Rhinovirus characteristics associated with viremia in childhood asthma.

Although rhinoviruses play a major role in exacerbations of childhood asthma, the presence of rhinovirus (RV) RNA in plasma, referred to as viremia, has been investigated in a few studies. The aim of the study was to investigate the presence of rhinovirus viremia at the time of asthma exacerbation and to describe the molecular characteristics of rhinoviruses associated with viremia. We conducted an observational, prospective, multicenter study in eight pediatric hospitals (VIRASTHMA2). Preschool-aged recurrent wheezers (1-5 years) hospitalized for a severe exacerbation were included. Reverse-transcription polymerase chain reaction (RT-PCR) and molecular typing for RV/enteroviruses (EV) were performed on nasal swabs and plasma. Plasma specimens were available for 105 children with positive RT-PCR for RV/EV in respiratory specimens. Thirty-six (34.3%) had positive viremia. In plasma, 28 (82.4%) of the typable specimens were RV-C, five (14.7%) were EV-D68, and one was RV-A (2.9%). In all cases, the RV/EV type was identical in the plasma and respiratory specimens. In conclusion, RV/EV viremia is frequent in severe exacerbations of preschool recurrent wheezers, particularly in RV-C infections.