COVID-19 Contact Tracing Indicators

Contact tracing is a public health tool that can help slow the spread of COVID-19.  Contact tracing involves two main steps:

1. Interviewing people who were diagnosed or tested positive for COVID-19 (“cases”) to recommend that they stay home (isolate) and find out how they were exposed and who they might have exposed while they were contagious (“contacts).

2. Interviewing these contacts to inform them that they might have been exposed to COVID-19 and recommend that they get tested, stay home (quarantine), and monitor their health.

Learn more about contact tracing in Virginia here.

How to Use the Dashboard: Use the box to the right of ‘Reporting Period’ to select a starting date for a 7-day timeframe of contact tracing data. Select a Friday date for a Friday-Thursday reporting period. The earliest date available is 9/4/2020. The dashboard will be updated each Friday to include data for the previous week. The boxes should be read clockwise, starting with ‘Case Interviews’ in orange, then ‘Known Exposure’ in blue, then ‘Contact Tracing’ in green, and finally ‘Contact Interviews’ in yellow. Each percentage will display the numerator and denominator when you hover over or click on the number. Detailed descriptions of each contact tracing indicator can be found in the table below the dashboard.
Contact Tracing Metric Descriptions
Metric Description
Case Interviews This category includes the percent of cases with a completed interview date documented by local health department staff, out of all cases within the reporting period. Also shown is the percent of interviews that were completed within 24 hours of VDH receiving the lab or medical report, out of all completed interviews. Interviews that have been completed but do not yet have a date documented are not included. 

Local health departments  have the goal to contact and interview all community-based cases within 24 hours of being notified of the case. Outbreaks at congregate living settings (such as long term care facilities, jails, and prisons) are investigated by specialized teams that work together with the facility’s medical team. 

Obstacles that prevent health departments from contacting all cases  include incorrect contact information given to the health department, people not responding to the health department, and the large number of reports received by the health department in a certain day. During times of significantly high case volumes, local health departments may need to prioritize follow-up to specific groups.

Known Exposure This category includes cases where the source of the COVID-19 exposure was documented, out of all cases with an interview date within the reporting period. This includes people who had known contact with someone with COVID-19 and people who were linked to a COVID-19 related outbreak. 

A case investigator will work together with the person who has COVID-19 to identify the potential source of infection. This helps public health learn more about the spread of the virus and prevent  future outbreaks. Often, it is not possible to determine the source of the person’s infection 

Contact Tracing This category includes the percent of cases who provided information about the people who they have been in close contact with, out of all cases with an interview date within the reporting period. Also included is the average number of contacts identified by each case. This number only includes contacts who have enough information to do follow-up and the contact is not a known case. 

This process of ‘contact elicitation’, identifying people who might have been exposed, requires trust and teamwork between the case investigator and the person with COVID-19. Protecting privacy and confidentiality is critical to public health. VDH will never share the name of the case with the contact, unless the case gives permission to VDH. 

Contact Interviews This category includes the percent of contacts who were interviewed by local health department staff and enrolled to provide daily symptom reports, out of all contacts identified within the reporting period. Also shown is the percent of contact interviews that were completed within 24 hours of being identified by the case, out of all completed contact interviews. 

Contact tracers ask all contacts to get tested, stay home (quarantine), and monitor their health. VDH uses a tool called Sara Alert to send daily symptom monitoring surveys to contacts. Sara Alert helps contacts monitor their health for any COVID-19 related symptoms. It also helps  contact tracers to reach out and connect people to medical care or support if needed. If people who were exposed (contacts) become infected with COVID-19, they become cases and the contact tracing cycle starts again.