Background The incidence of respiratory syncytial virus (RSV)-related hospitalisation is 4 to 6 times higher in infants with CLD compared to the general population. Professional organisations recommend PIP for all infants with CLD. Currently, there are no published data on incidence of RSV infection in infants with milder CLD. Hence, there is minimal evidence of the beneficial effects of PIP in this group.

Aims To identify the incidence of RSV-related hospitalisation in infants with CLD (mild, moderate and severe) and the benefit from PIP in these infants.

Methods A prospective, observational study, involving 12 hospitals in the Northwest region of England. All infants who received oxygen therapy at day 28 of life were diagnosed as having CLD and were eligible for the study. The infants were further categorised into mild, moderate and severe CLD based on oxygen requirement at 36 weeks corrected gestational age. All infants were prospectively followed-up during the RSV season, following discharge from the NICU. Infants received PIP according to local guidelines and practices. Details of RSV-related hospitalisation of all study participants were collected.

Results 229 infants were enrolled in the study; 85 (37%) mild, 80 (35%) moderate and 64 (28%) had severe CLD. 73 (32%) babies were on oxygen therapy when discharged from the neonatal unit. Of all study participants, 113 (45.4%) received PIP and 16 (7%) were hospitalised due to RSV bronchiolitis. Details of PIP in each category of CLD and their RSV-related hospitalisation were as follows (table 1).

Conclusions Infants with milder CLD have a lower risk of RSV-related hospitalisation compared with moderate and severe CLD. PIP is an expensive intervention; it may be better to target infants who have moderate and severe CLD as well as the infants on oxygen therapy when discharged home.