In residential congregate settings such as dormitories, group homes, boarding houses, overnight camps, barracks, shelters, jails or prisons:
At least three probable or confirmed COVID-19 cases* within a 14-day period in epidemiologically-linked† residents and/or staff.
In non-residential congregate settings, e.g., workplaces, adult and child daycare facilities, K-12 schools and colleges/universities:
At least three probable or confirmed COVID-19 cases* within a 14-day period in people who are epidemiologically-linked† in the setting, are from different households, and are not identified as close contacts‡ of each other in any other case investigation.
For large congregate non-healthcare, non-workplace settings (e.g., 100 or more persons in a potential risk cohort), particularly those in jurisdictions with widespread community transmission, local health departments may determine that a higher absolute or proportional (e.g., 5% or 10%) number of cases may be appropriate for defining an outbreak.
Local health departments that determine that a cluster of COVID-19 cases constitutes an outbreak should report the outbreak to CDPH using the Novel Coronavirus 2019 disease outbreak condition in CalREDIE or an alternate established process.
Local health departments may define reporting thresholds for non-healthcare, non-workplace congregate settings in their jurisdictions. A reporting threshold is the number of reported COVID-19 cases within a 14-day period in a specific setting that warrants prompt reporting by the setting to the local health department; reporting thresholds may vary by setting.
For workplace settings, when three cases are reported in a workplace within a 14-day period, employers are required to notify the local health department under current CDPH guidance. AB 685 will continue this requirement as state law when it takes effect on January 1, 2021.
Local health departments should inform non-healthcare, non-workplace congregate settings in their jurisdictions about reporting thresholds and instruct them to notify the local health department if they identify the number of cases that meets the setting specific reporting threshold.
When the reporting threshold is reached and cases are reported to the local health department, the local health department will determine if further investigation is warranted, and if investigated, whether the cases constitute an outbreak using the definitions above.
* Per the Council of State and Territorial Epidemiologists' Interim COVID-19 case definition.
Confirmed case: Meets confirmatory laboratory evidence (detection of SARS-CoV-2 RNA in a clinical or autopsy specimen using a molecular amplification test).
Probable case: Meets clinical criteria AND epidemiologic linkage‡ with no confirmatory lab testing performed for SARS-CoV-2; OR meets presumptive laboratory evidence (detection of SARS-CoV-2 by antigen test in a respiratory specimen); OR meets vital records criteria with no confirmatory laboratory evidence for SARS-CoV-2.
† Epidemiologically-linked cases include persons with close contact‡ with a confirmed or probable case of COVID-19 disease; OR a member of a risk cohort as defined by public health authorities during an outbreak. This includes persons with identifiable connections to each other such as sharing a defined physical space e.g. in an office, facility section or gathering, indicating a higher likelihood of linked spread of disease than sporadic community incidence.
‡ CDC defines close contact as being within 6 feet of an infectious case for at least 15 minutes.