Monkeypox virus: Infectious substances Pathogen Safety Data Sheet

Section I: Infectious agent

Name

Monkeypox virus

Agent type

Virus

Taxonomy

Family

Poxviridae

Sub-family

Chordopoxvirinae

Genus

Orthopoxvirus

Species

Monkeypox virus

Synonym or cross reference

MPXV, human monkeypox ^{Footnote 1Footnote 2Footnote 3Footnote 4}

Characteristics

Brief description

Virus belongs to family Poxviridae, sub-family Chordopoxvirinae and genus Orthopoxvirus ^{Footnote 1Footnote 3Footnote 4}. MPXV is a 200 to 250 nm brick- shaped enveloped virus with characteristic surface tubules and a dumbbell-shaped core component ^{Footnote 3}. The MPXV genome consists of linear double-stranded DNA. Monkeypox virus is antigenically related to the variola and vaccinia viruses ^{Footnote 5}.

Section II: Hazard identification

Pathogenicity and toxicity

Mpox (monkeypox) is characterised by the onset of non-specific symptoms which can include fever, headache, backache, lymphadenopathy and fatigue during a prodromal period of 2 to 3 days ^{Footnote 1Footnote 3Footnote 6}. This is followed by a 2 to 4 week period in which a rash develops and progresses from macules, to papules, to vesicles, and then to pustules, followed by umbilication, scabbing and desquamation ^{Footnote 3Footnote 4Footnote 7}. The rash usually occurs in a centrifugal distribution, often spreading to the palms and soles of the feet ^{Footnote 3}. Lesions can also develop on mucous membranes, conjunctivae, in the mouth, on the tongue, and on the genitalia ^{Footnote 4}. The clinical presentation of mpox is similar to that of smallpox except for the pronounced lymphadenopathy associated with mpox and generally milder symptoms ^{Footnote 5Footnote 8}. Lymphadenopathy is thus considered a key distinguishing feature of mpox ^{Footnote 4Footnote 8Footnote 9}. The case fatality rate is approximately 1 to 10% in Africa, with higher death rates among young children ^{Footnote 3Footnote 7}. In children unvaccinated against smallpox, the case-fatality rate ranges from 1% to 14% ^{Footnote 8Footnote 9}.

Communicability

MPXV is transferred from infected animals through a bite or through direct contact with the infected animal's blood, body fluids, or lesions ^{Footnote 1Footnote 4Footnote 6Footnote 7}. It can also be transferred from human-to-human via the respiratory tract, by direct contact with body fluids of an infected person, or with virus-contaminated objects ^{Footnote 4Footnote 6Footnote 9Footnote 16}. The rate of person-to person transmission is increasing, with a secondary attack rate of approximately 10% ^{Footnote 3Footnote 9}.

MPXV is capable of person-to-person transmission; a chain of up to six sequential human-to-human transmission events has been documented ^{Footnote 3Footnote 4Footnote 13}.

Epidemiology

Mpox affects all age groups; however, children under 16 years of age have constituted the greatest proportion of cases ^{Footnote 8}. The virus occurs naturally in West and Central Africa in the vicinity of tropical jungles ^{Footnote 3}. MPXV isolates originating from West Africa appear to be less virulent and/or transmissible to humans and non-human primates than those from the Congo Basin in Central Africa. Furthermore, the cessation of smallpox vaccination appears to have increased the susceptibility of humans to severe mpox.

In 1970, the first human case of mpox was identified in a 9 month old child in the Democratic Republic of the Congo (formerly Zaire) in a region where smallpox was eradicated in 1968 ^{Footnote 5Footnote 7Footnote 10}. In the following year, six additional cases of human monkeypox infection were reported in Liberia, Sierra Leone and Nigeria ^{Footnote 11}. From 1970 to 1979, 47 human cases of mpox were identified, 38 of which were from Zaire ^{Footnote 3Footnote 4}. In the Democratic Republic of the Congo, a total of 338 cases were reported between 1981 and 1986, and more than 400 cases were reported between February 1996 and October 1997 ^{Footnote 12Footnote 13}.

In 2003, the first cases of human mpox in the western hemisphere were reported after an outbreak was reported in Midwestern United States (Illinois, Indiana, Kansas, Missouri, Ohio and Wisconsin) due to the importation of MPXV-infected West African rodents from Ghana ^{Footnote 1Footnote 3Footnote 6Footnote 7Footnote 14}.

Host range

Natural host(s)

Humans, squirrels, non-human primates, black-tailed prairie dogs, African brush-tailed porcupines, rats, and shrews ^{Footnote 1Footnote 2Footnote 3Footnote 4Footnote 5Footnote 6Footnote 7Footnote 10Footnote 12Footnote 13Footnote 14Footnote 15}.

Infectious dose

Unknown.

Incubation period

Approximately 7 to 17 days ^{Footnote 3Footnote 7}.

Section III: Dissemination

Reservoir

Not fully understood but arboreal squirrels (Funisciurus spp., and to a lesser degree, Heliosciurus spp.) are believed to be a reservoir for MPXV ^{Footnote 3Footnote 5Footnote 12Footnote 15}.

Zoonosis/Reverse zoonosis

Yes ^{Footnote 1Footnote 3Footnote 4Footnote 5Footnote 6Footnote 7Footnote 8Footnote 10Footnote 12Footnote 13Footnote 14Footnote 15Footnote 17}.

Vectors

Unknown ^{Footnote 3}.

Section IV: Stability and viability

Drug susceptibility

Cidofovir is considered as a potential therapeutic agent for MPXV infections, as it has been shown to have activity against many DNA viruses in vitro, including MPXV ^{Footnote 18}.

Susceptibility to disinfectants

Orthopoxviruses are susceptible to 0.5% sodium hypochlorite, chloroxylenol-based household disinfectants, glutaraldehyde, formaldehyde, and paraformaldehyde ^{Footnote 19Footnote 20}.

Physical inactivation

Orthopoxviruses are inactivated by heat (autoclaving and incineration) ^{Footnote 19Footnote 20}.

Survival outside host

Orthopoxviruses are stable at ambient temperatures when dried ^{Footnote 16}.

Section V: First aid/medical

Surveillance

Monitor for symptoms (unexplained fever, rash or prominent lymphadenopathy) and confirm by laboratory diagnosis using virus isolation, PCR-based assays, haemagglutination inhibition assays, electron microscopy, ELISA, Western blotting, or immunohistochemistry ^{Footnote 3Footnote 4Footnote 5Footnote 6Footnote 7Footnote 9Footnote 15Footnote 17}.

Note: All diagnostic methods are not necessarily available in all countries. The specific recommendations for surveillance in the laboratory should come from the medical surveillance program, which is based on a local risk assessment of the pathogens and activities being undertaken, as well as an overarching risk assessment of the biosafety program as a whole. More information on medical surveillance is available in the Canadian Biosafety Handbook.

First aid/treatment

There are no licensed antiviral drugs available to treat MPXV infection; instead, treatment is supportive ^{Footnote 4}.

Note: The specific recommendations for first aid/treatment in the laboratory should come from the post-exposure response plan, which is developed as part of the medical surveillance program. More information on the post-exposure response plan can be found in the Canadian Biosafety Handbook.

Immunization

Vaccination with vaccinia virus (smallpox vaccine) is approximately 85% effective against mpox ^{Footnote 3Footnote 16}.

Note: More information on the medical surveillance program can be found in the Canadian Biosafety Handbook, and by consulting the Canadian Immunization Guide.

Prophylaxis

Vaccination with the smallpox vaccine, within 4 days and up to 14 days after initial contact with a confirmed mpox case ^{Footnote 4Footnote 16}.

Note: More information on prophylaxis as part of the medical surveillance program can be found in the Canadian Biosafety Handbook.

Section VI: Laboratory hazards

Laboratory-acquired infections

None reported to date ^{Footnote 16}.

Note: Please consult the Canadian Biosafety Standard and Canadian Biosafety Handbook for additional details on requirements for reporting exposure incidents. A Canadian biosafety guideline describing notification and reporting procedures is also available.

Sources/specimens

Lesion fluids or crusts, respiratory secretions, and tissues of infected hosts ^{Footnote 4Footnote 15Footnote 16}.

Primary hazards

Ingestion, parenteral inoculation, droplet or aerosol exposure of mucous membranes or broken skin, or contact with infectious fluids or tissues ^{Footnote 9Footnote 16}.

Special hazards

Bite of infected non-human primates or rodents, or objects contaminated with the virus (e.g. bedding, clothing) ^{Footnote 1}. In pregnant women, human mpox may cause fetal complications ^{Footnote 23}.

Section VII: Exposure controls/personal protection

Risk group classification

Monkeypox virus is a Risk Group 3 Human Pathogen, a Risk Group 3 Animal Pathogen, and a Security Sensitive Biological Agent (SSBA) ^{Footnote 21}.

Containment requirements

Containment Level 3 facilities, equipment, and operational practices outlined in the Canadian Biosafety Standard and in the Biosafety Advisory for Monkeypox virus (MPXV) for work involving infectious or potentially infectious materials, animals, or cultures.

Note that there are additional security requirements, such as obtaining a Human Pathogens and Toxins Act Security Clearance, for work involving SSBAs.

Protective clothing

Personnel entering the laboratory should remove street clothing and jewellery, and change into dedicated laboratory clothing and shoes, or don full coverage protective clothing (i.e., completely covering all street clothing). Additional protection may be worn over laboratory clothing when infectious materials are directly handled, such as solid-front gowns with tight fitting wrists, gloves, and respiratory protection. Eye protection must be used where there is a known or potential risk of exposure to splashes ^{Footnote 22}.

The applicable Containment Level 3 requirements for personal protective equipment and clothing outlined in the Canadian Biosafety Standard to be followed. At minimum, use of full body coverage dedicated protective clothing, dedicated protective footwear and/or additional protective footwear, gloves when handling infectious materials or animals, face protection when there is a known or potential risk of exposure to splashes or flying objects, respirators when there is a risk of exposure to infectious aerosols, and an additional layer of protective clothing prior to work with infectious materials or animals.

Note: A local risk assessment will identify the appropriate hand, foot, head, body, eye/face, and respiratory protection, and the personal protective equipment requirements for the containment zone must be documented.

Other precautions

All activities involving open vessels of pathogens are to be performed in a certified biological safety cabinet (BSC) or other appropriate primary containment device in combination with personal protective equipment. Centrifugation of infected materials must be carried out in closed containers placed in sealed safety cups, or in rotors that are loaded or unloaded in a biological safety cabinet. The use of needles, syringes, and other sharp objects should be strictly limited. Open wounds, cuts, scratches, and grazes should be covered with waterproof dressings. Additional precautions should be considered with work involving animals or large scale activities ^{Footnote 22}.

Additional information

For clinical diagnostic laboratories handling patient specimens that may contain MPXV, the following resources may be consulted:

• Local Risk Assessment Biosafety Guideline
• Human Diagnostic Activities Biosafety Guideline

Section VIII: Handling and storage

Spills

Allow aerosols to settle. Wearing protective clothing, gently cover the spill with absorbent paper towel and apply suitable disinfectant, starting at the perimeter and working towards the centre. Allow sufficient contact time before clean up (Canadian Biosafety Handbook).

Disposal

Decontaminate all materials for disposal by steam sterilization, chemical disinfection, and/or incineration. ^{Footnote 22}.

All materials/substances that have come in contact with the infectious agent must be completely decontaminated before they are removed from the containment zone. This can be achieved by using decontamination technologies and processes that have been demonstrated to be effective against the infectious material, such as chemical disinfectants, autoclaving, irradiation, incineration, an effluent treatment system, or gaseous decontamination (Canadian Biosafety Handbook).

Storage

In sealed containers that are appropriately labelled and locked in a Containment Level 3 facility ^{Footnote 22}. The applicable Containment Level 3 requirements for storage outlined in the Canadian Biosafety Standard are to be followed. Containers of security sensitive biological agents (SSBA) stored outside the containment zone must be labelled, leakproof, impact resistant, and kept in locked storage equipment that is fixed in place (i.e., non-movable) and within an area with limited access (Canadian Biosafety Handbook).

Inventory of security sensitive biological agents (SSBA) in long-term storage to be maintained and to include:

• specific identification of the pathogens, toxins, and other regulated infectious material; and
• a means to allow for the detection of a missing or stolen sample in a timely manner

Section IX: Regulatory and other information

Canadian regulatory context

Controlled activities with MPXV require a Human Pathogens and Toxins Licence issued by the Public Health Agency of Canada. MPVX is a non-indigenous animal pathogen in Canada; therefore, importation of MPVX requires an import permit, issued by the Canadian Food Inspection Agency.

The following is a non-exhaustive list of applicable designations, regulations, or legislations:

• Quarantine Act
• Transportation of Dangerous Goods Regulations
• Human Pathogen and Toxins Act and Human Pathogens and Toxins Regulations
• Non-Indigenous Animal Pathogen or OIE-listed disease (please contact the Canadian Food Inspection Agency)

MPXV is a Security Sensitive Biological Agent (SSBA). There are additional security requirements, such as obtaining a Human Pathogens and Toxins Act Security Clearance, for work involving SSBAs.

The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.

Updated

February, 2023

Prepared by

Centre for Biosecurity, Public Health Agency of Canada.

Disclaimer

The scientific information, opinions, and recommendations contained in this Pathogen Safety Data Sheet have been developed based on or compiled from trusted sources available at the time of publication. Newly discovered hazards are frequent and this information may not be completely up to date. The Government of Canada accepts no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information.

Persons in Canada are responsible for complying with the relevant laws, including regulations, guidelines and standards applicable to the import, transport, and use of pathogens in Canada set by relevant regulatory authorities, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment and Climate Change Canada, and Transport Canada. The risk classification and related regulatory requirements referenced in this Pathogen Safety Data Sheet, such as those found in the Canadian Biosafety Standard, may be incomplete and are specific to the Canadian context. Other jurisdictions will have their own requirements.

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