Upper Valley Sees Sharp Rise in Flu Cases This Winter

Health systems serving the Upper Valley experienced a notable uptick in influenza cases in December, driven largely by a new influenza A variant that does not closely match this season’s vaccine strain. Dartmouth Health recorded 877 lab-confirmed flu cases in December 2025, up from 244 in December 2024, and reported that counts of influenza-like illness more than doubled year over year. Regional providers including Gifford Health Care and community hospitals also reported increases in outpatient flu visits.

Because the majority of positive tests are this new influenza A variant, public health experts caution that vaccine effectiveness against infection may be reduced. Officials continue to recommend vaccination, noting that immunization is still expected to lower the risk of severe illness, hospitalizations and deaths. Local health authorities are emphasizing that even partial protection matters for people at higher risk of complications, including older adults, people with chronic medical conditions and the immunocompromised.

In response to rising cases among patients and staff, Dartmouth Health elevated masking recommendations for patient-facing staff and advised employees with respiratory symptoms to remain home. The measure aims to limit transmission within clinical settings and protect patients who are more vulnerable to severe influenza. Community hospitals and primary care clinics have been adjusting outpatient operations to manage increased demand while monitoring inpatient capacity.

As of early January, most school administrative units in the region, including districts serving Claremont and Newport, had not reported unusual surges in student absences or outbreaks that affected school operations. School administrators said they were watching attendance trends closely and coordinating with public health officials on prevention measures.

For Sullivan County residents, the immediate implications are practical: get vaccinated if you have not already, consider extra precautions if you or a household member is at high risk, and stay home when sick to avoid spreading illness. Health providers are urging cough and hand hygiene, and recommending that people with severe respiratory symptoms seek medical care promptly. Local clinics and health systems are monitoring the situation and may update guidance if the wave continues to grow.