COVID Levels in Illinois
In the week ending 10 October 2026, wastewater virus levels in Illinois were High or Very High for COVID-19 at 2 of 73 sites, Flu A at 0 of 73 sites, RSV at 0 of 73 sites. COVID-19 was High or Very High at 3% of the state's sampling sites. Source: CDC wastewater surveillance.
Very High High Moderate Low Very Low
Sampling sites in Illinois 73
| Counties served | People served | COVID-19 | Flu A | RSV |
|---|---|---|---|---|
| Cook | 1,263,110 | Low | Very Low | Very Low |
| Cook | 1,134,897 | Very Low | Very Low | Very Low |
| Cook | 1,127,737 | Low | Very Low | Very Low |
| Cook | 1,127,736 | Very Low | Low | Very Low |
| Winnebago | 353,599 | Low | Very Low | Very Low |
| Kendall | 286,000 | Very Low | Very Low | Very Low |
| Cook | 270,647 | Very Low | Very Low | Very Low |
| Cook | 217,106 | Very Low | Very Low | Very Low |
| Du Page | 164,781 | Very Low | Very Low | Low |
| Kane | 143,088 | Very Low | Very Low | Very Low |
| Peoria | 131,000 | Very Low | Very Low | Very Low |
| Lake | 126,629 | Very Low | Very Low | Very Low |
| Cook | 110,394 | Very Low | Moderate | Very Low |
| Lake | 105,208 | Very Low | Very Low | Very Low |
| Sangamon | 102,000 | Low | Very Low | Very Low |
| Champaign | 91,041 | Low | Very Low | Very Low |
| Macon | 88,500 | Very Low | Very Low | Very Low |
| Du Page | 86,000 | Low | Low | Very Low |
| Saint Clair | 85,593 | Very Low | Very Low | Very Low |
| Lake | 80,000 | Very Low | Very Low | Very Low |
| Du Page | 65,000 | High | Very Low | Very Low |
| Du Page | 63,000 | Low | Moderate | Very Low |
| Kankakee | 56,317 | Very Low | Very Low | Very Low |
| Lake | 55,735 | Very Low | Very Low | Very Low |
| Champaign | 52,000 | Very Low | Very Low | Very Low |
| Adams | 50,695 | Very Low | Very Low | Very Low |
| Will | 50,458 | Very Low | Very Low | Very Low |
| Sangamon | 50,000 | Low | Very Low | Very Low |
| De Kalb | 45,000 | Low | Very Low | Very Low |
| Du Page | 45,000 | Very Low | Very Low | Very Low |
| Kane | 44,703 | Low | Very Low | Very Low |
| Rock Island | 43,768 | Very Low | Very Low | Very Low |
| Du Page | 40,438 | Very Low | Very Low | Very Low |
| Knox | 39,153 | Very Low | Very Low | Very Low |
| Mchenry | 36,552 | Very Low | Very Low | Very Low |
| Tazewell | 32,540 | Very Low | Very Low | Very Low |
| Saint Clair | 32,289 | Very Low | Very Low | Very Low |
| Saint Clair | 26,150 | Low | Very Low | Very Low |
| Saint Clair | 26,150 | Very High | Moderate | Very Low |
| Kane | 25,766 | Very Low | Very Low | Very Low |
| Rock Island | 25,202 | Low | Very Low | Very Low |
| Boone | 25,134 | Very Low | Very Low | Very Low |
| Stephenson | 23,650 | Low | Very Low | Very Low |
| Kendall | 23,000 | Low | Very Low | Very Low |
| Du Page | 18,800 | Very Low | Very Low | Very Low |
| La Salle | 18,768 | Very Low | Very Low | Very Low |
| Whiteside | 18,678 | Very Low | Very Low | Very Low |
| Coles | 17,000 | Moderate | Very Low | Very Low |
| Williamson | 17,000 | Very Low | Very Low | Very Low |
| Mchenry | 15,947 | Very Low | Very Low | Very Low |
| Marion | 15,738 | Low | Low | Very Low |
| Mchenry | 15,360 | Very Low | Low | Very Low |
| Lee | 15,115 | Very Low | Very Low | Moderate |
| Mcdonough | 15,052 | Low | Very Low | Very Low |
| Cook | 13,098 | Low | Very Low | Very Low |
| Williamson | 12,500 | Moderate | Very Low | Very Low |
| Effingham | 12,384 | Moderate | Very Low | Very Low |
| Kane | 11,290 | Very Low | Very Low | Very Low |
| Warren | 10,836 | Very Low | Very Low | Very Low |
| Mchenry | 10,240 | Very Low | Very Low | Very Low |
| Wabash | 7,800 | Very Low | Very Low | Low |
| Bureau | 7,555 | Very Low | Very Low | Very Low |
| Randolph | 6,814 | Very Low | Very Low | Very Low |
| Carroll | 5,615 | Very Low | Very Low | Very Low |
| Cass | 5,446 | Low | Very Low | Very Low |
| Bureau | 5,400 | Very Low | Very Low | Very Low |
| Shelby | 5,329 | Very Low | Very Low | Very Low |
| Iroquois | 4,700 | Very Low | Very Low | Very Low |
| Macoupin | 4,480 | Very Low | Very Low | Very Low |
| Mchenry | 4,288 | Low | Very Low | Very Low |
| Jo Daviess | 3,460 | Very Low | Very Low | Very Low |
| Washington | 3,425 | Very Low | Very Low | Very Low |
| Greene | 3,064 | Very Low | Very Low | Very Low |
When levels are high where you live
- Stay current on vaccines for COVID-19 and flu, and RSV if you are 75+, 50–74 with risk factors, pregnant, or have an infant.
- Test if you have symptoms; antivirals for COVID-19 and flu work best in the first days and are meant for people at higher risk.
- A well-fitting mask in crowded indoor places and better ventilation cut the risk for you and for people around you.
- Stay home when sick. Outbreak news is in our epidemic record.
What this page shows, and what it misses
CDC's weekly wastewater viral activity level for each sampling site — a treatment plant or a point upstream — compared with that site's own baseline, in five categories from Very Low to Very High. State rows count sites; CDC's own state level, on its map, weighs sites differently and can differ from what these counts suggest. Places not on a sewer system, and sites that did not report this week, are not covered. Wastewater shows community spread, not the number of cases.
Data: Centers for Disease Control and Prevention, National Wastewater Surveillance System, "CDC Wastewater Viral Activity Level for SARS-CoV-2, Influenza A and RSV" (data.cdc.gov) — public domain U.S. Government work.