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Alliance Discussion with Dr. Edwin Oh, New Public Health Horizons: The Evolving Science of Wastewater Intelligence

Edwin Oh, PhD, associate professor at the Kirk Kerkorian School of Medicine at the University of Nevada, Las Vegas (UNLV), joined us for an alliance discussion to chat about the impact, potential, and limitations of wastewater “intelligence.” Among his diverse areas of expertise, Dr. Oh is breaking new ground in wastewater surveillance and analysis as a means of minimizing the toll of infectious diseases and other public health threats. Here are some of his thoughts on:

Utilizing next generation sequencing tools to track SARS-CoV-2 in wastewater:

“In 2020, everything came pretty much to a standstill, and we were unable to do the work that we wanted to do with our next generation sequencing tools. This is when we started talking with several people across the community and asking this one question, how can we use our genomic next generation sequencing tools to track the community transmission of SARS-CoV-2? We are not infectious disease specialists, but we thought we are quite good in characterizing nucleic acids – the DNA and RNA that’s present in all humans.”

“[Dr. Dan Gerrity, Dr. Katerina Papp, and I] were talking about some of the preliminary work that they had established from a small wastewater treatment plant. […] Over time, we were seeing this wastewater value track the new cases that were showing up over time. So, this seemed like a very innovative way of being able to look at community transmission of a virus without having to test a single individual.”

How wastewater surveillance works and the information it gives us:

“If we were to encounter an asymptomatic or symptomatic infected individual, viral particles will be present in fecal matter and in urine. Therefore, this SARS-CoV-2 viral quantity will be shed when we use the bathroom. It will also be present in saliva, so when we use a basin to brush our teeth. All this sewage will enter a highway of pipes under our feet, and head towards a wastewater treatment plant. All the wastewater treatment plants in Nevada are to the east so we can go there as a team, we can collect this wastewater and bring it back to our lab. After bringing it back to the lab, we can take this complex matrix and turn this into nucleic acids. From there, we can start analyzing for SARS-CoV-2 and a whole host of other pathogens.”

“More recently, we’ve discovered other proteins. This information about how much SARS-CoV-2 is in wastewater – if we’re increasing or decreasing and what variants might be present – can then be shared with public health folks. They can use this information to inform different actions such as the deployment of testing clinics, vaccination clinics, and also get a sense of whether cases are going to be increasing in a week or in a month.”

“Wastewater surveillance can give us an understanding of whether a virus is there, [and if so,] how much. What we can also do with wastewater monitoring programs, is look at the distribution of variants across the city of Las Vegas, all the way down to Boulder City.”

The Nevada Empower Program:

“We call it Empower (Enabling the Management of Public health Outcomes through Wastewater Resources), and on this website you can click on the various icons to better understand both urban and rural treatment plans and look at SARS-CoV-2 values. What you will see when you get on the website is a gray shaded area that represents cases, and a green line represents our wastewater viral counts. The wastewater values in many of our treatment plants predicted the number of cases that were going to show up over time. We’ve been tracking this for the last three years and we’re still going to continue doing this for SARS-CoV-2, plus a whole host of other pathogens.”

Wastewater intelligence as evidence for policy:

“A lot of this information has been used by policymakers in [Nevada]. When the mask mandate was ended, the governor of the previous administration used the number of overall cases, hospitalizations, and the virus detected in wastewater, to be able to justify why it was the appropriate time to end the  mask mandate. Other states’ administrators have also used this information for advising policy.”

Wastewater intelligence informing variant trends:

“When you look at January of 2022, what we found was quite striking. Most of the [SARS-CoV-2] variants were showing up much earlier in the dominance versus the clinical sequencing. For example, we were finding [SAR-CoV-2 Omicron variant] BA.2.12.1 in March of 2022 [in wastewater], and we didn’t find it until one or two months later in clinical samples. In some ways this was expected because of the fear of testing and/or the lack of viral sequencing testing across various communities. We can go to a treatment plant, bring the sample back, convert it into nucleic acids, sequence it, and we will have a representation of what’s going on in that community. So that’s why I really think that this type of information can be extremely helpful in better understanding trends in a community.”

Lessons from wastewater intelligence:

“We’ve worked on the viral counts and the variants that are dominant across a community. We’ve published several different papers where we’ve looked at SARS-CoV-2, influenza at elementary schools, and antimicrobial resistance. We’ve also found very rare variants in the wastewater, which then showed up in our communities, either a week later or a few months later. We’ve also used this method to work together with collaborators in Arizona to sequence genomes at a university dormitory. More recently, we’ve looked at how Omicron developed in tourist areas, and how this then increased in prevalence across local communities. What we’ve shown is that we can go to an airport, a shelter, hotels, other large areas, and deploy this method to collect intelligence.”

Using wastewater intelligence to deploy resources to different communities:

“I started talking a little bit more with different folks across the community and we asked this new question. Instead of going to the wastewater treatment plants where a lot of that wastewater would be diluted, could we now go to various regions across the Last Vegas Strip or North Las Vegas and break these cities up into various zones, so that we could test these communities for Mpox (Monkeypox) viral DNA. What we soon realized was that when we looked at the event onset date of these cases, we were able to identify an area where the wastewater Mpox level was mirroring what we were seeing in case counts. This was beneficial to us, because now we could say, “We have found an area that can potentially benefit from testing and vaccination.”

“One key reason why we’re doing this work is to provide choices for our communities. We want to bring services to the community and say here’s an immunization campaign, here are testing tools, it’s your choice to use them, and here’s the advantage of having these mobile testing facilities close to you. We can use wastewater intelligence to prioritize certain areas and deploy resources to areas that could potentially want these resources. The reason I say this is because in this specific case, for Mpox, we deployed this mobile vaccination testing unit from 10 PM to 1 AM, and sure enough, first shots and second shots of the vaccines were administered.”

How quickly can wastewater intelligence inform public health action:

“For us, there’s a difference between passive surveillance – looking at baseline – and active surveillance – acting on information. For example, at the Superbowl, if we were collecting wastewater from the stadium, we can set up a sampler from 10 AM to 10 PM and we can collect that wastewater from the 12-hour time window, bring it back to our lab, and within two hours our undergraduates can turn that complex matrix into nucleic acids. Then after an hour or two, we can get an answer about a pathogen that we’re looking for. That’s how real time it can be. The stadium is not too far from the University of Nevada, Las Vegas, it’s a 10-minute drive, and then we’re back in the lab and we’re able to execute quickly.”

Future directions for wastewater intelligence:

“One idea, in my previous and current work of neuroscience, that I didn’t fully understand was that this work with community partners is essential in growing a program that can provide services. This is the one part of the program that I think I’ve benefited from, and that our group has benefited from. In working with very diverse individuals who have diverse skillsets; coming together and asking questions about how our science can make a difference in a different discipline.”

“Now we’re extending our program to monitor other microbial content. We’re looking at sexually transmitted infections – gonorrhea, chlamydia, syphilis. We’re going to a dormitory or other areas and tracking increases in different bacterial pathogens – identifying areas where we can potentially put a tent to provide information about a disease that we’re seeing at higher levels.”

“We’re also looking at Candida auris – going to various treatment plants to monitor changes in this fungal pathogen. We can potentially sequence these genomes to identify antifungal treatment resistant mutations and say to a certain hospital, if you use this antifungal treatment, it’s not going to work because there are mutations in the genome, and this pathogen is going to be resistant to that treatment.”

“We’re also looking at opioids and high-risk substances. Fentanyl [addiction] is unfortunately a disease that is afflicting our country, so we want to better understand where we might find more opioids. Are there certain schools that we want to look at more closely? Are there certain times during the year that we see these spikes? Can we then introduce interventions to support individuals in our community?”

View his slides here. Watch the full discussion here.