MUMPS

INTRODUCTION

INTRODUCTION

• Mumps is a viral disease caused by the mumps virus that is preventable with vaccination. Mumps virus is most common cause of parotid gland enlargement in children. In severe cases, it can also orchitis and aseptic meningitis.
• Initial symptoms of mumps are non-specific and include fever, headache, malaise, muscle pain, and loss of appetite. These symptoms are usually followed by painful swelling of the parotid glands, called parotitis, which is the most common symptom of a mumps infection.
• Symptoms typically occur 16 to 18 days after exposure to the virus and resolve within two weeks.
• About one third of infections are asymptomatic.

PATHOGENESIS

PATHOGENESIS

• Transmission is through respiratory route via droplets, saliva and fomites.
• Primary replication occurs in the nasal mucosa or upper respiratory mucosa -----> infects mononuclear cells and regional lymph nodes -----> spills over to bloodstream resulting in viremia -----> dissemination.
• Target sites: Mumps virus has a special affinity for glandular epithelium. The classic sites include salivary glands, testis, pancreas, ovaries, mammary glands and CNS.

CLINICAL MANIFESTATION

CLINICAL

MANIFESTATION

• Incubation period is about 19 days (range: 7-23 days).
• Inapparent infection: Up to half of the infected people are either asymptomatic or present with non-specific symptoms such as fever, myalgia and anorexia. This is more common in adults than in children.
• Other manifestations include Bilateral parotitis, Epididymo-orchitis, Aseptic meningitis, Oophoritis, Pancreatitis.

EPIDEMIOLOGY

EPIDEMIOLOGY

• Mumps is endemic worldwide.
• It occurs mostly in unvaccinated people living in overcrowded areas. A peak rise in cases are observed typically during winter and spring.
• Period of communicability: Patients are infectious from one week before to 1 week after the appearance of symptoms. Most contagious period is within 1-2 days before the onset of symptoms.
• Infective material: Mumps virus shed in saliva, respiratory droplets and urine.
• Source: Both clinical and subclinical cases are the source of infection. There is no carrier state. Subclinical cases are responsible for maintaining the cycle of infection. Humans are the only reservoir of infection.

LAB DIAGNOSIS

LAB DIAGNOSIS

Specimen:

• Ideal Sample: Buccal or pharyngeal swab

• Other Samples: Saliva, CSF, urine, seminal fluids blood (rarely).

• Massaging of parotid gland area for 30 seconds prior to swabbing is recommended.

Direct viral antigen detection: Done by mumps specific immune fluorescent staining.

Virus isolation: Monkey kidney cell lines are used for inoculation. Viral growth after 1-2 weeks can be detected by cytopathic effect (cell rounding & giant cell formation).

Virus antibody detection: ELISA

Reverse transcription PCR is available to detect mumps specific RNA such as N gene.

TREATMENT

TREATMENT

There is no specific treatment for mumps. Most people recover within 3 to 10 days.

Steps you can take to aid recovery and lessen symptoms include:

• Rest.
• Pain relievers that you can get without a prescription such as Ibuprofen (Advil, Motrin IB, others) and acetaminophen (Tylenol, others).
• A cold or warm cloth for swollen salivary glands.
• A cold cloth or ice pack for swollen testicles.
• Drinking plenty of fluids.

PREVENTION

PREVENTION

• Vaccine strain: Live attenuated Jeryl Lynn strain is the recommended strain used worldwide.
• Mumps vaccine is prepared in chick embryo cell line.
• Mumps vaccine is available as Trivalent MMR vaccine (live attenuated Measles-Mumps-Rubella vaccine), Quadrivalent MMR-V vaccine (contains additional live attenuated varicella vaccine) and Monovalent mumps vaccine (not commonly used).
• Schedule: Two doses of MMR is given by subcutaneous route at 1 year (12–15 months) and 4–6 years (before starting of school).
• Efficacy is about 88% after the second dose. Neutralizing antibodies appear in 95% of the recipients. The duration of long-term immunity is unknown.

MCQ'S

MCQ'S

1. Which of the following statements about mumps is not correct?

a. Bilateral parotitis is the most common presentation

b. Other salivary glands are never involved

c. Atypical mumps presents as meningitis

d. Incubation period is about 19 days

2. What type of vaccine is MMR?

a. Live attenuated vaccine

b. Inactivated vaccine

c. Subunit vaccine

d. DNA vaccine

3. What is the route of administration of MMR vaccine?

a. Intramuscular

b. Subcutaneous

c. Intracutaneous

d. Oral