Infectious Diseases & Family Medicine & Public Health
Mumps (mumps parotitis)
Mumps — also known as epidemic parotitis — is an acute viral infectious disease caused by the mumps virusMumps virus), belonging to the genre Rubulavirus of the family of Paramyxoviridae. Transmitted by respiratory droplets and direct contact with the saliva of an infected person, the virus is highly contagious, with a basic reproduction index (R₀) estimated at 4 to 7 in a non-immune population. The most characteristic and well-known clinical manifestation is bilateral parotitis - painful swelling of the parotid glands on either side of the face giving the patient a characteristic «hamster» or «moon» appearance - although up to 20-30 % of infections are asymptomatic and 40-50 % present as non-specific upper respiratory symptoms without obvious parotid involvement. Before the introduction of the MMR (Measles-Mumps-Rubella) vaccine into Canadian immunization programs in 1969-1971, mumps was a major cause of acquired deafness in children, viral meningitis and orchitis in adolescents and young adults. Since then, incidence has fallen by more than 99 % in Quebec and the rest of Canada. However, epidemics persist in under-vaccinated communities and among young adults who have received two doses of vaccine but whose immunity has waned over time - a phenomenon observed during documented epidemics in several North American colleges and universities since 2006, explaining why some societies of preventive medicine recommend a third dose of vaccine in epidemic contexts. Mumps is a notifiable disease in Quebec. In unvaccinated adults, the disease is generally more severe than in children, with a higher risk of complications - orchitis (testicular inflammation) affecting 20 to 50 % of affected post-pubertal men, and leading to testicular atrophy and, in rare cases, male infertility.
Virology, transmission, and epidemiology
- Pathogen Paramyxovirus, negative-sense single-stranded RNA, enveloped, two surface proteins: hemagglutinin-neuraminidase (HN - cell receptor sialic acid binding) and fusion protein (F - membrane fusion and viral entry), 12 identified genotypes (A through N), genotypes C, D, G, H, and J currently most prevalent in North America, vaccines based on the Jeryl Lynn strain (genotype A) provide effective cross-protection against the majority of circulating genotypes despite genetic divergences
- Transmission: respiratory droplets (coughing + sneezing + talking) + direct contact with infected saliva (kissing + sharing utensils + sharing bottles) + the virus is present in saliva 7 days before the onset of parotitis up to 9 days after + maximal contagiousness period in the 2 days before and 5 days after the onset of symptoms
- Incubation period: 16 to 18 days (range: 12 to 25 days) + one of the longest incubations among common viral infections
- Pathogenesis: primary replication in the respiratory epithelium + viremia → dissemination to salivary glands (parotid ++), testes, ovaries, pancreas, meninges, inner ear + glandular acinar cell affection → inflammation + edema + local cell necrosis
- Epidemiology in Quebec: fewer than 100 cases reported annually since the 1990s + sporadic epidemics associated with university campuses + summer camps + religious communities refusing vaccination + importations during international travel + young adults born between 1970 and 1985 (having received only one dose of vaccine in childhood) represent a risk group during outbreaks
Clinical presentation
| Stage and manifestations | Clinical description | Duration and evolution |
|---|---|---|
| Prodrome (1 to 2 days before parotitis) | Moderate fever (38 to 39 °C) + headache + general malaise + muscle pain + anorexia + pain on chewing + ear pain, worsened by chewing or swallowing + preauricular pain can precede visible swelling by 24 to 48 hours | 1 to 2 days + often mild in children |
| Acute parotitis — characteristic phase | Gonflement douloureux des glandes parotides, d'abord unilatéral puis bilatéral dans 70 à 80 % des cas en 1 à 5 jours + aspect caractéristique en « hamster » — visage arrondi avec effacement du sillon préauriculaire + distal de la branche mandibulaire + le canal de Sténon (ostium excréteur de la parotide) apparaît érythémateux et œdémateux à l'examen de la muqueuse buccale (contrairement aux parotidites bactériennes suppurées où du pus est exprimé) + fièvre souvent entre 38 et 40 °C + douleur aggravée par les aliments acides (jus de citron + vinaigrette) qui stimulent la sécrétion salivaire | Maximum swelling by D3–D4 + progressive regression over 7 to 10 days + complete resolution in 10 to 14 days |
| Forms without parotitis | 20 to 30 % asymptomatic infections + 40 to 50 % present with nonspecific upper respiratory symptoms or isolated fever without overt parotid swelling + sometimes involvement of submandibular or sublingual glands alone (difficult to distinguish clinically from cervical adenopathy) | Identical contagiousness to forms with parotiditis + often missed diagnosis → epidemiological importance for transmission |
Complications
| Complication | Frequency and characteristics | Support |
|---|---|---|
| Ourlian orchid | 20 à 50 % des hommes post-pubères atteints + survient 4 à 8 jours après le début de la parotidite + unilatérale dans 80 à 90 % des cas + douleur testiculaire intense + gonflement + érythème scrotal + fièvre élevée (39 à 40 °C) + peut précéder la parotidite ou survenir sans parotidite dans 30 % des cas + atrophie testiculaire dans 30 à 50 % des testicules touchés + infertilité masculine dans moins de 13 % des cas d'orchite bilatérale (rare car l'orchite bilatérale ne touche que 15–30 % des hommes avec orchite) | Symptomatic treatment: scrotal suspension + NSAIDs or paracetamol + ice application + rest + corticosteroids (prednisolone 1 mg/kg/day × 3–5 days) to reduce inflammation and the risk of testicular atrophy in severe forms (efficacy not formally proven but used in practice) + no effective antiviral treatment available |
| Mumps aseptic meningitis | Most frequent complication of mumps (5 to 15 % of symptomatic cases) + often subclinical + headaches + stiff neck + photophobia + can precede + accompany or follow parotitis by several days + CSF: lymphocytic pleocytosis (10 to 2,000 cells/µL) + slightly elevated proteins + normal or slightly decreased glucose + virus is detectable in CSF by PCR + spontaneously favorable course in 3 to 10 days in almost all cases | Symptomatic treatment: pain relievers + rest + hydration + lumbar puncture if diagnostic doubt with bacterial meningitis + excellent prognosis + very rare neurological sequelae |
| Mumps encephalitis | Rare (1–2 per 10,000 cases) but severe + confusion + seizures + altered consciousness + can occur without parotitis + mortality 1.4 % + possible permanent neurological sequelae | Intensive care hospitalization + supportive treatment + anticonvulsants if epilepsy + no effective specific antiviral treatment |
| Sensorineural hearing loss | Unilateral sensorineural hearing loss in 1 in 20,000 cases + main cause of acquired unilateral hearing loss in children in countries without universal vaccination + mechanism: damage to the cochlea and cochlear nerve by the virus + often irreversible | Audiology from the acute phase if hearing symptoms (tinnitus + hearing loss) + hearing rehabilitation if permanent deafness + no curative treatment |
| Mumps pancreatitis | 4 % of cases + epigastric pain + nausea + vomiting + elevated lipase and amylase + generally mild and self-resolving + useful test: serum lipase (more specific than amylase for pancreatitis in this context + amylase can be elevated by mumps itself) | Symptomatic treatment + fluid diet + painkillers + post-mumps pancreatitis hypoglycemia is exceptional + resolution in 1 to 2 weeks |
| Oophoritis (in women) | 5 % of post-pubertal women with pelvic pain + adnexal pain + much less well-documented than male orchitis + definitive infertility rarely reported + premature ovarian failure exceptional | Symptomatic treatment + NSAIDs + analgesics |
ℹ️
Mumps orchitis in unvaccinated adult men is one of the most dreaded complications of mumps—30% to 50% % of affected testicles exhibit residual atrophy. Any adult man presenting with febrile bilateral parotitis should be warned of the risk of orchitis and seek immediate consultation if testicular pain appears in the following days, in order to initiate supportive treatment quickly and, depending on severity, corticosteroid therapy. This complication highlights the paramount importance of the MMR (two-dose) vaccination in all adults who did not receive the full schedule in childhood.
Biological diagnosis
- RT-PCR (reverse transcription polymerase chain reaction) on oral or urine sample: reference method + saliva or oral swab collection + to be performed within 9 days of the onset of parotitis (maximum sensitivity within the first 3 days) + allows for direct detection of viral genome + typing of the epidemic genotype for epidemiological surveillance + method recommended by the Institut national de santé publique du Québec (INSPQ) for case confirmation in an epidemic context
- Serology (IgM and IgG anti-mumps virus): IgM anti-mumps → present from the 3rd-5th day after symptom onset + persist for 2-3 months + indicate recent infection + can be falsely negative in the early days and in vaccinated individuals (attenuated IgM response in case of revaccination) + IgG → present 1-2 weeks after onset + persist for life (natural or vaccine-induced immunity) + seroconversion (rise in IgG titer between two samples 14 days apart) confirms acute infection in cases of negative IgM
- Additional biological assessment based on complications: serum lipase and amylase (pancreatitis) + CBC (leukopenia + relative lymphocytosis often seen in viral infections) + CSF if meningitis suspected (lymphocytic pleocytosis + mumps PCR on CSF) + audiometry if hearing loss
- Salivary amylase (S isoenzyme): Mumps (viral + bacterial + salivary calculi) can suggest the diagnosis but is not specific. Elevated total amylase in mumps does not necessarily indicate pancreatitis (pancreatic amylase P + salivary amylase S both contribute to total amylase).
Prevention — MMR vaccination and Quebec context
- MMR Vaccine (Measles-Mumps-Rubella): trivalent live attenuated vaccine containing vaccine strains Edmonston (measles) + RA27/3 (rubella) + Jeryl Lynn or RIT 4385 (mumps) + administered in two doses in the Quebec Immunization Program (QIP): 1st dose at 12 months + 2nd dose at 18 months (or catch-up upon entering kindergarten) + two doses offer protective efficacy against mumps of 88 %(95% CI %: 67–95 %) — slightly lower than that against measles (97 % ) and rubella (94 % )
- Vaccine catch-up for adults: Anyone born after 1969 in Quebec must have received two documented doses of the MMR vaccine. Adults without proof of vaccination or born before 1970 (assumed to have natural immunity) may receive a catch-up dose if there is a risk of exposure. The RAMQ reimburses the MMR vaccine for adult catch-up according to PQI criteria.
- Third dose in an epidemic context: during documented outbreaks in closed communities (university campuses + military facilities + summer camps) → a third dose of MMR may be recommended by the Public Health Department for people at high risk of exposure + effectiveness of a 3rd dose estimated at 88 % for the prevention of mumps during direct exposure
- Contraindications to MMR vaccine: Pregnancy (live attenuated vaccine + avoid pregnancy for 4 weeks after vaccination) + severe immunosuppression (chemotherapy + high-dose corticosteroids + advanced stage AIDS) + history of anaphylactic reaction to vaccine components (hydrolyzed porcine gelatin + neomycin) + egg allergy is not an absolute contraindication in current practice (modern MMR vaccine contains minimal traces of egg protein + administrable in a monitored medical setting)
- Control measures during a case: Mandatory reporting (MADO) to the Regional Public Health Department (DRSP) within 24–48 hours + exclusion from school or community for 5 days after symptom onset + identification and vaccination of unvaccinated contacts (vaccination within 72 hours can reduce risk in exposed contacts)
Situations requiring urgent medical assessment
Consult the emergency room immediately if mumps are accompanied by neck stiffness + severe headaches + photophobia + confusion or seizures (mumps meningitis or encephalitis) + or sudden unilateral hearing loss (mumps deafness — ENT emergency). Consult a doctor the same day if an adult man with mumps develops testicular pain + scrotal swelling + high fever (mumps orchitis — quickly initiate supportive treatment and assess the indication for corticosteroid therapy).
For diagnostic confirmation of mumps (RT-PCR + serology), mandatory public health reporting, RRO vaccination updates, and management of complications, Clinique Omicron offers medical consultations at its service points in Quebec and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
Consult at Clinique Omicron
Clinique Omicron's physicians and nurse practitioners (NPs) diagnose and manage mumps and its complications, prescribe mumps RT-PCR and serology, perform mandatory public health reporting, assess vaccination status and administer catch-up MMR vaccine to unvaccinated adults, and refer to ENT for auditory symptoms or to urology for severe orchitis. Consultations are available at several service points in Quebec and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
The content of this page is for informational purposes only and does not replace medical advice. Mumps is a reportable disease in Quebec — any confirmed or suspected case must be reported to the Regional Public Health Directorate. Two-dose MMR vaccination remains the most effective way to prevent mumps and its complications.
Omicron Clinic
Need to consult a doctor?
Treatment within 24-48 hours. In-clinic or telemedicine, anywhere in Quebec.
Insurance receipts. 7j/7. No family doctor required.