Respiratory morbidity 20 years after RSV infection in infancy

Abstract

Epidemiological data suggest that respiratory syncytial virus (RSV) infection in early life is a risk factor for later asthma. There are no prospective studies on RSV infection starting from infancy progressing through childhood into adulthood. We followed up a cohort of children, hospitalized for RSV bronchiolitis or RSV pneumonia before age 24 months, until age 18-20 years. The aim of the study was to evaluate early RSV infection as a risk factor for asthma, bronchial reactivity, and lung function abnormalities in young adults. The participants filled in a questionnaire on asthma and asthma-like symptoms. The clinical study included flow-volume spirometry (FVS), methacholine inhalation challenge (MIC), home PEF (peak expiratory flow) monitoring, and skin prick tests (SPT) to common allergens. Asthma was present in 17-22% of 36 index subjects, depending on asthma definition, compared to 11% of 45 controls. Furthermore, FEV% and MEF25 were lower, and MEF50 tended to be lower, in index than in control subjects. One or more abnormal lung function results were found in 16 (44%) index subjects, but only in 5 (11%) controls (P < 0.01). Bronchial reactivity (PD20 <4,900 microg methacholine) was demonstrated in 16 (46%) index subjects and 14 (32%) controls (NS). At least one positive SPT result was present in 21 (60%) index subjects; 6 (29%) had asthma (NS vs. nonatopic index subjects); 13 (62%) had abnormal lung function (P < 0.05); and 14 (67%) had bronchial reactivity (P < 0.01). In the logistic regression adjusted for atopy, as defined by SPT positivity, RSV infection in infancy was an independent risk factor for lung function abnormality (one or more abnormal results in FVS; OR, 5.27; 95% CI, 1.60-17.36), and also for decreased FEV% and MEF50 when these were analyzed separately. However, RSV infection in infancy was not a significant risk factor for asthma or bronchial reactivity. In young adults, lung function abnormalities may be associated with RSV infection which required hospitalization in infancy.

Decreased lung function precedes severe respiratory syncytial virus infection and post-respiratory syncytial virus wheeze in term infants

“…Although the underlying mechanisms whereby reduced Crs leads to RSV hospitalisation are unknown, it is possible that reduced Crs reflects differences in lung characteristics leading to both a severe RSV infection and childhood asthma. Several prospective studies have described the association between RSV bronchiolitis and the development of post-bronchiolitis wheeze [28][29][30]. Our data suggest that besides the severity of the RSV infection, premorbid increased Rrs and decreased Crs also are independent determinants of post-RSV wheeze.…”

A systematic review of early life factors which adversely affect subsequent lung function

“…They comprised 6 birth cohorts [17][18][19][20][21][22] and 19 population-based longitudinal studies. [12,13,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] Tables 1 and 2 give an overview of the included studies. The reasons for rejecting the remaining 30 papers [9,10, are summarised in Table 3.…”

The impact of respiratory viruses on lung health after preterm birth

“…Early-life exposure to such pathogens is likely to have lifelong respiratory consequences. Indeed, even in healthy term-born infants, hospitalisation with acute respiratory viruses in early life is associated with increased rates of childhood asthma, wheezing disorders and suboptimal lung function [29–31]. While preterm infants are often labelled as asthmatic, the underlying mechanisms of prematurity associated wheeze are likely to be different [32] although the long-term implications of exposure to acute respiratory viruses during early life remains to be elucidated in the preterm population.…”

“…Early-life exposure to severe RSV infection has also been identified as a main contributor in the development of suboptimal lung health and function later in life, with several studies reporting increased risks of late-onset or persistent wheezing phenotypes, asthma diagnosis, and impaired lung function in adolescents and young adults [29–31]. Even though the majority of the data on the long-lasting impact of RSV have been based on studies of healthy term-born infants, limited studies have demonstrated increased risk of asthma [68], recurrent wheeze [34,69,70] and lung function impairments [66] in preterm children with a history of RSV-related hospitalisation during infancy.…”