PITTSFIELD — City officials say that data showing a decline in the presence of COVID-19 in the city’s wastewater — it’s a measure that has served as a soft predictor for what will happen with coronavirus cases locally — is cause for optimism in the short term.
Last week, the amount of coronavirus detectable in city wastewater dropped to the lowest point in two months — at about 116,000 coronavirus RNA copies per liter.
The highest concentration of coronavirus RNA in city water came in early January, when there were 1.5 million RNA copies per liter, and about 190 contagious cases in the subsequent week.
But, officials caution that the city isn’t done with the coronavirus pandemic yet.
“What I would expect from the next [wastewater] results is that it will go up,” Commissioner of Public Services and Utilities Ricardo Morales said. He added that the results have tended to yo-yo between tests, but the general trend line in the amount of coronavirus present slowly is decreasing.
Morales said that thanks to financial support from the state, the city has begun testing wastewater samples three times a week, up from the one weekly test that has been conducted since July 2020.
Morales said the state is covering the additional testing through the end of November, at which point city officials will use their remaining test kits to analyze samples through the end of the year.
The additional testing helps create a sharper image for how the virus is working through the city’s population. The wastewater data generally indicates what will happen with contagious coronavirus cases in the seven days afterward.
Interim Health Department Director Andy Cambi presented data to the City Council on Tuesday night and said that recent tests have shown an impressive decrease from the start of the month, when the detectable amount of coronavirus had gone up to about 544,000 RNA copies per liter.
In the week that followed that test, the city’s estimation of actively contagious cases jumped from 39 on Oct. 1 to 65 on Oct. 7.
Cambi said in an interview Wednesday that the spike in wastewater data, and subsequent spike in contagious cases, likely were connected to end-of-summer travel.
“I see that [increase as being] with the type of activity that people are participating in, being the end of the summer and if they did any traveling,” Cambi said. “Because right here in the community, we’re doing a great job with vaccinations, we’re doing a great job with masking and taking the initiative to mask.”