OBJECTIVETo analyze the correlations between clinical features in paediatric patients with acute respiratory tract infection (ARTI) and viral load of human bocavirus.

METHODSA prospective study was conducted on 956 children < 5 years admitted with an acute respiratory tract infection from November 2009 to December 2010, and 251 healthy children conclused as control group in the corresponding period. Human bocavirus was investigated in nasopharyngeal aspirates (NPA) and throat swab by PCR, and viral load was detected by real-time polymerase chain reaction (RT-PCR) in HBoV positive sample. Clinical data were also prospectively recorded.

RESULTSA significant difference was found in HBoV positive rate between children with ARTI and control group at enrollment. There was a significant difference in HBoV viral load between children with upper respiratory tract infection and lower respiratory tract infection. HBoV viral load did not differ significantly between children with upper respiratory tract infection and control group. Among children with lower respiratory tract infection, no significant difference were detected between common and severe cases in HBoV viral load. HBoV viral load did not differ significantly whether the children were with or without co-infection.

CONCLUSIONSHBoV could be detected perennial and considered as a major pathogen associated with acute respiratory tract infection in children. However, HBoV may not be a independent factor in children with ARTI and the HBoV viral load was not associated with the severity of respiratory illness.