As many people, including me, have noted, the shortage of COVID-19 testing makes data about its prevalence in the community suspect. A perfect example came up at Thursday’s press conference by N.H. officials – here’s the item I reported for the Monitor:

The number of new cases of COVID-19 has risen sharply in the past two days but that’s a function of more testing, not necessarily more disease, state epidemiologist Benjamin Chan said Thursday.

“We do not believe this means there is an increase in the spread of COVID-19,” Chan said at an afternoon press conference Thursday. “Rather, we believe this increase is from an increase in the testing, a direct result of efforts we have been making to test more broadly.”

Chan said in recent days there have been between 800 and 900 tests per day in the state, as compared to 400 to 450 a week ago.

“We plan to continue to ramp that up,” he said, pointing to the value of testing to “identify and then suppress or contain clusters” of disease outbreaks. On Thursday the state reported three new deaths, all in people over age 60 at nursing homes or other community housing.

The state has reported 183 new cases of COVID-19 in the past two days, close to twice the total of any previous two-day total.

In response to questions, Chan said it can be misleading to look only at the number of new cases to judge the status of the coronavirus.

“There’s not any one specific number or metric … to show us when transmission spread in the community is really down-trending,” said Chan.

Lori Shibinette, commissioner of the Department of Health and Human Services, agreed: “It’s not just the number of cases, it the percentage of positive results, and hospitalization rates. They would have to decline for several weeks before I would be comfortable in saying we’re in a consistent downward trend.”