Respiratory syncytial virus infection in children hospitalised with acute lower respiratory tract infection.

BACKGROUND

Data are lacking on respiratory syncytial virus. (RSV) respiratory tract infections in children from developing countries.

OBJECTIVE

To determine the importance of RSV as a cause of acute lower respiratory tract infection (ALRTI) in Cape Town children.

METHODS

Children younger than 2 years of age admitted to hospital with ALRTI over a 15-month period from 1 June 1995 to 31 August 1996 were studied prospectively. Sociodemographic data, risk factors for severe RSV disease, clinical signs, diagnosis and hospital course were documented. A nasopharyngeal aspirate (NPA) for detection of RSV by enzyme immunoassay (EIA) was obtained in all cases. The NPA of every fifth child was sent for viral culture.

RESULTS

A total of 1,288 patients (60% male, 40% female) with a median age (25th-75th percentile) of 6 months (2-11 months) was enrolled; 32.4 had one or more risk factors for severe RSV infection. Pneumonia was diagnosed in 62.2%, bronchiolitis in 20.6%, laryngotracheobronchitis (LTB) in 8% and other respiratory illnesses in 9.2%. Mild disease, requiring admission to an overnight ward, was documented in 38.1%, while 48.9% and 13% respectively had moderate and severe disease requiring admission to a general ward and intensive care unit (ICU). Supplemental oxygen and mechanical ventilation were required by 68.9% and 8.5% of patients, respectively. The median duration of hospital stay was 5 days (range 1-10 days). RSV EIA was positive in 16.4% of cases, and there was no difference in detection rates according to diagnosis. Viral culture performed in 162 of the 1,288 study patients (12.6%) grew RSV in 11.7% of cases, adenovirus in 3.7%, para-influenza virus type 3 in 2.5% and influenza B virus in 0.6%. Patients who tested RSV EIA-positive did not significantly differ from those who tested negative with regard to demographic variables, clinical diagnoses, risk factors for RSV or length of hospitalisation. The only significant difference noted was the presence of hyperinflation, which occurred in 70.1% of EIA-positive patients compared with 57.1% of those testing negative (P = 0.0005). The mortality rate (2%) was similar for both groups.

CONCLUSION

This study indicates that RSV is an important cause of hospitalisation in infants and young children with ALRTI. Distinguishing RSV from other ALRTIs is difficult because of similarity in clinical presentation among children.