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Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the guidance for fully vaccinated people. CDC recommends universal indoor masking for all teachers, staff, students, and visitors to K-12 schools, regardless of vaccination status. Children should return to full-time in-person learning in the fall with layered prevention strategies in place.
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UPDATE
Travel requirements to enter the United States are changing, starting November 8, 2021. More information is available here.

When to Initiate Case Investigation and Contact Tracing Activities

When to Initiate Case Investigation and Contact Tracing Activities
Updated May 26, 2020
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Case investigation and contact tracing activities should be implemented at two distinct points in an epidemic:

  •  First, early on in an epidemic, during the containment phase, case investigation and contact tracing are needed to stop transmission and prevent a large outbreak from occurring. If efforts to contain the epidemic are unsuccessful and widespread transmission occurs in the community, then stricter community mitigation measures (such as stay-at-home orders, business closures, etc.) must be implemented. If the strict mitigation measures are effective, transmission will begin to decline, and the community will enter a suppression phase.
  • Second, once the community enters the suppression phase of the epidemic, the jurisdiction should begin to implement or scale up case investigation and contact tracing activities before the mitigation measures are fully lifted, in order to continue to reduce community transmission.

The decision to initiate or scale up COVID-19 case investigation and contact tracing activities will be unique to each area and will depend on the level of community transmission, characteristics of the community and their populations, and the local capacity to implement case investigation and contact tracing. It is critical that case investigation and contact tracing activities be adequately resourced and widely accepted in any community where they are implemented.

When to suspend case investigation & contact tracing activities

When a jurisdiction does not have the capacity to investigate a majority of its new COVID-19 cases, case investigation and contact tracing may not be the most effective approach. At that point, jurisdictions should consider suspending or scaling down contact tracing activities and reimplementing strict mitigation measures (such as stay-at-home orders, business closures, and school closures) until transmission begins to decline.