The McHenry County Department of Health (MCDH) conducts foodborne and waterborne illness investigations when clusters or outbreaks are identified. The finalized reports below detail the investigation process and findings.

2023

• E. Coli (STEC) Outbreak: Huntley High School (Huntley, Illinois) | September 2023 

2022

• Acute Gastroenteritis (AGE) Outbreak: D.C. Cobb's McHenry, Illinois - September 2022

2021

• Salmonellosis Outbreak: El Sombrero Fox River Grove, Illinois - September 2021

2015

• Funeral Luncheon: McHenry Moose Lodge #691 - Family Affair Catering - 2015

2002

• Gastrointestinal Outbreak: Grandma's Sandwich Shop Woodstock - July 2002
• Gastrointestinal Outbreak: Rosati's Pizza Cary, IL - August 2002

2000

• Gastrointestinal Outbreak: Church Potluck Hebron, IL - April 2000
• Foodborne Illness Investigation: Hob Nob Restaurant - December 2000

The McHenry County Department of Health (MCDH) collects monthly report data on all Illinois Reportable Diseases as defined by the Illinois Department of Public Health (IDPH) (for a complete list of the current Illinois reportable diseases click here). The below reports summarize the incident cases of all IDPH reportable conditions for their respective year. The frequency of incident cases are reported for each month. Incident cases include both probable and confirmed cases (note: 2024 data are provisional).

• 2024 (last updated: November 1, 2024)
• 2023
• 2022
• 2021 
• 2020
• 2019

The McHenry County Department of Health (MCDH) conducts West Nile Virus (WNV) surveillance from the beginning of May through the middle of October. Surveillance activities include tracking human cases of WNV in McHenry County (conducted year-round), collection and submission of dead birds for analysis, collection and analysis of Culex mosquitoes for WNV, and remediation of sites that promote mosquito breeding (i.e. dumps, discarded tires, abandoned pools). The following reports summarize the WNV surveillance data for their respective year.

• 2018