After looking for COVID in wastewater, Cary could soon test for RSV, other viruses

To better understand infectious diseases at the community level, wastewater in Cary could soon be tested for Respiratory Syncytial Virus, monkeypox and other viruses.

The Town of Cary has extended its agreement with the Wake County Public Health Department to continue monitoring COVID-19 in wastewater with the additions of new viruses for the next three years.

Cary has been working since 2020 with the county’s health department and North Carolina State University by collecting wastewater samples from three water treatment sites.

COVID-19 is shed through stool, according to health officials. When flushed down the toilet, the virus is carried through sewers to the wastewater collection treatment plants.

The samples are ultimately taken to the state Department of Health and Human Services, where officials have been looking at SARS-CoV-2, the virus that causes COVID-19, in human stool for the past year.

The wastewater data has been an early detector of the spread of the virus. It examines the virus in a community-wide sample to see if the levels are decreasing, increasing or stagnant, according to the state’s health department.

That’s especially helpful since monitoring the virus has changed in the past three years with the presence of at-home tests and less community-wide testing.

“I think some of the value to the public health officials is that each of our wastewater treatment plants represent collecting wastewater from a portion of Cary, Morrisville, the areas we collect,” said Donald Smith, the manager for Cary’s Wastewater Collection System.

“It gives the health officials a snapshot of what’s going on in the community, as opposed to having to collect information individually from patients.”

First, testing for opioids

This is not the first time the town has tested wastewater for health-related issues. In 2018, Cary sent samples to monitor the opioid crisis, Smith said.

The town was selected to participate in the Bloomberg Philanthropies Mayors Challenge to test for opioid-type drugs for six months. The $100,000 project was intended to help the town find solutions to the opioid crisis by collecting and sharing data.

“We transitioned from the opioid testing to COVID-19 testing, mainly because of the pandemic and the focus switching to that, since it was a big public health issue,” Smith said.

The North Cary, South Cary and Western Wake Regional Water Reclamation Facilities serve as the town’s three wastewater facilities. They have a combined total capacity to treat up to 42.8 million gallons of wastewater a day.

The wastewater samples are collected twice a week and sent once a week. After the Wake County Public Health Department collects the samples from Cary, they are transported to NCSU for laboratory analysis and then to the state health department, according to Leah Holdren, a spokesperson for the county.

Each week, the state sends the county a wastewater monitoring summary.

Testing for RSV

The same system to test COVID-19 in wastewater will be used to test Respiratory Syncytial Virus, according to Virginia Guidry, the head of Occupational and Environmental Epidemiology for NCDHHS.

Guidry said testing for RSV and other viruses in wastewater is still new. Cary has not provided those samples yet, but that could change.

“We’re really just starting to do it and starting to learn more about it and get the data and interpret them,” she said. “We share the data back to the wastewater treatment plants and local health departments.”

Right now, the state is only sharing the detection in wastewater of RSV, a common virus that causes infections to the respiratory tract, Guidry said. The virus has been more contagious this year and is the most common cause of bronchiolitis and pneumonia for small children, according to the Centers for Disease Control and Prevention.

The virus can be more serious for infants and older adults.

Guidry said the state began testing for the spreading virus in September.

“We have seen the number of detections increase over time,” she said. “We had detections in at least 1 sample of 20 or 21 sites for last week.”

The trends for both COVID-19 and RSV are found on the state health department’s website through the dashboard of charts. COVID-19 trends are updated every Wednesday and the data for RSV is updated every Thursday.