Chronic Manifestations of Respiratory Syncytial Virus Infection in Premature Infants

BACKGROUND:Respiratory syncytial virus (RSV) infection in healthy infants born at term results in long term sequelae. Infants born prematurely are at increased risk of severe acute RSV infection; thus it would seem likely that such infants would be at increased risk of long term respiratory sequelae. METHODS:Methods of assessing the long term outcome of RSV infection are discussed and the results of retrospective and prospective studies investigating chronic respiratory morbidity after RSV infection in premature infants are reviewed. RESULTS:Documentation of all health care utilization, parental documentation of symptom status and lung function measurement provide a comprehensive and quantitative assessment of respiratory outcome. Studies that have included such outcome measures have demonstrated that RSV hospitalization in infants born between 32 and 35 weeks of gestational age and in those born more prematurely who developed chronic lung disease was associated with more hospital admissions, inpatient days, physician contacts and outpatient visits in the first 2 years after birth. Children born before 32 weeks of gestation who developed chronic lung disease also required more outpatient attendances and prescriptions and respiratory medications in years 2 through 4. Prospective data collection has demonstrated that chronic respiratory morbidity occurs in very premature infants, regardless of whether their RSV infection required hospitalization. CONCLUSION:Chronic respiratory morbidity is increased in premature infants after RSV infection. The duration of this increased morbidity and the impact of other viral infections, particularly dual infection with RSV, on long term sequelae merit investigation.