High prevalence of Bocavirus infection among young children in Shanghai and co-infection with other respiratory viruses
Since the first discovery of Human Bocavirus (HBoV) in 2005, the detection of HBoV was reported worldwide. The researchers in Institut Pasteur of Shanghai have examined extensively the virological and serological characteristics of human bocavirus infection to find out the correlation between human bocavirus infection and humoral response, virus persistence, and co-infection with other respiratory viruses in children with acute respiratory infection.
HBoV, a novel member in the genus parvovirus, family Parvoviridae, was first identified in children with lower respiratory tract infection by a Sweden group in 2005. Since then, HBoV has been widely detected among children with respiratory tract infection throughout the world. The virus could be detected in various samples, including nasopharyngeal aspirate, serum, feces, and urine. It was significantly higher with symptoms of respiratory tract or gastroenteritis. Meanwhile, co-infection was frequently found in HBoV-positive patients. Thus, whether HBoV is responsible for the respiratory disease is still arguable.
The present study was carried out to better characterize the clinical and virological prevalence in outpatient children and to determine genetic and serologic characteristics of HBoV in Shanghai, China. Samples from 817 children with respiratory tract infection were collected, from Nanxiang Hospital during a 2-year period, in order to examine the presence of HBoV and its co-infection.
In the study, HBoV was detected in 11.8% of these children, the prevalence of which is only third after influenza and syncytial respiratory viruses. And infants less than 2 years -old were more frequently HBoV-positive than older ones. In addition, the number of IgG-positive cases increased with the age of the children, suggesting that infection of HBoV likely occurred in high rate during childhood.
Interestingly, co-infection rate with other respiratory viruses was as high as 51%, and patients with lower copies of HBoV were more frequently associated with co-infection. Persistence of HBoV was detected in the respiratory tract and in serum and urine up to one month after infection. Co-infection was often observed in persistently HBoV-infected patients.
Altogether, our study suggests that acute infection of HBoV causes systemic infection, induces immune responses, and may play a crucial role in respiratory disease of children.
This work was supported by the Li Ka-Shing Foundation (RESPARI project), the French Agency for Development (SISEA project), Chinese Academy of Sciences VisitingProfessorship for Senior International Scientists, and the Chinese National Science and Technology Major Project (The establishment of pathogen and immuno-response detection platforms for respiratory and central nervous system viral infections).
“Correlation between bocavirus infection and humoral response, and co-infection with other respiratory viruses in children with acute respiratory infection” J Clin Virol. 2009 Dec 16