Testing the Wastewaters: Researchers Develop a Fast and Effective Method for Detecting SARS-CoV-2

Rhys Waters 0:00

Welcome to Beyond Research, a podcast brought to you by Research Nova Scotia.

Stefan Leslie 0:08

Since the onset of the pandemic, researchers around the world in diverse fields of study have pivoted their work to support the fight against COVID-19.

Amina Stoddart 0:18

An increasing signal in wastewater can actually come about seven days before they’ve seen an increase in clinical cases. So the idea would be that if we’re sampling in the wastewater, and we start to see an increase in concentrations in the wastewater could be telling us seven days from now, we may be seeing clinical cases increase.

Stefan Leslie 0:40

Dr. Amina Stoddart is an assistant professor at Dalhousie University’s Department of Civil and Resource engineering, and a researcher at the Centre for Water Resources Studies. Today, she’ll explain how her research team is using their expertise in water treatment to design an ingenious method to detect the COVID-19 virus. This research supports frontline health care workers, and may be a critical piece in controlling the spread of the virus. Good morning. Thanks for coming in.

Amina Stoddart 1:08

Thank you for the invitation.

Stefan Leslie 1:10

What does the Centre for Water Resources Studies do?

Amina Stoddart 1:13

So we think of the centre as a kind of a hub of applied research in Atlantic Canada. And so we work with industry partners, we work with municipalities, we work with governments, we work with other researchers and universities to really put our knowledge to bear on water and wastewater challenges.

Stephan Leslie 1:33

We’ve talked a lot over the past several months of how research teams across this province have all shifted in some way, shape or form to COVID research. So how much of the centre’s work is now devoted towards understanding or managing the COVID-19 pandemic?

Amina Stoddart 1:52

Yeah, so wastewater has been a space that I’ve been sort of progressing into in the last two years. And this is a really interesting space within a space. We’ve been interested in emerging contaminants of concern, so things like microplastics with our wastewater work, and SARS CoV 2 is the most emerging of emerging contaminants of concern. There are a number of researchers within the center, particularly for our group, where we have the knowledge and disinfection and we do the wastewater treatment, we are within the wastewater treatment plants already doing work. It was sort of a relatively easy shift for us to start engaging in COVID-19 research, because we were kind of already in that space.

Stefan Leslie 2:41

So let’s talk about your wastewater work. So explain to me the link between what you’re doing with wastewater and the detection of the SARS CoV 2 virus.

Amina Stoddart 2:52

Right, so wastewater surveillance is not actually a new thing. We’re hearing a lot more about it with the pandemic. But it has been used to track poliovirus, it’s been used actually locally or nationally, I guess, to look at cannabis use pre and post legalization. So what it involves is just testing wastewater, so taking samples of wastewater either from you could take it from the sewer shed, so somewhere through a manhole to take just a grab sample or you can go to the wastewater treatment facility where all that water has now been collected at the head works of the plant, so the beginning of the plant and take a sample of the water coming into the plant before it’s treated, and then test it for the virus to see if it’s there and kind of what is the virus load.

Stefan Leslie 3:39

This testing of wastewater, it’s detecting the presence of virus. How do you know it’s SARS CoV 2?

Amina Stoddart 3:46

So we use an RNA signature, the unique signature that allows us to detect it and identify that it is in fact that virus.

Stefan Leslie 3:54

So you can detect that virus, so presumably you could then detect other viruses as long as you had that RNA signal.

Amina Stoddart 4:01

We could be testing anything in the wastewater, right? We could be testing influenza, we could be testing other things so it could have a life beyond SARS CoV 2.

Stefan Leslie 4:10

So for an urban setting, because I would imagine be different in different sized cities and of course in rural areas, describe to me how the sewer system is set up, you know, the water leaves your house or your your building, your office, and then it winds up in a sort of treatment plant. So how does that network function and how are you able to identify where you should be sampling from?

Amina Stoddart 4:35

The network, you obviously have your line from your house or your main line from your large building or apartment building, but then it does join that rest of the network and then it connects to kind of larger and larger pipes until it reaches the wastewater treatment plant. And so we’ve been working with our utility partners, Halifax water has been a big supporter of helping us, assisting us in sampling and they have the knowledge of their network to be able to indicate: Yes, you know, this would capture if you sampled here. This would capture this area. If you sampled here it would capture this area and that’s been guiding us in terms of where we would like to sample and then helping us kind of identify where exactly that is, from a sewer shed location.

Stefan Leslie 5:21

I understand that you can detect pre symptomatic and asymptomatic cases. So tell me a little bit about that. How does that work? So you’re testing wastewater, is that because people were already sick or about to get sick? How does that work?

Amina Stoddart 5:35

So what’s been identified in other communities is that the signal, an increasing signal in wastewater, can actually come about seven days before they’ve seen an increase in clinical cases. So the idea would be that if we’re sampling in the wastewater, and we start to see an increase in concentrations in the wastewater, it could be telling us seven days from now, we may be seeing clinical cases increase. So we may be able to get a sort of a jump on any kind of actions that we might want to take, or public health or public health leaders might want to take in terms of restrictions or what have you to try to curb that increase.

Stefan Leslie 6:16

So why wouldn’t it be better just to test everyone? If there’s a concern, why not individual tests? What’s the benefit of pool testing?

Amina Stoddart 6:25

Yeah, so I think one of the benefits of wastewater is that with one sample we can get a larger picture and it could help us or help us help public health leaders identify that, oh, we maybe do need, you know, larger scale clinical testing in this area of the city, or we should divert some resources to this community, because it does appear that their cases are increasing, or we should prepare this hospital for an increase in cases, you know, soon. There have been towns that I know of that have, you know, decided to offer testing to the kind of whole town and and that is a lot of tests, where maybe with a wastewater sample, if they could, you know, sort of have that indication of a widespread community with just one sample that could kind of lead them down the need for more clinical testing.

Stefan Leslie 7:18

How long have you been collecting samples and testing them?

Amina Stoddart 7:21

So we’ve been collecting samples in Halifax since the end of May. Initially, that work was that those samples were put into method development. So it’s not really reportable numbers, we were just using the wastewater to help us hone our method. I think probably as as anyone can appreciate, wastewater is a complex matrix and so really understanding how to clean that water up to isolate the RNA to be able to quantify it. That was really the focus of our work for for a number of months.

Stefan Leslie 7:58

So having described the work you’ve done to date, we’re about to embark on a whole new research area that will take us outside of Halifax. Talk about where some of the interesting areas are that that perhaps go beyond the Halifax boundaries.

Amina Stoddart 8:13

I think that that’s, kind of when I think about this work, I think there’s sort of two innovation areas that are needed. You know, we’ve identified and lots of researchers across the world and across Canada have identified that we can measure it in wastewater, we can isolate it and then measure quantify it. But I think one of the main things we’ve been really thinking about is accessibility. And so the test that we were working with Lumin Ultra to develop was designed to be able to be used not just in a university setting or hospital setting, but a simplified method that could be deployed elsewhere.

Stefan Leslie 8:49

You mentioned Lumin Ultra, so that’s a private company that well, tell me what do they do?

Amina Stoddart 8:55

Yeah, so Lumin Ultra has been a partner with the Centre for Water Resource Studies for over 10 years now. They are primarily or were primarily an environmental sort of testing. We used a lot of their equipment for testing bio mass loads in drinking water filters and wastewater treatment systems and drinking water distribution systems. And they early on, were able to provide clinical testing reagents to the Government of Canada. And then I think, kind of going back to their environmental roots, were really interested in developing a wastewater test. And so we worked very closely with them to develop a rapid test that could be used on site for detection of SARS CoV 2 in wastewater.

Stefan Leslie 9:45

So if I understand that correctly, rather than sampling and then having to send it into a specialized lab, you’re able instead to move the lab to the sample location.

Amina Stoddart 9:56

Yeah, so that would be the idea. A lot of the testing methods that we were looking at early on, were very much so university lab tests. Some of the equipment that was required was something that you really only find in a university lab, or in, you know, a hospital lab. It wasn’t really something that we would see possible to do, say, at the wastewater treatment plant. And so that sort of accessibility thing really kind of was something that we were grappling with and wondering, how do we get this out, so that other people can be doing it widespread? As you can imagine, there are, you know, many communities in Canada, that would be a challenge to ship a viable sample to a centralized lab and then get it analyzed and kind of have that feedback really rapidly. So with this test, the idea is that it could be done quickly and on site with minimal sort of specialized equipment and expertise.

Stefan Leslie 10:56

So when you say, quickly, and with minimal expertise, how long does it take? And what kind of training does the technician or the tester need to have in order to do it properly?

Amina Stoddart 11:05

Sure, yeah. So we’re looking at about an hour and a half to two hours, from sample to result in terms of having the sample in the lab and running it and then getting a result. So the most advanced part of the testing would be the actual sort of running of the qPCR instrument, which is the instrument that sort of measures, that quantifies the RNA and then sort of understanding the result that you get from that and what that means.

Stefan Leslie 11:34 So until this point, samples have been shipped to the lab for testing annd what you’re looking to do is move this out into the community really, to be able to test there. So what will it take in order to be able to effectively test the water closer to the source?

Amina Stoddart 11:51

Sure. So in terms of skills, there are some skills that we would see, that a normal sort of wastewater operator, maybe for a wastewater treatment plant would have, and they’d be able to use those skills for this test. The challenging part or the additional step where you’d need some additional expertise would be the operation of the instrument that actually detects the signature of the virus.

Stefan Leslie 12:19

This province is largely rural, or has has a greater proportion of its population in rural areas, but some major employers. How might this be relevant to smaller towns? Or even those, maybe even on septic systems? Is this something that would work there?

Amina Stoddart 12:35

Yeah, I think that you certainly could test in septic systems. But again, the closer you kind of get to that source, the fewer people you are testing. So I could see for large cities, it’s easier to understand kind of that one wastewater sample and collecting from a large, you know, group of people or a large population. And then as you start to move closer and closer to these sort of smaller sources, you start to, I think, maybe lose some of that advantage that you have with the wastewater testing. You could imagine testing closer to sites that you perceive as vulnerable to having the virus or could you know, we saw long term care facilities as a concern very early on in the pandemic. So you could start to get closer to those sources.

Stefan Leslie 13:35

So you mentioned long term care facilities. So would this then be possible to identify the proper sewer location that’s just downstream of a hospital, a long term care facility, a major employer, in order to target that pool of people?

Amina Stoddart 13:51

Yeah, with targeted sewer shed sampling, we could be targeting certain areas of our city which could be long term care facilities or university campuses, things like that. So areas where we know we have lots of people congregated, that are, you know, might create a particularly vulnerable situation that we might want to be able to kind of keep track of and kind of understand at that sort of larger, kind of zoomed out level that the wastewater surveillance could provide.

Stefan Leslie 14:27

Are you concerned that being able to detect the signal will allow you to detect actual cases?

Amina Stoddart 14:33

I think that that’s a next research step is linking detections and that concentration that we detect to actual cases that we that we know of, and I think that’s where partnership with with public health is really necessary. And we see that in some of these dashboards where they’re publishing their data sort of online to watch. We see often that trending is done with clinical cases and then concentrations in the wastewater and we see them sort of increase together. Usually the wastewater signal preceeding the actual increase in clinical cases. Now, how do we take that knowledge and that ability, to get to understand the numbers that we’re getting in a context that would be relevant to public health.

Stefan Leslie 15:25

You’ve got emerging technology from a company, you’ve got a whole bunch of problem areas or they could be problem areas you want to test, so is that where the research interest is? How it all gets pulled together?

Amina Stoddart 15:37

Definitely. Yeah, I think initially, our research interest was test development and now it’s what does this mean? And how can it be used? And how can we do this testing and help public health leaders potentially make decisions that would be important for our communities.

Stefan Leslie 15:54

Could this then be used as a way to manage the relaxing of the Atlantic bubble in due course, so that you could establish some approach that would allow you to do pooled testing in a monitored or managed way, as we begin to open up for business again?

Amina Stoddart 16:13

I think that’s one of the hopes for wastewater testing is that, yes, you could start to see increasing or decreasing trends or maybe long periods of non detects, and then use that to actually inform more stringent restrictions or yes, the relaxing of restrictions as well.

Stefan Leslie 16:33

Ideally, where do you see this research ending up in a year’s time?

Amina Stoddart 16:38

In a year’s time, I think we will have a surveillance system in place. I think we’ll be able to measure the virus and hopefully interpret the data effectively in that it can be used for public health decision making. And then I think beyond that, you know, as we as we move beyond, hopefully the pandemic, we can be using it to focus on other public health concerns.

Stefan Leslie 17:00

That’s fascinating work. I’m really looking forward to seeing where all this will go. Thanks Amina.

Amina Stoddart 17:04

Thank you for having me.

Rhys Waters 17:05

To find out more about this podcast and the research featured in this episode, visit researchns.ca. My name is Rhys waters and we will see you next time