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State of California—Health and Human Services Agency
California Department of Public Health

June 20, 2023

Local Health Departments

Non-Healthcare Congregate Facilities COVID-19 Outbreak Definitions and Reporting Guidance for Local Health Departments


This document provides guidance to local health departments (LHDs) on COVID-19 outbreak reporting requirements and recommendations for non-healthcare settings. This includes recommendations for when facilities should report to LHDs (reporting thresholds), and outbreak definitions to determine when LHDs should report to California Department of Public Health (CDPH).

Apart from these recommendations, LHDs may make determinations on how to prioritize investigation and response to reported clusters or outbreaks. Additional considerations for doing so are included below.  

For additional guidance on outbreak reporting in workplaces, LHDs should consult CDPH COVID-19 Workplace Outbreak Reporting Guidance.

COVID-19 Outbreak Definitions for Non-Healthcare Settings

This outbreak definition is used to determine when LHDs should report a COVID-19 outbreak to CDPH for surveillance purposes. 

Outbreak consists of:

  • At least three COVID-19 cases* within a 7-day period among people who are epidemiologically linked† in the setting, and are not known to be close contacts‡ of each other in any other case investigation, OR

  • For large settings (a facility or workplace with >100 persons present in the setting), particularly during high levels of community transmission, LHDs may determine that a higher proportion (at least 5%) of cases within a 7-day period may be sufficient for defining an outbreak, even in the absence of identifiable epidemiological linkages.​

LHD Reporting of Outbreaks to CDPH

Using the definition above, LHDs that determine that a cluster of COVID-19 cases constitutes an outbreak should report it to CDPH using the Novel Coronavirus 2019 disease outbreak condition in CalREDIE, the exposure event module in CalCONNECT or an alternate established process.

Reporting Thresholds from Settings to LHDs

  • For workplace settings, when three cases among workers are identified in a workplace within a 7-day period, employers are encouraged to notify the LHD. Employers must follow any local requirements in place regarding COVID-19 outbreak reporting in their public health jurisdictions, and should consult the Cal/OSHA COVID-19 Prevention Non-Emergency Regulations for additional requirements pertaining to COVID-19 outbreaks in the workplace.

  • For settings where non-workers are present (i.e., schools, residential settings, or other settings where members of the public are present), LHDs may define reporting thresholds for non-worker cases. For example, an LHD may require a school to report a certain number or proportion of cases among students in a classroom or school, among residents in a shelter or group home, or among attendees of a large event. While three cases in a setting within 7 days may be used as a default, LHDs may wish to vary reporting thresholds for non-worker cases by type of setting and other local or setting specific considerations. For example, LHDs may wish to use more sensitive reporting thresholds (such as fewer than 3 cases, or 3 cases within 14 days), for higher-risk settings.

  • LHDs should inform settings in their jurisdictions about reporting thresholds and instruct these settings to notify them if they identify the number of cases that meets the setting specific reporting threshold.

When cases meeting a reporting threshold are reported to the LHD, the LHD will then determine if further investigation is warranted, and whether the cases constitute an outbreak using the definitions above. LHDs may set their own criteria to determine which reported clusters warrant additional investigation and outbreak response. They may wish to consider factors such as size of the outbreak, settings and groups at increased risk, proportion of individuals testing positive, vulnerability of affected individuals, and/or other factors, including those described by CSTE, CDC, and CDPH.

Non-COVID-19 Respiratory Outbreaks

  • If laboratory testing in a non-healthcare congregate setting has identified an outbreak of another laboratory-confirmed respiratory viral infection (not COVID-19​​), the CDPH Influenza and Respiratory Illness Outbreak Quicksheet (PDF) should be used instead of this document. If COVID-19 testing has not been done, it may also be considered in these situations.


COVID-19 case:  A person who has received a positive result of the presence of SARS-CoV-2 virus as confirmed by a COVID-19 viral test or clinical diagnosis.  

‡ See CDPH COVID-19 Isolation Guidance for definition of "close contact."​​​

Originally Published on May 18, 2020