Material and Method: Children younger than 5 years old who were admitted to King Chulalongkorn Memorial Hospital between February 1, 2006 and September 30, 2008 due to LRI were recruited. Their nasopharyngeal aspirates were evaluated for respiratory virus by polymerase chain reaction (PCR) assays. Those who had positive PCR for HBoV and had no underlying diseases were studied. Their clinical presentations were evaluated and their clinical data about recurrent wheezing as well as pulmonary function tests were followed-up for 1 year.

Results: Fifteen patients with HBoV-LRI were regularly followed-up. Seven patients (47%) had co-infection with other respiratory viruses. Generalized wheezing was the most common lung sign detected in 73% of cases (11 cases) and 36% (4 cases) of them responded well to bronchodilators. During one year follow-up, serial pulmonary function tests were normal in all cases and most patients were doing well. However, 27% of HBoV infected patients (4 cases) developed recurrent wheezing associated with respiratory tract infections. Two of them had to be re-hospitalized. Compared to patients without recurrent wheezing, eosinophil count tended to be higher in those with recurrent wheezing and isolated HBoV infected patients tended to develop recurrent wheezing more than those with co-infection

Conclusion: Acute wheezing is a common presenting lung sign in HBoV-LRI. Although the pulmonary function tests of all patients were normal, more than a quarter of patients suffered from recurrent wheezing during one-year follow-up.

Keywords: Human bocavirus, Recurrent wheezing, Children, LRI