MPOX (formerly known as Monkeypox)
Reporting Obligations
Suspect, probable, and confirmed cases should be reported to the Health Unit by completing page 1 of the Reporting Form and faxing to 613-345-5777.
Epidemiology
Aetiologic Agent
Infectious agent for MPOX is the MPOX virus a species of Orthopoxvirus. There are two genetically distinct clades of MPOX virus: the West African clade and the Congo Basin clade. The West African clade is the one circulating in Canada and beyond Africa at this time.
The West African clade of MPOX virus is generally associated with less severe disease compared to the Congo Basin clade. The virus causes a disease with symptoms similar to, but less severe than smallpox. MPOX is typically mild and self-limiting, with most people recovering within 2–4 weeks. However, severe illness can occur in some individuals.
Clinical Presentation
A prodrome period may occur lasting 1–3 days and includes: fever, chills, myalgias, fatigue, headache, backache, and sometimes sore throat and cough. Lymphadenopathy is a prominent feature in the prodrome and early stages of MPOX illness. This is followed by a progressively developing rash over the next week or so. Lesions progress through stages of macules, papules, vesicles, pustules to crusts/scabs before falling off, and all lesions are usually at the same stage. Complications[1] of MPOX can include secondary infections, bronchopneumonia, sepsis, encephalitis, infection of the cornea with ensuing loss of vision, and myocarditis.
Please refer to CDC’s Clinical Recognition for examples of MPOX rashes.
Modes of Transmission
MPOX – MPOX virus is a completely different virus than the viruses that cause COVID-19 or measles. It is not known to linger in the air and is not transmitted during short periods of shared airspace. MPOX spreads through direct contact with body fluids or sores on the body of someone who has MPOX, or with direct contact with materials that have touched body fluids or sores, such as clothing or linens. It may also spread through respiratory secretions when people have close, face-to-face contact.
CDC MPOX Response: Transmission | CDC Online Newsroom | CDC
Incubation Period
From 3-21 days, commonly 7-10 days from onset of infection.
Period of Communicability
While monkey pox is communicable during the prodromal period, the highest risk of communicability is during the rash phase until all lesions have crusted, fallen off, and new skin has formed, about 2 to 4 weeks.
Risk Factors/Susceptibility
The key to prevention is to:
Be aware, know about symptoms, know what to do, and know how to reduce the risk (see above).
There are number of measures that can be taken to prevent infection with MPOX virus:
- Avoid contact with any materials, such as bedding, that has been in contact with a sick animal.
- Isolate infected people from others who could be at risk for infection.
- Practice good hand hygiene after contact with infected animals or humans. For example, washing your hands with soap and water or using an alcohol-based hand sanitizer.
- Use personal protective equipment (PPE) when caring for patients.
- Avoid contact with animals that could harbor the virus (including animals that are sick or that have been found dead in areas where monkeypox occurs).
There may be some protection for individuals who previously received Smallpox vaccine. [2]
Imvamune® vaccine for post-exposure prophylaxis (PEP) is available for adults 18 years of age and over, who meet the definition of a high risk contact of a confirmed or probable case. Please call the Vaccine Preventable Disease program at 1-800-660-5853, extension 2313, for more details and to discuss ordering and administration.
Diagnosis and Laboratory Testing
Refer to PHOL’s Laboratory testing information at: MPOX Virus – Public Health Ontario
Treatment
Tecovirimat (TPoxx®), is available for the treatment of hospitalized severely ill patients. Hospital clinicians can request product by contacting the Ministry of Health Emergency Operations Centre at [email protected] or by calling the Healthcare Provider Hotline at 1-866-212-2272.
Case and Contact Management
All individuals for whom MPOX testing is being performed should be advised to self-isolate at home (or in the community) pending test results.
Confirmed or probable cases in whom hospitalization is not clinically indicated should self-isolate at home until the end of the period of communicability for a MPOX case (i.e., until lesion scabs have fallen off and new intact skin has formed below, a process which varies by individuals but typically takes 2–4 weeks).
- Ending of the self-isolation period should be assessed on an individual case basis and in consultation with the local public health unit.
Contact Tracing is conducted by Public Health according to PHOs Interim Case and Contact Guideline – see above.
Imvamune vaccine can be used for pre or post exposure to MPOX for eligible groups. Detailed guidance can be found in the Ministry of Health’s MPOX Imvamune Guidance.
Additional Resources
Ministry of Health. Emergency Planning and Preparedness: MPOX virus.
Ministry of Health. MPOX (Monkeypox) Resources for health care professionals
Ministry of Health. Recommendations for the management of cases and contacts of MPOX in Ontario
Ministry of Health. MPOX Vaccine (Imvamune®) Guidance for Health Care Providers
Ministry of Health. MPOX Vaccine Information Sheet
Ministry of Health: MPOX Antiviral Guidance for Health Care Providers
Ministry of Health. MPOX Antiviral Information Sheet
References
Ministry of Health and Long-Term Care, Infectious Diseases Protocol, 2023.