Mumps virus: Infectious substances pathogen safety data sheet

For more information on Mumps virus, see the following:

• Mumps - Causes, symptoms, risks, treatment, prevention, surveillance, and information for health professionals

Section I – Infectious agent

Name

Mumps virus

Agent type

Virus

Taxonomy

Family

Paramyxoviridae

Genus

Orthorubulavirus

Species

Orthorubulavirus parotitidis

Synonym or cross-reference

Formerly known as mumps rubulavirus, mumps orthorubulavirus; etiological agent of mumps^{Footnote 1}. Mumps is also known as infectious parotitis or viral parotitis^{Footnote 2 Footnote 3}.

Characteristics

Brief description

Mumps virus (MuV) virions are enveloped and have an irregular spherical shape, measuring 90 to 300 nm in diameter^{Footnote 4}. The nucleocapsid has a helical structure. MuV has a single-stranded, negative-sense, linear RNA genome, approximately 15.3 kbp in size, with a G+C content of 42.3%^{Footnote 5 Footnote 6 Footnote 7}.

Properties

There are 12 MuV genotypes (A to N, excluding E and M) classified based on the small hydrophobic protein sequence^{Footnote 8Footnote 9}. Fusion and hemagglutinin-neuraminidase proteins appear to be the major determinants of immunity^{Footnote 4Footnote 10}. MuV can be grown in a variety of mammalian cell cultures and avian embryos^{Footnote 4}. The life cycle of MuV includes the following key stages: initial infection, systemic spread, viral replication, and immune response^{Footnote 5}. MuV first binds to the host cell surface via the hemagglutinin-neuraminidase glycoprotein receptor, sialic acid, which mediates virus-to-cell fusion and cell-to-cell membrane fusion, facilitating virus spread^{Footnote 5}. In humans, MuV mainly replicates in upper respiratory mucosa^{Footnote 11}.

Section II – Hazard identification

Pathogenicity and toxicity

Mumps is usually a self-limiting disease; approximately one-third to one-half of infections among unvaccinated individuals are asymptomatic or subclinical, whereas the frequency of asymptomatic infection among vaccinated individuals is unclear^{Footnote 12 Footnote 13 Footnote 14}. Symptoms include fever, malaise, muscle pain, and headache; followed by swelling/tenderness of one or both parotid glands, which usually persists for one week^{Footnote 3Footnote 15}. Swelling of other salivary glands may occur in conjunction with parotitis in 10% of cases^{Footnote 4}. Rare manifestations include meningitis (1-10%)^{Footnote 16}, epididymo-orchitis (25% to 38% of post-pubertal males)^{Footnote 3Footnote 4}, encephalitis (0.1%) with a mortality rate of 1.4%^{Footnote 4Footnote 17}, oophoritis (5% of post-pubertal females)^{Footnote 18}, transient high-frequency deafness (4%)^{Footnote 19}, permanent deafness (<0.01%)^{Footnote 20}, and pancreatitis (4%)^{Footnote 4Footnote 15}. Joint, myocardial, and ocular involvement have also been reported^{Footnote 3}. Complications include sialectasia and pharyngolateral edema^{Footnote 4Footnote 21}. Neurologic syndromes infrequently associated with mumps include cerebellar ataxia^{Footnote 22}, facial palsy^{Footnote 23Footnote 24}, transverse myelitis^{Footnote 25}, Guillain-Barré syndrome^{Footnote 26Footnote 27}, and poliomyelitis-like syndrome^{Footnote 28}. Extremely rare conditions associated with mumps include nephritis^{Footnote 29}, thyroiditis^{Footnote 30}, and thrombocytopenia^{Footnote 31}. Other sequelae, including paralysis, seizures, cranial nerve palsies, and hydrocephalus have also been reported but are uncommon^{Footnote 5}.

Epidemiology

Mumps is endemic worldwide^{Footnote 32}. Since the introduction of MuV vaccine in the 1960s, annual incidence of mumps has declined markedly; however in recent decades, there has been a resurgence of mumps prevalence^{Footnote 4Footnote 32}. Incidence of mumps in Canada and the United States is estimated to be 0.1 cases per 100,000 persons per year^{Footnote 32Footnote 33}. From 2015 to 2022, an estimated 24,000 cases were reported to the World Health Organization from North America^{Footnote 34}. Sporadic outbreaks primarily affect individuals living in close proximity with extensive personal contact (e.g., college campuses, summer camps, sports teams)^{Footnote 35 Footnote 36 Footnote 37 Footnote 38}. A large-scale outbreak occurred in northwest Arkansas in 2016-2017, comprising almost 3,000 cases and accounting for 41% of cases reported in the United States in 2016^{Footnote 39}. Out of 2917 patients, 2014 (69%) had their mumps immunizations up to date. About 92% of impacted children aged 5-17 years also had their mumps immunizations up to date^{Footnote 39}. Many of the patients affected by mumps outbreaks in the United States, Europe, and Australia are young adults and older adolescents, aged 18-35, who had received two doses of MuV vaccine^{Footnote 33Footnote 37Footnote 40 Footnote 41Footnote 42 Footnote 43}. This appears to be due in part to waning mumps-vaccine-conferred immunity^{Footnote 10Footnote 41}. Risk and severity of complications with MuV increases with age, however, complications are less likely to occur in vaccinated individuals^{Footnote 10Footnote 42}. Individuals living in close proximity with extensive personal contact to infected individuals are at high risk of infection^{Footnote 35Footnote 36Footnote 37Footnote 38}.

Host range

Natural host(s)

Humans^{Footnote 5}.

Other host(s)

Non-human primates, mice, and hamsters have been experimentally infected^{Footnote 44 Footnote 45Footnote 46 Footnote 47}.

Infectious dose

Unknown.

Incubation period

The incubation period for MuV is usually 16 to 18 days, but can range from 12 to 25 days post-exposure^{Footnote 4Footnote 48}. Virus shedding appears to be relatively low by 5 days after the onset of parotitis^{Footnote 49}.

Communicability

Human-to-human transmission occurs via direct contact with secretions from infected individuals, inhalation of infectious aerosols, and contaminated fomites^{Footnote 3Footnote 4}. The preferred mode of transmission is direct contact with saliva or respiratory droplets^{Footnote 50}. Infected individuals are contagious from 48 hours before to 9 days after onset of parotitis^{Footnote 3Footnote 15Footnote 51}. The estimated basic reproductive number (R₀) of MuV, which represents the number of secondary cases generated by a primary case in an otherwise susceptible population, is 10-12^{Footnote 52}.

Section III – Dissemination

Reservoir

Humans^{Footnote 5}.

Zoonosis

None.

Vectors

None.

Section IV – Stability and viability

Drug susceptibility/resistance

No antivirals are currently available to treat MuV infection. Ribavirin has shown virostatic activity in vitro^{Footnote 53}.

Susceptibility to disinfectants

MuV is sensitive to 1% sodium hypochlorite (NaOCl), chlorine dioxide (ClO₂) at a concentration of 1.0 mg/L for 30 minutes, 70% ethanol, and glutaraldehyde^{Footnote 54 Footnote 55}.

Physical inactivation

MuV is inactivated by autoclave treatment with moist heat (121°C for 30 minutes)^{Footnote 55}. An estimated disinfection rate of 97% has been reported from UV exposure at a mean dose of 45 J/m² (unspecified time period)^{Footnote 55}.

Survival outside host

MuV tends to remain infective for several hours in the external environment but can persist for days depending on environmental conditions such as temperature and humidity^{Footnote 56}. MuV has been noted to remain stable at 4°C for days, although environmental conditions were not specified^{Footnote 15}.

Section V – First aid/medical

Surveillance

Patients suspected of infection should be monitored^{Footnote 4}. Diagnosis is based on history of exposure and clinical symptoms such as parotid swelling/tenderness^{Footnote 4}. MuV can be detected in clinical specimens, such as saliva or cerebrospinal fluid using viral isolation and reverse transcription followed by polymerase chain reaction (RT-PCR) ^{Footnote 3Footnote 57Footnote 58}.

Note: 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

Treatment is supportive and may include rest, increased fluid intake, analgesics and antipyretics (e.g., aspirin, acetaminophen) to reduce pain, inflammation and fever^{Footnote 3Footnote 4Footnote 59}.

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

In Canada, mumps vaccine is available in combination with measles and rubella vaccine (MMR) or measles, rubella, and varicella (MMRV) vaccine. A two-dose regimen is recommended for children at 12-15 months and 4-6 years of age^{Footnote 4}. More than 120 countries include mumps vaccine as part of their national immunization program^{Footnote 60}. Cofactors that may affect vaccination recommendations include pregnancy, immunocompromised status, and being born before 1970^{Footnote 61}.

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

Prophylaxis

A third dose of mumps-containing vaccine is recommended by some national public health institutes, including the US Center for Disease Control and Prevention, for individuals who are at increased risk of contracting mumps due to an ongoing outbreak, those born after 1970, or those travelling to susceptible areas^{Footnote 42Footnote 61Footnote 62}.

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

Section VI – Laboratory hazard

Laboratory-acquired infections

Only a few MuV-associated laboratory-acquired infections have been reported^{Footnote 63Footnote 64}. However, no information regarding the root cause or route of exposure is available.

Note: Please consult the Canadian Biosafety Standard and Canadian Biosafety Handbook for additional details on requirements for reporting exposure incidents.

Sources/specimens

MuV can be found in saliva, cerebrospinal fluid, urine, blood, and throat swabs^{Footnote 3Footnote 16Footnote 65}.

Primary hazards

Inhalation of aerosolized infectious material and direct contact with secretions from infected individuals are the primary hazards associated with exposure to MuV^{Footnote 66}.

Special hazards

None.

Section VII – Exposure controls/personal protection

Risk group classification

Mumps virus is a Risk Group 2 Human Pathogen and a Risk Group 1 Animal Pathogen^{Footnote 67 Footnote 68}.

Containment requirements

Containment Level 2 facilities, equipment, and operational practices outlined in the Canadian Biosafety Standard for work involving infectious or potentially infectious materials, animals, or cultures.

Protective clothing

The applicable Containment Level 2 requirements for personal protective equipment and clothing outlined in the Canadian Biosafety Standard are to be followed. The personal protective equipment could include the use of a lab coat and dedicated footwear (e.g., boots, shoes) or additional protective footwear (e.g., boot or shoe covers) where floors may be contaminated (e.g., animal cubicles, PM rooms), gloves when direct skin contact with infected materials or animals is unavoidable, and eye protection where there is a known or potential risk of exposure to splashes.

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 and work activities must be documented.

Other precautions

The aerosol transmission of MuV necessitates the use of a BSC or other primary containment device for activities with open vessel; centrifugation to be carried out in sealed safety cups or rotors that are unloaded using a mechanism that prevents their release. Respiratory protection to be considered when BSC or other primary containment devices cannot be used; inward airflow is required for work involving large animals or large scale activities.

Use of needles and syringes are to be strictly limited. Bending, shearing, re-capping, or removing needles from syringes to be avoided, and if necessary, performed only as specified in standard operating procedures (SOPs). Additional precautions are required for work involving animals or large-scale activities.

Additional information

For diagnostic laboratories handling primary specimens that may contain MuV, the following resources may be consulted:

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

Section VIII – Handling and storage

Spills

Allow aerosols to settle. While wearing personal protective equipment, 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

All materials/substances that have come in contact with the regulated materials to be completely decontaminated before they are removed from the containment zone or standard operating procedures (SOPs) to be in place to safely and securely move or transport waste out of the containment zone to a designated decontamination area or third party. This can be achieved by using decontamination technologies and processes that have been demonstrated to be effective against the regulated material, such as chemical disinfectants, autoclaving, irradiation, incineration, an effluent treatment system, or gaseous decontamination (Canadian Biosafety Handbook).

Storage

The applicable Containment Level 2 requirements for storage outlined in the Canadian Biosafety Standard are to be followed. Primary containers of regulated materials removed from the containment zone to be labelled, leakproof, impact resistant, and kept either in locked storage equipment or within an area with limited access.

Section IX – Regulatory and other information

Canadian regulatory information

Controlled activities with MuV require a Pathogen and Toxin licence issued by the Public Health Agency of Canada.

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

• Human Pathogens and Toxins Act and Human Pathogens and Toxins Regulations
• Transportation of Dangerous Goods Act and Transportation of Dangerous Goods Regulations
• National Notifiable Disease (human)

Last file update

February 2024

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.

Copyright © Public Health Agency of Canada, 2024, Canada

References