Genotyping of circulating measles strains in Italy in 2010

Introduction. The European Regional Office of the World Health Organization developed a strategic approach to stop the indigenous transmission of measles in its 53 Member States by 2015. In Italy, laboratory surveillance activity is implemented by the National Reference Laboratory for Measles and Rubella at the Italian National Institute of Health (Istituto Superiore di Sanità, Rome). The role of the National Reference Laboratory is to strengthen surveillance systems through rigorous case investigation and laboratory confirmation of suspected sporadic cases and outbreaks. Genetic characterization of wild-type measles virus is an essential component of the laboratorybased surveillance. This study describes the molecular characterization of measles virus strains isolated during 2010. Methods. Dried blood spots, urine and oral fluid samples were collected from patients with a suspected measles infection. Serological tests were performed on capillary blood, and viral detection was performed on urine and oral fluid samples through molecular assay. Positive samples were sequenced and phylogenetically analysed. Results and discussion. The phylogenetic analysis showed a co-circulation of genotypes D4 and D8, and sporadic cases associated to genotypes D9 and B3. Then, molecular epidemiology of measles cases permitted to establish that D4 and D8 were the endemic genotypes in Italy during 2010.