An epidemiologic and serologic study of 126 mumps patients and their 233 family contacts selected from a quota survey of the Hillsborough County, Florida, population was carried out. The estimated annual incidence was 19.5 cases of mumps per 1,000 population per year. Physicians saw only 27% of the 126 cases and reported only 14% of those brought to their attention. Twenty-five percent of the family contacts presumably had inapparent infections. Secondary attack rates in households varied by age from 14% to 46%. No important difference in geometric mean complement fixation and hemagglutination titers was found between reexposed adults and a comparison group not recently reexposed in the family.
Levitt LP, Mahoney DH, Casey HL, Bond JO. Mumps in a General PopulationA Sero-epidemiologic Study. Am J Dis Child. 1970;120(2):134–138. doi:10.1001/archpedi.1970.02100070078008