Chatham-Kent Public Health is reporting that the most frequent infectious disease across the municipality last year was once again chlamydia.
The health unit noted that 193 cases of chlamydia were reported in 2025. That's 34 per cent of all infectious disease cases last year, but 21 cases lower than the previous year.
Females and those 15 to 24 years old had the highest chlamydia rates. However, rates for chlamydial infections decreased in 2025 compared to the previous five-year average and were comparable to the province, according to an information report going before the public health unit on Monday.
According to the data, measles was the second most reported infectious disease in 2025, with 169 cases reported or 30 per cent of all cases reported.
The information report stated that Chatham-Kent experienced one of the highest infection rates in the province during the measles outbreak of 2025, with unvaccinated children under the age of 15 making up the majority of those infected.
Gonorrhea was third on the list with 65 cases reported, almost double the number in 2024, followed by hepatitis C with 21 cases, and Campylobacter enteritis, a common form of food poisoning, rounding out the top five with 19 cases.
The 25 to 44 age group experienced the highest rates of gonorrhea.
Campylobacter enteritis, hepatitis C, and gonorrhea rates were comparable to the province and have not changed significantly in comparison to the previous five-year average, said the health unit.
The report showed 567 new cases of reportable infectious diseases among Chatham-Kent residents in 2025.
Excluding seasonal respiratory illnesses, the largest burden of reportable diseases across Chatham-Kent last year was sexually transmitted and blood-borne infections, according to the data. Those infections account for 297 cases or 52 per cent of all infectious diseases in Chatham-Kent last year. They're also up by 16 from 2024, but not as high as 2021, 2022, or 2023 when they ranged from 360 to 387.
The health unit also reported 190 vaccine-preventable diseases, 49 enteric, foodborne, and waterborne diseases, 21 diseases transmitted by direct contact or respiratory routes, and 10 vector-borne diseases.
The data also showed that respiratory activity was lower in 2025-26 compared to the 2024-25 respiratory season.
