engleski

Molecular epidemiology and genetic variability of human respiratory syncytial virus (HRSV) in Croatia, 2011-2014

Human respiratory syncytial virus (HRSV) is a paramyxovirus that causes common respiratory tract infections in infants, young children and among the elderly. The disease manifestation ranges from mild nonspecific respiratory symptoms to severe illness, such as bronchiolitis or pneumonia. By the age of 2, virtually all children have been infected at least once with HRSV. Reinfections are very common, even within the same epidemic season, due to limited immune protection from earlier exposures. HRSV strains are classified into two antigenic groups, A and B, representing separate genetic lineages. The molecular epidemiology of HRSV is rather complex as numerous genotypes exist, new genotypes emerge and some previously circulating genotypes appear to became extinct. To date, 15 HRSV A and 23 HRSV B genotypes have been established. Genotyping is based on sequences of the second hypervariable region (HVR2) of glycoprotein gene, located at the protein's C-terminus. Although this region accounts for only approx. 2% of the whole HRSV genome, it has been identified as the most reliable to describe the evolutionary changes of HRSV. Molecular characterization of HRSV detected in clinical samples of severely ill patients hospitalized in Croatia in 2011-2014, revealed strong predominance of HRSV A strains (genotypes NA1 and ON1). Among group B strains, we detected strains belonging to genotypes BA9 and BA10. Especially broad genetic diversity was detected among concurrently circulating NA1 strains, indicating high genetic plasticity of this globally dominant genotype.

human respiratory syncytial virus; molecular epidemiology; clinical samples; NA1; ON1; BA9; BA10

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