Acute Respiratory Illness (COVID-19, Influenza, and RSV, and Other) Outbreak Reporting

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Page last updated 10/29/2026.

Per All Facilities Letter (AFL) 23-08, all health facilities licensed by the California Department of Public Health (CDPH) Licensing & Certification (L&C) are required to report outbreaks and unusual infectious disease occurrences to the public health officer (PHO) and District Office (DO). 

  • Employers are subject to Cal/OSHA regulations and requirements, including maintaining a safe and healthful place of employment (per Labor Code, Section 6400) and establishing, implementing, and maintaining an effective Injury Illness Prevention Program per Title 8, California Code of Regulations, Section 3203.

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Outbreak Definitions

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  • Influenza
    • Acute Care and Critical Access Hospitals (per Council for Outbreak Response): ≥2 lab confirmed* cases in patients with symptom onset ≥ 72 hours after admission, with epi link^.
    • Long-Term Care Facilities (per Council for Outbreak Response): ≥2 lab confirmed* cases in residents identified within 72 hours and epi link^.
    • Congregate (Non-Healthcare) High Risk Settings (per local health jurisdiction, LHJ): ≥3 lab confirmed* cases within 72 hours among residents, with epi link.
    • Schools (High Risk Setting) (per LHJ): ≥5 lab confirmed cases within 72 hours among people with epi link^.

     

  • COVID
    • Acute Care and Critical Access Hospitals (per Council for Outbreak Response):
      • ≥2 cases of suspect% , probable or confirmed, COVID-19 among patients 4 or more days after admission for a non-COVID condition with epi link^, OR
      • ≥2 cases of suspect% , probable or confirmed, COVID-19 among healthcare personnel AND ≥ 1 case of suspect % , probable or confirmed, COVID-19 among patients 4 or more days after admission for a non-COVID condition with epi link^.
    • Long-Term Care Facilities (per Council for Outbreak Response):
      • ≥2 cases of suspect%, probable or confirmed, COVID-19 among residents with epi link^, OR
      • ≥2 cases of suspect% , probable or confirmed, COVID-19 among healthcare personnel AND ≥ 1 case of suspect % , probable or confirmed, COVID-19 among resident with epi link AND no other more likely sources of exposure for at least 1 of the cases.
    • Congregate (Non-Healthcare) High Risk Settings (per CDPH):
      • ≥3 lab cases of suspect, probable, or confirmed COVID-19 cases within a 7-day period among people who are epi 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), a higher proportion (at least 5%) of cases within a 7-day period may be sufficient for defining an outbreak.
    • Schools (High Risk Setting) (LHJ defined):
      • ≥5 cases of suspect, probable, or confirmed COVID-19 cases within a 7-day period among people who are epi-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), a higher proportion (at least 5%) of cases within a 7-day period may be sufficient for defining an outbreak. 
     
     
  • RSV and Other Respiratory
    • Healthcare and Congregate Settings (per 9003): ≥1 case of a lab confirmed* respiratory pathogen, other than influenza or SARS-CoV-2, in the setting of a cluster (≥2 cases) of acute respiratory illness within a 72-hour period.  

     

     

  • Pan-respiratory Approach
    • Community Settings (Not High Risk) (per CDPH): Public Health Concern – 
      • Greater than expected increase in acute respiratory illness cases linked in time/space.
      • Increased severity illness (hospitalization or death).
      • Infection control measures are ineffective and/or need additional support, and
      • Any case with exposure to animals known to transmit respiratory viruses associated with novel/variant influenza. 

     

 

* Lab confirmed cases should be of the same type/subtype if diagnostic testing allows.
^ Epi link is defined as common exposure within the facility.
% Modification to the Council of Outbreak Response (CORHA) definition. 

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Steps to Report

1. Notify local health jurisdiction  

  • Acute Care, Critical Access Hospitals, Long-Term Care Facilities, and Congregate (Non-Healthcare) High Risk Settings: Complete online Report Form (available in Spanish)
    • Please note, if all ill individuals are experiencing acute respiratory illness symptoms and the facility did not test for any pathogen, instead report via email to PHS.OutbreakReporting.HHSA@sdcounty.ca.gov. Include:
      • Facility Name
      • Facility Address
      • Facility Point of Contact Name and Title
      • Facility Point of Contact Phone Number
      • Number of Cases with Reported Symptoms
      • Any Additional Notes (if any)
  • Schools, Preschool, or Daycare: Report via email to PHS.EPI-Schools.HHSA@sdcounty.ca.gov. Include:
    • Email Subject Line: Reporting Outbreak – [Disease]
      • Examples: COVID-19, Influenza, RSV, or Other Respiratory Illness
    • Facility Name
    • Facility Address
    • Point of Contact
    • Point of Contact Phone Number
    • Point of Contact Email Address
    • Number of Employees/Staff Who Reported Testing Positive
    • Number of Students Who Reported Testing Positive
    • Brief Explanation of Circumstances or Reason for this Request

2. Maintain a case log for ill residents and staff at your facility. An investigator will reach out to request a completed case log if you meet the outbreak definition for the reported disease at your facility type.

3. If your facility would like a consultation at no-cost with the Healthcare-Associated Infections (HAI) Program, email PHS.HAI.HHSA@sdcounty.ca.gov. Include:

  • Facility Name
  • Facility Address
  • Facility Point of Contact Name and Title
  • Facility Point of Contact Phone Number
  • Short Summary of Issue/Problem:
  • Objective of Consultation:
  • Support Requested:
    • Select one of the following: On-site consultation, Phone consultation or questions, Training/In-Service (specify topic: Infection Control), or Other (specify).

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Key Infection Control Measures

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CDPH Guidance

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CDC Guidance

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Call the Immunization Unit at (866) 358-2966, or send an email, for more information.