A woman in a mask puts her bag in her car in front of the sign at Presque Isle's Walmart on Wednesday, July 8. Credit: David Marino Jr. / The Star-Herald

PRESQUE ISLE, Maine — The Maine Center for Disease Control and Prevention is examining whether an outbreak at the Presque Isle Walmart is associated with construction workers at the store, said Maine CDC Director Dr. Nirav Shah in a briefing Thursday.

The CDC has not detected any further cases in the outbreak it reported on Tuesday. Shah said the CDC has reached out to contractors and subcontractors who had recently done work at Walmart, but had not learned anything that would tie construction work to the surge of cases.

In Tuesday’s briefing, Shah said the CDC was working with Walmart management to contain the virus, including testing those who may have been exposed. Shah said that an essential part of the investigation was determining if employees contracted the virus on the job or while congregating outside the workplace.

Walmart has continued to stay open since the outbreak was announced. Shah said on Tuesday that the three employees who tested positive for COVID-19 were not currently working there. In Thursday’s briefing, he recommended that residents who had recently visited the Walmart consult their physicians if they were worried about exposure.

Walmart is Aroostook County’s busiest store. Earlier this month, it began requiring that customers wear face coverings. The new rule has increased the number of shoppers wearing facemasks — which had become very low before the rule change — though not all abide.

The CDC’s map of COVID-19 cases by municipality was also updated on Wednesday using data as of July 21. For the first time, it highlighted municipalities in the Presque Isle area where residents had contracted the virus: 1-5 cases in Presque Isle and the nearby communities of Mapleton and Washburn.

The Maine CDC reported two new COVID-19 cases in Aroostook County on Thursday, putting the total number in The County at 32. Based on Shah’s statements, those do not appear to be connected to Walmart.