title: Human bocavirus in the nasopharynx of otitis-prone children.
abstract: OBJECTIVE
  Human bocavirus (HBoV) is frequently identified in children with respiratory tract infections, and its role in acute otitis media (AOM) has been suggested. The disease associations for the closely related bocaviruses HBoV2-4 remain unknown. Increasing evidence shows that probiotics may reduce the risk of AOM of viral origin. Objectives of the study was to examine the prevalence and persistence of bocaviruses in consecutive nasopharyngeal samples (NPS) of otitis-prone children, and whether an association exists between HBoV and the child's characteristics, respiratory symptoms, and AOM pathogens, and whether probiotics reduce the occurrence of HBoV.
  
  
  METHODS
  In a double-blind, placebo-controlled, randomized, 6-month intervention study, 269 otitis-prone children (aged 9 months to 5.6 years), consumed daily either one capsule of probiotics (Lactobacillus rhamnosus GG, L. rhamnosus Lc705, Bifidobacterium breve 99 and Propionibacterium freudenreichii JS) or placebo. After a clinical examination and NPS collected at three-time points, the presence and persistence of HBoV1-4 DNA in NPS was determined by RT-qPCR at the baseline, after 3, and 6 months.
  
  
  RESULTS
  A high load (>10,000 copies/ml) of HBoV DNA was detected in 26 (17.1%) of 152 children, and 16 (10.5%) showed a prolonged presence of HBoV for at least 3 months. None had DNA of HBoV2-4. Higher number of siblings associated with increased HBoV prevalence (p=0.029). Prevalence or persistence of HBoV was not significantly associated with other characteristics, respiratory symptoms, or AOM pathogens. Probiotic intervention significantly reduced the number of HBoV DNA-positive samples (probiotic vs. placebo: 6.4% vs. 19.0%, OR=0.25, CI 95%=0.07-0.94, p=0.039).
  
  
  CONCLUSIONS
  HBoV, but not HBoV2-4, DNA occurs often in the nasopharynx of otitis-prone children, and may persist for 3-6 months. Probiotic treatment possibly reduced the presence of HBoV.
authors: Institute of Biomedicine, Department of Pharmacology, University of Helsinki, PO Box 63, 00014 University of Helsinki, Finland.
authors: Liisa
authors: L
authors: Lehtoranta
authors: Maria
authors: M
authors: Söderlund-Venermo
authors: Johanna
authors: J
authors: Nokso-Koivisto
authors: Hanna
authors: H
authors: Toivola
authors: Karin
authors: K
authors: Blomgren
authors: Katja
authors: K
authors: Hatakka
authors: Tuija
authors: T
authors: Poussa
authors: Riitta
authors: R
authors: Korpela
authors: Anne
authors: A
authors: Pitkäranta
mesh_terms: D000208:Acute Disease; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D004279:DNA, Viral / Q000032:analysis / Q000187:drug effects; D004198:Disease Susceptibility / Q000453:epidemiology / Q000821:virology; D004311:Double-Blind Method; D005260:Female; D005387:Finland; D005500:Follow-Up Studies; D056661:Human bocavirus / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D009305:Nasopharynx / Q000821:virology*; D016017:Odds Ratio; D010033:Otitis Media / Q000517:prevention & control / Q000821:virology*; D010322:Parvoviridae Infections / Q000175:diagnosis / Q000188:drug therapy*; D016133:Polymerase Chain Reaction / Q000379:methods; D019936:Probiotics / Q000008:administration & dosage*; D012016:Reference Values; D012141:Respiratory Tract Infections / Q000188:drug therapy / Q000517:prevention & control / Q000821:virology; D018570:Risk Assessment; D016896:Treatment Outcome
chemical_list: D004279:DNA, Viral