title: Determining Persistence of Bocavirus DNA in the Respiratory Tract of Children by Pyrosequencing.
abstract: BACKGROUND
  Although human bocavirus type 1 (HBoV1) is a respiratory pathogen, presence of HBoV-DNA in secretions of asymptomatic children raised the question on the significance of HBoV-positive results.
  
  
  METHODS
  Archived specimens from a prospective, longitudinal study were tested for HBoV. A total of 94 children (aged 6-36 months) were HBoV(+) during 172 upper respiratory tract infection (URI) and/or acute otitis media (AOM) episodes. We used pyrosequencing of NP1, VP1 and VP2 genes to type HBoV and subtype HBoV1 in these specimens.
  
  
  RESULTS
  Of the specimens tested, HBoV-DNA were successfully sequenced in 128 (74%) samples from 70 children; all were HBoV type 1. Subtypes identified (n = 108) were LWK/TW (63%), LWK/BJ (20%), Bonn/BJ (16%) and LWK/KU3 (1%). Of 46 children for whom shedding pattern could be determined, viral clearance within 30 days (13-29 days) occurred in 28%; another 22% of children had no recurrence after 32-267 days. Prolonged virus presence of >30 days (34-181 days+) occurred in 22%; intermittent detection (61+ to 170+ days) in 20%. Infection with the same HBoV1 subtype after 4-5 negative samples (244 and 265 days interval) occurred in 4%. Infection with 2 different HBoV1 subtypes (29 and 87 days apart) occurred in only 4%. Newly acquired HBoV1-URI resulted in AOM in 53% of cases.
  
  
  CONCLUSIONS
  Children with HBoV1 infection commonly shed for a prolonged period leading to repeated viral DNA detection. Recurrence after 8-9 months suggests possible persistence and reactivation. Infections with 2 different HBoV1 subtypes within 1-year period are uncommon. Newly acquired HBoV1-URI is often complicated by AOM.
authors.affiliation: From the *Department of Pediatrics, and †Department of Pathology, University of Texas Medical Branch, Galveston, TX.
authors.forename: Johana Castro
authors.initials: JC
authors.lastname: Wagner
authors.forename: Richard B
authors.initials: RB
authors.lastname: Pyles
authors.forename: Aaron L
authors.initials: AL
authors.lastname: Miller
authors.forename: J
authors.initials: J
authors.lastname: Nokso-Koivisto
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Loeffelholz
authors.forename: Tasnee
authors.initials: T
authors.lastname: Chonmaitree
mesh_terms: D052660:Bocavirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D002675:Child, Preschool; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification*; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D010322:Parvoviridae Infections / Q000821:virology*; D011446:Prospective Studies; D012008:Recurrence; D012137:Respiratory System / Q000821:virology*; D012141:Respiratory Tract Infections / Q000821:virology*; D017422:Sequence Analysis, DNA; D014775:Virus Activation
chemical_list: D004279:DNA, Viral