Human Bocavirus in Nasopharyngeal Secretion of Hospitalized Children with Acute Respiratory Tract Infection – First Year Results of a Four-Year Prospective Study

Sa？etak Background. Human bocavirus (HBoV) is a recently discovered parvovirus that may cause respiratory disease. The aim of this study was to determine HBoV prevalence among hospitalized children with acute respiratory tract infection (ARI) in two Croatian hospitals, Children’s Hospital Zagreb and General Hospital Karlovac, and to compare it with prevalence of other respiratory viruses. Methods. From May 2017 to April 2018 nasopharyngeal and pharyngeal swabs from a total of 275 children with ARI of suspected viral etiology were obtained and tested by multiplex- PCR for the presence of 15 respiratory viruses, including HBoV. Results. Viral etiology was proved in 221/275 (80.4%) of the patients. HBoV was detected in 17 (6.2 %) samples. Two thirds of HBoV positive patients were between one and three years of age. HBoV was detected in older children when compared to the children infected with respiratory syncytial virus (P < 0.001), but younger when compared to those infected with influenza (P = 0.009). Seventy six percent of HBoV positive patients had upper and 24% lower respiratory tract infection. HBoV was more often detected in multiple virus infections compared to the other respiratory viruses (P < 0.001). HBoV is detected throughout the year except for the summer months. Conclusion. Human bocavirus, although often detected in combination with other respiratory viruses, is one of the possible causes of ARI in children. Continuous laboratory detection of HBoV in the respiratory secretion of children with ARI is required in order to complete our findings on clinical significance and epidemiology of this infection