Viruses causing lower respiratory symptoms in young children: findings from the ORChID birth cohort

Sarna, Mohinder; Lambert, Stephen B; Sloots, Theo P; Whiley, David M; Alsaleh, Asma; Mhango, Lebogang; Bialasiewicz, Seweryn; Wang, David; Nissen, Michael D; Grimwood, Keith; Ware, Robert S

Viral acute respiratory infections (ARIs) are a common cause of morbidity in children, either on their own or in synergy with bacterial pathogens. 1 Virus-positive ARIs early in life are associated with developing wheeze and asthma during childhood and adolescence. 2 Community-based studies from the 1950s to 1960s examining the aetiology of ARIs by traditional laboratory detection methods remain the template for understanding childhood respiratory virus epidemiology. 3 Advances in molecular diagnostics, including PCR testing, have improved virus detection in those with ARIs. 4 However, this increased test sensitivity has also resulted in viruses being detected in asymptomatic individuals. 4 5 The clinical significance of finding respiratory viruses is not always straightforward, and a better understanding of the proportion of infections that are symptomatic for individual viruses is needed.