LEBANON — As some Upper Valley hospitals see higher than average flu rates in line with national trends, schools in the Twin States are by-and-large not reporting higher than usual illness rates, but caution that flu season is not over yet.
The Dartmouth Health system is seeing significantly higher confirmed and suspected flu cases this season, Dr. Gabriela Andujar Vazquez, Dartmouth Hitchcock Medical Center’s hospital epidemiologist, said Monday. The highest number of influenza-like illnesses, or those that present with flu symptoms with or without a positive test, are coming from Lebanon and Keene, N.H.
Across the Dartmouth Health system, which includes hospitals and clinics in both Vermont and New Hampshire, there were 877 lab-confirmed flu cases in December, compared to 244 in December 2024, Andujar said.
Influenza-like illnesses also have almost doubled from 786 cases in December 2024 to 1,420 in December 2025.
“We are definitely seeing higher numbers of patients with influenza when compared to this time last year,” Andujar said in an emailed statement Monday. “It could be due to an earlier start of the season, decrease in vaccinations compared to same time last year, and/or current circulating virus strain, but we will have to keep an eye out to see how it unfolds.”
Across the country about 130 million doses of flu vaccine had been distributed this season, as of mid-December, about 13 million less than the same time last year, according to the CDC. Also complicating factors is that 90% of positive flu tests belong to a new variant of influenza A that does not match the virus selected for this year’s flu vaccine, potentially making the immunization less effective and decreasing population immunity.
“Vaccination is still expected to play a key role in preventing illnesses, medical visits, hospitalizations, and deaths due to influenza this season,” the CDC reports.
Dartmouth Health notified staff Thursday that the system and surrounding community is experiencing an “exponential increase” in influenza-like illness and lab-confirmed flu cases, DH spokesperson Audra Burns said.
As a result, the health system elevated its masking recommendations for employees to the third of four levels and masks are now “highly recommended for all patient-facing staff.” Any staff with new respiratory symptoms are also being advised to stay home from work.
Flu levels are higher than usual across the country and are continuing to increase, according to the CDC. The federal agency expects flu activity to continue for several weeks. Beginning in the last week of the year, this flu season is considered “moderately severe,” the second level on a four-step scale.
Across all 50 states and U.S. territories, Vermont is one of only four jurisdictions that reported “low” influenza-like illness rates during the last week of 2025, according to the weekly influenza surveillance report from the U.S. Centers for Disease Control and Prevention.
Many other states, including the rest of New England and New York, are categorized as having “very high” influenza-like illness activity, between seven and eight steps higher on a 13-step scale.
Though Vermont’s flu levels have remained low, the state Department of Health expects this to change, a spokesperson said Wednesday.
“Several surveillance indicators are increasing, and the Health Department has received a growing number of reports of flu outbreaks among long-term care and childcare facilities,” said VDH Spokesperson Kyle Casteel in a statement. “We expect flu activity levels to increase and remain elevated in Vermont in the coming weeks.”
Current levels may not reflect reality because surveillance relies on people “presenting at a health care facility,” which may have been less common for milder cases during the holiday season, Casteel said.
Vermont also tracks respiratory illness levels, including flu, through wastewater testing three times a week, which is not included in CDC reporting.
This data shows “moderate” to “very high” levels of the influenza A virus at four out of five wastewater treatment facilities across the state where testing is done. The closest facility to the Upper Valley in Ludlow, Vt., is tracking very low influenza levels.
In Randolph, Gifford Health Care is expecting to see an increase in flu cases later in the season, which is in line with recent years, Gifford Chief Medical Officer Josh White said in a statement.
“If the rates continue as they are, we could expect an additional increase in January numbers.”
Seventy Gifford outpatients have tested positive for flu since Oct. 1, with 51 people testing positive in December and 13 positive tests so far in January, Tayo Kirchhof, Gifford’s spokesperson, said.
Because Gifford only tracks people who are tested, actual community cases may “potentially be higher,” White added.
Upper Valley schools also have yet to see a surge of flu cases affecting operations.
Despite the high illness rates in Lebanon, the school district has not seen unusually high levels of absences of students or staff compared to past years, Jack Rooney, the district’s spokesperson, said Wednesday.
Nurses across the district are not reporting “excessive absence rates” and attendance records for the weeks before and after winter break are on par with the last two years, Rooney said.
Other Upper Valley school districts including in the SAU’s in Claremont and Newport, the Mascoma Valley Regional School District, Hartford School District and White River Valley Supervisory Union all reported no unusually high flu activity this week.
The First Branch Unified District middle and pre-K campus in Chelsea even noted that students and staff seem to be healthier following the winter break, Principal Janet Cash said Tuesday.
But, school administrators also say they will be continuing to keep an eye out as flu season progresses.
Despite being late in the season, health care experts say it is not too late to get vaccinated against the flu.
“Since the flu virus is expected to be circulating at higher levels in the very near future, now is a great time to get vaccinated if you have not already done so,” Casteel said.