2019 Novel Coronavirus Disease (COVID-19)

2024 Case Definition

CSTE Position Statement Number: 22-ID-01

Clinical Description

A description of suggested criteria for case ascertainment of a specific condition.

Clinical Criteria

N/A

Laboratory Criteria

Laboratory evidence using a method approved or authorized by the FDA or designated authority * :

Confirmatory ** laboratory evidence:

• Detection of SARS-CoV-2 nucleic acid in a clinical or post-mortem specimen using a diagnostic molecular test (e.g., NAAT) performed by a CLIA-certified provider ** ,

OR

• Detection of SARS-CoV-2 RNA in a clinical or post-mortem specimen by genomic sequencing *** ,

OR

• Detection of SARS-CoV-2 specific antigen by diagnostic immunocytochemistry staining performed by a CLIA-certified provider ** .

Presumptive laboratory evidence:

• Detection of SARS-CoV-2 specific antigen in a clinical or post-mortem specimen using a diagnostic test performed by a CLIA-certified provider. **

Supportive laboratory evidence:

• Detection of SARS-CoV-2 RNA or specific antigen using a test performed without CLIA oversight. ^

* Note: The categorical labels used here to stratify laboratory evidence are intended to support the standardization of case classifications for public health surveillance. The categorical labels should not be used to interpret the utility or validity of any laboratory test methodology.

** Includes those tests performed under a CLIA certificate of waiver.

*** Some genomic sequencing tests that have been authorized for emergency use by the FDA do not require an initial PCR result to be generated. Genomic sequencing results may be all the public health agency receives.

^ Includes at-home tests.

Epidemiologic Linkage

N/A

Vital Records Criteria

A death certificate that lists COVID-19 disease or SARS-CoV-2 or an equivalent term as an underlying cause of death or a significant condition contributing to death.

Case Classifications

Confirmed:

• Meets confirmatory laboratory evidence.

Probable:

• Meets presumptive laboratory evidence.

Suspect:

• Meets supportive laboratory evidence, OR
• Meets vital records criteria AND with no laboratory evidence for SARS-CoV-2 infection.

Criteria to distinguish a new case of this disease or condition from reports or notifications which should not be enumerated as a new case for surveillance.

The following should be enumerated as a new case:

• Person was most recently enumerated as a confirmed or probable case with onset date (if available) or first positive specimen collection date for that classification >90 days prior ‡ ,

OR

• SARS-CoV-2 sequencing results from the new positive specimen and a positive specimen from the most recent previous case demonstrate a different lineage,

OR

• Person was previously reported but not enumerated as a confirmed or probable case (i.e., suspect) ‡‡ , but now meets the criteria for a confirmed or probable case.

‡ Some individuals, e.g., severely immunocompromised persons, can shed SARS-CoV-2 detected by molecular amplification tests >90 days after infection. For severely immunocompromised individuals, clinical judgment should be used to determine if a repeat positive test is likely to result from long term shedding and therefore not be enumerated as a new case. CDC defines severe immunocompromise as certain conditions, such as being on chemotherapy for cancer, untreated HIV infection with CD4 T lymphocyte count 20mg/day for more than 14 days.

‡‡ Repeat suspect cases should not be enumerated.

Date Updated: December 20, 2024