The molecular epidemiology of influenza viruses: a lesson from a highly epidemic season.

To analyse the epidemiological and molecular features of a long-lasting epidemic (12 weeks) of influenza in north-eastern Italy during the 2004\u201305 season. Morbidity rates were analysed by time and age. Influenza virus isolates (93 strains) were submitted to antigenic evaluation by haemagglutination inhibition test and to molecular assessment by sequencing. The incidence peak (16.4 per thousand) was the highest recorded over the last six years in north-eastern Italy. The epidemic was sustained by two subsequent waves of circulating viruses: an H3N2 variant and two type B variants, respectively. In addition, scattered isolation of an H1N1 variant occurred. Antigenic and molecular characterisation showed the emergence of an H3N2 virus drifted with respect to vaccine strain, which also had a substantial impact on morbidity in vaccinated subjects. Moreover, a single K145N substitution in the HA1 site of H3N2 was the starting point of two evolutionary branches

HHV-6, new perspectives [HHV-6: nuovi ruoli per un patogeno antico]

HHV-6 is the etiological agent of Exanthema subitum, and its role in human infection is well known. Recently, molecular diagnostics tools showed for HHV-6 new pathogenetic features and new clinical implication. The present paper highlights recent knowledge on HHV-6 infection and presents a number of results concerning HHV-6 infection in children who had undergone BMT and concerning the roles of endothelial cells as viral reservoir

Prevalence of tick-borne encephalitis virus in Ixodes ricinus from a novel endemic area of North Eastern Italy.

In Alpine area of extreme North Eastern Italy the first autochthonous case of TBE was reported in 1998 and was followed by 45 cases during the period 2001\u20132007, thus defining this area as definitely endemic. An ecological survey evaluated the tick density and the Tick-borne encephalitis virus (TBEV) infection prevalence in tick collected in selected sites. In addition, TBE strains were characterized by sequencing and phylogenetic analysis. Overall, 2,361 ticks (2,198 nymphs and 163 adults) of the Ixodes ricinus L. species collected during 2005 and 2006 were examined. Five samples were positive for TBEV, corresponding to an overall prevalence rate of 0.21%. When analyzed by place, TBEV was discovered in three sites where the highest tick density was found. Phylogenetic analysis showed that four sequences clustered with the Neudoerfl prototype, while the other clustered with the Isosaari 17 strain and with a number of Slovenian isolates