References:
- Global Infectious Diseases and Epidemiology Online Network: Infectious Diseases of the Philippines, 2013 eBook Edition, ISBN 978-1-61755-582-4, by Stephen Berger. Accessed here.
| Agent | VIRUS - RNA. Paramyxoviridae, Paramyxovirinae, Rubulavirus: Mumps virus |
| Reservoir | Human |
| Vector | None |
| Vehicle | Aerosol |
| Incubation Period | 14 to 24 days (As early as 12 days) |
| Diagnostic Tests | Viral culture (saliva, urine, CSF) indicated only in complicated cases Serology Nucleic acid amplification |
| Typical Adult Therapy | Respiratory isolation; supportive |
| Typical Pediatric Therapy | As for adult |
| Vaccines | Measles-Mumps-Rubella Mumps Rubella-Mumps |
| Clinical Hints | Fever, parotitis, orchitis (20% of post-pubertal males), meningitis (clinically apparent in 1% to 10%), oophoritis, or encephalitis (0.1%); most cases resolve within 1 to 2 weeks. |
| Synonyms | Bof, Epidemic parotitis, Fiebre urliana, Infectious parotitis, Kusma, Oreillons, Paperas, Parotidite epidemica, Parotiditis, Parotite epidemica, Passjuka |
One third of Mumps virus infections are asymptomatic.
Acute Illness
The prodrome of mumps consists of low-grade fever, anorexia, malaise, and headache.
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Usually within one cay, the patient complains “earache” and tenderness is noted over the parotid gland.
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The gland is soon visibly enlarged and progresses to maximum size over the next 2 to 3 days, often with lifting of the ear lobe upward and outward.
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The orifice of Stensen’s duct is edematous and erythematous, and trismus and pain on chewing may be present.
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It is important to remember that the enlarged gland obscures the angle of the mandible, while cervical adenopathy does not.
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Parotid involvement if unilateral in 25% of cases.
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As the disease progresses, fever may reach 40C.
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Subsequently pain, fever, and tenderness resolve, and the parotid gland returns to normal size within a week.
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Involvement of the other salivary glands occurs in 10% of cases, but are rare in the absence of parotid involvement.
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Presternal edema develops in 6% of patients, most often in those who have submandibular adenitis.
8% to 15% of patients will continue shedding Mumps virus 5 days after the onset of symptoms.
Neurological Manifestations
Central nervous system involvement is the most common extrasalivary gland manifestation of this disease.
- Cerebrospinal fluid pleocytosis has been documented in 51% patients with mumps, without other evidence of meningitis.
- Clinical meningitis occurs in 1 to 10% of persons with mumps parotitis; while parotitis is documented in less than 50% of patients with mumps.
- Meningitis may occur before, during or after salivary gland involvement.
- The features of mumps meningitis are similar to those of other viruses, and the clinical course is benign; however, polymorphonuclear CSF pleocytosis and reduced glucose levels are not unusual. Encephalitis occurs in less than 0.1% of cases, and may be accompanied by altered consciousness, seizures, paresis, aphasia, involuntary movements; and sequelae such as psychomotor retardation, deafness (1 per 1,000 to 20,000 cases) and convulsive disorders.
- Other neurological complications of mumps include cerebellar ataxia, facial nerve palsy, transverse myelitis, Guillain-Barre syndrome, and aqueductal stenosis.
Epididymo-orchitis
Epididymo-orchitis is the most common extra-salivary gland manifestation in adults, developing in 20 to 30% of infected postpubertal males.
- This complication is bilateral in 15% of cases, and appears during the first week of mumps in 70% of cases.
- Rarely, this is the only manifestation of mumps.
- Onset is abrupt, with elevation of fever, chills, headache, vomiting, and testicular pain.
- The testis is warm, swollen (to as much as four times normal size), and tender, with erythema of the scrotum.
- Epididymitis is present in 85%, and usually precedes the orchitis.
- Tenderness may persist for more than 2 weeks in 20% of cases; and some degree of atrophy is noted in 50% of the patients, even after 2 years.
- Impotence is not encountered, and sterility is rare.
Other Manifestations
Other features of mumps include oophoritis, fetal wastage 6 , migratory polyarthritis, monoarticular arthritis and arthralgia, electrocardiographic changes (with or without overt myocarditis), nephritis, thyroiditis, mastitis, prostatitis, hepatitis, cholecystitis and thrombocytopenia.