Mpox (monkeypox): Public health management of cases and contacts in Canada

February 23, 2023

Note

February 23, 2023 update

An update was made to the last version (October 18, 2022) of this document, in which the term “monkeypox” disease was updated to include “mpox”. This change aligns with the World Health Organization's (WHO) preferred nomenclature for the disease. The WHO recommended this change in November 2022 to help reduce stigma and other concerns associated with the previous terminology.

October 18, 2022 update

Updates have been made to the last version (June 21, 2022), and include the following changes:

• Identify populations who may be at greater risk of infection during the current outbreak, while recognizing that risk of exposure to mpox is not exclusive to any group or setting.
• Clarify advice for condom use following mpox infection
• Note that public health authorities may consider developing targeted messaging for gatherings/settings where close physical contact, including sexual activity may take place (e.g., parties, clubs, raves, festivals).
• Provide more information related to animals that have been exposed to a human case of mpox, including risk mitigation measures that may be put in place.
• Provide information on safer sex practices in the context of the mpox outbreak.

On this page

• Introduction
• Background
• Public health management of cases
• Public health management of contacts
• Additional resources
• Footnotes
• References

Introduction

The Public Health Agency of Canada (PHAC), in collaboration with provincial/territorial (PT) public health authorities (PHAs) and other relevant federal government departments, has developed this document to provide guidance to PHAs working at the federal/provincial/territorial (FPT) level in the event cases of monkeypox virus are suspected or confirmed within their jurisdictions.

The strategy outlined in this guidance relies on rapid case and contact management with the goal of outbreak containment, including among priority populations or populations at higher risk of exposure to mpox (monkeypox) and/or severe disease, and settings where transmission is occurring. To achieve this, the objectives for this guidance include rapidly stopping chains of transmission to prevent the establishment of mpox in Canada, and protecting public health and health care in Canada. This includes the protection of populations in Canada who are at risk of more severe disease from mpox infection (e.g., individuals who are immunocompromised, individuals who are pregnant, young children)^{Reference 1}.

In addition, because mpox is not widespread across Canada and the situation is quickly evolving, this document follows precautionary principles and approaches, in an effort to prevent the long-term establishment of mpox in Canada.

Guidance pertaining to diagnostic laboratory, specimen handling and transportation, clinical care, and infection prevention and control (IPAC) measures in other settings (e.g., Canadian points of entry, healthcare settings, long-term care facilities) are beyond the scope of this document.

This guidance is informed by the latest available scientific evidence, national and international epidemiological data and expert opinion; it is subject to change as new information becomes available and the situation in Canada evolves.

At the time of this update, the body of evidence surrounding mpox continues to be limited, with little recent scientific data available. PHAC continues to apply an evidence-informed approach to its case and contact management guidance for mpox; as new scientific information becomes available that triggers a shift in guidance, PHAC will adjust this document accordingly.

This guidance should be read in conjunction with relevant FPT and local legislation, regulations and policies, and adapted to local context as required. This document has been developed based on the Canadian situation and therefore may differ from guidance developed by other countries.

Background

Monkeypox virus in humans

Monkeypox virus can be spread to humans three ways: animal to human, human to human, and likely through fomites^{Reference 2Reference 3Reference 4} For more information on the modes of transmission, clinical manifestations, diagnosis and treatment for monkeypox virus, refer to PHAC's Mpox (monkeypox): For health professionals webpage. Information on mpox for the general public is also available.

Current status

The mpox situation in Canada is evolving quickly. For up-to-date information, refer to PHAC's Mpox (monkeypox): Outbreak update webpage.

At the time of this update, most cases of mpox in Canada are in persons with multiple sexual partners, particularly men who report intimate sexual contact with other men. However, it is important to stress that the risk of exposure to monkeypox virus is not exclusive to any group or setting.

Mpox (monkeypox) illness is usually self-resolving. However, severe cases can occur and may be fatal^{Reference 1}. Based on genomic sequencing available to date, the outbreaks occurring in Canada are the result of transmission of Clade IIb of monkeypox virus, which historically has reported a case fatality rate of approximately 1-3%^{Reference 5Reference 6Reference 7}. For additional information on further detail regarding the mpox epidemiology in Canada, please refer to PHAC's Mpox (monkeypox) epidemiological update page.

Public health management of cases

Case definitions

National case definitions for mpox have been established and are being used for the context of this document.

Public health activities for case management

PHA's activities for case management may include:

• Isolation of cases until deemed no longer contagious by the PHA
  • Cases may isolate at home when feasible, or in an alternate dwelling such as a hotel or self-containing accommodation as directed by the PHA, when necessary
    • Note: For the remainder of this document, “home” will be used as an all-encompassing term to refer to the case's place of isolation
  • Identifying and mitigating any barriers to effective isolation at the home , as well as providing appropriate supports as needed (e.g., should encompass health, psychological, material and essential supports needed for adequate living)
  • PHAs should take into account the unique characteristics of the case and their living situation (e.g., if the case is living in a congregate living setting like a homeless shelter, student residence or correctional facility) and adjust advice accordingly (e.g., recommending isolating the case in an alternative setting, when no other option is available)
• Active monitoring of mpox cases (i.e., through regular communication), recognizing that frequency may vary by PHA and the local context
  • Monitoring activities can support learning about the clinical evolution of the infection, address emerging issues, as well as encourage the appropriate isolation compliance, including by connecting the individual to community support as appropriate
• Providing information on public health measures (PHMs) that the case, along with their caregiver and household members, should follow (see section below)
• Providing general advice on steps to take if symptoms worsen, including instruction on self-care, when to contact their health care provider and how/when to access medical care

Identifying all contacts during the case's period of communicability, including, persons identified specifically as contacts by the case, and also groups of individuals potentially exposed during an event or while at a location, depending on the activities practiced while at those sites.

As individual situations vary and are unique, PHAs may need to modify isolation approaches used for cases. Modifications in isolation should be designed to maintain the objectives of this guidance (i.e., rapidly stopping chains of transmission, preventing the establishment of mpox in Canada, and protecting public health and health care in Canada).

Public health measures recommendations for suspected, probable and confirmed cases

When hospital-level care is not required, cases of mpox are recommended to isolate, from the start of symptoms until scabs have fallen off and there is evidence of epithelialization. This typically takes 2 to 4 weeks, but may take longer. The full spectrum of recommended PHM's are outlined below.

General recommendations for isolation

• Remain in isolation until deemed no longer contagious (i.e., once scabs have fallen off, and the wound is epithelialized and has a light pink / shiny pearl appearance)
  • Only leave isolation to access urgent medical care or for other such emergencies
  • When accessing medical care, cases should, as much as possible, alert health care providers of their infection in advance of the meeting
  • When possible, cases seeking medical care should not use public transportation
  • If public transportation is unavoidable, cases should wear a well-fitting medical mask, cover any lesions and maximize their distance from others
• As much as possible, have necessities delivered to the home, such as medication, groceries, etc.
• Postpone elective medical visits and other elective procedures (e.g., elective dental visits, elective blood tests)
• Do not donate blood or any other body fluid (including sperm) or tissue
• Do not travel to other cities, regions/provinces/territories or to other countries during the isolation period
• Maintain proper hand hygiene and respiratory etiquette

Recommendations for interactions with others

• Avoid direct touching of other people, including through sexual contact
• Avoid contact with populations at risk of more severe disease (e.g., individuals who are immunocompromised, individuals who are pregnant, young children)^{Reference 1} where possible
• Limit contact with others from outside the home during the isolation period
  • This includes not having visitors inside the home, with the exception of a health care provider who follows relevant IPAC measures to provide necessary patient care services
• If the case lives with others, isolate in a separate space (e.g., private room for sleeping and washroom) whenever possible, especially if the case has respiratory symptoms, lesions that are hard to cover (e.g., on the face, neck, hands), or weeping lesions
  • If a private room for sleeping is not possible, the case should maintain as much distance as possible from others (e.g., by sleeping in separate beds)
  • If a separate washroom is not possible, the case should clean and disinfect all surfaces and objects they have had contact with and immediately remove and launder used towels
• When interaction with others is unavoidable:
  • Cover all lesions with clothing or bandages as much as possible (including when accessing common spaces, even if others are not present)
  • Wear a well-fitting medical mask
    • When this is not possible, other household members should wear a medical mask when in the presence of the case
• Do not share clothes, bedding, towels, utensils, toothbrush, razors, sex toys, needles, or any other items that may be contaminated with infectious particles from lesions or body fluids
• Cases should consult their healthcare provider for advice, if they must have close contact with infants (e.g., a person providing care or breastmilk to an infant) given the potential for severe disease in very young children

Recommendations for interactions with animals (pets, livestock and wildlife)

• Cases should be advised they can transmit mpox to animals and to avoid contact with animals, including pets, when possible
  • The current spread of mpox disease in Canada is a result of human-to-human transmission of the monkeypox virus; however, people can also spread the virus to animals, who can then spread it back to people
  • Many different animal species are susceptible to monkeypox virus, especially rodent species (e.g., squirrels, rats), but the full range of animals susceptible to monkeypox virus, particularly in North America, remains unknown at this time
  • Dogs are now known to be susceptible, following a report in August 2022 of a dog with mpox infection in France after close contact with human cases in a household^{Reference 8}; it is prudent to assume that any mammal species could be infected with monkeypox virus
• To prevent possible spread to animals, including pets and livestock, cases should have another member of their household care for their animals
  • If this isn't possible, cases should:
    • cover all lesions with clothing or bandages
    • wear a well-fitting medical mask and gloves when near the animals, their food, bedding or other items
    • avoid close contact (e.g., petting, kissing, cuddling, sharing sleeping areas, sharing food)
    • clean and disinfect high-touch surfaces frequently
• Cases should avoid handling, feeding or working closely with wildlife to prevent any possible spread of the virus—this is to limit risk of creating a wildlife reservoir for this virus in Canada
• Do not have visiting pets inside the home
• Cases should be advised that if they have had close contact with animals (e.g. petting, kissing, cuddling, sharing sleeping areas, sharing food) during their contagious period, the animal(s) should be monitored for clinical signs for 21 days after the exposure and kept away from other animals and people during this time
  • If an animal develops clinical signs of mpox (e.g., fever, depression, not eating, respiratory signs, diarrhea, oral ulcers, skin lesions) within 21 days of having close contact with a case, a veterinarian should be consulted

Recommendations for environmental hygiene

The risk of fomite transmission of monkeypox virus remains difficult to characterize. In general, orthopoxviruses are known to be very stable in the environment and remain infectious for prolonged periods in scabs, especially in dark and cold environments^{Reference 9Reference 10Reference 11}. Materials contaminated with orthopoxviruses (e.g., clothes, paper, dust) can remain contagious for months to years if not disinfected^{Reference 9Reference 10Reference 11Reference 12Reference 13Reference 14}.

Some limited evidence has found persistent monkeypox virus DNA^{Reference 15Reference 16Reference 17Reference 18Reference 19}, and in some cases, potentially infectious virus^{Reference 17}, on surfaces and fabrics directly touched by cases. However, many unknown factors remain, including the viral load needed for transmission to occur and the stability of infectious virus on surfaces and fabrics in various environmental conditions. Some small experimental studies have shown that despite environmental stability, poxviruses can be inactivated when exposed to standard chemical disinfectants and temperature greater than 50 degrees Celsius^{Reference 20Reference 21Reference 22Reference 23}.

 In light of this, PHAs should advise cases and/or caregivers on proper environmental hygiene in the home, including recommendations for:

• handling laundry
• cleaning and disinfecting high-touch surfaces and objects
• cleaning and vacuuming furniture and carpets
• handling and cleaning dishware and utensils
• proper waste management in the home (e.g. contaminated materials should be disposed of in a manner that prevents access by pets or wild animals –rodents in particular)

Detailed advice on environmental hygiene is available for cases and their caregiver's on PHAC's website.

Post-recovery safer sex practices

• Post- recovery (i.e., once scabs have fallen off and the wound is epithelialized), cases should practice safer sex using barrier protection
  • The use of barrier protection (e.g., condoms, dental dams) during sexual activity may decrease the risk of exposure to monkeypox virus for the person engaging in sexual activity with the recovered case ^{Footnote a}
  • Additional information on barrier protection can be found at PHAC's Sexually Transmitted and Blood Borne Infections (STBBI) Prevention Guide
• PHAs should provide additional information to cases on safer sex practices in the context of mpox

Public health measures for caregivers at the home

Ideally, only one individual in the home should provide direct care to the case, if and when needed (referred to as the "caregiver”). Health care providers entering the home to provide medical care should follow appropriate IPAC protocols.

The caregiver should not be someone who is at risk of more severe disease from mpox (e.g., individuals who are immunocompromised, individuals who are pregnant, young children)^{Reference 1}. Caregivers should self-monitor for signs or symptoms for 21 days since their last exposure to the case (see contact management section below for further details). If signs or symptoms develop, they should immediately notify the PHA and follow their instructions.

Caregivers should be provided instructions by the PHA on how to reduce their risk of mpox infection, which may include:

• Avoiding close physical contact with the case
  • If close contact is unavoidable, the caregiver should wear a well-fitting medical mask and should cover any skin that could potentially come in contact with the case (e.g., consider wearing long pants, long sleeves, an apron, etc.)
  • If direct contact with lesions is unavoidable, the caregiver should also wear disposable gloves
• Practicing frequent hand hygiene
• Have the case handle their own laundry, utensils and dishware, and be responsible for cleaning and disinfecting in the home
  • If this is unavoidable, the caregiver or household member should follow specific instructions to reduce their risk of infection

Public health management of contacts

Contact tracing

The purpose of contact tracing is to:

• Ensure contacts are aware of:
  • their potential exposure,
  • expectations of monitoring for any signs and symptoms,
  • risk mitigation measures to practice for 21 days post-exposure, depending on the circumstances (e.g., ensure contacts are aware of and can evaluate the risks associated with planned activities including sexual activity, travelling, or attending social events/gatherings) 
  • what to do if they develop mpox symptoms (i.e., immediate isolation, advising PHAs)
• If eligible, provide information about post-exposure prophylaxis and referral to their health care provider, to prevent the onset of disease and stop further transmission
• Identify any symptomatic contacts as early as possible
• Facilitate prompt clinical assessment by a health care provider, laboratory diagnostic testing and treatment if signs or symptoms develop

In Canada, local PHAs are responsible for initiating contact tracing. Once a case is identified, PHAs assess the need to begin contact tracing using the epidemiological and clinical information provided.

In determining the need to initiate contact tracing, the following factors should be taken into consideration:

• Cases are considered contagious from onset of symptoms until after the scabs have fallen off, and there is evidence of epithelialization
• The timing, type (e.g. direct skin contact, respiratory route) and duration of exposure to the case, as well as mitigation measures in place (e.g., if wearing a well-fitting medical mask or gloves during exposure)
  • Priority for public health management should be given to contacts with a high-risk exposure

Proactive communications to potential contacts

In addition to traditional contact tracing activities, PHAs should consider proactive, non-stigmatizing communication and outreach strategies to target groups that may be at higher risk of exposure based on current epidemiological data, in collaboration with local community-based stakeholders and organizations. This could also be instituted even before cases appear in the community, as an upstream approach.

PHAs may also find it beneficial to provide targeted messaging and advice on risk mitigation strategies for settings where there are social gatherings that have the potential for close physical contact, including for some individuals to engage in sexual contact (e.g., parties, clubs, raves, festivals). PHAs could also highlight that gatherings where substances (e.g., drugs and/or alcohol) are being used may also impact individuals' assessment of risk and reduce adherence to safer sex practices^{Reference 24}.

Risk assessment of contacts

All individuals who are contacts of a confirmed, probable or suspected case are recommended to be rapidly identified and assessed by PHAs, to determine their risk of exposure and the appropriate public health recommendations to follow.

To facilitate determining the public health recommendations, contacts are classified according to their risk of exposure in Table 1 below. Note that Table 1 provides guidance for classifying contacts as either high, intermediate or low risk, depending on their exposure, for the purposes of determining recommended actions. The information provided in Table 1 is not intended to replace more personalized public health advice provided to contacts, based on clinical judgement and comprehensive risk assessments conducted by PHAs.

Table 1: Classification of contacts by exposure risk level.

Exposure risk	Description	Possible Examples
High	Prolonged or intimate contact, including any of the following: Skin/mucosa to skin contact with a case (regardless of the case's lesion location) Skin/mucosa contact with a case's biological fluids, secretions, skin lesions or scabs Skin/mucosa contact with surfaces or objects contaminated by a case's secretions, biological fluids, skin lesions or scabs Face-to-face interaction with a case, without the use of a medical mask by the case or contact	Sexual partner of a case Household members living with a case Roommate in a group home or student residence living with a case Skin/mucosa contact with a case's unwashed bedding, towels, clothing, lesion dressings, utensils, razors, needles, sex toys, etc.
Intermediate	Any of the following: Limited or intermittent, close proximity exposure to a case without wearing adequate PPE for the type of exposure risk (i.e., medical mask and gloves) Shared living space where there are limited interactions with a case or their belongings	Sitting next to case on plane Person sharing close proximity workspace with a case for long periods of time
Low or Uncertain	Any of the following: Very limited exposures to a case Consistently and appropriately using recommended PPE for the type of exposure risk (i.e., medical mask and gloves)	Brief social interactions with a case Colleagues not sharing a confined or close-proximity office space with a case
Acronyms PPE: Personal protective equipment
Note: This guidance is focused on community settings. For health care providers who have had an exposure to mpox, follow occupational health and safety advice or refer to PHAC guidance on infection prevention and control of mpox cases in healthcare settings.

Public health activities for contact management

For both high- and intermediate-risk mpox contacts, PHAs may conduct the following activities during the 21-day period since the contact's last exposure to the case:

• Conduct active (or passive, where appropriate) public health monitoring for signs and symptoms and counselling
• Provide instructions on what to do if symptoms develop
• Advise contacts that taking certain medications (e.g., acetaminophen, ibuprofen, acetylsalicylic acid) could mask early symptoms of mpox; if contacts need to take these medications, they should advise the PHA
• Provide appropriate information on which PHMs should be followed in order to reduce potential spread to others (see section below)
• Provide information on when and where to access diagnostic testing (where appropriate)
• Explore means of reaching out to high-risk exposure contacts related to events in situations where contacts are unknown (e.g., outreach to communities, stakeholder engagement, awareness campaign, etc.)
• Contacts may be advised to reach out to health care providers for advice on prophylaxis, especially in situations of high-risk exposure

Public health measures recommendations for contacts

Recommendations in Table 2 below apply for the 21-day period following the last exposure to a known suspected (unless mpox is ruled out), probable or known case.

Note: A risk assessment conducted by the PHA may further inform personalized PHMs recommendations, for example, PHAs may consider the following:

• If a contact has had previous smallpox vaccination
  • If so, PHAs should consider the time since the contact's last vaccine dose
• If the contact has recovered from a previous mpox infection

Table 2: Incremental public health measures recommendations for contacts based on exposure risk.

Exposure risk	Recommendations
For all exposures	Can be permitted to continue routine daily activities, with some specific PHMs in place Self-monitor for signs and symptoms of mpox infection Practice proper hand hygiene and respiratory etiquette Practice safer sex including: using condoms, dental dams, gloves and clothing to help reduce the risk of exposure to the monkeypox virus for the person engaging in sexual activity with the contact Notify the PHA and isolate immediately if signs or symptoms develop Alert any health care providers that provide medical care of the potential exposure Be aware that travelling during the 21-day post-exposure period could lead to unforeseen consequences if symptoms were to develop (e.g., the need to isolate abroad, seek medical attention and/or reschedule transportation, as well as the potential for additional financial costs)
For both intermediate- and high-risk exposure contacts	In addition to the above recommendations: Avoid high-risk settings (e.g., congregate living settings, such as correctional facilities or shelters) and populations at risk of more severe disease (e.g., individuals who are immunocompromised, individuals who are pregnant, young children)Reference 1, where possible If this is unavoidable, consider wearing a well-fitting medical mask in these settings or around populations at high risk of more severe disease populations For contacts who work in high-risk settings, refer to occupational health and safety advice or defer to the advice of their local PHA, based on a risk assessment As a precaution to prevent possible spread to animals, it is recommended to avoid any close contact with animals (e.g. petting, kissing, cuddling, sharing sleeping areas, sharing food)
For high-risk exposure contacts	In addition to the above recommendations: Wear a well-fitting medical mask whenever in the presence of others (including household members) Refrain from sexual contact with others Be especially vigilant when self-monitoring for symptoms if working with populations at risk of more severe disease

Additional resources

• National Advisory Committee on Immunization (NACI): Interim guidance Imvamune® in the context of mpox (monkeypox) outbreaks
• Federal, Provincial and Territorial Public Health Response Plan for the Management of the Mpox (monkeypox) Outbreak
• Public Health Ontario – Evidence Brief: Monkeypox Transmission Through Genital Excretions
• McMaster University – Living Evidence Profile: What is the best-available evidence related to the monkeypox outbreak?
• U.S. Department of Homeland Security Science and Technology – Evidence Brief: Master Question List for Monkeypox Virus
• World Health Organization: Mpox (monkeypox) Outbreak 2022
• Centers for Disease Control and Prevention: Monkeypox Signs and Symptoms