Mumps Virus IgG and IgM Antibodies
Mumps is an acute viral infection caused by a member of the Paramyxoviridae family. Mumps is transmitted from person to person by direct contact with respiratory secretions or saliva or indirect contact through fomites. The average incubation period is 16 to 18 days, with a range of 12 to 25 days. Mumps virus has been detected from 7 days before through 9 days after the development of parotitis.
Early symptoms include body aches, loss of appetite, fatigue, headache, and low grade fever followed by parotitis. Parotid swelling is unilateral initially, but later becomes bilateral. Fever usually resolves within 3 to 5 days, and parotid swelling within 7 to 10 days. Morbilliform rash has been reported in some mumps cases. Serum amylase levels are elevated during the first week of illness.
Most persons with mumps will recover completely though serious complications can occur. Complications include orchitis, aseptic meningitis, and rarely encephalitis, pancreatitis, deafness, and death.
Vaccination with the measles-mumps-rubella (MMR) and measles-mumps-rubella-varicella (MMRV) vaccines is the best way to prevent mumps. Two doses of the vaccine are 69 to 95% effective in protecting against mumps. Outbreaks can still occur in highly vaccinated communities, but the size of the outbreak is limited. In recent years, most outbreaks have occurred in schools, colleges, and camps.
Laboratory testing should be performed if mumps is suspected. Tests for acute mumps infection include serum mumps IgM antibody and real-time reverse transcription polymerase chain reaction (RT-PCR) on a buccal swab specimen. The early collection of buccal swab specimens provides the best means of laboratory confirmation, particularly among patients who have been vaccinated. Specimen requirement for antibody testing is one SST tube of blood.
Serum mumps IgM results may be negative and IgG results may be positive in individuals who have been vaccinated. RT-PCR may be negative if the buccal swab is collected more than 3 days after onset of parotitis.
Mumps serological tests are also performed to check for immune status during employee health screening. Testing for immune status requires only mumps IgG testing. IgM testing should be reserved for evaluation of atypical acute infections.
Reference range for IgM antibody is negative. The presence of IgM antibodies usually indicates acute infection. The presence of IgG generally indicates past exposure and immunity.
More information can be found at: http://www.cdc.gov/mumps/lab/index.html;.
