As high levels of community spread of COVID-19 continue in North Carolina, clusters of cases are being identified in workplaces, educational settings, and many other community locations. Identifying and responding to COVID- 19 clusters helps Local Health Departments (LHDs) and the state implement prevention and control measures, identify risk factors, and understand settings where transmission of COVID-19 is most likely to occur.
This report includes clusters identified by LHDs but underrepresents the full scope of clusters and associated cases occurring across the state. In part, this is due to the fact that many COVID-19 cases are never diagnosed or cannot be linked to a specific setting or specific cluster. Additionally, while congregate living settings, schools, and childcare facilities are required to report clusters or outbreaks to their LHDs, other settings are not required to report in the same manner. Thus, the cluster data provided in this report is limited to clusters that have been voluntarily reported to LHDs or identified through case investigation and contact tracing efforts.
The North Carolina Department of Health and Human Services (NC DHHS) defines clusters of COVID-19 in non- congregate living settings as:
• A minimum of 5 cases with illness onsets or initial positive results within a 14-day period AND
• Plausible epidemiologic linkage between cases*
*Cases should be present in the same general setting during the same time period (e.g., same shift, same classroom, same physical area) and there should not be a more likely source of exposure for identified cases (e.g., household or close contact to a confirmed case in another setting).
Cases and deaths included in this report represent only those linked to clusters meeting the above definition. Clusters are included if they were reported to public health on or after May 22, 2020, the date the cluster definition was published; the exception is clusters in meat and poultry processing facilities, which were tracked beginning in April 2020.
A cluster is considered over if there is not evidence of continued transmission within the setting. This is measured as 28 days after the latest date of onset in a symptomatic person or the latest date of specimen collection in an asymptomatic person, whichever is later. If additional cases are subsequently reported and a new cluster exists, it will be reported as a second, new cluster in that setting.
Clusters are often identified through the case investigation process, during which LHDs contact people newly diagnosed with COVID-19 to determine where they had been for the previous 14 days. This helps identify links to other cases with shared exposures. Confirmed or suspected clusters can also be reported directly to LHDs by individuals or businesses, although such reporting of clusters or outbreaks is only required by congregate living settings, child care programs and K-12 schools. Lists of ongoing outbreaks in congregate living settings and ongoing clusters in child care and school settings can be found in separate reports. Cluster data from the most recent weeks are preliminary and subject to change as case investigations proceed, as it can take time for LHDs to link cases to a specific cluster.
Spread of COVID-19 is most likely to occur in indoor settings with large numbers of people, particularly those where mask use and social distancing are not being observed. While clusters in some settings have decreased over time, continuing clusters in many workplace and community settings reinforces the need for all North Carolinians to practice the 3 W’s: Wear, Wait, and Wash.
This report includes 1) total cumulative reported clusters, cases and deaths by type of cluster since May 22, 2020 (except for meat and poultry processing facilities, which were tracked beginning in April 2020 and 2) graphs per type of cluster showing trends over time.