USE OF A MICROQUANTITY ENZYME-IMMUNOASSAY IN A LARGE-SCALE STUDY OF MEASLES, MUMPS, AND RUBELLA IMMUNITY IN ITALY

The seroprevalence of antibodies to measles, mumps, and rubella viruse s (MMR) was determined in 1498 subjects in Catania, Italy, ranging in age from 1 month to 25 years. The study population was divided into se ven age groups and screened by enzyme immunoassay using microquantitie s (10 mu l) of whole blood collected by fingerprick on filterpaper dis cs. The results showed that seroconversion for measles (87.6%) and mum ps (73.2%) occurred between 6 and 10 years of age. The seroprevalence of antibodies to rubella virus increased slowly through the age groups , reaching the highest rate (93.3%) between 16 and 20 years of age. Pa ssively transmitted maternal antibodies to mumps and rubella were abse nt in babies between 5 and 8 months of age, and a few cases positive f or measles antibodies were found among babies 6 and 7 months of age. T he enzyme immunoassay was demonstrated to be suitable for low-cost lar ge-scale screening for MMR immunity. The rate of vaccine failure was a lso evaluated and found to be 9.5% for the measles virus, 12.9% for th e mumps virus and 0.0% for the rubella virus.