Respiratory syncytial virus and asthma: still no final answer

During the past two decades, a large number of studies have addressed the association of viral respiratory events in early life and the subsequent development of recurrent wheezing and asthma later in life.1–4 Investigations performed both in animal models and in humans have provided new insights into potential pathogenetic mechanisms discernible during acute and convalescent stages of viral events and their potential association with the long-term consequences of these events.5 6 Retrospective analysis of clinical trials has suggested that the use of anti-respiratory syncytial virus (RSV) antibodies may decrease the incidence of subsequent asthma-like symptoms,7 but prospective data are lacking. The strongest data for the association between early RSV events and asthma comes from longitudinal studies. The Tucson Children's Respiratory Study was based on a healthy and representative population, and its results, if not automatically applicable to all communities given the peculiarities of the Arizona desert, have been replicated in other population-based studies. The main findings from the Tucson study indicated that RSV, independent of other known risk factors for asthma, was significantly associated with recurrent wheeze in the first decade of life.1 The results of a larger birth cohort, also population based, the ALSPAC study from Bristol points in the same direction as the Tucson study: children with a RSV bronchiolitis admission in the first year of life were more likely to have asthma at age 7 years, compared with controls and there was no relation with RSV infection and the development of atopy at this age.8 The issue of a possible relation between early life RSV bronchiolitis and the later development of atopy has been entertained by a series of studies, and the disparities of findings seem to be …