SEBAGO — Fifteen new cases of COVID-19 were reported in town in the last month, but only three of those positive cases are being reported in the state’s zip code-based data, according to the Maine Center for Disease Control.

A Sebago summer resident, who maintains primary residence in Florida, tested positive for the virus around Labor Day shortly after 11 family members had visited from Massachusetts.

All 11, who were in town for nine days, according to local health officer Helen Twombly, tested positive upon returning to Massachusetts.

“It’s kind of a strange community spread,” Twombly said last month.

Those cases “do not currently meet the criteria for an outbreak investigation,” according to Maine CDC Communications Director Robert Long.

“I can confirm that Maine CDC has been in communication with the local health officer to address concerns about potential exposure from nonresidents who tested positive for COVID-19,” Long said in an email to the Lakes Region Weekly Sept. 22.

Twombly said on Sept. 25 that there were three Sebago residents who tested positive in the last two weeks and the six other reported cases have all recovered.

The summer resident was hospitalized but returned home last week.

Since the 12 family members all maintain primary residence in other states, those numbers are not recorded in Maine’s numbers, regardless of the fact that they were positive for the virus while in town.

Long said this follows federal guidance.

“The (zip code-based) data are not meant to be an indicator of risk or community infection rates. Maine people and visitors should live their lives as if the virus is in their community and should not look to the data to assess personal risk,” Long said.

He added: “Outbreaks do not include people who claim residence in other states if their cases are epidemiologically linked.”

Twombly said all individuals or businesses that had come into contact with the positive individuals were contacted.

Despite this policy, however, some towns have used zip code-based data to justify more aggressive reopening measures.

In June, for example, the Windham Town Council passed a resolution urging state legislators to take the number of COVID-19 cases by zip code into account when evaluating closures and restrictions.

According to Covid Act Now, a nonprofit data analysis site, Cumberland County’s daily infection rates remain relatively low compared to larger outbreaks in York, Androscoggin and Kennebec counties.

As of the latest update to the Maine CDC’s data dashboard on Sept. 20, there are nine cumulative cases of COVID-19 in Sebago, which has a population of 1,978 primary residents.