Description of a human Bocavirus recombinant strain in the Americas

Human bocaviruses (HBoV) are mainly associated with respiratory and gastroenteric infections. These viruses belong to the family Parvoviridae, genus Bocaparvovirus and are classified in four subtypes (HBoV1-4). Recombination and point mutation have been described as basis of parvovirus evolution. In this study three viral sequences were obtained from positives HBoV sewage samples collected in two Uruguayan cities and were characterised by different methods as recombinant strains. This recombination event was localised in the 5' end of VP1 gene and the parental strains belonged to subtypes 3 and 4. These three Uruguayan strains are identical at the nucleotide sequences in the analysed genome region of the virus. As far as we known, this study represents the first detection of HBoV recombinants strains in the Americas.

Identification of Human Bocavirus type 4 in a child asymptomatic for respiratory tract infection and acute gastroenteritis - Goiânia, Goiás, Brazil

Abstract Human Bocavirus (HBoV) has been identified from feces and respiratory samples from cases of both acute gastroenteritis and respiratory illness as well as in asymptomatic individuals. The aim of this study was to detect and characterize HBoV from fecal samples collected from hospitalized children aged less than five years old with no symptoms of respiratory tract infection (RTI) or acute gastroenteritis (AGE). The study involved 119 children and one fecal sample was collected from each participant between 2014 and 2015. HBoV was detected using Nested-PCR, and the viral type identified by genomic sequencing. HBoV-4 was identified from one sample obtained from a hospitalized child with soft tissue tumor of the submandibular region. This is the first report of HBoV-4 identification in Brazil, but we consider that this type may be circulating in the country similar to the other types and new investigations are necessary.

Bocavirus en niños menores de 5 años con infección respiratoria aguda: Provincia del Chaco, 2014 / Bocavirus in infants under 5 years with acute respiratory infection. Chaco Province, Argentina, 2014

La infección respiratoria aguda (IRA) es la patología más frecuente a lo largo de la vida de una persona y es la causa más común de morbi-motalidad en menores de 5 años. El objetivo de este trabajo fue determinar la frecuencia de bocavirus (BoV) en pacientes menores de 5 años con diagnóstico presuntivo de IRA en una ciudad capital del norte argentino (Resistencia, Chaco). Se analizaron aspirados nasofaríngeos correspondientes a 488 niños durante el año 2014. Los mismos fueron testeados por PCR en tiempo real hallándose BoV en 36 casos (7.4%), de los cuales 26 (72.2%) fueron infantes de 6-18 meses de vida. La mayor concentración de positivos se registró en el período junio-septiembre con un total de 28 pacientes (77.8%). Los casos positivos para BoV se observaron como infección única en el 50% de los mismos y el resto como infecciones concomitantes con otros microorganismos. No conocemos que haya otro estudio de epidemiología molecular de BoV en el norte argentino y destacamos la importancia de investigar los nuevos virus capaces de generar infección respiratoria aguda, y difundir el conocimiento de su circulación en la comunidad.

Acute respiratory infection (ARI) is the most frequent pathology along human life, being the most common cause of morbidity and mortality in children under 5 years. The aim of this study was to determine the frequency of bocavirus (BoV) in infants under 5 years with symptoms of ARI from north Argentina (Chaco province). The study was performed on nasopharyngeal aspirates from 488 patients, in the period of January-December 2014. The samples were tested by real time PCR and 36 positive BoV cases (7.4%) were detected. The period with the highest detection rate was June-September with 28 cases (77.8%), of which 26 (72.2%) were infants between 6-18 moths of life. In half of BoV positive cases this virus was detected as single infection of the upper respiratory tract, and in the remaining 50%, as concomitant infection with other microorganisms. To our knowledge, this would be the first study on molecular epidemiology of BoV in northern Argentina. We emphasize the importance of investigating these new viruses capable of generating acute respiratory disease and also to disseminate awareness on their circulation within the community.

Detección de bocavirus humano en la población infantil de Tucumán y Santa Fe, Argentina / Detection of human bocavirus in children from Tucuman and Santa Fe, Argentina

Background: A large proportion of acute respiratory tract infections (ARTI) remain without etiologic diagnosis, reason why new pathogens are investigated continuously. Human bocavirus (HBoV) was discovered in 2005, as a new member of Parvoviridae family and proposed to cause ARTI. Aim: To know the prevalence of HBoV among pediatric populations hospitalized for ARTI in two provinces of Argentina: Santa Fe and Tucuman; and to describe epidemiological and clinical aspects associated to its detection. Materials and Methods: We studied nasopharyn-geal aspirates of patients younger than 5 years old that were hospitalized during 2013 due ARTI. HBoV DNA was assayed using PCR described by Allander et al. Traditional virnses were studied by immunofluorescence. Personal, clinical and epidemiological data were collected in a standardized form. Results: The HBoV was detected in 7% of the samples and was prevalent in spring and summer and in children younger of 2 years old. Other respiratory viruses were detected in 22% of HBoV positive samples. Discussion: We detected HBoV in these two provinces of Argentina. Further studies should be performed to determine if it’s a recent infection or prolonged viral shedding.

Introducción: Un alto porcentaje de las infecciones respiratorias agudas (IRA) permanece sin diagnostico etiológico, por lo cual se investigan nuevos patógenos continuamente. Bocavirus humano (HBoV) fue descubierto en 2005, como un nuevo miembro de la familia Parvoviridae y propuesto como causante de IRA. Objetivos: Investigar la prevalencia de HBoV en niños bajo 5 años de edad, hospitalizados por IRA en dos provincias de Argentina: Santa Fe y Tucumán y describir aspectos epidemiológicos y clínicos asociados a su detección. Materiales y Métodos: Se estudiaron retrospectivamente los aspirados nasofaríngeos (ANF) de pacientes bajo 5 años de edad, con diagnóstico de IRA, hospitalizados durante el año 2013. La presencia de HBoV se detectó mediante la RPC de punto final descripta por Allander y cols. Los virus tradicionales se estudiaron mediante inmunofluorescencia. Datos personales, clínicos y epidemiológicos se recolectaron en una planilla estandarizada. Resultados: HBoV fue detectado en 7% de las muestras con prevalencia en primavera y verano; y principalmente en pacientes bajo 2 años de edad. Se registró co-detecciones en 22% de los casos. Discusión: Hemos detectado HBoV en estas dos provincias de Argentina; estudios posteriores deberán efectuarse para determinar si se trata de una infección reciente o una excreción prolongada del virus.

Detection of respiratory viruses by real-time polymerase chain reaction in outpatients with acute respiratory infection

Viruses are the major contributors to the morbidity and mortality of upper and lower acute respiratory infections (ARIs) for all age groups. The aim of this study was to determine the frequencies for a large range of respiratory viruses using a sensitive molecular detection technique in specimens from outpatients of all ages with ARIs. Nasopharyngeal aspirates were obtained from 162 individuals between August 2007-August 2009. Twenty-three pathogenic respiratory agents, 18 respiratory viruses and five bacteria were investigated using multiplex real-time reverse transcriptase polymerase chain reaction (RT-PCR) and indirect immunofluorescence assay (IIF). Through IIF, 33 (20.4%) specimens with respiratory virus were recognised, with influenza virus representing over half of the positive samples. Through a multiplex real-time RT-PCR assay, 88 (54.3%) positive samples were detected; the most prevalent respiratory viral pathogens were influenza, human rhinovirus and respiratory syncytial virus (RSV). Six cases of viral co-detection were observed, mainly involving RSV. The use of multiplex real-time RT-PCR increased the viral detection by 33.9% and revealed a larger number of respiratory viruses implicated in ARI cases, including the most recently described respiratory viruses [human bocavirus, human metapneumovirus, influenza A (H1N1) pdm09 virus, human coronavirus (HCoV) NL63 and HCoV HKU1].

Frequency of human bocavirus respiratory infections among at-risk patients in São Paulo, Brazil / Frequência de bocavírus humano em infecções respiratórias entre pacientes de risco na cidade de São Paulo, Brasil

BACKGROUND AND OBJECTIVES: Human Bocavirus (HBoV) has been described since 2005 as an etiological agent of respiratory virus infections. From 2001 to 2008 we investigated the etiology of HBoV among adults and children in different groups at risk of presenting complications arising from acute respiratory infection, the investigation was carried out in a tertiary hospital health care system in Brazil. METHODS: HBoV DNA was assayed in 598 respiratory samples from community and hospitalized patients by PCR. RESULTS: Of the 598 tested samples, 2.44% (8/328) of children, including five children with heart disease, and 0.4% (1/270) of adult bone-marrow-transplant were HBoV positive. CONCLUSIONS: These data suggested lower HBoV frequency among different at-risk patients and highlights the need to better understand the real role of HBoV among acute respiratory symptomatic patients.

INTRODUÇÃO E OBJETIVOS: O bocavírus humano (HBoV) tem sido descrito desde 2005 como agente etiológico de infecções respiratórias virais. O presente estudo tem como objetivo investigar a etiologia da infecção respiratória pelo HBoV em pacientes adultos e crianças de diferentes grupos de risco para complicação de infecções respiratórias agudas desde 2001 até 2008 em um hospital terciário no Brasil. PACIENTES E MÉTODOS: O HBoV foi investigado, através de reação em cadeia da polimerase, em 598 amostras respiratórias coletadas de pacientes hospitalizados e não hospitalizados. RESULTADOS: Das 598 amostras testadas o HBoV foi detectado em 2,44% (8/328) das crianças, incluindo cinco crianças portadoras de cardiopatia congênita, e 0,4% (1/270) dos adultos em programa de transplante de células tronco hematopoiéticas. CONCLUSÃO: Os dados do presente estudo sugerem baixa freqüência de detecção do HBoV entre pacientes de risco, e destaca a necessidade de novos estudos para um melhor entendimento do verdadeiro papel desse agente em infecções respiratórias agudas em pacientes sintomáticos.

Human bocavirus 1 and 3 infection in children with acute gastroenteritis in Brazil

To determine the positivity rate of human bocavirus (HBoV) 1 and 3 among children who presented with acute gastroenteritis symptoms during the period of 1994-2004 in the Central-West Region of Brazil, 762 faecal samples were tested using polymerase chain reaction (PCR) for the detection of HBoV DNA. Primers for a segment of the non-structural viral protein 1 (NS1) gene of HBoV-1 and HBoV-3 were used. Twelve HBoV-positive samples were further characterised via genomic sequencing and phylogenetic analysis. Of the samples tested, 5.8% (n = 44) were positive for HBoV-1 or HBoV-3 and co-infection was observed in 14 (31.8%) of the 44 HBoV-positive samples. Nine of the 14 samples were also positive for Rotavirus A and five were positive for Aichi virus. The genomic sequencing of the NS1 partial sequence of 12 HBoV-samples showed that 11 samples were characterised as HBoV-1 and that one was characterised as HBoV-3. The phylogenetic analysis showed that the HBoV-1 samples had a high sequence homology to others previously identified in China, Sweden and Brazil. This is the first study conducted in the Central-West Region of Brazil to detect HBoV-1 and HBoV-3 in faecal samples from children with acute gastroenteritis. Further studies are required to define the role of HBoVs as aetiological agents of gastroenteritis.

High prevalence of human bocavirus 1 in infants with lower acute respiratory tract disease in Argentina, 2007 - 2009

Human bocavirus (HBoV) is a parvovirus whose association with respiratory disease is currently under investigation. OBJECTIVE: To determine HBoV prevalence in children with lower acute respiratory infection. METHODS: We investigated HBoV in 433 nasopharyngeal aspirates collected in 2007-2009 from children 0 to 5 years old hospitalized with bronchiolitis or pneumonia in Córdoba, Argentina. RESULTS: The general prevalence of HBoV was 21.5 percent and the positive cases (HBoV+) were more frequent during winter and spring. The mean age of HBoV+ patients was 6.9 months, with 87.1 percent of the detections corresponding to infants less than 1 year old (among which the prevalence of HBoV was 26.3 percent in patients < 3 months of age, 22.1 percent in 3 to 6 months, 25.3 percent in 6 to 9 months, and 18.8 percent in 9 to 12 months). The sequence analysis of the NP1 coding region of 15 isolates showed that all isolates from Cordoba were HBoV1 which exhibited a homology of nearly 100 percent both among themselves and with the originally discovered virus from 2005. CONCLUSION: Overall, our results indicate that HBoV is a significant pathogen that contributes to acute respiratory infection both on its own and during coinfection with other viruses.

Bocavirus humano en Chile: características clínicas y epidemiológicas en niños con infecciones respiratorias / Human bocavirus in Chile: clinical characteristics and epidemiological profile in children with acute respiratory tract infections

Background: Human bocavirus (HBoV) is a newly discovered parvovirus found in children with acute respiratory tract infections (ARTI). Objectives: To describe the epidemiological and clinical profile of children < 5 years old consulting for ARTI, comparing cases of HBoV monoinfection and coinfection with other known respiratory viruses. Furthermore, we aimed to estimate the prevalence of viral shedding in asymptomatic children and perform phylogenetic analysis. Patients and Methods: We investigated the presence of HBoV in nasopharyngeal secretions from children consulting for AlRTI and among asymptomatic controls, between 2007 and 2008, by polymerase chain reaction. Results: HBoV was detected in 79 (21.8 percent) of 362 nasopharyngeal swabs obtained from children with ARTI. In 60/79 (76 percent), coinfection with other respiratory viruses was confirmed. Most common symptoms were cough, fever and rhinorrhea. Children infected only with HBoV showed significantly lower frequencies of respiratory distress, oxygen requirements and hospital admission than those with coinfection. HBoV was detected in 6/16 (37.5 percent) samples from asymptomatic children. The phylogenetic analysis of viruses from Chilean patients revealed that circulating HBoV was closely related to original strains. Conclusions: HBoV was found either in symptomatic and asymptomatic children. The severity of the disease was greater when HBoV was associated to other respiratory viruses.

Introducción: Bocavirus humano (HBoV) es un nuevo parvovirus encontrado en niños con infecciones respiratorias agudas (IRA). Objetivos: Describir la epidemiología y perfil clínico en niños < 5 años con IRA, comparando aquellos con HBoV como único agente identificado, con los que tenían co-infección con otro virus respiratorio. Además se evaluó su prevalencia en niños asintomáticos, y se realizó análisis filogenético. Materiales y Métodos: Se investigó la presencia de HBoV, por medio de reacción de polimerasa en cadena, en muestras de secreción nasofaríngea obtenida en niños con IRA y en controles asintomáticos, entre 2007 y 2008. Resultados: Se detectó HBoV en 79 (21,8 por ciento) de 362 muestras obtenidas en pacientes con IRA. En 60/79 (76 por ciento), se demostró co-infección. Los síntomas más frecuentes fueron tos, fiebre y rinorrea. Los pacientes con HBoV como único agente identificado mostraron frecuencias significativamente menores de dificultad respiratoria, requerimiento de oxígeno y hospitalización, comparado con los co-infectados. HBoV se detectó en 6/16 (37,5 por ciento) muestras de niños asintomáticos. El análisis filogenético de las cepas chilenas demuestra estrecha relación con las cepas originales. Conclusiones: HBoV está presente en niños chilenos con IRA y asintomáticos. La gravedad de la enfermedad fue mayor en el grupo con co-infección.

Human Bocavirus in Patients with Respiratory Tract Infection / 대한진단검사의학회지

BACKGROUND: Human bocavirus (HBoV) is a newly identified viral pathogen, and its clinical epidemiology and significance in respiratory infections have not yet been completely elucidated. We investigated the prevalence of HBoV infection and the association between viral (HBoV) load and clinical features of the infection in patients of all age-groups. METHODS: Nasopharyngeal aspirates from patients with symptoms of respiratory infection were tested for presence of HBoV by using real-time polymerase chain reaction. HBoV-positive patients were categorized into low- and high-viral-load groups using 1.0x10(6) copies/mL as the threshold value of viral load. RESULTS: Detection rate of HBoV was 4.8% (N=93) in a total of 1,926 samples with peak incidence of infection being observed in patients aged 6-12 months. HBoV infection was more frequently observed in young children, especially, in children aged less than 5 yr, and the HBoV load decreased with increase in age. HBoV was codetected with other respiratory viruses in 17 (18.3%) of the 93 HBoV-positive patients and 15 patients (88.2%) belonged to the low-viral-load group. Patients infected with HBoV alone showed a higher viral load than those patients in whom HBoV was codetected with other respiratory viruses (median load, 3.78x10(5) copies/mL vs. 1.94x10(4) copies/mL, P=0.014). Higher pulse rate (P=0.007) and respiratory rate (P=0.021) were observed in patients with a high-viral-load. CONCLUSIONS: Our results suggest that HBoV may be the causative agent of respiratory infection in the high-viral-load group.

Human Bocavirus in Patients with Respiratory Tract Infection / 대한진단검사의학회지

BACKGROUND: Human bocavirus (HBoV) is a newly identified viral pathogen, and its clinical epidemiology and significance in respiratory infections have not yet been completely elucidated. We investigated the prevalence of HBoV infection and the association between viral (HBoV) load and clinical features of the infection in patients of all age-groups. METHODS: Nasopharyngeal aspirates from patients with symptoms of respiratory infection were tested for presence of HBoV by using real-time polymerase chain reaction. HBoV-positive patients were categorized into low- and high-viral-load groups using 1.0x10(6) copies/mL as the threshold value of viral load. RESULTS: Detection rate of HBoV was 4.8% (N=93) in a total of 1,926 samples with peak incidence of infection being observed in patients aged 6-12 months. HBoV infection was more frequently observed in young children, especially, in children aged less than 5 yr, and the HBoV load decreased with increase in age. HBoV was codetected with other respiratory viruses in 17 (18.3%) of the 93 HBoV-positive patients and 15 patients (88.2%) belonged to the low-viral-load group. Patients infected with HBoV alone showed a higher viral load than those patients in whom HBoV was codetected with other respiratory viruses (median load, 3.78x10(5) copies/mL vs. 1.94x10(4) copies/mL, P=0.014). Higher pulse rate (P=0.007) and respiratory rate (P=0.021) were observed in patients with a high-viral-load. CONCLUSIONS: Our results suggest that HBoV may be the causative agent of respiratory infection in the high-viral-load group.