Mumps

Mumps is an acute viral illness that causes swelling of the salivary glands, usually the parotid glands. The disease shares similar features with measles and rubella as the causative agents of all three illnesses belong to the same family of viruses. Mumps is usually a benign, self-limiting disease, but in areas where there is no vaccination against it, it can cause severe complications. Immunization against mumps was first introduced in the United States in 1967.

The disease is caused by a virus called Rubulavirus, which belongs to the family of Paramyxoviridea. The natural host for the virus is humans, and it shares similar features with the human influenza virus. In non-immunized individuals, the virus can cause serious complications, some of which can be life-threatening.

Following are the routes of transmission for the virus:
Droplet transmission- via coughing, sneezing, saliva, etc.
Contact transmission- by touching infected individuals
Fomites- that is transmitted through infected objects such as utensils or clothes etc.

Risk factors for the infection include:

• Lack of immunization
• International travel to areas where the virus is endemic
• Immunocompromised state due to a disease or medication
• The incidence of mumps varies depending upon geographical regions due to factors like socioeconomic conditions, vaccination status of populations, access to healthcare, etc.
• There is no association with gender as such, and the virus attacks both males and females equally. The incidence in the young, school-going children aged between 5 to 14 years is the highest compared to adults.

The incubation period for the virus is around 16 to 18 days, after which the first symptoms appear. These include:

• Low-grade fever
• Malaise (generalized weakness)
• Myalgias (body pains)
• Anorexia (loss of appetite)
• Headache
  After around 48 hours of the initial symptoms, the disease progresses to:
• Facial swelling, usually on both sides due to swelling of the parotid glands, is the most common clinical feature in symptomatic patients.
• Facial pain
• Earache
  The virus can attack several other systems of the body as well, causing:
• Encephalitis
• Deafness
• Acute pancreatitis
• Orchitis (inflammation of testes) in males
• Oophoritis (inflammation of the ovary) in females
  Several other complications due to systemic involvement can also occur. These include:
• Thyroiditis
• Myocarditis
• Mastitis
• Pneumonia
• Arthritis
• Thrombocytic purpura

Following investigations are often ordered to reach the diagnosis:

• Serum amylase levels (amylase S)- raised  levels to indicate the involvement of parotid glands
• Complete blood count- that shows decreased white blood cells with reactive lymphocytosis
• Inflammatory markers such as CRP and ESR are raised
• Viral culture of blood, urine, fluid from the  buccal cavity
• Lumbar puncture for CNS involvement
• PCR of the throat, nasal, and buccal swabs for viral antigens
• Mumps specific IgM and IgG antibodies

Differential diagnoses for mumps include:

• Viral diseases that can affect the parotid glands include influenza, parainfluenza, cytomegalovirus, adenovirus, etc.
• Parotid gland infection due to bacterial causes such as staphylococcus aureus
• Parotid calculus
• Mixed tumors of the parotid gland
• Orchitis
• Ovarian torsion
• Mastoiditis
• Drug and allergic reactions
• HIV infection
• Measles
• Rubella

• Typical cases without any complication can be managed at home through symptomatic treatment.
• Infected individuals should be separated from other family members for at least five days to stop the spread of infection.
• No antiviral therapy is used against mumps as the disease takes its natural course and is usually self-limiting.
• Rehydration with oral fluids is encouraged.
• Analgesics are given for pain management due to facial swelling and headaches.
• Avoid eating acidic or spicy foods during the infection as the oral pain can be worsened.
• Where there is scrotal involvement, more potent painkillers are recommended with bed rest and ice packs.
• Patients with severe complications are managed in a hospital, where they are provided with intravenous rehydration and pain management. They are closely observed for life-threatening complications.
• Patients who have already developed complications with multi-system involvement are managed accordingly through multi-disciplinary approaches.

The prognosis of mumps that does not lead to any complications is excellent. Common complications such as encephalitis and sensorineural deafness can be managed with proper care and hospitalization. Orchitis and oophoritis can rarely cause infertility in males and females, respectively. Infection during pregnancy can have dangerous outcomes for the fetus.

• Prevention is achieved through vaccination against mumps. All children under seven years of age should receive the vaccine. The vaccine is usually combined with the MMR vaccine (Measles, Mumps, Rubella). It consists of two doses. The first dose is given at 12 months of age, and the second dose is between the age of 4 to 6 years.
• In case of infection, the infected individual should be separated from otherwise healthy individuals for at least five days to stop the spread through infected droplets or contact.
• Practice hand-hygiene.
• Immunization records of children in pre-schools should be checked to make sure they are vaccinated against the disease. Vaccination should be ensured for those who have missed their shots.