Next semester the University of Hawaii Manoa will test sewage from 11 dorms to monitor the prevalence of COVID-19 on campus and track mutations of the virus. It’s the continuation of a successful citywide pilot project that tested sewage at Honolulu’s wastewater treatment plants throughout 2020.
Tao Yan’s lab at UH started studying wastewater samples from two UH dorms last November to develop a process to detect COVID-19 outbreaks before students start showing symptoms.
SARS-CoV-2, the virus that causes COVID-19, can be detected in someone’s feces within three days of infection, far earlier than the 14 days it can take to develop physical symptoms.
Each UH dorm has a designated sewage pipe, and in the fall graduate students will collect samples every Monday and Thursday. Researchers will determine how much viral load is in each sample and if the amount increases, the university would have an indicator that a student may be spreading the virus.
“We are trying to use this as a real-time detection mechanism,” said Yan. “Everybody hoped that this disease would just go away but we need to be careful just in case there’s a flare up or some new variants arrive here.”
It’s a continuation of lessons learned from Yan’s work analyzing samples from Honolulu’s public wastewater treatment plants throughout 2020. At the beginning of the city’s pilot project, it would take up to four days to determine the viral load in a wastewater sample. But now Yan’s lab can return results in 24 hours. Now the city is considering participating in a national wastewater study.
“Four days could mean a lot more transmission of an infection so this lets us detect an infection as soon as possible,” Yan said.
UH spokesman Dan Meisenzahl said no decisions have been made yet on how the sewage results will be used to shape university policy on COVID-19 testing or quarantine.
Studies have found monitoring sewage at nursing homes can detect even small outbreaks before patients start showing symptoms, and it’s likely this kind of research will continue at dorms, military barracks and other residential living facilities across the country.
The university is requiring all students to be fully vaccinated against COVID-19 in the fall but vaccinated people can still catch the virus, just at far lower rates than unvaccinated people. Robust data from multiple countries shows vaccines greatly reduce the likelihood of developing symptoms, being hospitalized or dying from the disease.
Yan said successful vaccines are one reason why wastewater testing will be useful to scientists and public health officials. Asymptomatic people are unlikely to be tested for the virus, so it could be difficult for officials to track which variants of the disease are circulating through the population.
Yan’s lab is working on a process that will determine variants of SARS-CoV-2 in a sewage sample.
“Once we have that method established and approved we will see how vaccination affects the evolution of this virus,” he said.
Information about mutations and variants of the virus could help scientists create more effective vaccines and boosters. Just as the flu virus mutates every year, requiring annual shots, COVID-19 vaccines may require boosters to remain effective against different variants.
“We can use wastewater as a sampling platform for the whole community and we can track how this virus is evolving in the population,” he said.
Sewage from Honolulu’s nine public wastewater treatment plants was analyzed for SARS-CoV-2 from May to December of 2020.
Originally the city was sending samples to BioBot, a company in Massachusetts, but it took weeks to get results. Eventually Josh Stanbro, who was leading the city’s wastewater testing efforts at the time, partnered with Yan at UH.
“It’s crazy to look back at how fast things were moving,” Stanbro said.
The Honolulu Department of Environmental Services took nine wastewater samples a week and delivered them to Yan’s lab, which would test the samples, compare results to the city’s nasal-swab testing data to determine accuracy, and send the final analysis back to the city.
“It would have taken five years normally to set up the protocols, go through the contracting and to get everybody’s buy-in to do it,” Stanbro said. “Here you had a sprint of a few months and everyone really stepped up.”
That’s not to say there weren’t bumps in the road. In August, Stanbro and Yan said the Hawaii Department of Health wasn’t providing enough data to aid the analysis. Eventually DOH did provide information, but it wasn’t as specific as Stanbro had hoped. But Yan and his lab were still able to build accurate models to determine how the viral load in a sample of sewage correlated to the virus’s spread throughout Oahu. Overall, Stanbro considers the city’s wastewater testing program a success. Real-time data from the project was published online from mid-summer through December, which he hopes helped people make informed decisions.
“More data and more transparency is always more helpful when you’re in a situation like that where people are looking for clarity,” he said. “Especially when we think back and remember what it was like last spring, last summer when it was difficult to even get enough COVID tests.”
“It was a very fruitful collaboration,” Yan said.
An analysis of viral load in Honolulu’s sewage during the first lockdown was recently published in a national journal. Yan’s lab compared wastewater results with testing data from the city to prove that wastewater analysis is an accurate way to determine the virus’ spread in a population.
The citywide testing was funded through the CARES Act, and so monitoring stopped when funds expired at the end of 2020. But the U.S. Department of Health and Human Services is funding a national program to monitor the presence of COVID-19 and identify variants of concern.
The nine-week study will cover over 100 million Americans across 49 states and territories, according to emails from BioBot, the company that will conduct the testing and send results back to municipalities within 48 hours of samples arriving at its lab.
Hawaii is the last state to sign on, but Markus Owens, spokesman for the Honolulu Department of Environmental Services, said in an email the department only found out about the program on Wednesday but is “open to the idea.”