COVID-Like Illness (CLI) Emergency Department Visits

  • covid-19
  • health
  • public health
  • syndromic surveillance

COVID-Like Illness (CLI) Emergency Department Visits

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This is the source data for some of the metrics available at

For all datasets related to COVID-19, see

The National Syndromic Surveillance Program (NSSP), a collaboration among CDC, federal partners, local and state health departments, and academic and private sector partners, is used to capture Emergency Department (ED) visits for COVID-19-Like illness (CLI). CLI is defined as fever and cough or shortness of breath or difficulty breathing or the presence of a coronavirus diagnosis code. Visits meeting the CLI definition that also have mention of flu or influenza are excluded. ED data are collected before cases are diagnosed or laboratory results are confirmed, providing an early warning system for infections. 

Only Chicago residents who visit any hospital in Illinois are included. Residency is based on the home address as reported by the medical provider.

All data are provisional and subject to change. Information is updated as additional details are received and it is, in fact, very common for recent dates to be incomplete and to be updated as time goes on. At any given time, this dataset reflects visits currently known to Chicago Department of Public Health (CDPH).

Numbers in this dataset may differ from other public sources due to sources used, when data are updated, and similar factors.

Data Source: Illinois Hospital Emergency Departments reporting to CDPH through the National Syndromic Surveillance Project (NSSP)


NameSocrata field nameColumn name in sgr mountData typeDescription
CLI Percent - 7 day averagecli_percent_7_day_averagecli_percent_7_day_averageNumber7-day rolling average of CLI percentage
CLI Percent - Dailycli_percent_dailycli_percent_dailyNumberPercentage of ED visits attributed to CLI
Total ED Visits - Dailytotal_ed_visits_dailytotal_ed_visits_dailyNumberTotal Number of ED visits on the date.
Total CLI - Dailytotal_cli_dailytotal_cli_dailyNumberTotal numbers of CLI visits on the date.
DatedatedateCalendar dateDate of ED visit
CLI Count - 7 day averagecli_count_7_day_averagecli_count_7_day_averageNumber7-day rolling average of CLI counts

Upstream Metadata