This study was planned to investigate the prevalence and clinical features of the illnesses associated with human bocavirus (hBoV) in children with acute disease. We prospectively enrolled all subjects aged less than 15 years attending an emergency room in Milan, Italy, on Wednesdays and Sundays between 1 November 2004 and 31 March 2005 for any acute medical reason, excluding surgical diseases and trauma. Nasopharyngeal swabs were collected at admission to detect hBoV; influenza A and B viruses; respiratory syncytial virus; human metapneumovirus; parainfluenza viruses 1, 2, 3, and 4; rhinovirus; adenovirus; and coronaviruses 229E, OC43, NL63, and HKU1 by real-time PCR. Among the 1,332 enrolled children, hBoV was the fifth most frequently detected virus (7.4%). The rate of hBoV coinfections with other viruses was significantly higher than for the other viruses (50.5% versus 27.5%; P < 0.0001). Eighty-nine of the 99 hBoV-positive children (89.9%) had a respiratory tract infection, and 10 (10.1%) had gastroenteritis. hBoV coinfections had a significantly greater clinical and socioeconomic impact on the infected children and their households than hBoV infection alone. In conclusion, these findings show that the role of hBoV infection alone seems marginal in children attending an emergency room for acute disease; its clinical and socioeconomic importance becomes relevant only when it is associated with other viruses.Two years ago, a previously unknown human parvovirus called human bocavirus (hBoV) was identified in Swedish children suffering from respiratory tract infection (RTI) (2), and subsequent studies carried out in different geographic areas have shown that it circulates widely and can be found in a significant percentage of subjects with upper or lower respiratory tract disease, mainly young children (1, 4-7, 10, 11, 16, 17, 19-22, 24, 25, 28, 30, 32, 33, 39). Healthy carriers of this virus have not been identified. Thus, this strongly supports the hypothesis that hBoV may really be the cause of the diagnosed disease when it is detected in respiratory secretions (3,26).Epidemiological studies seem to indicate that, in young children, hBoV is less important than respiratory syncytial virus (RSV) but at least as important as influenza viruses, human metapneumovirus (hMPV), adenovirus, and parainfluenza virus type 3 (1,4,11,16,19,25). However, the full spectrum of the diseases associated with hBoV, the prevalence of complications, the frequency of the spread of hBoV in households and close contacts, and hBoV's social consequences are not known. Moreover, the role of coinfections with hBoV and other respiratory viruses remains to be clarified. This information is essential for establishing the real impact of hBoV infections in pediatrics and deciding whether specific preventive or therapeutic measures need to be developed.The aim of this study was to investigate the prevalence and clinical features of the illnesses associated with hBoV infections in children attending an emergency room.
MATERIALS AND METHODS
Stu...