A health care worker administers a COVID-19 test at a Maine Medical Partners drive-in clinic on St. John Street in Portland on Thursday, Dec. 17, 2020. Credit: Troy R. Bennett / BDN

Maine’s growing backlog of positive COVID-19 tests is obscuring a likely drop in cases in recent weeks reflected in wastewater and hospitalization data.

Throughout the pandemic, the number of daily cases has been the most widely shared measure of how the virus is spreading. Since January, Maine’s cases have been consistently undercounted because officials have been swamped by the highly contagious omicron variant. That backlog has grown from 46,000 tests to 58,000 as of earlier this week.

It has given Maine the appearance of being the only state in the country where 14-day case counts are rising, according to a New York Times tracker. But other figures such as declining positive tests, hospitalizations and newly released wastewater data indicate the state has likely followed the rest of the country on a significant drop in cases.

“It’s challenging at this point, because we’re getting these numbers from these different sources that can contradict each other,” said Dr. Gibson Parrish, an epidemiologist in southern Maine who used to work for the U.S. Centers for Disease Control and Prevention.

State health officials have deemphasized the importance of case counts and stressed the other measures during the backlog, which for a time led the federal government to send the state fewer doses of monoclonal antibodies, a key treatment for those more vulnerable to the virus.

The number of positive tests, an overarching figure that differs from total cases because state officials have not necessarily reviewed them to make sure the same person did not send in multiple tests, dropped from an average of 2,500 two weeks ago to 1,655 last week, Nirav Shah, the director of the Maine Center for Disease Control and Prevention, said Wednesday.

The number of patients hospitalized with COVID-19 rose slightly to 355 on Friday, but is still down nearly 20 percent from a mid-January peak. MaineHealth, the state’s largest hospital system, reported fewer than 100 virus patients hospitalized Thursday for the first time in two months.

All of these metrics, Shah said, are indicators the virus may be waning in Maine, but also that it is “too early to tell for sure.” He said Wednesday the state is still working through its backlog but did not indicate when it might be finished.

Widespread wastewater testing data released Friday by Shah in a Twitter thread also show positive signs, although it will be some time before trends can be established. Data from Westbrook, Gorham and Portland also show concentration of the virus has fallen steadily since the beginning of January, according to data released by the Maine CDC on Friday.

The backlog was likely keeping Maine’s case counts low earlier in the month, Parrish said. But he noted wastewater data in his hometown of Yarmouth points to positive signs. Wastewater data there shows virus levels have dropped steadily since the beginning of January. Pooled testing in the school district has also shown declines after peaking in early January, he said.

Parrish said case data may still have merit, depending on how the state processes it. If Maine corrects past data, people could get a sense of where the virus was spreading most. Clearing the data without that correction would artificially inflate case counts.

“We’ll know there were lots and lots of cases [at one point],” Parrish said in that scenario. “But we already knew that.”