ABSTRACT
To investigate systemic cytokine responses in human bocavirus (HBoV)-associated lower respiratory tract infection, serum cytokine profiles were analyzed in HBoV positive-children (n=14) using multiplex immunoassay. Concentrations of TNF-a, IL-2, IL-5 and IL-8 on admission were significantly different from those of respiratory syncytial virus-positive children (n=28). This unique cytokine response might partly explain some characteristic clinical features of HBoV-associated respiratory infection.
Subject(s)
Cytokines/blood , Human bocavirus/isolation & purification , Parvoviridae Infections/blood , Respiratory Tract Infections/blood , Child, Preschool , Cytokines/immunology , Female , Human bocavirus/genetics , Humans , Infant , Male , Parvoviridae Infections/immunology , Parvoviridae Infections/virology , Respiratory Tract Infections/immunology , Respiratory Tract Infections/virologyABSTRACT
BACKGROUND AND OBJECTIVE: Clinical characteristics of human bocavirus (HBoV) infection have been studied worldwide, but their importance of those characteristics remains unknown. We investigated distinctive clinical features of HBoV-positive children with lower respiratory tract infection (LRTI). METHODS AND RESULTS: During April 2007-July 2009, for 402 hospitalized children younger than 2 years with LRTI, we prospectively examined virus genomes in nasopharyngeal swabs for HBoV, respiratory syncytial virus (RSV), rhinovirus, metapneumovirus, parainfluenzavirus, and adenovirus. The HBoV genomes were identified in 34 patients (8.5%). Clinical and laboratory data of HBoV-positive and other virus/bacteria-negative patients (n = 18) were analyzed and compared with data of RSV-single positive patients (n = 99). The seasonal distribution of HBoV exhibits a concentration of cases during March-September, with most RSV cases occurring during winter in Japan. The minimum age of HBoV-positive patients was 5 months, although 44 patients (44%) with RSV were younger than 6 months. The main clinical features were respiratory distress and hypoxia. Hypoxia advances within 3 days after onset. The mean oxygen saturation on arrival was 92.8%, which was significantly lower than that in patients with RSV (p < 0.001). White blood cell counts were similar among groups. However, the percentage of neutrophils in white blood cells were significantly higher in HBoV-positive patients (62 vs. 45%, p < 0.001). Their prognoses were good. Their hospital stays were 6.6 days. CONCLUSIONS: HBoV-single positive patients show several clinical characteristics, such as seasonality, age, hypoxia, and neutrophilia, which differ from those with RSV infection.
