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

Background. Data are lacking on respiratory syncytial virus (RSV) respirato ry tract infections in children from developing countries. Objective. To determine the importance of RSV as a cause of acute lower res piratory tract infection (ALRTI) in Cape Town children. Methods. Children younger than 2 years of age admitted to hospital with ALR TI over a 15-month period from 1 June 1995 to 31 August 1996 were studied p rospectively. Sociodemographic data, risk factors for severe RSV disease, c linical signs, diagnosis and hospital course were documented. A nasopharyng eal aspirate (NPA) for detection of RSV by enzyme immunoassay (EIA) was obt ained 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 ha d one or more risk factors for severe RSV infection. Pneumonia was diagnose d in 62.2%, bronchiolitis in 20.6%, laryngotracheobronchitis (LTB) in 870 a nd other respiratory illnesses in 9.2%. Mild disease, requiring admission t o an overnight ward, was documented in 38.1%, while 48.9% and 13% respectiv ely had moderate and severe disease requiring admission to a general ward a nd intensive care unit (ICU). Supplemental oxygen and mechanical ventilatio n were required by 68.9% and 8.5% of patients, respectively The median dura tion 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 r egard to demographic variables, clinical diagnoses, risk factors for RSV or length of hospitalisation. The only significant difference noted was the p resence 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 (270) was similar for both groups. Conclusions. This study indicates that RSV is an important cause of hospita lisation in infants and young children with ALRTI. Distinguishing RSV from other ALRTIs is difficult because of similarity in clinical presentation am ong children.