Incidence of Respiratory Syncytial Virus-Associated Lower Respiratory Tract Infection Until 6 months of Corrected Age in Preterm Infants with Bronchopulmonary Dysplasia: A Pilot Prospective Cohort Study.

OBJECTIVES

To determine the incidence of respiratory syncytial virus (RSV)-associated lower respiratory tract infections (LRTIs) in preterm infants with bronchopulmonary dysplasia (BPD).

METHODS

Preterm infants < 32 wk' gestation and requiring oxygen till day 28 of life were prospectively followed up till 6 mo of corrected age. Nasopharyngeal swab sample was collected in infants with suspected LRTI within 48 h and processed by multiplex polymerase chain reaction (PCR) for RSV and other viral pathogens. For each episode of LRTI the need for hospitalization and duration of hospital stay, oxygen supplementation, mechanical ventilation, and deaths were recorded.

RESULTS

Of 44 enrolled infants, 21 developed at least one LRTI episode (total 22 episodes) during follow-up. A nasopharyngeal swab for RSV PCR was sent for 16 episodes, of which nine were positive. Incidence of RSV infection until 6 mo of corrected age was 56% (95% CI 35-87) among infants with LRTI in whom PCR testing was done. Incidence rate among all infants with BPD was 1.13 per 1000 person-days (95% CI 0.58-2.17). Eight RSV-LRTI episodes occurred after discharge: five (62%) required re-hospitalization and two (25%) required ICU admission, with a median duration of hospital stay of 12 d (10-37 d) and a median oxygen requirement of 10 d (2-33 d). No infant died during an active RSV-LRTI episode.

CONCLUSIONS

Nearly half of the LRTI episodes among preterm infants with BPD are caused by RSV, with high rates of hospitalizations and ICU admissions. RSV prophylaxis using monoclonal antibodies is a high priority in these infants.