蜜柚直播

They鈥檝e tracked levels of coronavirus genetic material in untreated wastewater from one of Pima County鈥檚 sewage plants since March 14. That came not long after local health officials obtained the first positive test result in an individual here.

Professor Ian Pepper, the director of the UA research lab that runs the wastewater testing, said last week he鈥檚 confident the testing results are representative of what鈥檚 going on with the virus, communitywide.

In the untreated wastewater, 鈥淲e鈥檝e seen concentrations originally negative, then become positive, then decrease,鈥� said Pepper. He is director of the UA鈥檚 Water and Energy Sustainable Technology Center, which lies near the county鈥檚 Aqua Nueva sewage plant, where the tested wastewater comes from.

鈥淭he last samples we took, I鈥檓 guessing within the last two weeks, were negative,鈥� he said.

Pepper said he believes the risk to people here from the virus is now lower than two months ago, but that there鈥檚 still a need to be vigilant because it could return.

鈥淭here does seem to be a natural progression. It seems to spread, levels off, and decreases. In addition to that, the heat may help to do a number on it,鈥� he said.

There is no community risk from the virus in wastewater, authorities say. There鈥檚 no coronavirus material found in the treated wastewater that the sewage plant dumps into the Santa Cruz River.

Researchers don鈥檛 know if the virus is inactivated in wastewater, or if it鈥檚 partitioned into solids that are pulled from the wastes during treatment, Pepper said. But in effluent they鈥檝e analyzed from other treatment plants, they see some where it was disinfected and the virus wasn鈥檛 found, and some that weren鈥檛 disinfected where the virus was found.

鈥淭hat鈥檚 what you would expect,鈥� Pepper said. 鈥淐hlorination kills the virus.鈥�

Researchers at the UA and others around the United States see wastewater as a big asset during the pandemic, rather than a threat. That鈥檚 because the virus often shows up there days before it shows up in individuals.

When the virus does hit people, studies have found that many infected are asymptomatic, but can spread the disease to others.

鈥淚n terms of monitoring for things like the possible return of the virus in the fall, this is very useful,鈥� said Pepper, a professor of environmental microbiology.

鈥淪ewage is a leading indicator of the pandemic,鈥� he said. 鈥淒eath is a lagging indicator.鈥�

Worldwide interest in wastewater testing

The UA鈥檚 activity matches a burgeoning national and global interest in this technique as a supplement to testing of individuals for COVID-19.

Individual testing has proven very challenging and slow to advance as the pandemic spreads, due to its cost, to shortages in key testing materials and to numerous other problems.

Wastewater testing for the virus has drawn buzz in the scientific press and gained public attention from the National Academy of Sciences. The academy hosted a virtual panel discussion Wednesday on what鈥檚 known as wastewater-based epidemiology.

The UA research center tests wastewater weekly from a plant that serves 183,000 households and businesses and other customers in most of 蜜柚直播 proper, and in a healthy chunk of the Catalina Foothills.

鈥淲e will be able to determine if the virus persists in the community even if there are no reported new cases,鈥� said Charles Gerba, a microbiologist and professor of environmental science in the College of Agriculture and Life Sciences, who is also working on this research. 鈥淭o me, it鈥檚 a key to tracing the spread of a virus.鈥�

The UA facility, commonly known as the WEST Center, has tested wastewater from 25 other communities, from California to New York. The UA is also collaborating with the U.S. Centers for Disease Control and Prevention. CDC is using virus data produced by the WEST Center to test its computer model that鈥檚 trying to estimate the number of infections in a community.

鈥淒r. Pepper鈥檚 team has been on the leading edge of this work since the beginning of the COVID-19 response,鈥� said Amy Kirby, a CDC environmental microbiologist. 鈥淏y measuring viruses in sewage, we may be able to detect infections in people who do not have symptoms or have not been tested. Additionally, sewage virus concentrations may be able to provide an early indication that COVID-19 cases are increasing in a community.鈥�

蜜柚直播 State doing similar research

蜜柚直播 State University is testing wastewater from 100 sewer systems worldwide, along with those in Tempe, Guadalupe and other Phoenix-area communities. Rolf Halden, an ASU professor who heads up the effort, says ASU鈥檚 Human Health Observatory operates the world鈥檚 largest wastewater monitoring network.

His group鈥檚 research has traced a similar trend to 蜜柚直播鈥檚 of first increasing, then decreasing levels of the coronavirus genetic material in Tempe鈥檚 wastewater. But in neighboring Guadalupe, where personal incomes are much lower than in Tempe, the wastewater has had particularly high counts of coronavirus genetic material, he said.

In that heavily Latino community, 鈥淭he speculation is that with its lower socioeconomic status, people have to be out and making money to put food on the table,鈥� Halden said. 鈥淣ot everyone has the luxury of living off savings, or working at home. In that income bracket, if you don鈥檛 show up at work, you don鈥檛 make money.鈥�

Halden co-authored a peer-reviewed study that concluded the wastewater monitoring could track the virus鈥檚 progress at a fraction of the cost of individual testing, worldwide.

He says wastewater monitoring could locate virus hotspots and clusters, followed by testing of individuals in those areas.

鈥淲e could, within a matter of weeks, measure 70% of the U.S. population, repeatedly every week,鈥� said Halden, an environmental engineering professor who is director of the Center for Environmental Health Engineering at ASU鈥檚 Biodesign Institute.

鈥淲e would be diverting 1% of the samples we鈥檙e doing now to wastewater, and allow you to move coverage from 3% to 70% of the U.S. population. That seems like a no brainer to me,鈥� he said.

Other researchers say the idea has promise, but that work needs to be done to come up with standardized methods of detecting the virus in wastewater and determining how much of the virus is present. UA鈥檚 monitoring can tell whether concentrations of the virus are increasing or decreasing but officials don鈥檛 have specific concentrations.

鈥淲hat鈥檚 going on nationally is that there鈥檚 a big push to standardize methods of getting concentrations of gene copies,鈥� said Pepper. 鈥淯ntil we get that information of concentrations of gene copies, it鈥檚 at best just an estimate.鈥�

Monitoring for COVID-19 in sewage has great potential to complement what public health experts are doing with data on deaths, hospitalizations and infections, said professor David Sedlak, of the University of California鈥檚 Berkeley Water Center, who moderated last week鈥檚 National Academy of Sciences panel.

鈥淚n my opinion, the ability of sewers to sample large numbers of homes simultaneously and anonymously could be a powerful tool but to date, federal and state funding has been limited to a few research projects. If we are to have a chance of using this kind of information to save lives we may need to consider a fast-track approach for scaling it up,鈥� Sedlak said.

During the panel discussion, Sedlak joked as panelists went into a break, 鈥淲hen you go to the toilet, remember you鈥檙e not just satisfying a biological need. You are contributing to someone鈥檚 scientific study.鈥�

Yale study potentially breaks new ground

The use of wastewater detection got a scientific boost May 19, when Yale University researchers published early results of a study of coronavirus genes in sewage sludge 鈥� the solids that fall out of wastewater as it鈥檚 treated. The study found coronavirus RNA concentrations in sludge were 鈥渉ighly correlated鈥� with those found in local testing and with hospital admissions.

Concentrations in sludge would show up about seven days ahead of when they appeared in tests of individuals, and three days ahead of hospital admissions in the New Haven area, the researchers wrote in an online publication. The study hasn鈥檛 been peer-reviewed, making its findings preliminary.

鈥淭hat it鈥檚 not peer reviewed offers a word of caution but they were very exciting results,鈥� UA鈥檚 Pepper said. 鈥淢ost importantly it was a leading indicator. A week can be an eternity with this thing.鈥�

An old technique

Studying viruses in wastewater is hardly a new technique, observed the UA鈥檚 Gerba, a longtime germ and virus specialist. It was used to help detect polio during the 1950s, he said.

Vaccines for the polio virus have dramatically reduced its incidence over recent decades, although it persists in Nigeria, Afghanistan and Pakistan. Just like the coronavirus, polio鈥檚 most severe symptoms occur only in a fraction of the total infections. Environmental surveillance programs with wastewater have been used to pinpoint 鈥渟ilent transmission鈥� of that virus, UA said in a news release discussing its recent coronavirus research.

鈥淲e have tested for hepatitis A, enteroviruses and noroviruses. We have approximately 15 different viruses that we regularly test for in sewage and recycled waters for reuse applications,鈥� said Walter Betancourt, a microbiologist with expertise in environmental virology and an assistant research professor in the Department of Environmental Science.

Similarly, at ASU, Halden鈥檚 research group started using wastewater to detect opioids such as heroin and fentanyl in 2018, and last year started using it as an early warning system for the flu.

Nationally, a water research group says it鈥檚 seen efforts able to detect the genetic material of coronaviruses in wastewater at levels amounting to as few as one case per 100,000 people, said Peter Grevatt, CEO of the Denver-based Water Research Foundation.

鈥淎 rapid rise in wastewater can be an indication that a community is soon to enter a public health crisis,鈥� Grevatt said.

In an effort to standardize testing methods, Grevatt鈥檚 group will launch a study this week. The UA鈥檚 WEST Center will participate.

Sewage from UA dorms to be tested this fall

This fall, WEST Center will also be heavily involved in the UA鈥檚 reopening to students after the shutdown due to the pandemic, Pepper said.

The UA will employ one team to test every student for the virus, another team to test antibodies, and his team to conduct sewage surveillance from the campus dormitories, he said.

Pepper said this will allow researchers to develop good correlations between what鈥檚 in the wastewater and what students are personally experiencing.

鈥淭his will offer a unique situation,鈥� he said. 鈥淵ou don鈥檛 usually have defined communities where you have a defined history of the virus.鈥�