At UCSD, samples are collected and delivered to the Knight Lab at the Center for Microbiome Innovation, which developed the advanced technologies to conduct wastewater tests on a large scale. Credit: UCSD
On August 4, the Biden Administration declared monkeypox a public health emergency with more than 7,000 cases reported nationwide. It is just the fifth such national emergency since 2001—the COVID-19 pandemic being the most recent. In fact, today the nation remains in a state of emergency over the coronavirus pandemic. And while having two active public health emergencies is never a good thing, scientists in California are using it to their advantage by expanding their previous SARS-CoV-2 detection methods to monkeypox.
In May 2020, University of California San Diego (UCSD) launched its “Return to Learn” program that was conceived and built on three pillars: viral detection, risk mitigation and intervention. The viral detection pillar included a then-modest wastewater sequencing program on campus that was ultimately found to enable early detection of 85 percent of COVID-19 cases.
By March 2021, the incredibly successful wastewater surveillance program was expanded to include multiple samples sequenced each week from San Diego County’s primary wastewater treatment plant at Point Loma, with a catchment size of 2.3 million people.
Now, the same team of scientists is expanding the program a second time to include monkeypox.
“It’s the same process as SARS-CoV-2 qPCR monitoring, except that we have been testing for a different virus. Monkeypox is a DNA virus, so it is a bit of a surprise that our process optimized for SARS-CoV-2, which is an RNA virus, works so well,” said Rob Knight, professor and director of the Center for Microbiome Innovation at UCSD.
Knight and his team began experimenting with the possibility their test might work with both virus types in May and started monitoring wastewater from the Point Loma treatment plant in early June for the presence of monkeypox virus.
The first positive indicator occurred July 10, 2022 at levels near the limit of detection: 10,565.54 viral copies per liter of wastewater. Levels have dramatically increased since then, rising and falling slightly, but trending upward with a current high of 189,309.81 viral copies per liter of wastewater on Aug. 2, 2022.
However, Knight said it remains to be seen whether monitoring monkeypox virus load levels in wastewater can predict future infection or case rates.
“We don’t yet know if the data will anticipate case surges like with COVID,” he said. “It depends on when the virus is shed from the body relative to how bad the symptoms are that cause people to seek care. This is, in principle, different for each virus, although in practice wastewater seems to be predictive for multiple viruses.”
The CDC is showing that to be true with their recent wastewater testing in New York state for polio, which has reemerged in the U.S. for the first time since 2013.
In July 2022, an unvaccinated young man in Rockland County tested positive for polio, before eventually being paralyzed by the disease. Since the county was still collecting wastewater samples for COVID-19 testing, the CDC was able to analyze both old and new samples. The public health agency said they found traces of the polio virus dating back to early June, when the man was first hospitalized with a then-unidentified illness. Positive wastewater samples were also found in neighboring Orange County, as well.
Friday morning, the New York state health department said they have detected polio in New York City's wastewater as well, "a sign the virus is quiety spreading among unvaccinated people."
In 2019, research into using wastewater to monitor health was understudied and underperformed. The coronavirus pandemic changed that in the short-term, and most likely in the long-term. In a paper published in April 2022, Arizona State University researchers highlight how a technique known as wastewater-based epidemiology (WBE) can be used to accurately assess community-wide health.
The researchers identified 25 different classes of biomarkers that can provide valuable health statistics on community levels of hunger, stress, cardiovascular disease, pulmonary afflictions and cancer. The team behind the study said WBE can also be used to quantify stress metabolites and psychotropic drugs—as possible indications of high suicide risk/rate—as well as assist in the management of chemical risks, like microplastics, and a range of environmental contaminants, including volatile organic compounds indicative of air pollution.