Incidence and Persistence of Mumps-Specific IgM and IgA in the Sera of Mumps Patients

Abstract

Sera from 72 patients with serologically confirmed diagnosis of mumps were tested by immunofluorescence technique for presence of IgM and IgA antibodies directed against mumps virus antigen. In addition, the persistence of such antibodies was studied on 28 sera drawn from 22 out of the 72 patients 2–10 months after onset of mumps. In 82% of the investigated patients IgM was demonstrated in one or both of the acute and convalescent serum samples. The corresponding figure for IgA was 90%. During the first 5 days of clinical disease about 60% of the sera were positive in the IgM test, whereas about 80% were positive 5—20 days from onset. After 2 months positive IgM results were still obtained in about 70% and after 6—9 months in 3 out of 24 of the cases. IgA was detected in almost all sera collected during the first 5 days and in 80—90% during the period 5—20 days after onset. The rate of positive IgA findings dropped successively to about 6 out of 23 sera collected 6—9 months after onset of disease. Some practical implications of these findings are discussed.