Key Points, updated 5/30/2025

• Overall acute respiratory illness activity level in Chicago remains Minimal. Flu activity has dropped to Minimal; COVID-19 and RSV activity remain Minimal.
• ED visits, hospitalizations, and ICU admissions for flu, RSV, and COVID-19 remain low across all age groups.
• Test positivity rates for influenza, RSV, and COVID-19 remain low. However, in the past two seasons, COVID-19 test positivity has tended to rise during the summer months. Refer to the Respiratory Illness Dashboard for updates.
• The percentage of specimens testing positive for rhinovirus/enterovirus has been rising since March but have declined the last two weeks, aligning with typical seasonal patterns observed in previous years.
• Overall wastewater concentrations for RSV remain minimal and COVID-19 remain low. Flu A and Flu B concentrations have decreased to minimal.
• The CDC has issued interim estimates of 2024-25 Seasonal Influenza Vaccine Effectiveness (VE) and 2024-25 COVID-19 VE, which suggest that this season’s influenza and COVID-19 vaccines were effective in preventing medically-attended illness, including hospitalization, in the US. 
• For information on the national bird flu outbreak, see the CDPH H5N1 Bird Flu webpage and the CDPH HAN: Flu Page for clinicians.