Ineffectiveness of isolation of patients as a method of preventing the spread of mumps. Failure of the mumps skin-test antigen to predict immune status.

Abstract

Abstract During an outbreak of mumps all susceptible children on an open ward were infected despite the fact that cases were isolated at the first sign of parotid swelling. The ineffectiveness of isolation could probably be attributed to the finding that virus was recovered from the pharynx of children before the onset of parotid swelling. Moreover, only nine of 13 mumps infections were manifested by parotitis. Mumps skin-test reactions of children who did not get mumps were less than 10 mm in four, 15 mm or more in one and intermediate in one. Reactions of children in whom mumps subsequently developed were 15 mm or more in four, less than 10 mm in five and intermediate in three. All nine of the children who did not have detectable serum antibody and none of the six who had antibody at the time of exposure subsequently contracted mumps. The neutralizing-antibody test, in contrast to the mumps skin test, proved to be a reliable method for predicting immunity to mumps.