* The CDC updated their definition of a "close contact" on August 5, 2021. 

Close Contact through Proximity and Duration of Exposure: Someone who was within 6 feet of an infected person (laboratory-confirmed or a clinically compatible illness) for a cumulative total of 15 minutes or more over a 24-hour period (for example, three individual 5-minute exposures for a total of 15 minutes). An infected person can spread SARS-CoV-2 starting from 2 days before they have any symptoms (or, for asymptomatic patients, 2 days before the positive specimen collection date), until they meet criteria for discontinuing home isolation.

Exception: In the K–12 indoor classroom setting, the close contact definition excludes students who were within 3 to 6 feet of an infected student (laboratory-confirmed or a clinically compatible illness) if both the infected student and the exposed student(s) correctly and consistently wore well-fitting masks the entire time. This exception does not apply to unvaccinated teachers, staff, or other adults in the indoor classroom setting.

Public Health Recommendations: Except in certain circumstances, people who have been in close contact with someone who has COVID-19 should quarantine. However, the following people with recent exposure may NOT need to quarantine:

• People who have been fully vaccinated
• People who were previously diagnosed with COVID-19 within the last three months

Additional Information:

A number of factors can influence a person’s risk of exposure to COVID-19, including the type, proximity, and duration of their exposure, environmental factors (such as crowding and ventilation), vaccination status, prior COVID-19 infection, and mask use.

Correct and consistent mask use is a critical step that people can take to protect themselves and others from COVID-19. However, the type of masks used and whether they are used consistently and correctly varies throughout the general population. Except in K–12 indoor classroom settings as described above, mask use is not considered when defining a close contact during case investigation and contact tracing, regardless of whether the person diagnosed with COVID-19 or the person exposed to SARS-CoV-2 was wearing a mask. (Note: Exposure risk in the healthcare setting is determined separately and outlined in CDC guidance).

The infectious period is defined as the 48 hours prior to symptom onset through the duration of their 10-day minimum isolation. The infectious period of an asymptomatic case is defined as the 48 hours prior to the lab sample being taken through their 10-day minimum isolation. 

• The risk of exposure by asymptomatic persons can be reduced utilizing layers of mitigation. 
• Source control: contact tracing and quarantine, daily screening, temperature checks, masking, etc.
• Ventilation: increased air exchange rates, HEPA filters, increased outside air, UVC lights, etc.
• Distancing and PPE: unidirectional seating, optimized desk spacing, planned and limited cohort exposure, masks, etc.
• Hygiene: frequent hand washing, not touching the face, cleaning high touch surfaces and floors routinely, etc.

Only those individuals determined to have had close contact will be required to stay home for the requisite quarantine period. 

If a teacher or student tests positive or has symptoms, contact tracing will be used to determine close contacts among students, faculty, and staff, and they will be notified of the need to quarantine.

Guidelines are subject to change as the situation evolves and we learn more about COVID-19. Updated 8/13/21