LEWISTON – COVID-19 cases are on the rise again locally and across the state, though it’s not clear if it’s because of a  post-July 4 surge, the spread of the highly contagious delta variant, or some combination of factors.

State health officials Tuesday reported 153 new cases of COVID-19 in Maine, with about half from York and Cumberland counties. Six cases were from Androscoggin County, four from Franklin and one from Oxford. There were no additional deaths.

Apart from Franklin County, the seven-day average of new daily cases across the state and in central and western Maine was up from two weeks ago. When adjusted for population, the seven-day average of new daily cases per 10,000 individuals across the three counties was lower Tuesday than the statewide average for what might be the first time in months.

As of Tuesday, there was an average of 0.2 new cases per 10,000 residents over the past seven days in Androscoggin, 0.29 cases per 10,000 residents in Franklin County and 0.17 cases per 10,000 residents in Oxford County.

Statewide, the seven-day average per capita was 0.37.

The rolling average of new daily cases over seven days smooths the daily blips and dips in numbers and provides a more complete snapshot of case trends. Adjusting the seven-day averages for population is most accurate for comparison’s sake.

Still, the tri-county region is still seeing fewer daily new cases on average compared to one month ago. Androscoggin and Oxford counties saw a decrease of nearly 30% in new daily cases per capita over a seven-day period Tuesday compared to June 22. Franklin County’s average decreased by just under 22%.

Across the state, however, Tuesday’s seven-day average per capita was a nearly 50% jump from June 22 – and a 270% increase from two weeks ago.

The delta variant, a highly contagious strain of the virus first detected in India, has led to renewed urgings from some public health officials across the country for individuals, both vaccinated and unvaccinated, to wear face coverings indoors and to social distance in some situations.

Local health departments, from Los Angeles County to Provincetown, Massachusetts, have issued new recommendations in light of the recent uptick in caseloads, a move that U.S. Surgeon General Vivek Murthy publicly supported earlier this week as a “mitigation measure.”

The U.S. Centers for Disease Control and Prevention has not announced any changes to their recommendations that fully vaccinated people need not wear face coverings.

As of the latest round of genome sequencing for the delta variant in Maine from July 9, there were five confirmed cases and five suspected cases.

A spokesperson for the Maine CDC said Tuesday that the state is not considering changes to its masking or social distancing guidelines, nor considering reinstating restrictions on travelers from other states.

“We have no plans at this time to adjust these policies and continue to encourage those who are unvaccinated to wear a mask while indoors and to get vaccinated,” Maine Department of Health and Human Services spokesperson Jackie Farwell said in an email.

Representatives from Lewiston’s two hospitals – Central Maine Medical Center and St. Mary’s Regional Medical Center – said the delta variant is not top of mind when it comes to treating COVID cases, at least not yet.

“We cannot stress enough the importance of vaccination for putting an end to the pandemic,” said Dr. John Alexander, chief medical officer of Central Maine Healthcare, CMMC’s parent company. “It’s the best way to protect yourself and others from what has become preventable tragedies. We know that the delta variant is highly transmissible, with a viral load 1,000 times greater than that of the original strain of the virus.”

On Tuesday, there were three confirmed COVID-19 in-patients in noncritical care beds at CMMC. So far this month, there have been three in-patient days where an individual with a confirmed case was in the intensive care unit and was also connected to a ventilator.

No confirmed patients in June required a ventilator, according to numbers provided by the hospital, and 11 out of 159 total inpatient days were of individuals in the ICU.

“It also makes sense to consider extra layers of protection, such as being both vaccinated and masked, as Dr. (Anthony) Fauci has said, if you’re in an area where COVID is active,” Alexander said.