The link above will direct you to the CDC website page that has a nice graph that explains how to determine an exposure and what to do when a person is exposed.
A person is considered exposed if they have close contact with a person from 2 days prior to onset of symptoms/positive test date.
This page can also be accessed from the PA Dept of Education page in the link below if you scroll down to the heading SYMPTOM MONITORING and click on “exposure”
You will find much more school specific guidance on this page as well.
The health department also publishes guidance for providers and facilities that can be accessed on the public website.
This is called PA HAN guidance and the link is below.
When a person tests positive for COVID the guidance is to isolate themselves at least ten days from onset of symptoms.
A person may be released from isolation upon the following criteria: ten days since onset or positive test date if asymptomatic, 24 hours fever free and improvement in symptoms.
This specific guidance can be found below.
A 14 day quarantine period is recommended by the CDC after an exposure.
This is also on page 3 of the document below.