OBJECTIVE: We sought to determine the frequency and effects of nosocomial respiratory viral infections (RVIs) in premature neonates, including those who may be asymptomatic. STUDY DESIGN: We performed a year-long surveillance for RVIs in infants <33 weeks gestational age admitted to two Syracuse neonatal intensive care units (NICUs). Infants were enrolled within 3 days of NICU admission and were sampled for RVIs until discharge using a multiplex PCR assay capable of detecting 17 different respiratory viruses or subtypes. RESULTS: 26 of 50 prematurely born infants (52%) tested positive for a respiratory virus at least once during their birth hospitalization. Testing positive for a respiratory virus was significantly associated with longer length of stay (70 days vs. 35 days, p = 0.002) and prolonged ventilatory support (51 vs. 13 days, p = 0.002). Infants who tested positive for a respiratory virus during their birth hospitalization had more than twice the rate of developing bronchopulmonary dysplasia (BPD; p < 0.05). CONCLUSION: Nosocomial RVIs were frequent in our study population, despite the absence of clinical indicators of illness. Length of hospital stay was significantly longer and a diagnosis of BPD was more common in those premature infants who had respiratory viruses detected.
Incidence and implications of unrecognized viral respiratory tract infections in premature infants during their birth hospitalization: a prospective surveillance study in two neonatal intensive care units