RESUMO
OBJECTIVES: 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.
Assuntos
Bocavirus Humano/efeitos dos fármacos , Nasofaringe/virologia , Otite Média/virologia , Infecções por Parvoviridae/tratamento farmacológico , Probióticos/administração & dosagem , Doença Aguda , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Intervalos de Confiança , DNA Viral/análise , DNA Viral/efeitos dos fármacos , Suscetibilidade a Doenças/epidemiologia , Suscetibilidade a Doenças/virologia , Método Duplo-Cego , Feminino , Finlândia , Seguimentos , Bocavirus Humano/isolamento & purificação , Humanos , Lactente , Modelos Logísticos , Masculino , Razão de Chances , Otite Média/prevenção & controle , Infecções por Parvoviridae/diagnóstico , Reação em Cadeia da Polimerase/métodos , Valores de Referência , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/prevenção & controle , Infecções Respiratórias/virologia , Medição de Risco , Resultado do TratamentoRESUMO
A case of severe diarrhoea associated with synergistic human bocavirus type 1 (HBoV) and human herpes virus type 6 (HHV6) is reported. The case supports the hypotheses that HBoV infection under clinical conditions may depend on helper viruses, or that HBoV replicates by a mechanism that is atypical for parvoviruses, or that HBoV infection can be specifically treated with cidofovir.
