Overview
Viral infection primarily affecting the salivary glands, causing painful facial swelling. Largely prevented by MMR vaccination.
Transmission
Overview
Viral infection primarily affecting the salivary glands.
Overview
Mumps is caused by the Mumps paramyxovirus spread via respiratory droplets and direct contact with saliva. The hallmark is parotid gland swelling. Once common in childhood, it is now rare in countries with high MMR vaccine coverage, though outbreaks occur in close-contact settings.
Emergency Signs
Seek urgent medical care if:
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Sudden severe testicular pain or swelling (orchitis)
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Severe headache, stiff neck, or sensitivity to light (meningitis)
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Severe abdominal pain (pancreatitis)
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Sudden hearing loss
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High fever (>39.5°C) not responding to antipyretics
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Altered consciousness or seizures
Detailed Symptoms
Most common signs and symptoms
Prodromal phase (1–2 days): Low-grade fever, headache, malaise, and muscle aches.
Active phase (up to 10 days): Painful swelling of one or both parotid glands (parotitis), causing "chipmunk cheek" appearance. Swelling peaks 2–3 days after onset. Earache when chewing. Fever 38–39°C.
Up to 20% of infections are asymptomatic. Orchitis (testicular inflammation) develops in 20–50% of post-pubertal males after parotitis onset, presenting with sudden testicular pain and swelling.
Knowing the symptoms is the first step to a quick response.
Course of Disease
Typical disease course:
- Incubation period: 16–18 days (range 12–25 days).
- Prodromal phase (1–2 days): Low-grade fever, malaise, headache, myalgia, anorexia.
- Parotitis (peak day 2–3, duration 5–10 days): Unilateral then often bilateral parotid gland swelling. Pain worsened by chewing or eating acidic foods. Earache. Peak swelling at day 2–3, then gradually resolves.
- Complications window (days 5–14): Orchitis typically develops 4–8 days after parotitis onset. Meningitis may occur before, during, or after parotitis.
- Recovery: Parotitis resolves within 7–10 days. Orchitis resolves within 1–2 weeks.
Asymptomatic infection: 20–30% of mumps infections are subclinical. Another 40–50% present with nonspecific respiratory symptoms only.
Diagnosis
How this disease is identified
Clinical diagnosis is confirmed by parotid swelling in an unvaccinated individual with epidemiological exposure. Laboratory confirmation:
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Serology: IgM antibody detection (positive 5 days after symptom onset)
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RT-PCR from buccal swab or urine — most sensitive within first 5 days
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Viral culture: reference laboratories Consider mumps in any vaccinated individual with parotitis during an outbreak.
Treatment
Available treatment methods
No specific antiviral therapy. Supportive management:
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Analgesics (paracetamol/ibuprofen) for pain and fever
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Warm or cold compresses over swollen glands for comfort
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Adequate hydration; soft, easy-to-chew foods
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Orchitis: scrotal support, bed rest, analgesics; corticosteroids in severe cases
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Viral meningitis: supportive care with monitoring
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Isolation for 5 days after parotid swelling onset to prevent transmission
Most cases are effectively treated with early diagnosis.
Prevention Details
How to protect yourself
Two-dose MMR vaccine provides approximately 88% protection against mumps:
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Dose 1: 12–15 months of age
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Dose 2: 4–6 years of age
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Third dose considered during outbreaks in vaccinated populations
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No post-exposure prophylaxis (immunoglobulin not effective for mumps) Close contacts in outbreak settings should receive a third MMR dose if two prior doses were received more than 3 years ago.
Preparation is the best protection.
Travel Advice
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Ensure 2 doses of MMR before travel to regions with active outbreaks.
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Risk is elevated in settings with close contact: camps, pilgrimages (Hajj), universities.
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Mumps is reportable in most countries — inform local health authorities of suspected cases.
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Travelers in outbreak areas may benefit from a third MMR dose if their last dose was >3 years ago.
How common is it?
Statistics and geographic data
Before vaccination, mumps was endemic worldwide with peak incidence in children 5–9 years. The MMR vaccine reduced incidence by >99% in high-coverage countries. Outbreaks continue in vaccinated populations in close-contact settings (universities, military, sports teams), suggesting waning immunity. Europe and North America have documented resurgence since 2005. Immunity from 2-dose MMR wanes over 10–15 years.
Risk Factors
Who is most at risk
Risk factors for mumps infection:
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Vaccination status: Unvaccinated or incompletely vaccinated individuals have the highest risk. However, waning immunity means that even two-dose MMR recipients become increasingly susceptible over time (particularly >10 years after the second dose).
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Close-contact settings: University dormitories, military barracks, boarding schools, prisons, and sports teams create ideal conditions for transmission. Most contemporary outbreaks in vaccinated populations occur in these settings.
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Age: In the prevaccine era, peak incidence was in children aged 5–9 years. In the vaccine era, outbreaks have shifted to young adults (18–25 years), reflecting waning immunity from childhood vaccination.
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Travel: Exposure to regions with endemic mumps or ongoing outbreaks, particularly areas with low MMR coverage.
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Crowding and shared living spaces: Household secondary attack rate in susceptible contacts is 40–50%.
Risk factors for complications:
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Post-pubertal age: Orchitis occurs almost exclusively in post-pubertal males (15–30% of post-pubertal male mumps cases vs. <1% in prepubertal boys). Oophoritis occurs in 5% of post-pubertal females.
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Age >15 years: Meningitis and encephalitis are more common in adolescents and adults than in young children.
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Male sex: Males are 3–5 times more likely to develop mumps encephalitis than females.
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Immunosuppression: Limited data, but immunocompromised individuals may have atypical presentations and prolonged viral shedding.
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Genotype: Some evidence suggests that genotype G (currently dominant globally) may be associated with higher rates of complications in vaccinated populations, possibly due to antigenic differences from the Jeryl Lynn vaccine strain (genotype A), though this remains debated.
Complications Details
Potential complications
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Orchitis: 20–50% of post-pubertal males
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rarely causes infertility (~13% of bilateral cases)
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Oophoritis: 5% of post-pubertal females
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rarely affects fertility
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Viral meningitis: 1–10% of cases
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usually self-limiting with complete recovery
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Encephalitis: rare (<2/100,000)
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can cause long-term neurological sequelae
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Pancreatitis: mild, self-limiting, <4% of cases
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Sensorineural hearing loss: rare, may be permanent
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associated with labyrinthitis
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Myocarditis: very rare
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electrocardiographic changes in ~15% of mumps cases without clinical symptoms
Recovery & Outlook
Expected outcomes and recovery
Overall: Excellent prognosis. CFR ~0.01%. Self-limiting in the vast majority.
Complications:
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Orchitis (testicular inflammation): 15–30% of post-pubertal males. Bilateral in 15–30% of orchitis cases. Subfertility is rare (<5%); complete sterility is extremely rare.
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Oophoritis: 5% of post-pubertal females.
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Aseptic meningitis: 1–10% (usually benign, resolves in 3–10 days).
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Sensorineural deafness: 1 in 20,000 (usually unilateral, may be permanent).
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Pancreatitis: 4% (usually mild, self-limiting).
Immunity: Lifelong after natural infection. Vaccine-induced immunity may wane (secondary vaccine failure contributing to outbreaks in vaccinated populations).