LAUSR

BACKGROUND The seasonality of Respiratory Syncytial Virus (RSV) epidemics have been disrupted during the Covid-19 pandemic, possibly because of lockdowns and social restrictions reducing viral transmission. Given uncertainties around the severity of upcoming RSV bronchiolitis epidemics, debate exists whether Palivizumab (RSV prophylaxis) should be administered to infants with Congenital Diaphragmatic Hernia (CDH), who may be vulnerable due to lung hypoplasia and pulmonary hypertension. AIM To evaluate (1) if CDH infants have higher risk of admission with RSV bronchiolitis than infants in the general population; (2) if Palivizumab prophylaxis may reduce this risk. METHODS We included all eligible studies examining the risk(s) of RSV-positive bronchiolitis requiring hospital admission in (1) CDH infants without Palivizumab prophylaxis vs infants in the general population and (2) CDH infants with prophylaxis vs CDH infants without prophylaxis. The primary outcome evaluated was the risk of admission with RSV bronchiolitis. Data are reported descriptively and meta-analysed when appropriate. RESULTS Three eligible retrospective cohort studies were identified: One study found CDH to be an independent risk factor for RSV hospitalisation (Odds ratio 3.30, 95% confidence interval 2.01-4.4); two studies compared RSV hospitalisation rates in CDH patients who had Palivizumab vs those that did not. The pooled Risk Ratio was 1.11 (95% CI 0.29-4.23, p=0.88). Overall, the quality of evidence was considered poor and one study was industry funded. CONCLUSION Whether CDH infants are at particular risk of severe bronchiolitis remains unclear. There is no evidence from this current systematic review that CDH infants should routinely receive Palivizumab vaccination prophylaxis. This article is protected by copyright. All rights reserved.