By CBS3 Staff

MONTGOMERY COUNTY, Pa. (CBS) — Pennsylvania health officials announced on Tuesday three new presumptive positive coronavirus cases in Montgomery County, bringing the county’s total to eight. This brings the state’s total number of presumptive positive COVID-19 cases to 12.

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Officials are recommending those most vulnerable stay home and avoid large crowds.

What You Need To Know: Latest Coronavirus Information From Pennsylvania, New Jersey And Delaware Health Departments

“While we anticipate that there will be more Pennsylvanians with COVID-19 in the coming days and weeks, it is important for residents to know the commonwealth is prepared and to be prepared themselves,” Pennsylvania Health Secretary Dr. Rachel Levine said in statement. “Right now, you have a higher chance of testing positive for COVID-19 if you have traveled to a country or state with known community outbreaks or have come in contact with someone who has the virus. We are working with the health care community across Pennsylvania to keep them informed, consult on patient testing and ensuring they have the resources they need to care for patients.”

School districts across the county closed their doors Tuesday. Lower Merion was among them, saying places like Merion Elementary would get a deep cleanse.

The move was triggered by word that a Children’s Hospital of Philadelphia cardiologist in King of Prussia, who tested positive, had treated two dozen patients. That doctor is said to be in critical condition in a Philadelphia hospital.

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Of the three new presumed positive cases announced Tuesday, officials say a 70-year-old woman in Cheltenham may be the first instance of community spread.

Meanwhile, for students home from school, there is some calm, even humor, amid concern.

“We call it ‘Corona Day,’ a joke of a day, but there are underlying worries. Every period you hear, ‘Is there another outbreak near us?’ So there is worry behind the laughter,” Lower Merion junior Kate Steel said.

“I work with little kids so I don’t want to get anyone sick or get them sick,” junior Michaela Craig said.

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CBS3’s Joe Holden contributed to this report.