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Monkeypox Information for Physicians


Effective June 16, 2022, 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 (HPPA).

Persons required reporting DOPHS and/or communicable diseases under the HPPA are now required to report directly to the local Medical Officer of Health in accordance with the reporting requirements in the Act, as per routine disease processes.

Suspect, probable, and confirmed cases of Monkeypox must be reported to Halton Region Public Health by calling 905-825-6000, ext. 7341 during regular business hours and 311 after hours.

Complete pages 1-4 of the Ontario Monkeypox Investigation Tool (external link) and fax to Halton Region Public Health at 905-825-8797.

  • Laboratory testing is helpful for reporting and case/contact management purposes for any individual with rash/symptoms similar to monkeypox, either testing for monkeypox and/or other infections on the differential diagnosis.
  • Testing for monkeypox can be done by primary care providers with the specimen having the same transport requirements (i.e. category B) as other microbiology specimens such as a swab collected for gonorrhoea, blood collected for syphilis, urine for routine culture and susceptibility.
  • The outer packaging (bag) must be labelled certified for UN3373 and must be marked on a contrasting background with “TU 0886 Temporary Certificate”.
  • All specimens from a patient being investigated for monkeypox, including specimens submitted for other tests, should indicate on the requisition that this patient is suspected of having monkeypox.
  • All specimens from a patient being investigated for monkeypox are considered dangerous goods and as such, appropriate training is required for the handling, offering for transport, or transport of the specimens. For more information on training, refer to guidance from Temporary Certificate TU 0886 (external link).
  • Detailed information on testing, specimen collection and specimen transport is available on PHO Lab website (external link).

Monkeypox is a self-limiting orthopoxvirus endemic to Central and West Africa. Public Health agencies around the world have recently reported cases of monkeypox. It is a viral zoonotic disease, but can also spread between people. The virus causes a flu-like illness that leads to a maculopapular rash. The West African strain of the virus has recently (May 2022) been detected in confirmed cases.

Symptoms may begin in a prodromal phase that includes:

  • Fever/chills
  • headache
  • swollen lymph nodes
  • intense fatigue
  • sweating
  • muscle aches
  • joint stiffness

The incubation period is usually 6 to 13 days but can range from 5 to 21 days. Within 1-3 days after symptom onset, a rash appears at the site of inoculation, then may appear on other parts of the body including oral mucosa, genital area, conjunctiva, palms of the hands and soles of the feet.

Atypical presentations include initial signs of a genital or perianal rash prior to prodrome symptoms which may not spread to other parts of the body, and having lesions at different stages of development. The rash turns into vesicular lesions that will eventually fall off to be replaced by new skin. The time for scabs to fall off varies by individual but typically takes 2-4 weeks.

Epidemiology on recent cases reported in the US, UK, Canada, and Western Europe shows that some cases have been clustered in men who have sex with men. In addition, many of these cases have reported atypical symptoms, including painful unusual rash/lesions in the mouth and/or genitals.

As the situation continues to evolve, guidance is being updated frequently. For up to date recommendations, please see IPAC Recommendations for Monkeypox in Health Care Settings (external PDF).

If a patient has symptoms of monkeypox, they should immediately self-isolate and call their health care provider. If contact with others is mandatory (e.g., seeking health care), patient should wear a high quality medical mask and cover up all lesions.

Consider the diagnosis of monkeypox in individuals with signs and symptoms that may be compatible with the disease such as a rash that includes painful genital/oral lesions, fever, lymphadenopathy, chills and/or sweats, headache, back pain/ache, sore throat and/or cough, coryza, malaise/listlessness, and prostration/distress.

At this time, Public Health will follow up with all reported cases. Cases must isolate at a minimum until test results and until they meet the criteria outlined in the Recommendations for the management of cases and contacts of monkeypox in Ontario. Contacts should monitor for symptoms for 21 days after their last exposure. If they develop a fever or rash, they should immediately self-isolate, contact Public Health, and see their primary health care provider.

Key Messages

  • Imvamune® vaccine is approved in Canada for protection against monkeypox (external PDF) for both Pre-Exposure Prophylaxis (PrEP) and Post-Exposure Prophylaxis (PEP).
  • Individuals with signs or symptoms of monkeypox infection should not receive the vaccine as the vaccine is not indicated in the treatment of monkeypox infection.
  • The most common side effects of Imvamune® vaccine include reactions at the injection site like pain, erythema, induration and swelling. The most common systemic reactions observed after vaccination are fatigue, headache, myalgia, and nausea. Most of the reported adverse drug reactions observed in clinical trials were of mild to moderate intensity and resolved within the first seven days following vaccination.

Imvamune® vaccine for Pre-Exposure Prophylaxis (PrEP)

Based on Ontario Ministry of Health's guidelines (external PDF), persons who qualify for PrEP at this time are:

  • 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:
    • Have had two or more sexual partners within the last 21 days, or may be planning to, OR
    • Diagnosed with chlamydia, gonorrhea, or syphilis infection in the past two months, OR
    • Attended bath houses, sex clubs and other venues for sexual contact within the last 21 days including workers & volunteers in these settings, OR
    • Have had anonymous/casual sex in the last 21 days, for example using an online dating or hookup app, OR
    • Engage in sex work or may be planning to, and their sexual contacts.

Imvamune® vaccine for Post-Exposure Prophylaxis (PEP)

  • The provision of Imvamune® vaccine for PEP requires an assessment of the risk of exposure by Halton Region Public Health.
  • PEP should be given within 4 days of exposure, but can be given up to 14 days after last exposure.
  • If a patient self-identifies as a high-risk contact of a confirmed or probable case of monkeypox, the community health care provider should contact the patient’s local public health unit for further assessment to see if PEP would be recommended.

Halton Region Public Health Sexual Health Clinics will be offering Imvamune® vaccine for Pre-Exposure Prophylaxis (PrEP) by appointment only to individuals who meet Ontario’s current eligibility criteria (external link). Eligible individuals can call 311 to book an appointment; no OHIP card or ID is required.

If a patient has had a high or intermediate risk exposure to monkeypox, the community health care provider should contact 311 to request Imvamune® vaccine for Post-Exposure Prophylaxis (PEP) to be administered in the health care provider’s office. The provision of Imvamune® vaccine as PEP for high-risk contacts requires an assessment of the risk of exposure by Halton Region Public Health.

For further information please see: