Last updated: November 2, 2022

Monkeypox virus is an orthopoxvirus that causes a disease with symptoms similar to, but less severe than, smallpox and is endemic to parts of Central and West Africa. There are two clades (strains) of monkeypox: the Central African clade and the West African clade.  Human infections with the Central African clade are typically more severe and have a case fatality rate around 10%. Illness with the West African clade is usually self-limiting within 2-3 weeks with a case fatality rate around 1%. Previously, cases of monkeypox in countries other than those in Central and West Africa have only been identified as a direct result of travel to these regions.

As of May 2022, many countries where monkeypox is not endemic have documented clusters of cases which are not linked to direct travel to Central or West Africa. For more information see the US CDC 2022 Monkeypox Outbreak Global Map. Current epidemiological analysis  suggest that these infections are spreading via close physical contact with an individual who is infectious with monkeypox, and many (but not all) cases self-identify as men who have sex with men (MSM).

For a rapid review of the evidence related to a specific aspect or emerging issue related to the 2022 worldwide monkeypox outbreak review Public Health Ontario’s “What We Know So Far” document.

To view the latest data on Monkeypox in Toronto, visit Public Health Ontario’s Monkeypox webpage and click on the latest Summary Report.

NOTE: If you see a patient with suspected or confirmed monkeypox, please ask them to self-isolate and share Toronto Public Health’s self-isolation guidance with them.

Prior to the current outbreak, monkeypox infections have been thought to follow a fairly typical pattern, as outlined below. However, some jurisdictions with new outbreaks of monkeypox are noticing atypical presentations which may include:

The rash may occur before, with or without the febrile systemic illness. Initial lesions may appear at sites of inoculation, such as the face and neck with kissing, and the penis and perianal region with sexual exposure. Lesions display pleomorphism, presenting in various stages simultaneously. Vesicles and pustules may be smaller than classically described, sometimes noticed only with surrounding pain, pruritis or erythema. Complications have been reported, including myocarditis, proctitis and epiglottitis, but there have been no reported deaths. (A case of human monkeypox in Canada)

Typical Presentation:

  • Incubation period (usually 6-13 days, but can be 5-21 days)
  • Prodrome phase (1-4 days): occurs prior to onset of rash, or at same time
    • May involve fever, chills, headache, myalgia, fatigue
    • Lymphadenopathy may occur during the prodrome phase, and would be unusual in other diseases that may have similar types of rash (such as chickenpox, syphilis and HSV)
  • Rash phase
    • Typically begins in the mouth or on the face
    • May then spread to body, extremities, anogenital area, palms and soles of feet
    • Typical lesions can be described as: deep-seated and well-circumscribed lesions, often with central umbilication
    • The lesion typically progress through the following stages: macules, papules, vesicles, pustules, and finally scabs
    • Rash may be localized, or generalized. If generalized, it may be similar to smallpox, with a centrifugal distribution
  • Recovery
    • Rashes scab, fall off, and new skin forms

Differential diagnosis:

This includes, but is not limited to:

  • chickenpox/herpes zoster,
  • herpes simplex virus-1/herpes simplex virus-2,
  • primary syphilis (with a painless chancre)/ secondary syphilis (with widespread rash),
  • Hand-foot-and-mouth disease,
  • molluscum contagiosum,
  • chancroid.

For distinguishing infectious causes of vesicular lesions see a case of human monkeypox in Canada.

Monkeypox is spread to people through direct contact with the bodily fluids or lesions of infected animals or people, via respiratory droplets from an infected person, or from mother to fetus. In can also be transmitted indirectly through contact with materials contaminated with the virus, such as bedding and clothing. At this time, it is not known if monkeypox can spread through semen or vaginal fluids.  A cautious approach that recommends cases utilize barrier contraception methods during sexual intercourse for 8 – 12 weeks following resolution of their infection should be considered pending the availability of further scientific evidence. For more information, visit Public Health Ontario’s Monkeypox Transmission Through Genital Excretion.

Period of Communicability

Monkeypox can spread from the time symptoms start until the rash has fully healed and a fresh layer of skin has formed. People who do not have monkeypox symptoms cannot spread the virus to others.

Refer to PHO’s Monkeypox Virus Test Information Sheet for up to date  information on who to test and sample collection and submission.

Transporting Monkeypox Samples for Laboratory Testing

  • Monkeypox specimens require the same packing and transportation/courier systems that are used for other microbiological testing in outpatient settings
  • The key difference for monkeypox specimen transportation is that the transport container must be marked – using a contrasting background – with “TU 0886” (see Appendix 1 for a printable copy of this label)
  • The same laboratory courier systems that currently pick up specimens from primary care clinical practice locations for microbiology testing can be used for transporting monkeypox specimens

In addition to routine precautions, the following measures are recommended for health care workers when interacting with individuals with suspected, probable, or confirmed monkeypox infection:

  • Place the individual with suspect, probable, or confirmed monkeypox infection in a single patient room, with the door closed. Inpatients should be placed in a single-person room with a dedicated bathroom
  • Perform hand hygiene as per the four moments of hand hygiene
  • Use recommended personal protective equipment (PPE) such as gloves, gown, eye protection (e.g., face shields, safety glasses or goggles), and a fit-tested and seal-checked N-95 respirator (or equivalent); perform seal check after donning N95 respirator
  • Ensure patients wear a well-fitting medical mask
  • Perform routine environmental cleaning and disinfection and ensure all horizontal surfaces that may be touched by the patient and equipment that may have been used by or shared between patients are cleaned and disinfected after every use. Special and/or additional environmental cleaning and disinfection measures are not required.

More information:

Tecovirimat (TPoxx®) has recently been authorized for sale and use in Canada, for the treatment of human smallpox disease in adults and pediatric patients weighing at least 13 kg based on limited clinical testing in humans. TPoxx® does not have an approved indication for the treatment of monkeypox in Canada. However, a licensed healthcare professional may request this drug for eligible patients based on their clinical judgement for treating severe monkeypox infections.

A limited supply of TPoxx® is available in Ontario for individuals who are severely ill/disabled due to monkeypox infection or at high risk for severe disease.

Eligibility Criteria

TPoxx® should be considered for the following:

  • Hospitalized patients with severe disease (e.g., hemorrhagic disease, sepsis, encephalitis, myocarditis, esophagitis, or other conditions requiring hospitalization)
  • Persons who may be at high risk of severe disease:
    • Persons who are severely immunocompromised (e.g., individuals with HIV with current CD4 counts < 200/mm3 or with uncontrolled viral loads; receiving active treatment for solid tumour or hematologic malignancies such as chemotherapy, targeted therapies, or immunotherapy; recipients of solid-organ transplant and taking immunosuppressive therapy; recipients of hematopoietic stem cell transplant within 2 years of transplantation or taking immunosuppression therapy; autoimmune with immunodeficiency as a clinical component; on treatment with agents such as tumor necrosis factor or high-dose corticosteroids);
    • Pediatric populations, particularly patients younger than 10 years of age
    • Pregnant or breastfeeding women
    • Persons with one or more complications (e.g., severe secondary bacterial skin infection; gastroenteritis with severe nausea/vomiting, diarrhea, or dehydration; bronchopneumonia; concurrent disease or other comorbidities).
  • Persons with monkeypox virus infections with lesions that are leading to

significant disability (e.g., proctitis, keratitis or other ocular involvement,

pharyngitis/epiglottitis or other breathing/swallowing compromise).

How to Order TPoxx®

TPoxx® will initially be provided to clinicians as part of Health Canada’s Special Access Program (SAP). Given the limited supply of TPoxx® available in Ontario, TPoxx® should be prescribed based on the eligibility criteria described above.

Clinicians need to request TPoxx® by contacting the Ministry of Health Emergency Operations Centre (MEOC) at EOCoperations.MOH@ontario.ca or by calling the Healthcare Provider Hotline at 1-866-212-2272. When contacting MEOC, you should include the exact number of patients that have consented to receive the TPoxx® treatment.

Health Canada’s SAP has mandatory reporting requirements for clinicians using the Follow-Up Form (Form C), including treatment response outcomes. This form should be returned to the MEOC at EOCOperations.MOH@ontario.ca. The MEOC will send the forms back to SAP on behalf of the clinician.

For more information, please refer to the following resources:

Imvamune vaccine can be used for protection against monkeypox before getting exposed to the virus (Pre-Exposure Prophylaxis or PrEP) or after being exposed (Post-Exposure Prophylaxis or PEP).

Imvamune is a live-attenuated, non-replicating vaccine which is active against both monkeypox and smallpox.

Note: Imvamune vaccine is not required for health care workers who are seeing patients with monkeypox infection in their clinical office practice.

Vaccination clinics

Imvamune vaccine clinics are being provided by TPH and community partners for both PrEP and PEP (full list of clinic locations).

Based on Ontario Ministry of Health guidelines, the vaccine is available for the following eligible groups:

For Pre-Exposure Prophylaxis (PrEP)

  1. Two-spirited, non-binary, transgender men and women or cis-gender individuals who self-identify or have sexual partners who self-identify as belonging to the gay, bisexual and other men who have sex with men (gbMSM) community AND at least one of the following:
    • Had a confirmed sexually transmitted infection within the last year;
    • Recently had two or more sexual partners or may be planning to;
    • Recently attended venues for sexual contact (e.g. bathhouses, sex clubs) or may be planning to, or who work/volunteer in these settings;
    • Recently had anonymous/casual sex (e.g. using hook up apps) or may be planning to;
    • A sexual contact of an individual who engages in sex work
  2. Anyone who engages in sex work or may be planning to.
  3. Household and/or sexual contacts of people who are eligible for PrEP – listed above in parts (a) or (b) – AND have a weak immune system or are pregnant. These individuals should contact a healthcare provider or Toronto Public Health for more information.

For Post-Exposure Prophylaxis (PEP)

  • TPH follows up with all monkeypox cases and identifies their contacts. Contacts are assessed and, if eligible, are referred to receive Imvamune PEP.
  • PEP should be offered as soon as possible and within 14 days since last exposure. Vaccine must be given within four days from the date of exposure in order to prevent onset of the disease. Given between four to 14 days after the date of exposure, vaccination may reduce the symptoms of disease, but may not prevent disease.

Second Dose Eligibility

  • Based on Ontario Ministry of Health guidelines, everyone eligible to receive Imvamune® as pre-exposure prophylaxis (see eligibility criteria above) can now receive a second dose with a minimum spacing of 28 days.
  • Those that received a single dose of Imvamune® as post-exposure prophylaxis may receive a second dose if the risk of exposure continues beyond or is expected to continue beyond 28 days following their first dose.

More information:

All suspected and confirmed cases of monkeypox must be reported to TPH by:

  • Completing TPH’s Reportable Disease Form and faxing to 416-392-0047, OR
  • Calling 416-392-7411 during work hours (8:30 am to 4:30 pm, Monday to Friday) or 311 after hours