To evaluate rates of rehospitalisation due to respiratory illness in preterm infants of 29–36 weeks gestation without chronic lung disease.

Retrospective single centre cohort study including infants from 1998 to 1999 with follow-up over two respiratory syncytial virus (RSV) seasons.

Of 435 infants included 61 infants (14%) experienced 78 rehospitalisations. The overall RSV attack rate was 4.4% over two consecutive RSV seasons for infants below 6 months of age at onset of RSV season (7.7 and 1.1%, respectively, p=0.015), with significant differences between infants of 29–32 and 33–36 weeks gestational age (10.5% vs. 2.3%, p=0.008). None of the infants needed mechanical ventilation or admission to the intensive care unit. Infants with RSV infection were younger of age (mean 4.2 vs. 8.2 months; p=0.015), had longer stays at the hospital (11.5 vs. 7.0 days; p=0.006), and more severe courses of disease (score 3.0 vs. 1.8; p<0.001). Additional risk factors for RSV infection were multiple gestation (OR 5.5; CI 95% 1.439–21.028) and congenital heart disease (OR 4.2; CI 95% 1.005–17.669).

The total burden of respiratory disease and RSV infection in this population was low. A lower gestational age, multiple gestation, and congenital heart disease were associated with increased risk of RSV infection.