Molecular detection and genetic characterization of circulating measles virus in northern Italy

•Measles continues to be endemic in Italy.•Laboratory diagnosis plays an essential role to interrupt viral indigenous transmission.•Serological and molecular methods showed both a good efficiency for measles diagnosis.•Sampling time after the onset of rash can affect measles laboratory diagnosis.•Genotyping analysis revealed circulation of endemic MV strains: D8, D4 and B3. Laboratory diagnosis of measles virus (MV) infection and genetic characterization of circulating MV play an essential role in measles surveillance, allowing proper interventions to interrupt endemic transmission. We describe results obtained using serological and molecular methods to confirm MV infection among suspected cases reported in a large region in the north of Italy during 2010–2014 and the genotyping of the MV strains detected. Three hundred seventy-two samples (361 urine and 11 oral fluids) were tested for MV-RNA detection. In 281 cases, the serological results for MV-IgM detection were also available. A total of 276 cases were classified as confirmed measles and MV-RNA detection resulted positive for 239/276 cases. Nucleotide sequence analysis revealed sporadic cases of genotypes D9 and different circulations of endemic MV strains (D8, D4 and B3). This data suggests that there is still an unvaccinated part of the population maintaining the endemic circulation of MV in Italy.