title: High human bocavirus viral load is associated with disease severity in children under five years of age.
abstract: Human bocavirus (HBoV) is a parvovirus and detected worldwide in lower respiratory tract infections (LRTIs), but its pathogenic role in respiratory illness is still debatable due to high incidence of co-infection with other respiratory viruses. To determine the prevalence of HBoV infection in patients with LRTI in Shanghai and its correlation with disease severity, we performed a 3-year prospective study of HBoV in healthy controls, outpatients and inpatients under five years of age with X-ray diagnosed LRTIs. Nasopharyngeal aspirates were tested by PCR for common respiratory viruses and by real time PCR for HBoV subtypes 1-4. Nasopharyngeal swabs from healthy controls and serum samples and stools from inpatients were also tested for HBoV1-4 by real time PCR. Viral loads were determined by quantitative real time PCR in all HBoV positive samples. HBoV1 was detected in 7.0% of inpatients, with annual rates of 5.1%, 8.0% and 4.8% in 2010, 2011 and 2012, respectively. Respiratory syncytial virus (RSV) subtype A was the most frequent co-infection detected; HBoV1 and RSVA appeared to co-circulate with similar seasonal variations. High HBoV viral loads (>10(6) copies/ml) were significantly more frequent in inpatients and outpatients than in healthy controls. There was a direct correlation of high viral load with increasing disease severity in patients co-infected with HBoV1 and at least one other respiratory virus. In summary, our data suggest that HBoV1 can cause LRTIs, but symptomatic HBoV infection is only observed in the context of high viral load.
authors: Microbiology Laboratory, Shanghai Municipal Center for Disease Control and Prevention, Shanghai, People's Republic of China.
authors: Baihui
authors: B
authors: Zhao
authors: Xuelian
authors: X
authors: Yu
authors: Chuanxian
authors: C
authors: Wang
authors: Zheng
authors: Z
authors: Teng
authors: Chun
authors: C
authors: Wang
authors: Jiaren
authors: J
authors: Shen
authors: Ye
authors: Y
authors: Gao
authors: Zhaokui
authors: Z
authors: Zhu
authors: Jiayu
authors: J
authors: Wang
authors: Zhengan
authors: Z
authors: Yuan
authors: Fan
authors: F
authors: Wu
authors: Xi
authors: X
authors: Zhang
authors: Reena
authors: R
authors: Ghildyal
mesh_terms: D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D060085:Coinfection / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000821:virology; D005260:Female; D056661:Human bocavirus / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D006801:Humans; D007223:Infant; D008297:Male; D010322:Parvoviridae Infections / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology* / Q000821:virology; D010802:Phylogeny; D012141:Respiratory Tract Infections / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology / Q000821:virology; D012720:Severity of Illness Index; D019562:Viral Load
references: J Infect Dis. 1997 Apr;175(4):814-20
references: 9086135
references: J Clin Microbiol. 2010 Nov;48(11):4044-50
references: 20844210
references: J Clin Virol. 2011 Nov;52(3):251-3
references: 21907613
references: Rev Med Virol. 2012 Jan;22(1):46-64
references: 22038931
references: Clin Infect Dis. 2007 Apr 1;44(7):904-10
references: 17342639
references: World J Pediatr. 2010 Feb;6(1):65-70
references: 20143214
references: J Clin Virol. 2010 Feb;47(2):148-55
references: 20022295
references: Emerg Infect Dis. 2011 Dec;17(12):2303-5
references: 22172367
references: Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi. 2011 Aug;25(4):271-3
references: 22097604
references: Eur J Clin Microbiol Infect Dis. 2011 Jun;30(6):799-805
references: 21286929
references: Eur J Pediatr. 2010 Sep;169(9):1087-92
references: 20383526
references: Pediatr Pulmonol. 2010 Jun;45(6):585-91
references: 20503284
references: Korean J Lab Med. 2011 Jul;31(3):179-84
references: 21779192
references: Proc Natl Acad Sci U S A. 2005 Sep 6;102(36):12891-6
references: 16118271
references: Singapore Med J. 2011 May;52(5):365-9
references: 21633772
references: Pediatr Infect Dis J. 2010 Jun;29(6):557-8
references: 20508481
references: Res Vet Sci. 1985 Mar;38(2):209-19
references: 2988093
references: Pediatr Pulmonol. 2010 Feb;45(2):120-6
references: 19960524
references: PLoS One. 2011;6(6):e21083
references: 21701591
references: Clin Microbiol Infect. 2012 Apr;18(4):E74-6
references: 22309610
references: PLoS One. 2011;6(6):e21362
references: 21738642
references: J Virol. 2009 Aug;83(15):7739-48
references: 19474096
references: J Infect Dis. 2010 Jun 1;201(11):1625-32
references: 20415535
references: J Clin Virol. 2010 Nov;49(3):158-62
references: 20833582
references: J Med Virol. 2012 Jun;84(6):901-5
references: 22499013