Table 1.
Existing COVID-19 case definitions, respiratory illness surveillance case definitions, and derived compound symptom combinations assessed for diagnostic performance in a community cohort of 185 individuals with household COVID-19 exposure in Utah and Wisconsin, United States, March–May 2020
| Case definition category | Case definition | Criteria |
|---|---|---|
| Existing COVID-19 case definitions | U.S. Centers for Disease Control and Prevention (CDC) COVID-19-like illness (CLI)a | Fever, cough, or shortness of breath |
| CDC symptom listb | Fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, diarrhea | |
| U.S. Council of State and Territorial Epidemiologists (CSTE) COVID-19 original clinical criteria (CSTE combination 1)c | At least one of the following: cough, shortness of breath, or discomfort breathing, OR at least two of the following: fever, chills, rigors, myalgia, headache, sore throat, new olfactory disorder and taste disorders | |
| CSTE COVID-19 revised clinical criteria (CSTE combination 2)d | At least one of the following: cough, shortness of breath, discomfort breathing, new olfactory disorder, new taste disorder, or at least two of the following: fever, chills, rigors, myalgia, headache, sore throat, nausea or vomiting, diarrhea, fatigue, congestion or runny nose | |
| Existing respiratory illness surveillance case definitions | Influenza-like illness (ILI)e | Fever AND cough and/or sore throat |
| World Health Organization (WHO) acute respiratory infection (ARI) definition for community-based respiratory syncytial virus (RSV) surveillancef | At least one of the following: shortness of breath or cough, sore throat, or coryza | |
| Derived compound symptom combinationsg | Derived compound combination 1 | Taste and/or smell dysfunction, OR one of the following: shortness of breath, myalgia, or fever or chills |
| Derived compound combination 2 | Taste and/or smell dysfunction or discomfort breathing, OR at least two of the following: shortness of breath, wheezing, or fever or chills | |
| Derived compound combination 3 | Taste and/or smell dysfunction, OR at least two of the following: shortness of breath, wheezing, discomfort breathing, or fever or chills | |
| Derived compound combination 4 | Taste and/or smell dysfunction, OR shortness of breath and fever or chills |
aU.S. Centers for Disease Control and Prevention (CDC) COVID-19-like illness (CLI) definition was used to guide early diagnostic testing strategies from 17 January 2020–08 March 2020 (https://emergency.cdc.gov/han/han00426.asp)
bU.S. Centers for Disease Control and Prevention (CDC) list of symptoms that may indicate COVID-19 infection (https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html). This symptom list was last updated on 13 May 2020
cU.S. Council of State and Territorial Epidemiologists (CSTE) original clinical criteria for COVID-19 reporting (https://cdn.ymaws.com/www.cste.org/resource/resmgr/2020ps/interim-20-id-01_covid-19.pdf). This interim position statement (Interim-20-ID-01) was approved on 05 April 2020 and was replaced by Interim-20-ID-02 on 07 August 2020
dU.S. Council of State and Territorial Epidemiologists (CSTE) revised clinical criteria for COVID-19 reporting (https://cdn.ymaws.com/www.cste.org/resource/resmgr/ps/positionstatement2020/interim-20-id-02_COVID-19.pdf). This interim position statement (Interim-20-ID-02) was approved on 07 August 2020 and replaced Interim-20-ID-01
eInfluenza-like illness (ILI) outpatient visit information collected through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) (https://www.cdc.gov/flu/weekly/overview.htm#anchor_1539281266932). This collaborative effort between CDC, state and local health departments, and healthcare providers has been tracking patients with ILI since the 1997–1998 influenza season
fWorld Health Organization (WHO) acute respiratory infection (ARI) definition for community-based respiratory syncytial virus (RSV) surveillance (https://www.who.int/influenza/rsv/rsv_case_definition/en/). Last updated 04 February 2020
gCompound symptom combinations were derived from all symptoms recorded at any time prior to enrollment (and after the index case’s symptom onset date) through the end of the 14-day observation period