Biosafety advisory: Monkeypox virus (MPXV)

On this page

• 1.0 Background
• 2.0 Risk group classification and licensing requirements
• 3.0 Biosecurity requirements
• 4.0 Biosafety recommendations for diagnostic activities
• 5.0 Biosafety requirements for in vitro and in vivo activities with MPXV
  • Animal work considerations
• 6.0 Transportation
• 7.0 Reportable and immediately notifiable diseases
• 8.0 Contact information
• 9.0 References and resources

This biosafety advisory is being provided by the Public Health Agency of Canada (PHAC) to assist clinical, diagnostic, and research laboratories in implementing proper biosafety procedures to safely handle materials that may contain the Monkeypox virus (MPXV). MPXV is classified as a Risk Group 3 (RG3) human pathogen and an RG3 animal pathogen, as well as a prescribed pathogen, also referred to as a security sensitive biological agent (SSBA). The regulatory oversight of MPXV is under the authority of the PHAC and the Canadian Food Inspection Agency (CFIA). This biosafety advisory is based on the scientific evidence available as of its publication date, and is subject to review and revisions as new information becomes available.

1.0 Background

Mpox (monkeypox) is a viral zoonosis caused by the Monkeypox virus (MPXV), an enveloped double-stranded DNA virus belonging to the Orthopoxvirus genus within the Poxviridae family.^{Footnote 1} Amongst the poxviruses, Variola virus is the most widely known owing to its role as the etiological agent of smallpox, which was declared eradicated in 1980. In the following years, the closely related MPXV has emerged as the predominant source of human orthopoxvirus infection.^{Footnote 1}, ^{Footnote 2} A variety of species, including humans, non-human primates and wild rodents, are susceptible to MPXV infection.^{Footnote 1}, ^{Footnote 3}, ^{Footnote 4} Mpox was previously considered a rare and classical zoonotic illness, with the majority of human cases being attributed to contact with affected animals, including their blood, bodily fluids, and lesions.^{Footnote 1}, ^{Footnote 5} However, recent outbreaks have demonstrated that human-to-human transmission is increasingly common.^{Footnote 5}, ^{Footnote 6} Human-to-human transmission can occur through close contact with an infected person, including their respiratory secretions, skin lesions, and contaminated materials.^{Footnote 1},^{Footnote 4}, ^{Footnote 7} Although human-to-animal transmission has not been reported thus far, there remains a potential risk for such transmission to occur in susceptible animals.^{Footnote 3}

2.0 Risk group classification and licensing requirements

MPXV is classified as an RG3 human pathogen and an RG3 animal pathogen, as well as an SSBA. It is regulated under both the Human Pathogens and Toxins Act (HPTA) and the Health of Animals Act (HAA). Licensing and permit requirements are determined based on sample and activity type, and on whether material containing MPXV is imported:

RG3 Human Pathogen including RG3 SSBA Licence

• Required when conducting controlled activities with MPXV, as defined in Section 7 of the HPTA
• Not required when MPXV is in an environment in which it naturally occurs and has not been cultivated or intentionally collected or extracted (e.g., when performing non-propagative diagnostic activities)
• Issued as a Pathogen and Toxin Licence by the PHAC

RG3 Terrestrial Animal Pathogen Permit

• Required when importing pure cultures and/or biological materials containing MPXV (e.g., human/environmental primary specimens, quality control samples, proficiency panels)
• Issued as a Pathogen and Toxin Licence by the PHAC

Permit to Import

• Required when importing any animal product or by-product containing MPXV (e.g., tissue, serum, blood)
• Issued as a standalone document by the CFIA

For information on obtaining a licence issued by the PHAC, please visit the licensing program web page or contact licence.permis@phac-aspc.gc.ca.

For information on obtaining a permit issued by the CFIA, please contact 1-855-212-7695 or permission@inspection.gc.ca.

3.0 Biosecurity requirements

An HPTA Security Clearance is required to conduct controlled activities with MPXV as it is an SSBA. Please refer to our website for more information on SSBAs and the HPTA Security Clearance program, as well as associated Service Standards.

4.0 Biosafety recommendations for diagnostic activities

A pathogen in a primary specimen (i.e., in its natural environment) is excluded from the HPTA and is therefore not regulated by the PHAC if the pathogen has not been cultivated or intentionally collected or extracted (e.g., concentrated, cultured). Primary specimens will generally contain lower concentrations of pathogens than found in cultures (i.e., propagated pathogens). Examples of primary specimens include skin lesion scrapings, rectal swabs, blood, plasma, respiratory specimens (e.g., sputum), feces, and tissues collected directly from patients. Diagnostic specimens from naturally infected animals (i.e., not resulting from in vivo studies) are also considered primary specimens.

Although non-propagative laboratory analyses or diagnostic activities with primary specimens are excluded from the HPTA, it is recommended that, at minimum, good microbiological laboratory practices be followed in work areas where primary specimens are handled. ^{Footnote 8} Routine practices and universal precautions are also recommended in laboratories where primary specimens that may contain MPXV are handled.^{Footnote 9}

As described in the Canadian Biosafety Guideline: Human Diagnostic Activities, facilities are encouraged to conduct a local risk assessment (LRA) for diagnostic activities, taking into consideration the potential for infectious aerosol and droplet production and the risk of exposure. This will assist in determining appropriate mitigation measures that reduce site-specific and activity-specific risks. Examples of diagnostic activities that may result in the production of aerosols include the inoculation of culture media, preparation of samples for PCR, and preparation of frozen sections (unfixed tissues) with a cryostat. Best practices for conducting an LRA can be found in the Canadian Biosafety Guideline: Local Risk Assessment.^{Footnote 10}

As more information regarding the current mpox outbreak becomes available, it may be determined that there is a lower risk of exposure when handling certain types of primary specimens. For example, preliminary evidence suggests that blood poses a lower risk of exposure compared to skin lesion swabs or scrapings because of the short duration of viremia, which peaks early in the course of the infection, usually before the skin lesions appear.^{Footnote 1},^{Footnote 11}

5.0 Biosafety requirements for in vitro and in vivo activities with MPXV

MPXV is classified as an RG3 human pathogen and an RG3 animal pathogen, as well as an SSBA. As such, strict containment requirements must be met to reduce the risks of exposure to, and release of, concentrated or propagated material. Table 1 summarizes the minimum containment requirements for laboratories where MPXV is handled and stored.

Table 1: Canadian containment level requirements for MPXV

Activities with MPXV	Minimum containment level required
Non-propagative in vitro activities Examples of these activities include, but are not limited to: preparing human or animal specimens with the goal of concentrating or isolating MPXV for research purposes (e.g., concentration of virus by centrifugation)	CL3
Propagative in vitro activities Examples of these activities include, but are not limited to: culturing specimens (e.g., propagating the virus) preparatory work for in vivo activities and processing a culture that contains MPXV (i.e., handling propagated or cultivated virus) for packaging and distribution to laboratories	CL3
In vivo work activities Examples of these activities include, but are not limited to: preparing inoculum inoculating animals and collecting specimens from experimentally infected animals	CL3Footnote 1
Table 1 Footnote 1 Work in small animal containment zones (SA zones) must meet the applicable requirements in the CL3 column of the Canadian Biosafety Standard (CBS), whereas work in large animal containment zones (LA zones) must meet the applicable requirements in the CL3-Ag column of the CBS. Table 1 Return to footnote 1 referrer

Many of the CBS requirements are risk- and performance-based and, as such, require facilities to conduct an LRA to determine if additional biosafety measures above the minimum CL3 requirements are needed.

Animal work considerations

Animal-to-human transmission occurs through direct contact with infected live or dead animals or indirect contact with their bodily fluids^{Footnote 4},^{Footnote 7}, ^{Footnote 12}. As such, the following additional precautions are considered for work with animals:

• Primary containment caging should be used when working with MPXV in small animals (e.g., rodents).
• Personnel should avoid directly handling MPXV-infected animals to minimize risk of injury to, or exposure of, the handler. Restraint equipment/chemicals are employed when possible.
• Additional face protection (e.g., faceshield) is considered when:
  • handling bedding or waste of MPXV-infected animals;
  • collecting specimens (e.g., tissues, blood) from MPXV-infected animals.

6.0 Transportation

The transportation of MPXV is subject to the Transportation of Dangerous Goods Regulations (TDGR) and must meet the packaging requirements stipulated in the standard CAN/CGSB-43.125.

Materials that may contain MPXV, except for patient specimens, are assigned to UN2814, INFECTIOUS SUBSTANCE, AFFECTING HUMANS, Class 6.2, Category A for transport.

Medical or clinical waste related to MPXV, except for waste generated from patient care, or the collection or testing of patient specimens, is assigned to:

• UN2814, if it may contain Category A infectious substances, such as propagated or concentrated MPXV;
• UN3291, “CLINICAL WASTE, UNSPECIFIED, N.O.S.”, “BIOMEDICAL WASTE, N.O.S.”, “MEDICAL WASTE, N.O.S.”, or “REGULATED MEDICAL WASTE, N.O.S.”, if there are reasonable grounds to believe that it has a low probability of containing infectious substances such as MPXV; or
• UN3549, MEDICAL WASTE, CATEGORY A, AFFECTING HUMANS, solid, in accordance with the conditions of the CAN/CGSB-43.125 Standard.

In accordance with the conditions of Temporary Certificate TU 0886.1:

• Patient specimens that may contain MPXV, but no other Category A infectious substance listed in Subsection 2.36(3) of the TDGR, may be assigned to UN3373, BIOLOGICAL SUBSTANCE, CATEGORY B, Class 6.2, Category B; and
• Waste generated from patient care, or the collection or testing of patient specimens, that may contain MPXV, but no other Category A infectious substance listed in Subsection 2.36(3) of the TDGR, may be assigned to UN3291, “CLINICAL WASTE, UNSPECIFIED, N.O.S.”, “BIOMEDICAL WASTE, N.O.S.”, “MEDICAL WASTE, N.O.S.”, or “REGULATED MEDICAL WASTE, N.O.S.”.

This temporary certificate has been issued to assist medical professionals with the increased need for transporting MPXV diagnostic samples and waste associated with patient care, and specimen collection and testing. Please note that this is a temporary measure to help Canada address the current mpox outbreak.

Materials that are not considered infectious as per the TDGR or that are exempt from the packaging requirements of the TDGR are still required to meet normal transportation conditions, such as leak-proof packaging. Please consult the TDGR if other infectious substances/dangerous goods are present.

For more information, consult the Transport Canada Transportation of Dangerous Goods website or the Transport Canada Shipping Infectious Substances bulletin. To obtain further assistance, contact Transport Canada at:

• TDG-TMD@tc.gc.ca (for general inquiries)
• TDGMOC-TMDContenants@tc.gc.ca (for means of containment)
• TC.TDGClassification-ClassificationTMD.TC@tc.gc.ca (for classification)

In the event of an emergency involving dangerous goods, call CANUTEC at 1-888-CANUTEC (226-8832), 613-996-6666 or *666 on a cellular phone.

7.0 Reportable and immediately notifiable diseases

The World Organisation for Animal Health (WOAH) encourages reporting of MPXV detection in an animal to the WOAH through the relevant national Veterinary Authority. In Canada, the CFIA must be notified immediately if MPXV is detected in an animal. To notify the CFIA that MPXV has been detected in an animal, or to receive more information regarding reportable and immediately notifiable diseases in animals, please contact the CFIA cfia.notification-notification.acia@inspection.gc.ca.

8.0 Contact information

Further biosafety information may be obtained by visiting the PHAC Centre for Biosecurity website or contacting us by:

• phone: 613-957-1779
• fax: 613-941-0596
• email: pathogens.pathogenes@phac-aspc.gc.ca

For information on obtaining a licence issued by the PHAC, please visit the licensing program web page or contact licence.permis@phac-aspc.gc.ca.

For information on obtaining a permit issued by the CFIA, please contact 1-855-212-7695 or permission@inspection.gc.ca.