Measles outbreaks in the Emilia-Romagna Region, Italy, during 2016

Background and aim. Despite the availability of a vaccine,measles continues to be endemic in Italy, where an increase of cases was reported during 2016. This study describes the measles outbreaks in Emilia-Romagna Region (ERR), one of the Italian regions mostly affected.
Materials and Methods. A total of 101 suspected cases were reported in ERR during 2016. Laboratory diagnosis by serological and/or molecular methods was performed on 142 specimens (78 urine, 19 oral fluid and 45 sera) related to 97 suspected cases. For positive cases, measles virus (MV) strains involved were identified.
Results. Among 101 suspected cases, 72 (71.3%) were confirmed. Vaccination status was known for 61 (84.7%) cases, of which 56 (91.8%) were unvaccinated. The highest incidence was found in the age group 15-39 years. In addition, for the 34.7% (25/72) of confirmed cases, the transmission occurred in nosocomial settings, where healthcare workers were involved (60% of cases). Roma/Sinti population were also involved in 12.5% (9/72)or confirmed cases. Both groups are considered hard-to-reach for immunization. The phylogenetic analysis showed circulation of MV strains belonging to genotype B3 and D8 in 45 (80.4%) and 11 cases (19.6%), respectively. In 94.7% of cases, the measles endemic transmission was demonstrated.
Conclusions. This data obtained through active surveillance showed the endemic transmission of MV within a population with immunity gaps including healthcare workers (20.8% of confirmed cases), among which the spread of two endemic MV strains was observed.