the combination of immunological and molecular assays is the most sensitive approach to the diagnosis of respiratory viral infections; and infections caused by the less investigated hCoVs and hMPVs represent a fair proportion of respiratory infections.

pp67 mRNA NASBA can safely replace antigenemia, with some apparent advantages (semiautomation and objectivity of test results) and disadvantages (overtreatment of patients and greater duration of overall treatment).

(i) Human metapneumovirus is a major viral pathogen in the Italian pediatric patient population; (ii) the severity of lower respiratory tract infections approaches that of human respiratory syncytial virus; (iii) there are preliminary indications that the duration of virus excretion may reach 2-3 weeks and that the level of viral load in NPA correlates with the clinical stage of human metapneumovirus infection.