Though many facets of life have returned to normal as the coronavirus pandemic has slowed, wastewater monitoring data shows COVID-19 continues to circulate.
Concentrations of COVID-19 in wastewater at the Santa Rita Water Reclamation Facility in Durango have increased dramatically over the last few weeks as cases in Colorado have once again risen as omicron subvariants spread.
Though case rates remain low in La Plata and Archuleta counties, San Juan Basin Public Health expects cases and hospitalizations will increase in the coming weeks.
“Wastewater monitoring is the earliest indicator that we have. It’s first set of data,” said Megan Graham, spokeswoman for SJBPH. “Then from there it’s positivity rates, case incidence and then hospitalization and those all lag behind the wastewater data.”
COVID-19 concentrations in Durango’s wastewater have increased by 279% in the last 16 days, reaching levels last seen in early February as the omicron peak waned, according to a news release Wednesday from SJBPH.
COVID-19 concentrations increased 147% from May 2 to May 5, up more than 700% over the last month, according to Colorado Department of Public Health and Environment data.
While wastewater shows a rebound in COVID-19 in Durango, La Plata County added just five new cases Tuesday and Archuleta County added none.
Testing positivity rates in the two counties have remained relatively steady over the last week at about 6% and 4.5%, respectively, data from SJBPH showed Wednesday. However, both have jumped since the end of April.
“The state is modeling right now that we’re going to see an uptick over the next couple of months with each of those metrics increasing,” Graham said.
Cases in Colorado have already begun to increase with the state’s seven-day average reaching 1,069 new cases per day Monday after a low of 303 on March 26.
Rising cases are being driven by two omicron subvariants, both of which are believed to be more transmissible than omicron.
In a late April modeling report, the Colorado School of Public Health estimated the BA.2 omicron subvariant would cause hospitalizations in Colorado to increase and peak sometime in June or July with about 500 to 750 patients hospitalized across the state, though the authors cautioned that both the timing and severity of the peak will depend on the infectiousness of the subvariant and the protective measures that are in place.
Public health officials believe BA.2.12.1, a new subvariant spreading rapidly across the U.S. is 25% more transmissible than BA.2, which was an estimated to be 30% to 60% more transmissible than omicron, according to the American Medical Association and a SJBPH presentation to the La Plata County commissioners.
At omicron’s peak in January, nearly 1,700 Coloradans were hospitalized with COVID-19.
La Plata and Archuleta counties remain in the “low” category for the Centers for Disease Control and Prevention’s COVID-19 community levels, a measure of COVID-19 risk, as of Wednesday.
However, Graham said the levels for both counties may increase if the state’s projected rise in cases is accurate.
“State modeling is suggesting that many, if not most, counties in Colorado will transition into medium and then into high during that (peak) arc,” she said.
With higher community levels, the CDC recommends additional precautions.
At medium risk, the CDC advises those who are immunocompromised or at high risk of severe disease talk with their health care provider about wearing a mask and taking other precautions. The CDC also recommends that their family members consider wearing masks indoors with them.
If community levels hit high, the public agency encourages everyone to return to wearing masks indoors in public regardless of their vaccination status. Those who are immunocompromised or at high risk should consider avoiding nonessential visits to indoor public spaces, according to the CDC’s guidelines.
SJBPH follows the CDC’s COVID-19 community levels when issuing public health advisories, but Graham said the local public health agency has not yet decided how it would react to La Plata or Archuleta county returning to medium or high risk.
“We’re going to have to monitor the situation and make decisions accordingly to protect community health and follow CDC guidance,” she said.
CDPHE’s COVID-19 wastewater monitoring program is voluntary and both the Purgatory Metro District and the Hermosa Sanitation District in La Plata County have joined Durango. However, neither Purgatory nor Hermosa have received consistent results yet as CDPHE catches up on the monitoring data, according to SJBPH’s presentation to the county.
Bayfield’s participation is pending.
As cases again climb, residents of La Plata and Archuleta counties should continue to take the precautions public health officials have espoused throughout the pandemic, including booster shots and mask wearing in public for those who are at high risk, Graham said.
“Folks should make sure they’re up to date on their vaccines and high-risk individuals should be vigilant,” she said.
ahannon@durangoherald.com
