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Case of the Month

July 2016

A 23-year-old man presented with a 5-day history of headache and photophobia, and 3 days history of fever and vomiting. The headache was predominantly frontal, and refractory to simple analgesia. The vomiting was not associated with any precipitant, and had occurred approximately 4 times per day since its onset.

The patient had no previous medical or surgical history of note, and described himself as being in perfect health prior to this episode. He had tested negative for HIV four months previously. He was not on any medications, and gave no history of alcohol, smoking or recreational drug use. He was unemployed and lived with his brother in a house in Soweto with full amenities. He was not sexually active, and had no travel history and no pets.

On examination, his blood pressure was 112/63 mmHg, his pulse was 67 beats per minute, and his temperature was recorded as 36.7°C. He had no oral lesions or stigmata of HIV. A neurological exam revealed meningism, with positive Kernig and Brudzinski signs. He was well-orientated and had a normal sensorium with no focal neurology.

Question 1: Is the clinical syndrome most compatible with a migraine, meningitis or encephalitis?

The rest of the examination was normal, with the exception of what was recorded in the admission notes as “facial swelling” (see below):

Admission bloods revealed a leukopenia (a combined neutropenia, lymphopenia and monocytopenia, but with a relative lymphocytosis) and a normal C-reactive protein level.

He underwent a lumbar puncture. The findings are below:

Question 2.  Based on the history, examination and the above results, what is the most likely diagnosis?

Answer to Q2:

Mumps meningitis. The patient has aseptic meningitis, with findings in keeping with a viral cause, as well as bilateral parotidomegaly. This syndrome is most typical of mumps meningitis. The leukopenia with a relative lymphocytosis is also a typical, but non-specific finding.

Question 3.  If confirmation of the diagnosis were required, what would be the most appropriate way to do this?
Answer to Q3:
Mumps serology. Either a positive mumps IgM result, or a 4-fold rise in mumps IgG tires between acute and convalescent specimens is sufficient. This patient’s mumps IgM result came back as positive.

Other diagnostic options, seldom required, are isolation of mumps virus (viral culture) or nucleic acid (PCR) from appropriate fluid (e.g. saliva, urine, CSF in the case of mumps meningitis).

It is not necessary to confirm the diagnosis in uncomplicated cases where the clinical syndrome is clear.

Discussion

Mumps virus is a single-stranded negative sense RNA virus belonging to the Paramyxovirus group. There is only a single serotype. The incidence of mumps peaks around school age, and respiratory droplets, direct contact and fomites spread the virus. Peak viral shedding occurs in the days just prior to the onset of symptoms. It is highly contagious and spreads quickly amongst susceptible people living in close quarters.

Mumps infection is characterized by a prodrome of low-grade fever, myalgias, anorexia, and headache, followed 1-2 days later by parotitis (in 95% of symptomatic cases), which is the hallmark of the condition. The parotid swelling lasts for approximately a week, and is almost always ultimately bilateral, although there may be a delay of several days before the contralateral parotid gland becomes inflamed.

Complications include:

  • Orchitis (only in post-pubertal males; resultant sterility is very rare).
  • Neurological complications – predominantly aseptic meningitis but occasionally encephalitis, deafness, or transverse myelitis
  • Arthritis
  • Pancreatitis
  • Carditis
Treatment of the parotitis is purely symptomatic, with antipyretics and cold or warm compresses applied topically to the parotid glands. There is no specific treatment for mumps. Patients with mumps should be isolated until approximately 5 days after symptoms start, or until the parotitis has subsided.

Vaccination against mumps is recommended as part of the MMR vaccine schedule. 2 doses are given, but immunity does wane with time, and so a 3rd dose may be useful in outbreak settings. As with other live attenuated vaccines, MMR vaccination is contraindicated in immunosuppressed individuals (including HIV positive patients with CD4 < 200), pregnant women and people with advanced malignancies. As the MMR vaccine is not part of South Africa’s Expanded Programme on Immunization (EPI) schedule, the vast majority of South Africans remain susceptible to the virus.

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