Seroprevalence of measles antibodies in the Italian general population in 2019–2020

In Italy, the measles elimination target has not yet been reached despite a significant reduction in cases. A multicenter study was conducted to estimate the prevalence of anti-measles (MV) IgG antibodies in the Italian population by age, sex and geographical area. To determine the level of MV-specific antibodies in sera, the immunoenzymatic assay ELISA was used (Enzygnost Anti-VZV/IgG, Siemens Healthcare Diagnostic Products GmbH, Germany). Overall, 3746 serum samples collected in the years 2019-20 from healthy subjects aged 6-64 years residing in 13 Italian regions. The overall seroprevalence of anti-MV IgG was 91.2 % (90.6 % male, 91.7 % female). Significantly higher seroprevalence values (p < 0.05) were recorded for the extreme age groups of the study population (6-9 years: 94.2 %; 40-64 years: 97.6 %). Subjects 20-39 and 40-64 years old had significantly higher antibody titers suggesting a protection against measles mainly derived from natural infection. Seroprevalence was significantly higher in the South (93.2 %) than in the Northern-Central Italy (88.9 %). The results indicate an increase in the overall seroprevalence data compared to previous investigations. However, further efforts must be made to implement and maintain high measles vaccination coverage to avoid the risk of future epidemic outbreaks.