Distinctive clinical features of human bocavirus in children younger than 2 years.
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).


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.
Moriyama
Yoko
Y
Department of Pediatrics, Tokyo Women's Medical University Yachiyo Medical Center, 477-96 Owada-shinden, Yachiyo, Chiba 276-8524, Japan.
Hamada
Hiromichi
H
Okada
Mineyuki
M
Tsuchiya
Nozomi
N
Maru
Hiromi
H
Shirato
Yuri
Y
Maeda
Yasuhiro
Y
Hirose
Yosuke
Y
Yoshida
Masaki
M
Omura
Yoh
Y
Honda
Takafumi
T
Muto
Ayako
A
Hayashi
Kitami
K
Terai
Masaru
M
D000367:Age Factors; D004417:Dyspnea / Q000821:virology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D056661:Human bocavirus / Q000302:isolation & purification*; D006801:Humans; D000860:Hypoxia / Q000821:virology*; D007223:Infant; D007297:Inpatients; D007564:Japan / Q000453:epidemiology; D008297:Male; D009503:Neutropenia / Q000821:virology*; D010100:Oxygen / Q000378:metabolism; D010322:Parvoviridae Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D011379:Prognosis; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis* / Q000453:epidemiology; D012136:Respiratory Syncytial Viruses / Q000302:isolation & purification; D012141:Respiratory Tract Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology*; D012621:Seasons; D013997:Time Factors
D010100:Oxygen
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