Impact of Breastfeeding on the Incidence and Severity of RSV Bronchiolitis in Infants: Systematic Review

Background: Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections (LRTI) in infants worldwide, and an important cause of morbidity, hospitalization, and mortality. Millions of infants and young children are hospitalized yearly with RSV disease and majority live in developing world. Breastfeeding has shown to reduce incidence, morbidity and mortality of RSV bronchiolitis; however, exact mechanism is still unknown. Ireland reports one of the lowest breastfeeding rates in developed world. The primary aim is to determine the impact of breastfeeding on the incidence, severity and mortality of RSV bronchiolitis in infants (0-12months). The secondary aim is to draw conclusions on using breastfeeding as a cost-effective intervention to decrease RSV bronchiolitis global burden.

Methods: Preliminary database search was conducted using agreed key words and MeSH headings. Articles were screened based on set inclusion/exclusion criteria for infants aged 0-12 months. Database search was carried out in MEDLINE, PubMed, Google Scholar, EMBASE, MedRxiv and Cochrane Reviews. Full text, abstract and conference articles published in English were included from 2000 to 2021. Covidence® software was used for evidence extraction using paired investigator agreement and PRISMA guidelines were followed. Data was extracted manually on Microsoft Excel, generating summary tables. References were compiled in EndNote X9 Software.

Results: 1368 studies were screened and 217 were eligible for full text review. 183 were excluded based on pre-agreed criteria. 34 articles were selected for data extraction: 23 studies on RSV-positive bronchiolitis and 15 on viral bronchiolitis, with some of the articles discussing both. Results showed that breastfeeding is associated with lower hospitalization of infants diagnosed with RSV bronchiolitis. Exclusive breastfeeding for >4 months significantly lowered hospitalization and supplemental oxygen use. Breastfeeding for 4 to 6 months also reduced healthcare utilization in the form of unscheduled GP visits and ED presentation. Hospitalised infants were significantly more likely to be breastfed for ≤ 2 months or not at all. Formula-fed infants face higher risks of infectious morbidity in the first year of life.

Conclusion: Breastfeeding has been shown to have a protective effect for infants with RSV bronchiolitis. WHO recommends minimum 6 months of exclusive breastfeeding for maximal immune protection against viral infections in infants. This review shows that exclusive and partial breastfeeding reduces severity of disease, length of hospital stay and supplemental oxygen requirement. Palivizumab is a monoclonal antibody that provides passive immunity against RSV bronchiolitis. However, it is expensive and mostly available in developed countries where adequate healthcare is readily available. Breastfeeding practices significantly minimizes disease severity and hospitalization. Therefore, it should be encouraged and supported as a cost-effective intervention.