OBJECTIVETo understand the relationship between human rhinovirus (HRV) and acute respiratory infections in infants and young children in Beijing.

METHODSThroat swab/nasopharyngeal aspirates were collected from 3292 infants and young children with acute respiratory tract infections in Beijing from November 2002 to November 2006. Primers derived from the highly conserved 5'-noncoding region of human rhinovirus were used to detect HRV from clinical specimens by nested RT-PCR for which the sensitivity and specificity had been determined previously.

RESULTSOut of these 3292 specimens, 507 were (15.4%, 507/3292) HRV positive with RT-PCR method. HRV were detected from 220 out of 1315 outpatients and 287 out of 1977 inpatients with positive rates as 16.7% and 14.5% respectively. HRV was detected from 50.0% (8/16) of the patients with pharyngitis. Among 280 specimens collected from patients with acute bronchitis, 43 (15.4%) were HRV positive, including 14 from 80 patients with wheezy bronchitis (17.5%). High positive rates were also found in specimens from patients with pneumonia (12.6%, 150/1189), bronchiolitis (16.0%, 42/262) and asthma (12.8%, 10/78). In 53 patients with initial diagnosis as hematic disease or other complicate respiratory infections, 14 were HRV (26.4%, 14/53) positive. As for the seasonal distribution, HRV were detected in most of the months during thie period of research. The highest positive rate of HRV in each year fell in September (32.6%), February (24.2%) of 2004, February of 2005 (35.3%) and March (31.3%) from 2003 to 2006, respectively. Among these HRV positive patients, 44.8% were under 1 year of age (227/507), 15.4% (78/507) were 1 to 2 years old and 12.4% (63/507) were 2 to 3 years old.

CONCLUSIONHRV was associated with acute upper respiratory infections and lower respiratory infections including bronchitis, pneumonia and bronchiolitis in pediatric patients. Patients with lower immunity such as those with hematic diseases, were more susceptible to be infected by HRV. HRV could be detected in all age groups in this study, but the positive rates were decreasing with the increase of patients' age. Infants under 1 year of age seemed to be more likely to get HRV infection.