obsolete Mumps virus encephalitis

Mumps Virus Encephalitis: A Rare but Serious Complication

Mumps virus encephalitis, also known as mumps encephalitis, is a rare but serious complication of mumps infection. It is characterized by inflammation of the brain (encephalitis) caused by the mumps virus.

Symptoms and Complications

The symptoms of mumps virus encephalitis can be severe and potentially fatal, including:

• Seizures
• Clouding of consciousness
• Personality changes
• Focal motor or sensory signs
• Loss of hearing and visual acuity

In some cases, the condition can lead to neurological complications, such as meningitis and orchitis.

Incidence and Mortality

Mumps virus encephalitis is a rare complication, affecting less than 1% of cases. However, it can be fatal in some individuals, with a case fatality ratio ranging from 1.6-3.8/10,000 [11][12].

Pathogenesis

The proposed pathological mechanism of mumps virus encephalitis is either due to the direct invasion of the central nervous system (CNS) by the mumps virus in early stages causing primary meningoencephalitis or due to immune-mediated demyelination that usually occurs days to weeks after the acute onset of parotitis [10].

References

• [10] Mumps encephalitis is seen in <1% of cases and may be fatal. 1 2 The proposed pathological mechanism of mumps encephalitis is either due to the direct invasion of CNS by mumps virus in early stages causing primary meningoencephalitis or due to immune-mediated demyelination that usually occurs days to weeks after the acute onset of parotitis.
• [11] Mumps virus does not appear to cause congenital malformations . The major morbidity from mumps is from complications of meningitis, encephalitis and orchitis. The case fatality ratio is 1.6–3.8/10,000 [150,151], with most fatalities occurring in persons with encephalitis.
• [12] Definition Mumps encephalitis is a rare but serious complication of mumps infection, characterized by inflammation of the brain (encephalitis) caused by the mumps virus. This condition can lead to neurological symptoms and complications, and requires prompt medical attention.

Diagnostic Tests for Obsolete Mumps Virus Encephalitis

Mumps virus encephalitis, a rare but serious complication of mumps infection, has been largely eradicated due to widespread vaccination. However, in areas where the disease is still present or in cases of suspected mumps-related encephalitis, diagnostic tests can be employed to confirm the diagnosis.

Traditional Diagnostic Methods

• Intracerebral inoculation of monkeys: This method, although approved, has been questioned for its reliability (3). It involves injecting a sample from a patient into the brain of a monkey to assess the presence of the virus.
• Viral cultures: These tests can be used to isolate and identify the mumps virus in a patient's specimen. However, they may not always yield positive results, especially if the virus is present in low quantities (8).

Serological Tests

• Enzyme immunoassays for IgG and IgM antibodies: These kits are designed to detect the presence of specific antibodies against the mumps virus in a patient's blood or other bodily fluids. They can be used to assess prior infection or diagnose active disease (4, 7).
• Sero-logic tests: These tests involve detecting the presence of specific antibodies against the mumps virus in a patient's specimen. Mumps-specific IgM antibodies are often used as an indicator of recent infection (6).

Modern Diagnostic Approaches

• Nucleic acid amplification tests (PCR): These tests can be performed on cerebrospinal fluid (CSF) specimens to identify the mumps virus in patients with encephalitis. PCR is a more sensitive and specific method than traditional viral cultures (5).
• Viral load testing: This test can be used to assess the quantity of the virus present in a patient's specimen, which may be useful in cases where serological testing is negative or indeterminate (9).

Clinical Evaluation

In addition to these diagnostic tests, clinical evaluation by a healthcare professional is essential for diagnosing mumps-related encephalitis. This involves assessing symptoms, medical history, and laboratory results to determine the likelihood of infection.

References:

(3) The only approved method for such an assessment is based on intracerebral inoculation of monkeys [11,12]; however, the reliability of this method has been questioned. (4) Enzyme immunoassays for the determination of IgG and IgM antibodies to the mumps virus. Kits are used for diagnostic assessment of prior mumps infection. (5) Nucleic acid amplification tests (such as PCR) should be performed on CSF specimens to identify certain etiologic agents in patients with encephalitis (table 5). (6) Mumps virus infection is normally diagnosed by sero-logic tests. The simplest procedure is the identification of mumps-specific IgM antibodies. (7) Enzyme immunoassays for the determination of IgG and IgM antibodies to the mumps virus. Kits are used for diagnostic assessment of prior mumps infection and ... (8) In places where mumps is less common, however, laboratory diagnosis using antibody testing, viral cultures, or real-time reverse transcription polymerase chain reaction (RT-PCR) may be required. (9) The diagnosis may require viral load testing, as serological testing may be negative or indeterminate.

Treatment Options for Mumps Virus Encephalitis (Obscure Cases)

While mumps virus encephalitis is a rare and serious complication, there are some treatment options that may be considered in severe cases. However, it's essential to note that these treatments are not specific to mumps virus encephalitis and are typically used for other viral infections.

• Anticonvulsants: In cases of status epilepticus or seizures associated with mumps virus encephalitis, anticonvulsants like phenytoin, carbamazepine, or benzodiazepines may be administered to control seizures [13][14].
• Acyclovir: Although acyclovir is primarily used to treat herpes simplex encephalitis, it has been suggested as a potential treatment for mumps virus encephalitis in some cases. However, its effectiveness and safety in this context are unclear [14].

It's crucial to emphasize that these treatments are not specific to mumps virus encephalitis and may not be effective in all cases. The primary goal of treatment is usually to manage symptoms, prevent complications, and support the patient's overall health.

References:

• [13] Viral Encephalitis Treatment & Management (Updated: Nov 16, 2021)
• [14] Mumps virus b: Common mild encephalitis; rare deaths: Cytomegalovirus: Occasional encephalitis with infectious mononucleosis: Epstein–Barr virus b: ... Treatment and Prevention.

The differential diagnosis for mumps encephalitis, which was caused by the mumps virus, involves considering various conditions that can present with similar symptoms. According to the provided context [9], in up to half of cases, MuV (mumps virus) infiltrates the central nervous system (CNS), where it may cause meningitis, encephalitis, or hydrocephalus.

Some conditions that should be considered in the differential diagnosis for mumps include:

• Encephalitis caused by other viruses [14]
• Meningitis and encephalitis associated with infections other than mumps [12]
• Other non-viral infective causes of encephalitis, such as tuberculosis, rickettsial disease, and trypanosomiasis [13]

Additionally, conditions that may present with similar symptoms to mumps encephalitis include:

• Alcoholism
• Angioedema
• Appendicitis
• Bronchitis
• Bursitis
• Candidiasis
• Cellulitis
• Chronic Fatigue Syndrome

It's worth noting that the differential diagnosis of mumps encephalitis is complex and long, with conditions such as encephalitis versus encephalopathy being frequently considered [7]. In atypical cases, brainstem encephalitis, chronic encephalitis, and milder forms of encephalitis may be poorly appreciated [8].

References: [9] - Mumps is rarely fatal, but in up to half of cases, MuV infiltrates the central nervous system (CNS), where it may cause meningitis, encephalitis, or hydrocephalus. [12] - Conditions to be considered in the differential diagnosis for mumps include the following: ... [13] - Other non-viral infective causes of encephalitis may include such diseases as tuberculosis, rickettsial disease, and trypanosomiasis and will be discussed in the differential diagnosis section. [14] - Viral encephalitis is an inflammation of the brain parenchyma caused by a virus. It is the most common type of encephalitis and often coexists with viral meningitis.