The contribution of child, family and health service factors to respiratory syncytial virus (RSV) hospital admissions in the first 3 years of life: birth cohort study in Scotland, 2009 to 2015

Abstract

IntroductionSeveral vaccines for respiratory syncytial virus (RSV) are under development. Designing an effective vaccination programme for RSV requires information about the relative contribution of risk factors for severe RSV symptoms.AimTo inform preventive strategies in Europe by quantifying the contribution of key child, family and health service risk factors to the burden of RSV hospital admissions in young children.MethodsWe constructed a birth cohort study of all singleton children born in Scotland between October 2009 and September 2012 using linkage between birth registration, maternity, vaccination and hospital admission records, with follow-up until the age of 3 years. RSV-confirmed hospital admissions were defined using linkage to national laboratory surveillance data. We estimated hospital admission rates per 1,000 child years and length of stay according to each risk factor. Cox proportional hazard regression models were used to estimate adjusted hazard ratios.ResultsThere were 5,185 RSV admissions among the 169,726 children in the cohort: 48.6% of admissions occurred before the age of 6 months, and 29.6% after the age of 1 year. Children born prematurely, small for gestational age, between July and December, with chronic conditions, older siblings, mothers < 30 years old or delayed infant vaccination had a significantly increased risk of admission. Minimising the risk posed by older siblings could reduce RSV admissions by up to 34%.ConclusionFuture RSV vaccination programmes must protect children throughout early childhood. Vaccination and/or interventions to reduce transmission by older siblings could substantially reduce RSV hospital admissions.

Respiratory syncytial virus (RSV): a scourge from infancy to old age

“…18 19 Another strong risk factor is the presence of older siblings. 20 Older siblings are a greater source of spreading infection than adults as they spend significant time in nurseries and schools where RSV can spread with ease.…”

Integrating epidemiological and genetic data with different sampling intensities into a dynamic model of respiratory syncytial virus transmission

“…Though several studies have predicted a maternal vaccination would be effective [14][15][16] by extending the duration of protection by passive immunity early in life, the vaccination of older children has also been theorized as an effective alternative or complementary strategy by producing a heard immunity effect [17][18][19][20]. Elder and, particularly, school going children have been shown in previous work to be associated with increased risk of infant (sibling) infection [21][22][23][24] -though no direct infection link between the older siblings and the infant was confirmed -and have been identified as drivers of the initial epidemic phase [25]. Identifying the role of different age and social groups in RSV transmission networks may provide further evidence for optimal vaccine target groups.…”

Maternal childhood and lifetime traumatic life events and infant bronchiolitis

“…Not yet! The high point estimate of the risk ratio for three childhood TLEs compared to none (2.65, 95% confidence interval [CI] 1.45, 4.85) is similar to the excess risk of respiratory infection admissions among children with severe and chronic heart or lung conditions . There are several reasons why this high risk ratio may have been observed, and why caution is required pending further studies.…”

“…The high point estimate of the risk ratio for three childhood is similar to the excess risk of respiratory infection admissions among children with severe and chronic heart or lung conditions. 8 There are several reasons why this high risk ratio may have been observed, and why caution is required pending further studies. First, the association between maternal childhood TLEs and infant bronchiolitis was based on few infants with bronchiolitis (9/20 of dyads with childhood TLEs in all three categories).…”