Evaluation of the new EIA kit for detection of anti-mumps IgM antibody *
As efforts have has been directed to progress in the diagnosis and elimination of mumps virus infection, laboratory confirmation of mumps has become more and more important. However, high IgM-positive rates of mumps among healthy individuals and the long persistence of IgM after the convalescent phase of mumps virus-related diseases are sometimes reported. Until now, there have been no kits that can be fully assessed by clinically defined relative performance. However, in this study, we evaluated a new enzyme-immunoassay （EIA） kit for the detection of anti-mumps virus IgM antibody. This method is based on the IgM-capture EIA for clinical serodiagnosis of recent mumps virus infection. Among healthy individuals, the IgMseropositivity rate was 0.3% （1/336）. Using sera collected during mumps prevalent seasons, the rate for IgM positivity was 92.1%（ 128/139） in acute phase parotiditis patients with mumps virus （detected with the RT-PCR）. Anti-mumps IgM antibody persisted for five months from the time of being clinically defined as mumps-related parotiditis. This EIA kit can distinguish parotiditis and meningitis-causing mumps virus infection from other causes. (Accepted on March 5, 2009)
