Mumps Virus Infection (or Epidemic Parotitis)
Mumps (epidemic parotitis) is the specific highly contagious acute virus disease, which primarily affects parotid, sublingual, and submandibular salivary glands with subsequent involvement of other glandular organs and tissues (pancreas, ovaries, or testes), kidneys and central nervous system. Only 1 serotype of virus is known.
Pathogenesis, clinical findings and immunity in mumps
Mumps virus infects humans, predominantly young children. It is anthroponotic infections, humans are the only sources of infection.
Disease transmission rate in unvaccinated children is near 50-70%. Mumps virus often gives epidemic outbreaks.
The disease is contracted by airborne route.
Incubation period varies from 2 to 3 weeks.
Primary viral replication is determined in nasal and upper respiratory tract epithelial cells. Then the virus spreads to the salivary glands and further to susceptible tissues and organs.
The most typical symptoms of epidemic parotitis are the enlargement and swelling of the parotid gland.
Systemic viral dissemination affects different inner organs and central nervous system because of viral ability to propagate within epithelial cells.
Specific pancreatitis and orchitis that may cause sterility are developed. Meningitis and meningoencephalitis are the main complications on central nervous system in epidemic parotitis.
During the disease course the virus is eliminated from the body mainly with saliva and urine.
One-third of patients display inapparent forms of mumps.
Post-infectious specific humoral immunity is lifelong and stable due to one antigenic type of virus. Antibodies appear to various viral antigens (HN-, F-proteins, nucleoproteins, etc.) They maintain immune response for many years.
Newborn child is protected by maternal passive immunity within 6 months.
Laboratory examination is useful for diagnosis of inapparent forms of mumps and for differential diagnosis.
For express diagnostics immunofluorescence assay with anti-mumps antibodies is used.
For virus isolation the specimens are obtained from saliva, urine or cerebrospinal fluid. Inoculation is performed into primary monkey kidney cell cultures. Mumps virus displays characteristic cytopathic effect with cell rounding and giant cell formation. In the cell culture virus is detected by hemadsorption or hemagglutination.
Mumps virus tidentification is performed by hemadsorption or hemagglutination inhibition tests.
Serological diagnosis confirms acute mumps infection by ELISA detection of anti-mumps IgM-class antibodies.
Principles of disease treatment and prophylaxis
Treatment of the disease is solely symptomatic.
High-effective attenuated live vaccine is used worldwide for mumps specific prophylaxis. Near to total coverage of children with anti-mumps vaccination lowered the disease incidence in most of states to the sporadic events. Mumps vaccine can be applied as monovaccine, but in most of cases it is administered like triple MMR vaccine in combination with attenuated measles and rubella viruses. It confers high-grade long lasting immunity.