000 annually per building with a cooling tower, with its price per test being roughly the same as the price per gold-standard culture test.
Lem further noted that there are roughly 200,000 buildings with cooling towers in the US alone. "The US is about one third of the global market, so you're probably looking at 500,000 cooling towers across the world," he said. This equates to a potential market of around $5 billion.
"The interesting thing we're finding about this market is that it is dominated by very large property management groups and property owners … We just have to reach the vice-president in charge of the portfolio and in charge of testing, and then they can make the decision to roll out testing across their entire portfolio," Lem said.
Building managers may be less familiar with running lab tests than clinicians, but Spartan's platform is simple enough that it can be used by people who may have never heard of DNA, Lem said. "To them it may be a black box inside, but what they care about is that they get really accurate results really fast," he said. This is particularly true when compared to the current standard of sending water samples off to a lab, since that can take two weeks to get results back and results are not as accurate.
In the US, the incidence of Legionnaires' disease has been on the rise for more than a decade, according to the US Centers for Disease Control and Prevention. In 2000, incidence stood at about 0.4 cases per 100,000 people, but by 2015 the rate had jumped to nearly 2 cases per 100,000. This could reflect increased awareness and testing, increased susceptibility to infection, more bacteria in the environment, or a combination of factors, the CDC has said.
Legionnaires' disease is also a public health menace, and while the death rates are not terribly high, outbreaks cause a great deal of alarm and fear until the source is pinpointed. An outbreak in New York City in the summer of 2015, for example, caused more than 140 cases and killed 12 people, and led the city council to resolve that all buildings cooling towers be inspected.
The state of New York has since passed a law that mandates culture-based testing for Legionnella every 30 days while a cooling tower is in use.
"There is something like 20,000 cooling towers across of New York State, and all of them have to be tested once a month," said Lem.
The 2016 law says all Legionella culture analyses must be performed by a laboratory certified by the New York State Environmental Laboratory Approval Program, or ELAP. But monthly culture does have limitations.
As previously reported, Legionella can be finicky to culture and can take up to two weeks to grow. The sensitivity of culture ranges from 80 percent to as low as about 10 percent and depends on the sample type and a lab's experience, according to a review authored by CDC researchers.
Furthermore, there have been fatal outbreaks in New York City even after culture-based testing became mandatory. The CDC has determined Legionella culture can underestimate actual levels by a factor of 10 or more, and in one evaluation of culture-based detection 12 percent of cultured samples were false negatives.
PCR-based assays are increasingly embraced by the Legionella testing community. A representative at the US Food and Drug Administration's National Center for Immunization and Respiratory Diseases previously told GenomeWeb that international and academic members of its Environmental Legionella Isolation Techniques Evaluation, or ELITE, program routinely perform PCR, and program administrators are well aware of the PCR trend and encourage its use as a screening tool to help triage sample processing when high throughput and quick turnaround are required, such as when responding to an outbreak.
According to its website, the ELITE Program is planning to add additional performance evaluation criteria to its reports next year, including PCR and bacterial enzyme detection.
Spartan meanwhile is working with the Canadian federal government on a pilot project that will show how weekly qPCR testing compares to existing testing methods. In Canada, Lem noted that Legionella testing is standard for all federal government buildings, as well as every cooling tower in the province of Quebec.
One problem with PCR in the past has been that it is so much more sensitive that culture and can show positive results even if the Legionella bacteria is no longer living. In the European guidelines, PCR is suggested for outbreaks to rapidly rule out possible sources, but the guidelines note that studies are ongoing to understand how PCR results correlate with the gold-standard colony-forming-unit values determined using bacterial culture.
The Spartan test has addressed the problem of detecting dead bacteria by screening out all free DNA and using filtration to concentrate the sample.
Although rapid molecular clinical tests are still lacking, according to the 2015 CDC review, Lem said Spartan does not plan to pursue those at this time.
"Our hope is that if Legionella DNA testing becomes widespread for cooling towers then it will prevent the reservoir of infection at the source," he said.
Meanwhile, Spartan will continue to pursue its clinical menu as well. It plans to go after menu items in POC pharmacogenetic testing and expects to be a leader in that space, Lem said. It is also looking into infectious disease tests and additional environmental testing.
Spartan also markets a 30-minute cheek swab assay for mutations in the apolipoprotein E (APOE) gene that is being used to select patients for Alzheimer's studies. The firm is "getting a lot of interest and customers from large pharmaceutical companies running clinical trials," Lem said, but he was not free to name any collaborators at this time.