Coronavirus Disease 2019 (COVID-19) Outbreak Investigation and Reporting Thresholds

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AFL 20-75 From the California Department of Public Health

September 22, 2020

TO: All Facilities

SUBJECT: Coronavirus Disease 2019 (COVID-19) Outbreak Investigation and Reporting Thresholds

AUTHORITY:     Title 17 California Code of Regulations (CCR) sections 25002501, and 2502; Title 22 CCR sections 70737707397252372539, and 72541

All Facilities Letter (AFL) Summary

This AFL reminds licensed health facilities of requirements to report outbreaks and unusual infectious disease occurrences to their local health department (LHD) and Licensing and Certification District Office and provides investigation and reporting thresholds for reporting for COVID-19.

​The national Council of State and Territorial Epidemiologists (CSTE) recently posted Proposed Investigation/Reporting Thresholds and Outbreak Definition for COVID-19 in Acute Care Hospitals, Critical Access Hospitals, Long-Term Care Facilities (LTCFs) and Long-Term Care Acute Hospitals (PDF). These thresholds are intended to expedite facilities’ investigation of COVID-19 cases and reporting to public health authorities, to help ensure early detection of possible outbreaks and timely intervention to prevent the virus’ spread. Reporting of outbreaks and unusual infectious disease occurrences does not replace reporting of individual COVID-19 cases as part of state and local COVID-19 surveillance nor daily reporting for upload on their behalf to the National Healthcare Safety Network (NHSN).[1] When the reporting threshold is reached and reported, LHDs will determine if the cases constitute an outbreak.

Acute Care Hospitals:
Threshold for Additional Investigation by Facility

  • ≥1 case of confirmed COVID-19 in a patient 7 or more days after admission for a non-COVID condition;
  • ≥1 case of confirmed COVID-19 in Healthcare Personnel (HCP)

Threshold for Reporting to Local Public Health

  • ≥2 cases of confirmed COVID-19 in a patient 7 or more days after admission for a non-COVID condition, with epi-linkage[2];
  • ≥2 cases of confirmed COVID-19 in HCP with epi-linkage[3] in counties with <4 daily new cases per 100k population or <5% test positivity based on the county positivity rate reported in the past week[4]or
  • ≥3 cases of confirmed COVID-19 in HCP with epi-linkage3 in counties with ≥4 daily new cases per 100k population or ≥5% test positivity based on the county positivity rate reported in the past week[4].

Outbreak Definition

  • ≥2 cases of confirmed COVID-19 in a patient 7 or more days after admission for a non-COVID condition, with epi-linkage[2];
  • ≥2 cases of confirmed COVID-19 in HCP with epi-linkage[3] who do not share a household, and are not listed as a close contact of each other outside of the workplace during standard case investigation or contact tracing in counties with <4 daily new cases per 100k population or <5% test positivity based on the county positivity rate reported in the past week[4]or
  • ≥3 cases of confirmed COVID-19 in HCP with epi-linkage[3] who do not share a household, and are not listed as a close contact of each other outside of the workplace during standard case investigation or contact tracing in counties with ≥4 daily new cases per 100k population or ≥5% test positivity based on the county positivity rate reported in the past week[4].

The determination of epi-linkage should generally be made irrespective of whether HCP were wearing a respirator or facemask. Although respirator or facemask use mitigates the risk of exposures, a cluster of cases meeting the investigation and reporting thresholds suggests a breach or lapse in practice (for example, HCP not using appropriate personal protective equipment while caring for a patient with unrecognized COVID-19, or HCP not physically distancing and wearing facemasks in breakrooms) that should be further investigated and reported.

Long-Term Care Facilities and Long-Term Acute Care Hospitals:

Threshold for Additional Investigation by Facility

  • ≥1 probable[5] or confirmed COVID-19 case in a resident or HCP;
  • ≥3 cases of acute illness compatible with COVID-19 in residents with onset within a 72-hour period

Threshold for Reporting to Local Public Health

  • ≥1 probable[5] or confirmed COVID-19 case in a resident or HCP;
  • ≥3 cases of acute illness compatible with COVID-19 in residents with onset within a 72-hour period

Outbreak Definition

  • ≥1 facility-acquired[6] COVID-19 case in a resident

If you have any questions about this AFL, please contact the CDPH Healthcare-Associated Infections Program via email at HAIProgram@cdph.ca.gov.   

Sincerely,

Original signed by Heidi W. Steinecker

Heidi W. Steinecker
Deputy Director

Resources:


[1] CDPH collects data from skilled nursing facilities and hospitals daily and transmits data to NHSN on behalf of those facilities that have conferred rights to CDPH.
[2] Epi-linkage among patients is defined as overlap on the same unit or ward for any duration or having the potential to have been cared for by common HCP within a 14-day time period of each other.
[3] Epi-linkage among HCP is defined as having the potential to have been within 6 feet for 15 minutes or longer while working in the facility during the 14 days prior to the onset of symptoms or positive test (for example, worked on the same unit during the same shift). 
[4] Facilities and LHDs should refer to the California Blueprint for a Safer Economy website for their county’s daily new cases per 100k population and percent test positivity.
[5] Probable case is defined as any one of the following: a person meeting clinical criteria AND epidemiologic evidence with no confirmatory laboratory testing performed for COVID-19; a person meeting presumptive laboratory evidence AND either clinical criteria OR epidemiologic evidence; a person meeting vital records criteria with no confirmatory laboratory testing performed for COVID-19.
[6] Facility-acquired COVID-19 infection in a long-term care resident is defined as a confirmed diagnosis 14 days or more after admission for a non-COVID condition, without an exposure during the previous 14 days to another setting where an outbreak was known or suspected to be occurring.