COVID-19 continues to spread at a high rate in New Hampshire, with no clear sign yet of the kind of decline most other states are seeing.

“Compared to the rest of the country, we are really not on the downtrend,” said Dr. Aalok Khole, an infectious-disease specialist at Cheshire Medical Center in Keene. “If you look at sort of the state graph, we’ve waxed and waned, but we’re really not seeing a progressive decline, which a lot of the other parts of the country are seeing.”

According to a New York Times data tracker, cases have dropped over the past two weeks in nearly every state. The outliers include New Hampshire and Vermont, both of which have seen double-digit percentage increases in that time.

The seven-day average of new cases in New Hampshire has fallen in recent days, but it’s unclear if that signals the start of a trend. Cases have sometimes fluctuated briefly in the past two months before continuing their upward trajectory. As of Friday, the state was averaging 521 new cases per day.

Locally, the percent positivity of tests administered by Cheshire Medical Center trended up in the first half of October, after a downtick last month. The share of tests that were positive rose from 7.3 percent the week ending Sept. 30 to 9.6 percent the week ending Oct. 14, the most recent for which data were available.

Khole said the hospital is seeing that reflected in its COVID-19 patient numbers.

“We had started declining, and then we are sort of going back up and plateauing again,” he said.

The N.H. Department of Health and Human Services continues to rate every county in New Hampshire as having “substantial” transmission, the highest of its three levels. There have been 432 new cases in Cheshire County over the past two weeks.

Statewide, hospitalizations and deaths — which tend to follow case rates, at a lag — have also been rising.

On Friday, New Hampshire’s hospitals held 218 confirmed COVID patients, compared to 140 on Oct. 13, according to the state health department.

And the state has been averaging about three deaths per day, having climbed from fewer than one per day in early August.

The state announced 21 COVID-related deaths in the past week, two of them involving Cheshire County residents.

This past week, Cheshire Medical shifted to its most restrictive visitation status, citing the rate of transmission in the community — the first time it’s moved to “red” status since it implemented the current color-coded system in mid-March.

Khole offered a few possible reasons for why New Hampshire is faring worse than the country at large right now.

“Parts of the state did have major surges, but we never really had these rapid peaks and rapid falls like say, for example, Florida or Texas or Michigan,” he said. “As a result of this, there’s a chance that the rates of natural immunity by infection in our population may not be as much.”

Additionally, because the state has an older population, many residents got vaccinated early on; that protection may have waned somewhat since. And vaccine uptake among younger Granite Staters has been disappointing, Khole said.

“Once the age groups opened up, we really didn’t have the younger population jumping on as we would have liked,” he said. “That stalled us on a vaccine percentage level.”

He said he fears “it will only get worse as the season gets colder and other respiratory viruses also start moving around, which we’re already seeing hints of.”

Vaccinations remain the most effective tool to fight the virus, Khole said, and Cheshire Medical has seen that first-hand. When vaccinated people do come down with COVID-19 or become hospitalized, they still tend to fare better than unvaccinated people.

“We’re seeing a clear distinction between who’s needing higher levels of care and who’s not,” he said. “... Also, from an outcomes perspective, the ones that tend to do worse, even amounting to death, is pretty much the unvaccinated population.”

He said it’s frustrating to see those cases despite the wide availability of vaccines.

“It’s more disheartening as a health care worker to see someone suffer from this illness, and have a bad outcome, knowing that it was preventable,” he said.

Khole urged anyone who hasn’t done so to get vaccinated. And while he acknowledged it can be frustrating after 18 months, he stressed that it’s important that everyone continue mitigation measures like mask-wearing, hand-washing and staying home when sick.

If vaccination rates don’t increase, he said, these surges could continue. That gives the virus more opportunity to evolve into an even worse variant — as happened with the more contagious delta strain, which now predominates in the U.S.

“The problem is, the more you allow the virus to linger, the more you allow the virus to spread — delta’s a problem today, but virus, by its own nature, mutates if you give it a chance to spread,” he said. “And if you give it a chance to spread because of lack of vaccinations, there is a likelihood that this may not be the last strain that we see to create trouble within the country.”