Cumulative counts by date of Chicago residents who received at least one COVID-19 vaccine dose or have completed a vaccine series.

Note: This map and the underlying dataset are no longer updated but are being kept for historical reference. For the Department of Public Health’s current COVID-19 testing information at any time, please see the Testing section of https://www.chicago.gov/coronavirus.

Map of locations offering COVID-19 testing in Chicago.

For more information on COVID-19 testing, see https://www.chicago.gov/city/en/sites/covid-19/home/managing-your-health.html?#tab-shouldtest.

This is the place to look for important information about how to use this dataset, so please expand this box and read on!

This is the source data for some of the metrics available at https://www.chicago.gov/city/en/sites/covid-19/home/latest-data.html.

For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

Only Chicago residents are included based on the home ZIP Code, as provided by the medical provider, or the address, as provided by the Cook County Medical Examiner.

Cases with a positive molecular (PCR) or antigen test are included in this dataset. Cases are counted on the date the test specimen was collected. Deaths are those occurring among cases based on the day of death. Hospitalizations are based on the date of first hospitalization. Only one hospitalization is counted for each case. Demographic data are based on what is reported by medical providers or collected by CDPH during follow-up investigation.

Because of the nature of data reporting to CDPH, hospitalizations will be blank for recent dates They will fill in on later updates when the data are received, although, as for cases and deaths, may continue to be updated as further data are received.

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 data currently known to CDPH.

Numbers in this dataset may differ from other public sources due to definitions of COVID-19-related cases, deaths, and hospitalizations, sources used, how cases, deaths and hospitalizations are associated to a specific date, and similar factors.

Data Source: Illinois National Electronic Disease Surveillance System, Cook County Medical Examiner’s Office

This is the place to look for important information about how to use this dataset, so please expand this box and read on!

This is the source data for some of the metrics available at https://www.chicago.gov/city/en/sites/covid-19/home/latest-data.html.

For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

Only Chicago residents are included based on the home ZIP Code as provided by the medical provider. If a ZIP was missing or was not valid, it is displayed as "Unknown".

Cases with a positive molecular (PCR) or antigen test are included in this dataset. Cases are counted based on the week the test specimen was collected. For privacy reasons, until a ZIP Code reaches five cumulative cases, both the weekly and cumulative case counts will be blank. Therefore, summing the “Cases - Weekly” column is not a reliable way to determine case totals. Deaths are those that have occurred among cases based on the week of death.

For tests, each test is counted once, based on the week the test specimen was collected. Tests performed prior to 3/1/2020 are not included. Test counts include multiple tests for the same person (a change made on 10/29/2020). PCR and antigen tests reported to Chicago Department of Public Health (CDPH) through electronic lab reporting are included. Electronic lab reporting has taken time to onboard and testing availability has shifted over time, so these counts are likely an underestimate of community infection.

The “Percent Tested Positive” columns are calculated by dividing the number of positive tests by the number of total tests . Because of the data limitations for the Tests columns, such as persons being tested multiple times as a requirement for employment, these percentages may vary in either direction from the actual disease prevalence in the ZIP Code.

All data are provisional and subject to change. Information is updated as additional details are received.

To compare ZIP Codes to Chicago Community Areas, please see http://data.cmap.illinois.gov/opendata/uploads/CKAN/NONCENSUS/ADMINISTRATIVE_POLITICAL_BOUNDARIES/CCAzip.pdf. Both ZIP Codes and Community Areas are also geographic datasets on this data portal.

Data Source: Illinois National Electronic Disease Surveillance System, Cook County Medical Examiner’s Office, Illinois Vital Records, American Community Survey (2018)

COVID-19 vaccinations administered to Chicago residents based on the home ZIP Code of the person vaccinated, as provided by the medical provider in Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE). The ZIP Code where a person lives is not necessarily the same Zip Code where the vaccine was administered. Daily counts are shown for the total number of doses administered, first doses only, and number of people who have completed the necessary doses to be considered fully vaccinated, as well as cumulative totals for each measure as of that date. Requirements to be considered fully vaccinated vary depending on the vaccine manufacturer. Current vaccines require two doses of vaccine to be administered over a period of time specific to each vaccine brand; future vaccines may only require one dose to be considered fully vaccinated. Vaccinations are counted based on the day the vaccine was administered.

Coverage percentages are calculated based on cumulative first doses administered and cumulative number of people considered fully vaccinated in each Zip Code.

Population counts are from the American Community Survey 2014-2018 5-year estimates.

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 data currently known to CDPH.

Numbers in this dataset may differ from other public sources due to when data are reported and how City of Chicago boundaries are defined.

For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

Data Source: Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE) U.S. Census Bureau American Community Survey

COVID-19 Cases, Deaths, and Hospitalizations by day

NOTE: This program is no longer active. This dataset is only for historical reference.

The Chicago Department of Public Health is distributing condoms at several locations across the City.

COVID-19 vaccinations administered to Chicago residents based on the home Zip Code of the person vaccinated, as provided by the medical provider in Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE). The Zip Code where a person lives is not necessarily the same Zip Code where the vaccine was administered. Daily counts are shown for the total number of doses administered, first doses only, and number of people who have completed the necessary doses to be considered fully vaccinated. Cumulative totals for each measure as of that date are also provided. Requirements to be considered fully vaccinated vary depending on the vaccine manufacturer. Initial vaccines require two doses of vaccine to be administered over a period of time specific to each vaccine brand; future vaccines may only require one dose to be considered fully vaccinated. Vaccinations are counted based on the day the vaccine was administered.

Coverage percentages are calculated based on cumulative doses administered and cumulative number of people considered fully vaccinated in each Zip Code.

Population counts are from the U.S. Census Bureau American Community Survey 2015-2019 5-year estimates and can be seen in the Zip Code, 2019 rows of the Chicago Population Counts dataset (https://data.cityofchicago.org/d/85cm-7uqa).

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 data currently known to CDPH.

Numbers in this dataset may differ from other public sources due to when data are reported and how City of Chicago boundaries are defined.

For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

Data Source: Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE), U.S. Census Bureau American Community Survey

City of Chicago Mental Health, Sexually Transmitted Infection (STI) Specialty, and Women Infant Children (WIC) clinic locations, hours of operation and contact information.

COVID-19 vaccinations administered by COVID-19 vaccine providers in the City of Chicago, as reported by medical providers in Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE). This includes Chicago and non-Chicago residents who were vaccinated at sites in the City of Chicago.

Daily counts are shown for the total number of doses administered, first dose, and second dose, as well as cumulative totals as of that date. Vaccinations are counted based on the day the vaccine was administered.

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 data currently known to CDPH.

Numbers in this dataset may differ from other public sources due to when data are reported and how City of Chicago boundaries are defined.

For information about the number of vaccine doses administrated to Chicago residents and number of residents considered fully vaccinated regardless of if they were vaccinated in Chicago, see https://data.cityofchicago.org/Health-Human-Services/COVID-19-Daily-Vaccinations-Chicago-Residents/2vhs-cf6b.

For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

Data Source: Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE)

Case, test, and death metrics for a single Chicago ZIP Code, which can be selected from the filter area.

In comparing charts for different ZIP Codes or for the same ZIP Code captured at different times, please note that the y-axis scales adjust to the data for readability so may be different between two images.

Due to a 5/29/2020 change described at http://dev.cityofchicago.org/open%20data/data%20portal/2020/05/29/covid-19-weekly-ZIP-percent-positive.html, Percent Tested Positive - Weekly percentages may have changed from previous versions of this chart.

Due to a 10/29/2020 change discussed at https://www.chicago.gov/content/dam/city/depts/cdph/statistics_and_reports/COVID%20POSITIVITY%20RATE%20CHANGES%20102720.pdf and in the description of the “Source Data” dataset, the “Percent Tested Positive – Weekly” line in this chart is based on individual tests, not unique people as it was previously. Therefore, it may differ significantly from versions of this chart printed or saved before this change.

To compare ZIP Codes to Chicago Community Areas, please see http://data.cmap.illinois.gov/opendata/uploads/CKAN/NONCENSUS/ADMINISTRATIVE_POLITICAL_BOUNDARIES/CCAzip.pdf. Both ZIP Codes and Community Areas are also geographic datasets on this data portal.

Counts by date of Chicago residents who received at least one COVID-19 vaccine dose and completed a vaccine series.

Date is the end date of a seven-day window over which the number of daily cases is averaged before using population to calculate the rates.

Note that because of delayed reporting, counts from recent dates are likely to be preliminary and to increase as the Department of Public Health gets additional reports.

A filtered view of only ZIP Code records from the parent CCVI dataset.

COVID-19 vaccinations administered to Chicago residents, by home ZIP Code of the person vaccinated. The vaccinations did not necessarily take place in the same ZIP Code.

This is the place to look for important information about how to use this dataset, so please expand this box and read on!

This is the source data for some of the metrics available at https://www.chicago.gov/city/en/sites/covid-19/home/latest-data.html.

For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

This dataset is a companion to the COVID-19 Daily Cases and Deaths dataset (https://data.cityofchicago.org/d/naz8-j4nc). The major difference in this dataset is that the case, death, and hospitalization corresponding rates per 100,000 population are not those for the single date indicated. They are rolling averages for the seven-day period ending on that date. This rolling average is used to account for fluctuations that may occur in the data, such as fewer cases being reported on weekends, and small numbers. The intent is to give a more representative view of the ongoing COVID-19 experience, less affected by what is essentially noise in the data.

All rates are per 100,000 population in the indicated group, or Chicago, as a whole, for “Total” columns.

Only Chicago residents are included based on the home address as provided by the medical provider.

Cases with a positive molecular (PCR) or antigen test are included in this dataset. Cases are counted based on the date the test specimen was collected. Deaths among cases are aggregated by day of death. Hospitalizations are reported by date of first hospital admission. Demographic data are based on what is reported by medical providers or collected by CDPH during follow-up investigation.

Denominators are from the U.S. Census Bureau American Community Survey 1-year estimate for 2018 and can be seen in the Citywide, 2018 row of the Chicago Population Counts dataset (https://data.cityofchicago.org/d/85cm-7uqa).

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 cases and deaths currently known to CDPH.

Numbers in this dataset may differ from other public sources due to definitions of COVID-19-related cases and deaths, sources used, how cases and deaths are associated to a specific date, and similar factors.

Data Source: Illinois National Electronic Disease Surveillance System, Cook County Medical Examiner’s Office, U.S. Census Bureau American Community Survey

COVID-19 vaccinations administered to Chicago residents, by home ZIP Code of the person vaccinated. The vaccinations did not necessarily take place in the same ZIP Code. Daily counts are shown for people with at least one dose and vaccine series completed, as well as cumulative totals as of that date.

NOTE, 3/30/2023: We have added columns for bivalent (updated) doses to this dataset. We have also added age group columns for 0-17 and 18-64 and stopped updating the 5+ and 12+ columns, although previously published values remain for those columns.

COVID-19 vaccinations administered to Chicago residents based on the home ZIP Code of the person vaccinated, as provided by the medical provider in the Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE). The ZIP Code where a person lives is not necessarily the same ZIP Code where the vaccine was administered.

Definitions:
·People with at least one vaccine dose: Number of people who have received at least one dose of any COVID-19 vaccine, including the single-dose Johnson & Johnson COVID-19 vaccine.

·People with a completed vaccine series: Number of people who have completed a primary COVID-19 vaccine series. Requirements vary depending on age and type of primary vaccine series received.

·People with a bivalent dose: Number of people who received a bivalent (updated) dose of vaccine. Updated, bivalent doses became available in Fall 2022 and were created with the original strain of COVID-19 and newer Omicron variant strains.

·Total doses administered: Number of all COVID-19 vaccine doses administered.

Data Notes:
Daily counts are shown for the total number of doses administered, number of people with at least one vaccine dose, number of people who have a completed vaccine series, and number of people who have received a bivalent dose. Cumulative totals for each measure as of that date are also provided. Vaccinations are counted based on the day the vaccine was administered.

Coverage percentages are calculated based on cumulative number of people who have received at least one vaccine dose, cumulative number of people who have a completed vaccine series, and cumulative number of people who have received a bivalent dose in each ZIP Code.

Population counts are from the U.S. Census Bureau American Community Survey 2015-2019 5-year estimates and can be seen in the ZIP Code, 2019 rows of the Chicago Population Counts dataset (https://data.cityofchicago.org/d/85cm-7uqa).

Actual counts may exceed population estimates and lead to >100% coverage, especially in areas with small population sizes. Additionally, the medical provider may report a work address or incorrect home address for the person receiving the vaccination which may lead to over or under estimates of vaccination coverage by geography. 

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 data currently known to CDPH.

Numbers in this dataset may differ from other public sources due to when data are reported and how City of Chicago boundaries are defined.

For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

Data Source: Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE), U.S. Census Bureau American Community Survey

NOTE: This dataset is historical-only as of 5/10/2023. All data currently in the dataset will remain, but new data will not be added. The recommended alternative dataset for similar data beyond that date is  https://healthdata.gov/Hospital/COVID-19-Reported-Patient-Impact-and-Hospital-Capa/anag-cw7u. (This is not a City of Chicago site. Please direct any questions or comments through the contact information on the site.)

During the COVID-19 pandemic, the Chicago Department of Public Health (CDPH) required EMS Region XI (Chicago area) hospitals to report hospital capacity and patient impact metrics related to COVID-19 to CDPH through the statewide EMResource system. This requirement has been lifted as of May 9, 2023, in alignment with the expiration of the national and statewide COVID-19 public health emergency declarations on May 11, 2023. However, all hospitals will still be required by the U.S. Department of Health and Human Services (HHS) to report COVID-19 hospital capacity and utilization metrics into the HHS Protect system through the CDC’s National Healthcare Safety Network until April 30, 2024. Facility-level data from the HHS Protect system can be found at healthdata.gov.

Until May 9, 2023, all Chicago (EMS Region XI) hospitals (n=28) were required to report bed and ventilator capacity, availability, and occupancy to the Chicago Department of Public Health (CDPH) daily. A list of reporting hospitals is included below. All data represent hospital status as of 11:59 pm for that calendar day. Counts include Chicago residents and non-residents.

ICU bed counts include both adult and pediatric ICU beds. Neonatal ICU beds are not included. Capacity refers to all staffed adult and pediatric ICU beds. Availability refers to all available/vacant adult and pediatric ICU beds. Hospitals began reporting COVID-19 confirmed and suspected (PUI) cases in ICU on 03/19/2020. Hospitals began reporting ICU surge capacity as part of total capacity on 5/18/2020.

Acute non-ICU bed counts include burn unit, emergency department, medical/surgery (ward), other, pediatrics (pediatric ward) and psychiatry beds. Burn beds include those approved by the American Burn Association or self-designated. Capacity refers to all staffed acute non-ICU beds. An additional 500 acute/non-ICU beds were added at the McCormick Place Treatment Facility on 4/15/2020. These beds are not included in the total capacity count. The McCormick Place Treatment Facility closed on 05/08/2020. Availability refers to all available/vacant acute non-ICU beds. Hospitals began reporting COVID-19 confirmed and suspected (PUI) cases in acute non-ICU beds on 04/03/2020.

Ventilator counts prior to 04/24/2020 include all full-functioning mechanical ventilators, with ventilators with bilevel positive airway pressure (BiPAP), anesthesia machines, and portable/transport ventilators counted as surge. Beginning 04/24/2020, ventilator counts include all full-functioning mechanical ventilators, BiPAP, anesthesia machines and portable/transport ventilators. Ventilators are counted regardless of ability to staff. Hospitals began reporting COVID-19 confirmed and suspected (PUI) cases on ventilators on 03/19/2020. CDPH has access to additional ventilators from the EAMC (Emergency Asset Management Center) cache. These ventilators are included in the total capacity count.

Chicago (EMS Region 11) hospitals: Advocate Illinois Masonic Medical Center, Advocate Trinity Hospital, AMITA Resurrection Medical Center Chicago, AMITA Saint Joseph Hospital Chicago, AMITA Saints Mary & Elizabeth Medical Center, Ann & Robert H Lurie Children's Hospital, Comer Children's Hospital, Community First Medical Center, Holy Cross Hospital, Jackson Park Hospital & Medical Center, John H. Stroger Jr. Hospital of Cook County, Loretto Hospital, Mercy Hospital and Medical Center, , Mount Sinai Hospital, Northwestern Memorial Hospital, Norwegian American Hospital, Roseland Community Hospital, Rush University M

COVID-19 vaccinations administered to Chicago residents based on home address, as reported by medical providers in the Illinois Comprehensive Automated Immunization Registry Exchange (I-CARE). I-CARE includes doses administered in Illinois and some doses administered outside of Illinois and reported in I-CARE by Illinois providers.

Definitions:
·People with at least one vaccine dose: Number of people who have received at least one dose of any COVID-19 vaccine, including the single-dose Johnson & Johnson COVID-19 vaccine.

·People with a completed vaccine series: Number of people who have completed a primary COVID-19 vaccine series. Requirements vary depending on age and type of primary vaccine series received.

·People with an original booster dose: Number of people who have a completed vaccine series and have received at least one additional monovalent dose. This includes people who received a monovalent booster dose and immunocompromised people who received an additional primary dose of COVID-19 vaccine. Monovalent doses were created from the original strain of the virus that causes COVID-19.

·People with a bivalent dose: Number of people who received a bivalent (updated) dose of vaccine. Updated, bivalent doses became available in Fall 2022 and were created with the original strain of COVID-19 and newer Omicron variant strains.

·Total doses administered: Number of all COVID-19 vaccine doses administered.

Daily counts are shown for the total number of doses administered, number of people with at least one vaccine dose, number of people who have a completed vaccine series, number of people with a monovalent booster dose, and number of people with a bivalent dose. Cumulative totals are also provided for each measure as of that date. Vaccinations are counted based on the day the vaccine was administered.

Coverage percentages for the City of Chicago are calculated based on cumulative number of people with that vaccination status.

Daily totals of all doses, number of people with at least one vaccine dose, number of people who have completed a vaccine series, number of people with a booster dose, and number of people with a bivalent dose are shown by age group, gender, and race/ethnicity.

Denominators are from the U.S. Census Bureau American Community Survey 1-year estimate for 2019 and can be seen in the Citywide, 2019 row of the Chicago Population Counts dataset (https://data.cityofchicago.org/d/85cm-7uqa).

The Chicago Department of Health (CDPH) uses the most complete data available to estimate COVID-19 vaccination coverage among Chicagoans, but there are several limitations that impact our estimates. Data reported in I-CARE only include doses administered in Illinois and some doses administered outside of Illinois reported historically by Illinois providers. Doses administered by the federal Bureau of Prisons and Department of Defense, are also not currently reported in I-CARE. The Veterans Health Administration began reporting doses in I-CARE beginning September 2022. Due to people receiving vaccinations that are not recorded in I-CARE that can be linked to their record, such as someone receiving a vaccine dose in another state, the number of people with a completed series or a booster dose is underestimated. Inconsistencies in records of separate doses administered to the same person, such as slight variations in dates of birth, can result in duplicate first dose records for a person and overestimate of the number of people with at least one dose and underestimate the number of people with a completed series or booster dose.

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 data currently known to CDPH.

Numbers in this dataset may differ from other public sources due to when data are reported and how vaccination

The total number of Chicago residents by age group who received at least one dose of COVID-19 vaccine.

This dataset is historical only and ends at 5/7/2021. For more information, please see http://dev.cityofchicago.org/open%20data/data%20portal/2021/05/04/covid-19-testing-by-person.html. The recommended alternative dataset for similar data beyond that date is https://data.cityofchicago.org/Health-Human-Services/COVID-19-Daily-Testing-By-Test/gkdw-2tgv.

This is the source data for some of the metrics available at https://www.chicago.gov/city/en/sites/covid-19/home/latest-data.html.

For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

This dataset contains counts of people tested for COVID-19 and their results. This dataset differs from https://data.cityofchicago.org/d/gkdw-2tgv in that each person is in this dataset only once, even if tested multiple times. In the other dataset, each test is counted, even if multiple tests are performed on the same person, although a person should not appear in that dataset more than once on the same day unless he/she had both a positive and not-positive test.

Only Chicago residents are included based on the home address as provided by the medical provider.

Molecular (PCR) and antigen tests are included, and only one test is counted for each individual. Tests are counted on the day the specimen was collected. A small number of tests collected prior to 3/1/2020 are not included in the table.

Not-positive lab results include negative results, invalid results, and tests not performed due to improper collection. Chicago Department of Public Health (CDPH) does not receive all not-positive results.

Demographic data are more complete for those who test positive; care should be taken when calculating percentage positivity among demographic groups.

All data are provisional and subject to change. Information is updated as additional details are received.

Data Source: Illinois National Electronic Disease Surveillance System

COVID-19 vaccinations administered to Chicago residents based on the home ZIP Code of the person vaccinated, as provided by the medical provider. The ZIP Code where a person lives is not necessarily the same ZIP Code where the vaccine was administered.

This is the place to look for important information about how to use this dataset, so please expand this box and read on!

This is the source data for some of the metrics available at https://www.chicago.gov/city/en/sites/covid-19/home/latest-data.html.

For all datasets related to COVID-19, see https://data.cityofchicago.org/browse?limitTo=datasets&sortBy=alpha&tags=covid-19.

This dataset contains counts of unique tests and results for COVID-19. This dataset differs from https://data.cityofchicago.org/d/t4hh-4ku9 in that each person is in that dataset only once, even if tested multiple times. In this dataset, each test is counted, even if multiple tests are performed on the same person, although a person should not appear in this dataset more than once on the same day unless he/she had both a positive and not-positive test.

The positivity rate displayed in this dataset uses the method most commonly used by other jurisdictions in the United States.

Only Chicago residents are included based on the home address as provided by the medical provider.

Molecular (PCR) and antigen tests received through electronic lab reporting are included. Individuals may be tested multiple times. Tests are counted on the day the specimen was collected. A small number of tests collected prior to 3/1/2020 are not included in the table.

Not-positive lab results include negative results, invalid results, and tests not performed due to improper collection. Chicago Department of Public Health (CDPH) does not receive all not-positive results.

All data are provisional and subject to change. Information is updated as additional details are received.

Data Source: Illinois Department of Public Health Electronic Lab Reports

List of locations and test results for pools of mosquitoes tested through the Chicago Department of Public Health Environmental Health program. The Chicago Department of Public Health maintains an environmental surveillance program for West Nile Virus (WNV). This program includes the collection of mosquitoes from traps located throughout the city; the identification and sorting of mosquitoes collected from these traps; and the testing of specific species of mosquitoes for WNV.