Monkeypox detected in Hamilton wastewater testing


Published December 15, 2023 at 1:31 pm


Traces of the monkeypox virus have been found in wastewater testing samples, Hamilton Public Health reported Friday.

The city’s public health agency declared the monkeypox outbreak over and said no human cases of the virus have been reported since September 2022 but cautioned that detection of monkeypox in wastewater “may indicate undiagnosed sporadic monkeypox cases.”

Monkeypox is an orthopoxvirus that causes mpox, a disease similar to, but less severe than smallpox. The disease is usually mild and self-limiting, however severe illness can occur. Mpox infection presents with symptoms of fever, chills, headache, myalgias, lymphadenopathy, and fatigue, followed one to three days later by a progressively developing rash. The rash typically begins on the face, then spreads to other parts of the body, including the hands, feet, mouth, genital, and/or peri-anal region.

Hamilton Public Health (HPH) is asking health care providers to consider mpox as a diagnosis in patients presenting with compatible clinical illness. While gay men are at highest risk, anyone with close personal contact could also be at risk for infection.

Health care providers should continue to consider similarly diagnosed illnesses, such as syphilis, herpes simplex virus and chancroid, which may be hard to distinguish from mpox.

HPH recommends Imvamune vaccine as pre-exposure prophylaxis to eligible individuals. The vaccine is given in two doses, with at least 28 days between the first and second dose, and HPS is encouraging patients to complete their two-dose series, with the rate for second doses administered extremely low in Hamilton at just 9.03 per cent.

HPH offers mpox vaccination for at-risk populations at the Sexual Health Clinic located at the David Braley Health Sciences Centre. Individuals who meet the provincial criteria for vaccination to prevent mpox infection can book an appointment by calling (905) 528-5894, Monday to Friday from 8:30 a.m. to 4:30 p.m. An OHIP card is not required.

The next mpox clinic is Wednesday, December 20. The clinic will be offered again in the new year on Wednesday January 3.

The Public Health Ontario Laboratory has a Monkeypox virus test information sheet which can be found at

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