Credit: Staff illustration/Andy Castillo

After a brief reprieve from coronavirus surges, COVID-19 cases in New Hampshire are slowly rising again.

The number of COVID-19 cases in New Hampshire has increased 55% over the last two weeks, according to state data.

Data from the N.H Department of Health likely doesn’t tell the full story. Ever since at-home COVID tests became widespread, many experts believe that data from local health agencies dramatically undercounts the number of active COVID-19 infections.

Whether this uptick in cases results in a new surge depends on the community’s vaccination rate and the degree of community mitigation strategies, said DHHS spokesperson Jake Leon.

A subvariant of Omicron could be behind the recent rise in cases. Dr. Michael Calderwood, an infectious disease expert from Dartmouth Health, said BA.2 is about 30% more transmissible than the original Omicron variant.

In New England, where cases have been rising, BA.2 now makes up about 90% of all COVID-19 cases, according to the Centers for Disease Control and Prevention. Between 73 and 78% of sampled infections in New Hampshire are currently due to the BA.2, according to CDC data and genetic sequencing at the NH Public Health Laboratories.

Leon said it is especially crucial for people with symptoms to isolate and test.

“The currently circulating BA.2 does not seem to cause more severe illness than BA.1, but without any doubt being up to date on the safe and effective COVID vaccinations will be the most important strategy to avoid severe illness and hospitalization,” he said. 

Those older than 50 or who have a compromised immune system should consider scheduling a second booster appointment for maximum protection, he said. 

In Concord, virus levels in wastewater have sharply increased, according to the CDC’s surveillance system. Increasing concentrations of the virus in wastewater is often an early warning that more cases are on the way.

For federal health officials, the rise in cases isn’t a cause for concern yet. Dr. Ashish K. Jha, the White House’s newly appointed COVID-19 response coordinator, told several news outlets that he is closely watching the numbers, but doesn’t see an immediate need to change guidelines from the Centers for Disease Control and Prevention.

According to the CDC’s community-level metrics, all counties in NH are currently experiencing a “low” level of COVID-19. Coronavirus-related hospitalizations have risen slightly, but the New Hampshire Hospital Association has yet to see a significant increase in patients, said NHHA President Steve Ahnen.

This comes just weeks after New Hampshire’s hospitals reported record-low COVID-19 patients and DHHS dismantled testing and vaccination sites. 

In mid-March, just one COVID patient was reported in the hospital, and just one in the Franklin and Laconia hospitals owned by the health system.

All of the state-managed COVID-19 vaccination sites closed at the end of March. Four of the seven mobile vaccination teams were demobilized on the same day.

“The numbers are going up, something which we are obviously concerned about and watching closely, given that we don’t know what the BA.2 variant will bring relative to cases and hospitalizations,” Ahnen said.