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 GLOBAL.hEALTH Monkeypox Outbreak Tracker. 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.

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:

  • Presentation of lesions at site of contact prior to the onset of systemic symptoms
  • Rashes in the mouth, genital, or anorectal areas
  • Absence of prodrome

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:
    • primary syphilis (with a painless chancre),
    • secondary syphilis (with widespread rash),
    • chickenpox/shingles (primary or reactivation of varicella zoster),
    • herpes simplex, chancroid.
  • Given some of the atypical presentations with early lesions in the mouth, genital or anorectal regions, consider monkeypox alongside other sexually transmitted infections.
  • It is possible for monkeypox to occur concurrently with other rash illnesses, including varicella-zoster virus and herpes simplex virus infections.

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.

  • Period of communicability:
    • Onset of lesions until all lesions have scabbed, fallen off and new skin has formed
    • Some individuals may be contagious during the prodrome phase (before rash develops or is noticed) when they have non-specific symptoms, such as fever, malaise and headache
    • Most contagious at the onset of initial lesions

Who to test:

Individuals with a compatible clinical illness, where monkeypox is suspected should be tested.

Approval for monkeypox testing is not required, nor is it required to contact Public Health Ontario (PHO) Customer Service Centre prior to specimen submission.

Contact PHO Customer Service (416-235-6556/1-877-604-4567) or after hours the on-call Duty Officer (416-605-3113) if you wish to consult prior to sample collection and shipment.

Samples may include: nasopharyngeal, throat or lesion swabs, samples/scrapings of scabbed lesions.

Refer to PHO’s Monkeypox Virus Test Information Index for detailed information on sample collection and submission.

How to ship:

Transport Canada has issued Temporary Certificate TU 0886 for the transportation of monkeypox sample shipments by land (in a road vehicle, railway vehicle, vessel, between two points in Canada). The exemption does not apply to other modes of transportation. Specimens will need to comply with Transport Canada regulations.

As of June 2, 2022, clinical specimens from patients undergoing monkeypox testing have been temporarily reclassified as UN3373 Biological Substance, Category B for land transport. In addition to the routine category B requirement, the outer packaging must be marked, on a contrasting background, with “TU 0886”, “Temporary Certificate – TU 0886” or “Certificat Temporaire – TU 0886”. For full details on packaging and transporting, the temporary certificate can be downloaded by searching “TU 0886” at the Transport Canada website.

Primary health care providers with no access to a Transportation of Dangerous Goods (TDG) certified shipper and/or the special packaging must refer the patient to a location with such resources for specimen collection and transport. It is currently advised to refer patients to a nearby hospital with a laboratory capable of shipping Category B packages for specimen collection. It is also advised to call the hospital ahead to notify of the patient referral in order for the hospital to implement appropriate infection prevention and control measures immediately on the patient’s arrival.

PHO has developed the following IPAC Recommendations for Monkeypox in Health Care Settings (1st revision, May 2022):

Room Placement:

  • An individual with suspect or confirmed monkey pox is to be placed in a single-patient room with the door closed with a dedicated toileting facility. An Airborne Isolation Room (AIR) is not necessary, but can be used if available and depending on other IPAC considerations (e.g., Varicella or Measles on the differential diagnosis).
  • If a single- patient room is not available, then precautions should be taken to minimize exposure to surrounding individuals such as having the patient don a medical mask over their nose and mouth as tolerated and covering exposed skin lesions with clothing, sheet or gown as best as possible.

Hand hygiene as per the Four Moments of Hand Hygiene.

Personal Protective Equipment (PPE) for health care workers:

  • Gloves
  • Gown
  • Eye protection (e.g., face shields or goggles)
  • Fit-tested and seal checked N-95 respirator (or equivalent); perform seal check after donning N95 respirator.

Duration: Additional Precautions are maintained until all scabs have fallen off and new skin is present.

Patient Transport: Have the patient wear clean clothes/gown, wash their hands, wear a medical mask and cover their lesions to the best extent possible for transport.

Laundry: Soiled laundry is to be managed in accordance with Routine Practices. Staff are to protect themselves from potential cross-infection from soiled linen by wearing appropriate PPE (gloves, gown, fit-tested and seal-checked N95 respirator and eye protection) when handling soiled linens. Staff are to clean their hands upon removal of PPE. Care should be taken in the management of soiled laundry to avoid shaking or handling in a manner that may cause dispersal of microorganisms.

Waste disposal: Containment and disposal of contaminated waste (e.g., dressings) in accordance with facility-specific/public health guidelines for infectious waste.

Environmental cleaning: Healthcare-grade cleaning and disinfecting agents, with a Drug Identification Number (DIN) are appropriate for cleaning and disinfection of environmental surfaces and shared equipment in the patient care environment. Follow the manufacturer’s recommendations for dilution and contact time.

Food Services: Food service items are to be managed in accordance with Routine Practices. Dishware and eating utensils are effectively decontaminated in commercial dishwashers with hot water and detergents. Reusable dishware and utensils may be used; disposable dishes are not required.

There is no specific treatment available for monkeypox. Most patients will recover from monkeypox without intervention. Some may require hospitalization and supportive care.

Some antivirals that have been developed for the treatment of smallpox may be effective, but they are not widely available at this time. In Canada, Tecovirimat (TPoxx®) is authorized by Health Canada under an extraordinary use indication for the treatment of human smallpox disease in adults and pediatric patients weighing at least 13 kg:

  • While the drug does not have an approved indication for the treatment of monkeypox in Canada, a licensed healthcare provider may use their clinical judgement to prescribe TPoxx® off-label for the treatment for severe monkeypox infections
  • A limited supply is available in Ontario for hospitalized severely ill patients.
    • Hospital clinicians can request product by contacting the Ministry of Health Emergency Operations Centre at MOH@ontario.ca or by calling the Healthcare Provider Hotline at 1-866-212-2272

More information: Ministry of Health’s Interim Vaccine Guidance for Post-exposure Prophylaxis and How to Access Tecovirimat.

Vaccination after an exposure to monkeypox infection may prevent infection or may lessen severity in those who still go on to develop infection after receiving the vaccine as PEP. IMVAMUNE is a live-attenuated, non-replicating vaccine which is active against both monkeypox and smallpox.

  • Vaccination clinics will be held in Toronto for those who meet the provincial criteria for Imvamune (see below)
  • Based on Ontario Ministry of Health’s guidelines, these clinics are intended for:
    • Residents 18 years and older trans or cis-gender individuals who self-identify as belonging to the gay, bisexual & other men who have sex with men (gbMSM) community AND at least one of the following:
      • Identified as a contact of someone that recently tested positive for monkeypox, OR
      • Had 2 or more sexual partners within the past 21 days, or may be planning to, OR
      • Diagnosed with a chlamydia, gonorrhea, or syphilis infection over the past 2 months, OR
      • Attended bath houses, sex clubs and other venues for sexual contact within the past 21 days. This includes workers & volunteers, OR
      • Had anonymous/casual sex in the past 21 days for example using an online dating or hookup app, engaging in or planning to engage in sex work, and their sexual contacts.

More information: 

  • The Chief Medical Office of Health issued a memo on June 16, 2022 indicating that monkeypox has been designated a Disease of Public
    Health Significance (DOPHS) as “Smallpox and other Orthopoxviruses including Monkeypox” under the Health Protection and Promotion Act
  • All suspected and confirmed cases of monkeypox must be reported to TPH’s Communicable Disease Surveillance Unit 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

Suspect and Probable Cases

  • All individuals for whom monkeypox testing is being performed should be advised to self-isolate at home (or in the community) pending test results
  • Individuals in whom monkeypox is clinically suspected but testing is unavailable or not completed, should self-isolate at home (or in the community) until the end of the period of communicability (i.e., until all scabs have fallen off and new intact skin has formed below)

Confirmed Case

  • For individuals in whom hospitalization is not clinically indicated, self-isolation at home (or in the community) is indicated until the end of the period of communicability for a monkeypox case (i.e., until lesion scabs have fallen off and new intact skin has formed below, a process which varies by individual but typically takes two to four weeks)
  • Ending of the self-isolation period will be assessed on an individual case by case basis and in consultation with the local public health unit

Contact Management

  • Contacts should monitor for signs and symptoms for 21 days from last exposure including new skin rash/lesions, fever, chills, headache, myalgias, and lymphadenopathy
  • Asymptomatic contacts are not required to self-isolate and can attend routine daily activities (e.g., go to work, school). Should any symptom(s) of monkeypox develop (including prodromal symptoms of fever, headache, myalgia, or lymphadenopathy which can develop up to 3 days prior to the rash), individuals should self-isolate immediately
  • Asymptomatic intermediate and high risk contacts (see PHO’s Monkeypox Virus: Interim Case and Contact Management Guidance for Local Public Health Units – Table 2 for risk of exposure assessment) should avoid non-essential interactions in enclosed indoor settings with those at higher risk of severe monkeypox illness including immunosuppressed people, pregnant people, and children under 12 years old
  • Asymptomatic contacts should consider wearing a mask for source control when in enclosed indoor settings.

More information can be found on Public Health Ontario’s Monkeypox Virus: Interim Case and Contact Management Guidance for Local Public Health Units.