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Communicable Disease Case Counts

Communicable disease case counts are shown below for vaccine preventable diseases, selected communicable diseases, and sexually transmitted infections in suburban Cook County. Case counts are provided quarterly for the current year only.

 

Vaccine Preventable Diseases2025-Q3*202420232022202120205-yr Median
Diphtheria0000000
Haemophilus Influenzae†29464336161536
Hepatitis B (Acute) 9938434
Hepatitis B (Chronic) 162265309259353324309
Measles3250000
Mumps1275222
Pertussis (Whooping Cough)1356302801586868
Pneumococcal Disease (Invasive)¶4663233
Rubella0000000
Tetanus0000000
Varicella (Chickenpox)60585839301339
Selected Communicable Diseases2025-Q3*202420232022202120205-yr Median
Campylobacteriosis285421358309271244309
Cryptosporidiosis43764867403348
E.coli O157:H73794717
Hepatitis A4698388
Hepatitis C (Chronic)263381357428578468428
Histoplasmosis26482922411529
Legionnaires' Disease671141119214557111
Listeriosis712114545
Lyme Disease1225869271162258
Malaria51712117112
Meningococcal Disease3112211
Salmonellosis245364298275260216275
Shigellosis691108783544083
Tuberculosis 52707565625365
Typhoid Fever35711435
West Nile Virus (Neuroinvasive)2916379161216
West Nile Virus (Non-Neuroinvasive)10320422
Sexually Transmitted Infections2024202320222021202020195-yr Median
Chlamydia**10,80610,94211,13210,50712,23410,942
Gonorrhea**3,0613,2413,9323,9523,5363,536
HIV (Any Stage) **211239265214271239
Syphilis§**157159204167170167

Excludes Chicago, Evanston, Oak Park, Skokie and Stickney Township. For tuberculosis, excludes Chicago only.
* Provisional cases through the third quarter of 2025
† Includes type B
¶ Reportable only in those under 5 years of age
§ Primary and secondary syphilis
** Due to reporting lags, data are not available

Updated October 1, 2025, 11:30 AM