Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus)
Overview
Plain-Language Overview
Mumps is a contagious viral infection that primarily affects the salivary glands, especially the parotid glands located near the jaw. It is caused by the mumps virus, which spreads through respiratory droplets from coughing or sneezing. The infection often leads to painful swelling of the cheeks and jaw, known as parotitis. In some cases, it can also cause inflammation of the testicles (orchitis) in males or the brain lining (aseptic meningitis), which can lead to more serious complications. The illness mainly impacts the head and neck region but can affect other organs, causing fever, headache, and muscle aches.
Clinical Definition
Mumps is an acute viral illness caused by the mumps virus, a single-stranded RNA virus of the Paramyxoviridae family. The core pathology involves viral replication in the upper respiratory tract followed by viremia and infection of the salivary glands, particularly the parotid glands, leading to characteristic parotitis. The disease is highly contagious and transmitted via respiratory droplets. Major clinical manifestations include bilateral or unilateral parotid gland swelling, orchitis in post-pubertal males, and aseptic meningitis as a common neurological complication. The infection can also cause pancreatitis and oophoritis. Diagnosis is clinically suspected based on symptoms and confirmed by serology or viral RNA detection. The disease is significant due to its potential for complications and its prevention by vaccination.
Inciting Event
Exposure to respiratory droplets containing mumps virus from an infected individual.
Close contact in crowded environments such as schools or dormitories.
Lack of prior MMR vaccination or waning immunity after childhood vaccination.
Introduction of virus into a susceptible population during seasonal outbreaks.
Contact with asymptomatic viral shedders during the prodromal phase.
Latency Period
The incubation period is typically 16-18 days (range 12-25 days) from exposure to symptom onset.
Parotitis usually develops 1-3 days after prodromal symptoms such as fever and malaise.
Orchitis generally occurs 7-10 days after initial parotid swelling.
Aseptic meningitis symptoms may appear during or shortly after parotitis.
Viral shedding can begin several days before symptom onset, contributing to transmission.
Diagnostic Delay
Initial symptoms are often nonspecific (fever, malaise) leading to misattribution to common viral illnesses.
Lack of awareness or suspicion in vaccinated individuals with atypical or mild presentations.
Parotitis may be mistaken for bacterial sialadenitis or other causes of facial swelling.
Orchitis symptoms may be confused with testicular torsion delaying diagnosis.
Limited access to serologic or PCR testing in some settings can delay confirmation.
Clinical Presentation
Signs & Symptoms
Prodromal fever, myalgia, and malaise preceding glandular swelling.
Painful swelling of the parotid glands causing facial fullness and difficulty chewing.
Testicular pain and swelling in postpubertal males indicating orchitis.
Headache, neck stiffness, and photophobia suggestive of aseptic meningitis.
Possible earache and trismus due to parotid inflammation.
History of Present Illness
Prodrome of fever, headache, myalgia, and malaise lasting 1-3 days precedes glandular symptoms.
Development of unilateral or bilateral parotid gland swelling with pain and tenderness.
In males, onset of testicular pain and swelling occurs about 1 week after parotitis.
Symptoms of aseptic meningitis include headache, neck stiffness, and photophobia.
Respiratory symptoms such as cough and nasal congestion may be present early.
Past Medical History
History of incomplete or absent MMR vaccination increases risk of mumps infection.
Previous episodes of parotitis or viral infections may be relevant.
Immunodeficiency or chronic illnesses can affect disease severity and course.
No specific prior conditions are required but recent exposure to mumps cases is important.
History of orchitis or infertility may be relevant in recurrent or complicated cases.
Family History
No known heritable predisposition to mumps infection or complications.
Family members may share exposure risk in household outbreaks.
No familial syndromes are associated with increased susceptibility to mumps virus.
Vaccination status often clusters within families affecting risk.
Rarely, genetic immunodeficiencies affecting viral immunity could be relevant but are not typical.
Physical Exam Findings
Bilateral or unilateral parotid gland swelling with tenderness and erythema overlying the gland.
Orchitis presenting as testicular swelling, tenderness, and erythema, typically unilateral in postpubertal males.
Aseptic meningitis signs including neck stiffness and photophobia without purulent discharge.
Fever and malaise accompanying the glandular swelling.
Possible trismus due to inflammation near the mandibular branch of the facial nerve.
Diagnostic Workup
Diagnostic Criteria
Diagnosis of mumps is primarily clinical, based on the presence of acute onset of unilateral or bilateral parotid gland swelling lasting more than 2 days without other apparent cause. Confirmatory diagnosis involves detection of mumps-specific IgM antibodies or a significant rise in IgG titers in serum. Alternatively, RT-PCR testing of saliva or cerebrospinal fluid can detect viral RNA. Epidemiologic linkage to a confirmed case or outbreak supports diagnosis. Imaging is rarely needed but may show enlarged, hypoechoic parotid glands on ultrasound.
Pathophysiology
Key Mechanisms
Mumps virus infects epithelial cells of the upper respiratory tract and spreads hematogenously to target organs.
Viral replication in salivary glands causes parotitis due to glandular inflammation and edema.
Immune-mediated inflammation leads to orchitis, aseptic meningitis, and other systemic manifestations.
Direct viral invasion of the central nervous system causes aseptic meningitis with lymphocytic pleocytosis.
Testicular inflammation from viral infection can cause edema, pain, and potential infertility.
| Involvement | Details |
|---|---|
| Organs | Parotid glands are the most commonly affected organs, presenting with painful swelling in mumps. |
Testes may develop painful inflammation (orchitis) leading to potential complications such as infertility. | |
Central nervous system involvement can cause aseptic meningitis, presenting with headache, neck stiffness, and photophobia. | |
| Tissues | Salivary gland tissue is the primary site of inflammation causing parotitis in mumps. |
Testicular tissue can become inflamed during orchitis, a complication of mumps in post-pubertal males. | |
Meningeal tissue is involved in aseptic meningitis caused by mumps virus infection. | |
| Cells | Macrophages are involved in phagocytosis of infected cells and antigen presentation during mumps virus infection. |
T lymphocytes mediate cellular immune response critical for viral clearance in mumps. | |
Epithelial cells of the salivary glands are primary targets for mumps virus replication causing glandular inflammation. | |
| Chemical Mediators | Interferon-alpha is produced in response to mumps virus infection and helps inhibit viral replication. |
Cytokines such as IL-1 and TNF-alpha mediate inflammation and contribute to symptoms like fever and swelling. | |
IgM antibodies are produced early in infection and serve as markers for acute mumps. |
Treatments
Pharmacological Treatments
Analgesics and antipyretics
- Mechanism:
Reduce pain and fever by inhibiting prostaglandin synthesis and acting on central nervous system pathways
- Side effects:
Gastrointestinal upset
Liver toxicity with overdose
- Clinical role:
Supportive
Non-pharmacological Treatments
Apply warm or cold compresses to the parotid glands to relieve pain and swelling.
Ensure adequate hydration and rest to support immune response and recovery.
Isolate infected individuals to prevent transmission of the mumps virus via respiratory droplets.
Prevention
Pharmacological Prevention
MMR vaccine containing live attenuated mumps virus is the primary pharmacological prevention.
No antiviral therapy is currently approved for mumps treatment or prophylaxis.
Non-pharmacological Prevention
Isolation of infected individuals during contagious period to reduce spread.
Good hand hygiene and respiratory etiquette to prevent droplet transmission.
Avoidance of sharing utensils or cups during outbreaks.
Public health surveillance and outbreak control measures in community settings.
Outcome & Complications
Complications
Orchitis leading to testicular atrophy and potential infertility in males.
Aseptic meningitis causing prolonged headache and neurological symptoms.
Oophoritis and mastitis in females, though less common.
Pancreatitis with abdominal pain and elevated pancreatic enzymes.
Deafness due to viral involvement of the cochlea or auditory nerve.
| Short-term Sequelae | Long-term Sequelae |
|---|---|
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Differential Diagnoses
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) versus Bacterial Parotitis
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) | Bacterial Parotitis |
|---|---|
Infection with Mumps virus, a paramyxovirus | Infection with Staphylococcus aureus or mixed oral flora |
Gradual onset with non-purulent parotid swelling and low-grade fever | Rapid onset with purulent discharge from Stensen's duct and high fever |
Supportive care; no response to antibiotics | Improves with intravenous antibiotics and hydration |
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) versus Acute HIV Infection
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) | Acute HIV Infection |
|---|---|
Exposure to respiratory droplets or contact with infected saliva | Recent high-risk sexual exposure or needle sharing |
Positive mumps IgM serology or PCR with lymphocytic pleocytosis in CSF | Positive HIV RNA PCR and p24 antigen with lymphopenia |
Predominant parotitis, orchitis, or aseptic meningitis without generalized rash | Systemic flu-like illness with generalized lymphadenopathy and rash |
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) versus Coxsackievirus Infection (Herpangina, Hand-Foot-and-Mouth Disease)
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) | Coxsackievirus Infection (Herpangina, Hand-Foot-and-Mouth Disease) |
|---|---|
Infection with Mumps virus (paramyxovirus) | Infection with Coxsackievirus A or B (enterovirus) |
Parotid gland swelling without vesicular rash | Oral vesicles and ulcers with hand and foot rash |
Common in children and young adults, often older than 5 years | Primarily affects young children under 5 years |
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) versus Bacterial Meningitis
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) | Bacterial Meningitis |
|---|---|
CSF shows lymphocytic pleocytosis, normal glucose, and mildly elevated protein | CSF shows neutrophilic pleocytosis, low glucose, and high protein |
Subacute onset with mild meningismus and less severe systemic symptoms | Rapid progression with severe headache, neck stiffness, and altered mental status |
Supportive care; antibiotics not indicated | Requires urgent intravenous antibiotics and supportive care |
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) versus Parotid Tumor
Mumps (Parotitis, Orchitis, Aseptic Meningitis - Mumps Virus) | Parotid Tumor |
|---|---|
Acute, painful parotid swelling with systemic viral symptoms | Chronic, painless parotid swelling without systemic symptoms |
Diffuse gland enlargement without discrete mass | Mass lesion on ultrasound or MRI with well-defined borders |
Positive mumps serology or viral PCR | Fine needle aspiration biopsy showing neoplastic cells |