What can wastewater tell us about the spread of disease? Could the coronavirus鈥檚 signature RNA sequence tip public health officials to where the next COVID-19 outbreaks will occur? In this episode, we鈥檒l talk to two researchers who are leading the effort to monitor 精东影视鈥檚 wastewater streams for coronavirus, in partnership with treatment facilities throughout the state.
Wastewater treatment facilities are partnering with researchers in the College of Engineering to monitor levels of coronavirus in 43 areas throughout the state. Photo by Scott Nelson, courtesy city of Bend.
[MUSIC: , by Kevin MacLeod, used under a ]
KEITH HAUTALA: At the time we鈥檙e recording this, Nov. 25, 2020, the day before Thanksgiving, nearly 13 million cases of COVID-19 have been reported in the United States. More than 260,000 have died of the disease. And yesterday, there were another 2,216 coronavirus deaths and 178,200 new cases. The infection rate is soaring. 精东影视 just set a new record, with more than 1,500 new cases in a single day.
STEVE FRANDZEL: And the only way to know how many Americans have been infected is through testing. From the start of the pandemic, public health experts have advocated for widespread testing.
HAUTALA: Individuals need to know if they鈥檙e infected. But there are bigger reasons for extensive testing. Zooming out a bit, doctors鈥 offices and hospitals, for instance, want to know if patients there for routine visits unwittingly pose a danger of spreading the disease to healthcare providers and other patients.
FRANDZEL: And pulling out further, local and state governments want to know if their communities are becoming hot spots or if they鈥檙e keeping the spread of COVID-19 under control. This knowledge is crucial for understanding the progression of the disease through communities: Is it getting worse? Is it getting better?
HAUTALA: That information is important for leaders to determine if they should push for things like mask mandates and restricting the size of public gatherings, whether restaurants can serve inside or if they have to stick to outdoor seating and carryout. This episode will focus on testing. But probably not the type of testing most people have in mind.
[MUSIC: The Ether Bunny, by Eyes, Closed Audio, used with permission under a ]
FRANDZEL: From the College of Engineering at 精东影视 State University, this is Engineering Out Loud.
HAUTALA: And we鈥檙e back!
FRANDZEL: I鈥檓 Steve Frandzel with the鈥攈ow do we usually introduce each other?
HAUTALA: Say whatever you want.
FRANDZEL: I鈥檓 your co-host for this episode, Steve Frandzel, and I鈥檓 joined by Keith Hautala.
HAUTALA: Hi, I鈥檓 Keith Hautala. And I鈥檓 joined by Steve Frandzel, in a virtual sense. Because of the social distancing requirements, we are recording this in our separate home studios.
FRANDZEL: Yeah, and that might make for a few unwanted interruptions by critters like particularly loud cats 鈥
HAUTALA: Please bear with us.
FRANDZEL: Birds, dogs, and um [dog barks.] Good boy, thank you, thank you! That鈥檚 our dog, Baloney, protecting us from squirrels, deer, turkey, and an occasional UPS person.
HAUTALA: We鈥檙e sure you can overlook any minor technical difficulties we may encounter along the way.
FRANDZEL: Yep.
HAUTALA: Let鈥檚 talk about testing, Steve.
FRANDZEL: OK. So here鈥檚 a vastly simplified description of the commonly used COVID testing. And it鈥檚 pretty much like what you see on the news: Someone sticks a swab into your nose to collect a sample of nasal secretions. In some of the tests, that swab goes really deep into your nose, and it鈥檚 not particularly pleasant. But other tests swab just inside your nostrils.
HAUTALA: So, then one of two types of diagnostic tests is performed at a lab. So there鈥檚 molecular tests to detect the virus鈥檚 genetic material, and then there are antigen tests which detect specific proteins on the surface of each virus particle. But swabbing has some pretty big limitations, and we鈥檒l get to that.
FRANDZEL: So, there鈥檚 another type of testing that can help leaders make those decisions鈥攐ne that鈥檚 not focused on individuals at all, but on communities. And it doesn鈥檛 require any swabbing, and while it won鈥檛 tell you or me if I鈥檓 infected or you鈥檙e infected, it鈥檒l identify important trends about how widespread COVID-19 is in a community, a city, a town, and how fast its spreading, or decreasing. And it鈥檚 called sewer surveillance.
HAUTALA: Sewer surveillance?
FRANDZEL: Sewer surveillance.
HAUTALA: Like, they鈥檙e spying on the sewers?
FRANDZEL: Well, kind of 鈥
TYLER RADNIECKI: One of the great things with sewer surveillance is we have 100% participation rates. You know, as long as you are flushing the toilet, you participated in the surveillance. And we can reach everybody that鈥檚 hooked up to a sewer system.
HAUTALA: That鈥檚 Tyler Radniecki. He鈥檚 an associate professor of environmental engineering here at the College of Engineering. In this episode, Tyler and his colleague Christine Kelly, who is a professor of bioengineering, will help us sort out sewer surveillance and the role it can play in helping to end this pandemic.
FRANDZEL: So, how does it work? What are they actually doing?
HAUTALA: Well, they鈥檙e literally looking for traces of the coronavirus in the sewer system to figure out where the disease is prevalent. Maybe we should just have Christine Kelly tell us more about it.
CHRISTINE KELLY: The concept of sewer surveillance is that infected individuals, whether they鈥檙e symptomatic or asymptomatic, shed the virus in their feces. And when, of course, they use the bathroom, those feces go into the sewer systems.
[MUSIC: , by Kevin MacLeod, used under a ]
RADNIECKI: So, sewer surveillance has been used for quite a while. Those with some history of environmental microbiology will recognize this from the post-World War II days and tracking down polio through sewer surveillance systems, and the most recent case of that was in Israel, where they set up a countrywide sewer surveillance system to track polio. I believe that was in, 鈥89, I think is when that went up.
FRANDZEL: Christine and Tyler鈥檚 participation actually began with an email.
KELLY: So I was standing outside Tyler鈥檚 door. and Tyler said, 鈥淟ook at this email Ken Williamson sent!鈥
HAUTALA: Just an aside: Ken Williamson is director of research and innovation at Clean Water Services in Hillsboro and a professor emeritus in the School of Chemical, Biological, and Environmental Engineering. He鈥檚 one of 精东影视鈥檚 top wastewater experts.
[MUSIC: , by Kevin MacLeod, used under a ]
KELLY: He suggests we should look into wastewater surveillance of coronavirus. And I said, 鈥淪end that to me, Tyler!鈥
FRANDZEL: Christine did some digging and wrote a rough white paper. And the more she learned about the topic, the more appealing the idea got to her.
KELLY: And I was pretty enthusiastic and said, 鈥淭yler, Tyler, we gotta do this! We gotta do this!鈥 We went back and forth a bit. I was kind of ready and I couldn鈥檛 get a hold of Tyler, so I went to his house. I knocked on the door and said, 鈥淎re you in?鈥
HAUTALA: And the rest is history. Well, history in the making. We鈥檒l jump over some of the details, but the result was a proposal to the National Science Foundation.
RADNIECKI: So that鈥檚 what got us started, was a $100,000 NSF RAPID award. And really the reason we got that money funded, according to the program director, was that we were one of the few universities that proposed to go into the sewer lines, as opposed to just at the wastewater treatment plants, and go into neighborhoods and try to identify hotspots. And that was very unique. We can only do that with the collaboration from Clean Water Services giving us all that access to sample the sewer lines.
FRANDZEL: It was a modest beginning, but their mission grew pretty quickly and kept growing. And one big development was a collaboration with 精东影视 State鈥檚 TRACE-COVID-19 program.
HAUTALA: So, TRACE is a public health project that was established to track the prevalence of the virus through random sampling with conventional testing techniques, using nose swabs. And that partnership effectively opened up the whole state to these researchers.
RADNIECKI: And that got us going much more quickly, because with the TRACE team we started going to hotspots that were identified throughout the state that were having outbreaks. So, for instance, Newport was the first opportunity we had where we went in to a known outbreak. And it was really the first chance we had to test to see if sewer surveillance would work the way that we hoped it would. Because we had previously done surveillance monitoring in Corvallis and in Bend, but in both communities at those times, the prevalence was so low, we really didn鈥檛 see much. But when we went to Newport with their outbreak, we saw that, yes, we could detect strong signals in the sewer, and yes, we could identify which neighborhoods within the city were having the highest levels of viral shedding to the sewer system. And then by working with the TRACE team, we were able to correlate our results with nasal swab studies, and they matched up very very well. And that鈥檚 gotten the entire team very excited.
HAUTALA: One question I have is whether they鈥檙e able to actually quantify how much virus is in the community, or is it just like a yes or no, positive/negative kind of deal?
FRANDZEL: I had the same question. And the answer is yes, they can kind of quantify, but it鈥檚 not that simple.
HAUTALA: It never is, is it?
FRANDZEL: Well, it鈥檚 not quite a one-to-one correlation, but over time 鈥
RADNIECKI: It鈥檚 a little more than just a binary. We do get quantitative, so we can tell you how many gene copies per liter we detect in the wastewater. And it gives you a relative sense of how much infection may be in that community. We鈥檝e seen a significant correlation between the amount of virus we detect in the wastewater and the prevalence and the caseloads detected in those communities through our TRACE studies and looking at county health authority data. But to get to the point where we can say that we have this copy number in the wastewater, so therefore we must have this many sick individuals is currently not possible. But its most powerful aspect is the trend data. If you look at it over time, you can see if the signal is getting higher or if it鈥檚 getting lower. And if you start to correlate that with different things, such as did the county recently reopen, was there a mask ordinance recently put in place? How do these different decisions affect the overall viral load to the wastewater system? That鈥檚 shown to be a pretty powerful tool.
HAUTALA: So they hook up with the TRACE program, and they鈥檙e going from hotspot to hotspot, just chasing the virus through the sewers like some kind of environmental Indiana Jones?
FRANDZEL: Uh, yeah, that鈥檚 quite a picture you paint there, Keith. Yeah, initially, it kind of was like that, but then OHA got involved.
HAUTALA: You mean the 精东影视 Health Authority.
FRANDZEL: Yeah. So, OHA got involved 鈥
RADNIECKI: And since then, we鈥檝e gone on to other outbreaks such as Hermiston, and the Boardman area was the next stop. Then, OHA started paying more attention to what we were doing and got more and more excited. And they approached us, actually, to submit a proposal to take our sewer surveillance, instead of going just from hotspot to hotspot, instead create a network across the state of 精东影视 to continuously monitor for the presence and spread of coronavirus.
FRANDZEL: That meant they were getting additional funding, which the OHA funneled from the CDC.
HAUTALA: The Centers for Disease Control and Prevention, in Atlanta.
FRANDZEL: So now, they could greatly expand their research. They just had to figure out how to allocate resources most effectively.
KELLY: And so that criteria turned out to be facilities, wastewater treatment facilities, in the state, that served 6,000 or more population.
HAUTALA: Forty-three facilities met those conditions, including in Bend 鈥
FRANDZEL: Bend.
HAUTALA: Newport 鈥
FRANDZEL: Newport.
HAUTALA: And Corvallis 鈥
FRANDZEL: Corvallis.
HAUTALA: Yeah. So that鈥檚 where the campuses are of 精东影视 State University, and they had already been testing wastewater in those locations. So now, they鈥檙e getting weekly samples from all 43 treatment plants and testing those samples for the SARS-CoV-2 RNA sequence in the wastewater.
FRANDZEL: And because of that, they鈥檙e able to cover a much broader area that encompasses all the state鈥檚 major population centers, or at least those that are connected to sewer lines.
HAUTALA: Yeah but, I mean, doesn鈥檛 this represent kind of a paradigm shift? Instead of looking at what鈥檚 going through sewer lines in specific neighborhoods, they鈥檙e sampling everything that鈥檚 coming into a treatment plant from an entire community.
FRANDZEL: Exactly. So, first we zoomed the camera back, so to speak, from a single individual鈥檚 nostril, to the sewer line in that individual鈥檚 neighborhood, and now to the city where that individual lives.
HAUTALA: So you鈥檝e got kind of the proverbial 30,000-foot view, to mix metaphors.
FRANDZEL: Uh huh, yeah.
KELLY: The statewide network is weekly monitoring of these facilities for two and a half years. But it is the whole city, it鈥檚 not trying to narrow down in certain neighborhoods. But it鈥檚 a sustained effort that we can identify when a city might be having an outbreak.
[MUSIC: by The Whole Other, used with permission of the artist]
KELLY (continues): And sometimes that can come earlier than traditional measures of caseloads, because fecal shedding of the virus can and does occur typically prior to symptoms. So it鈥檚 possible, depending on when that sample is taken, that you could find an outbreak a little bit before the actual clinical testing shows. We will submit the data as soon as we get it to the state health authority and the county-level health authority. And then that will just provide another stream of data regarding infection in an area for those authorities to make decisions around interventions.
RADNIECKI: The information is, as Christine said, primarily for decision-makers, but the general public as well will be able to track the progress of what鈥檚 happening in their community or their area.
HAUTALA: OK, so, sewer surveillance isn鈥檛 going to replace individual testing.
FRANDZEL: And it鈥檚 not 颅meant to. But颅颅 it offers some advantages to the public and to researchers.
RADNIECKI: And a big issue with more traditional approaches is, one, reaching all of the individuals, especially those that aren鈥檛 as affluent, to be honest with you, as oftentimes in those communities, it鈥檚 difficult to reach all the individuals. And then, two, with this virus, we know the importance of routine testing over and over is. Just because you are not infected this week doesn鈥檛 mean that you won鈥檛 have it by next week, depending on your exposure. But at the same time, sampling fatigue is real. How many times do you want someone coming by and asking for a saliva test or sticking a swab up your nose?
KELLY: What we鈥檙e talking about here is centralized sewer systems, but about 30% of the population is not on centralized sewer systems. They鈥檙e on septic tanks or other onsite type of waste颅 treatment. So that鈥檚 one group of people that this type of surveillance does miss. And also, the sewer surveillance is a scalable technology. Whereas nasal swab testing, or any kind of individual testing, if you test two people, it鈥檚 twice as expensive as one person. Whereas sewer surveillance, you can do 10,000 people for the same price as 100 people. You can do a lot for people for not very much money or resources.
HAUTALA: There are some technical and logistical challenges with sewer surveillance and lots of questions to answer.
FRANDZEL: Fortunately, Tyler and Christine have been able to tap in to a sprawling support network of researchers who are doing similar stuff all around the U.S.
RADNIECKI: And so there were a lot of unknowns when we first started. I mean, the first question that we went back and forth on was is the virus free-floating in the water, or is it stuck to solids that are in there? And we had this huge debate, and we changed our minds three or four times before we proved it to ourselves that, yes indeed, in this case, the virus is stuck to the solids.
HAUTALA: That information helped to guide decisions about how to isolate and detect the virus.
FRANDZEL: Yeah, but in the early days of the pandemic, nobody really had the answers. Nobody knew any of that.
RADNIECKI: There鈥檚 different methods going on. The first step you have to do is concentrate the virus in the wastewater, and there鈥檚 different ways to do that. Do you centrifuge it, do you precipitate it, do you filter it? And they鈥檙e all going to have different detection limits and pluses and minuses. Everyone was kind of doing their own thing as far as how to detect it. And we didn鈥檛 really know.
HAUTALA: So there was a lot of uncertainty still about how to kind of merge together the findings from these dozens of different studies with different methodologies to create a reliable, comprehensive and clear picture about the prevalence and spread of coronavirus.
RADNIECKI: That鈥檚 where the Water Research Foundation got involved. So, the Water Research Foundation is a network of wastewater utilities and university researchers across the country, and actually internationally. And so one of the projects they funded was how do we know which techniques are the best? How do we take all these different studies that are happening all over the country, all over the world, and how do we compare their results? What they have done is they have sent out wastewater samples to 50 or participating labs. We鈥檙e all going to do the various techniques, multiple labs, we鈥檒l do the same techniques. And then we can start to understand how do these different techniques affect the final answer and then how much variability is there even between labs doing the same technique? Because right now we don鈥檛 know the answer to those questions. It鈥檚 a big effort across the country to get it done. And we鈥檙e proud to be a part of that. So as you can imagine the pressure鈥檚 been high, the workload鈥檚 been high. The craziness at times is a little bit out of control. But at the same time, it feels very rewarding to know that you鈥檙e doing your part and that you鈥檙e having a positive impact. It makes the lack of sleep worth it, as we just keep moving forward and keep doing our best to help out in any way that we can.
[MUSIC: , By Emily A. Sprague, used with permission of the artist]
HAUTALA: This episode was produced by me and Steve. I鈥檓 Keith Hautala.
FRANDZEL: And I鈥檓 Steve Frandzel, signing off.
HAUTALA: Our intro music, as always, is 鈥淭he Ether Bunny鈥 by Eyes Closed Audio. You can find them on SoundCloud, and we used their song with permission of a Creative Commons Attribution License. For more episodes and bonus content, look for us at engineeringoutloud.oregonstate.edu. Subscribe to this podcast by searching for its title, 鈥淓ngineering Out Loud,鈥 on Spotify, iTunes, or wherever you get your podcasts. On behalf of the College of Engineering and all of us here at 精东影视 State, I want to wish you a happy, safe, and, above all, healthy holiday season. That鈥檚 it for now. We鈥檒l see you again in the new year.
STEVE: As we were finishing up this episode, the world learned that the United Kingdom became the first Western country to begin administering COVID-19 vaccinations to its general public. So that lets us end this podcast with some very good news. Good luck everybody.