Seroepidemiology of measles, mumps and rubella infections in Apulia, Italy.

Background. – The seroepidemiological study of measles, mumps and rubellainfections was conducted in 1‰ of the population comprising groups aged 1–15 years in Apulia, according to the 1991 census. Methods. – The concentration of human IgG antibodies for the three viruses was determined with an ELISA immunoenzymatic test (Dade-Behring); the geometric mean titer (GMT) specific for each disease and adjusted to the age groups (1, 2–4, 5–9, and 10–15 years) was also calculated. Results. – Seroprevalence showed a typical trend. Following the physiological fall in maternal antibodies, an increased prevalence was recorded after 1 year. The trend recorded and, in particular, the marked increase in the seroprevalence data between the 1-year and the 2–4 year age groups are indicative, at least partially, of the impact of vaccination; this aspect is less evident in the case of mumps, where seroprevalence increases progressively with age. It should be noted that the number of individuals susceptible to the three viruses remains high (> 35%) in the 2–4, 5–9, and 10–15 age groups. Conclusion. – This seroprevalence study seems to confirm an insufficient impact of vaccination and a continuous circulation of the wild-type viruses; for these reasons an implementation of vaccination programs is mandatory.