Human bocavirus-1 screening in infants with acute lower respiratory tract infection

Human bocavirus infections in paediatric patients in a tertiary care hospital in Kerala, India

Human bocaviruses (HBoVs) can cause respiratory illness in young children. Although the first HBoV infection in India was reported in 2010, very little information is available about its prevalence, clinical features, or geographic distribution in this country. This study was conducted using 136 respiratory samples from paediatric patients in a tertiary care hospital in Kerala, 21 of which tested positive for HBoV1 and were further characterized through VP1/VP2 gene sequencing. We found that different strains of HBoV1 are co-circulating in the region and that HBoV1 can be detected in children with severe acute respiratory infections, either alone or coinfections with other pathogens, without any significant differences in their clinical characteristics.

Nasopharyngeal carriage of Streptococcus pneumoniae among Brazilian children: Interplay with viral co-infection

Nasopharyngeal transmission of Streptococcus pneumoniae is a prerequisite for the development of pneumococcal diseases. Previous studies have reported a relationship between respiratory viruses and S. pneumoniae infections. However, there are few studies on this issue among healthy children. This study aimed to examine the relationships between these agents in healthy children from Southern Brazil. This cohort study included 229 nasopharyngeal samples collected from children aged 18-59 months at baseline. S. pneumoniae was detected using bacterial culture, whereas respiratory viruses were identified using quantitative polymerase chain reaction. A questionnaire was used at the time of sample collection and medical records were reviewed 14 days after participant inclusion. The prevalence of pneumococcal carriage was 63.7% (146/229), while respiratory viruses were detected in 49.3% (113/229) of the children. Respiratory viruses were more frequently found among pneumococcal carriers than among non-carriers (54.4% vs. 39.7%, p = 0.033). Additionally, rhinovirus (hRV) was more frequent among the pneumococcal carriers (39% vs. 21.7%, p = 0.012), and the presence of human bocavirus (hBOV) alone was associated with the absence of pneumococcal carriage (2.7% vs. 10.8%, p = 0.016). No differences were found in the frequency of pneumococcal carriage, respiratory virus detection, or the co-occurrence of clinical symptoms and diagnosis in the participants 14 days after specimen collection. Our findings revealed a positive relationship between pneumococcal carriage and respiratory virus detection, particularly for hRV. However, we did not observe a relationship between nasopharyngeal respiratory viruses and pneumococci detection during medical appointments, respiratory symptoms, or diseases. This study was one of the first investigations in Latin America to explore the relationship between respiratory viruses and pneumococcal carriage in a healthy children.

Unmasking bocavirus: is it a co-infectious agent or an actual respiratory pathogen?

OBJECTIVES

Although human bocavirus (HBoV) is primarily linked to respiratory tract infections, its exact role as a respiratory pathogen remains unclear. This study aims to investigate HBoV detection rates, as well as clinical, laboratory, microbiological, and radiological characteristics, length of stay in the emergency department (ED), rate of hospitalization, and severity of illness in cases where HBoV is detected in respiratory secretions.

METHODS

We conducted a retrospective analysis of all consecutive patients under 18 years who visited a large-volume tertiary pediatric ED from January to December 2023 and tested positive for HBoV in their respiratory viral panel (RVP).

RESULTS

Among the 14,315 patients who underwent RVP testing during the study period, 591 (4%) tested positive for HBoV. After excluding those with incomplete data, 528 patients (57% male) were included in the analyses. The median age was 2.8 [1.2-4.9] years. The most common symptoms were cough (67%), fever (58%), runny nose/nasal congestion/sore throat (34%), and respiratory distress (24%). Thirty percent of the patients had a history of antibiotic use before admission. Thirteen percent of the patients had at least one chronic illness. Co-infection with HBoV occurred in 37% of the patients, with respiratory syncytial virus (RSV) being the most frequently co-detected virus (45%). Lymphopenia was documented in 12% of patients, and 36% had elevated C-reactive protein levels (median 21 [12-38] g/dl). Abnormal chest X-rays were noted in 85% of patients. The management approach included outpatient care for more than half of the patients (69%). Clinical severity was classified as high in 11% of patients (n = 60), necessitating ICU admission.

CONCLUSION

Although typically mild, HBoV infections can escalate to severe respiratory illnesses, requiring respiratory support and intensive care.

Uncovering the Presentation and Diagnosis of Human Bocavirus in a Patient at a Tertiary Care Center: A Case Report

A toddler, thriving well, developmentally normal, and fully immunized, presented with fever, cough, and cold for a day, followed by breathing difficulty. Although the child was not ill upon admission, he had a fever and was breathing rapidly. On examination, visible sub-costal retractions and wheezing in both lungs were noted. He required Intensive Care Unit (ICU) management for a brief period, with oxygen supplementation, round-the-clock nebulization, and other supportive care. Initially, he was diagnosed with a wheeze-associated lower respiratory tract infection, as his chest X-ray showed bilateral hyperinflated lung fields. Blood investigations revealed microcytic hypochromic anemia, and his renal function tests, electrolytes, and liver function tests were within normal limits. C-reactive protein (CRP) was positive at 15.1 mg/L (≥10 mg/L considered positive), and the blood culture was sterile. A nasopharyngeal swab on day 2 of admission tested positive for reverse transcription-polymerase chain reaction (RT-PCR) of Human Bocavirus (HBoV). Gradually, the child's condition improved, and he was able to be taken off oxygen support two days after admission. Upon discharge, the child was managed symptomatically with oral medications.

Analysis of a Cohort of 165 Pediatric Patients with Human Bocavirus Infection and Comparison between Mono-Infection and Respiratory Co-Infections: A Retrospective Study

INTRODUCTION

Human Bocavirus (HBoV) is mainly associated with respiratory tract infections. However, its role as respiratory pathogen is not fully understood for a high co-infection rate in symptomatic patients and a significant HBoV detection rate in asymptomatic subjects. This study aimed to describe a large cohort of children with HBoV infection and to compare HBoV mono-infection and co-infections.

METHODS

We retrospectively reviewed data from 165 children admitted to Meyer Children's Hospital IRCCS from March 2022 to March 2023 with the diagnosis of HBoV infection, detected using Reverse Transcription qPCR from nasal swabs. Thereafter, we compared patients with HBoV mono-infection (Group A) and those with HBoV co-infections (Group B) in terms of disease severity, established by the length of stay (LOS), the requirement of Pediatric Intensive Care Unit (PICU), and advanced respiratory support (ARS).

RESULTS

The median age was 1.5 years; 80% of patients presented with respiratory symptoms. The discharge rate from the emergency department (ED) within 24 h was 42.4%. Most cases (57.6%) were hospitalized, and 7.3% were admitted to PICU due to respiratory failure. Group A comprised 69 patients, and Group B 96 children (95% viral co-infections, 2% bacterial, 3% viral and bacterial). Group A and Group B were similar in hospitalization rate but differed significantly in LOS (median 3 vs. 5 days) and requirement of PICU admission (0 vs. 12 patients, p < 0.001). Patients with a respiratory disease history (17.5%) showed significantly longer LOS and more necessity of inhaled bronchodilator therapy.

CONCLUSIONS

HBoV should be considered a relevant respiratory pathogen especially in viral co-infections. Patients with HBoV co-infections have a higher risk of necessitating advanced respiratory support with more PICU admission and longer LOS; a previous respiratory disease puts them at a higher risk of longer hospitalization.

Human Bocavirus in Childhood: A True Respiratory Pathogen or a "Passenger" Virus? A Comprehensive Review

Recently, human bocavirus (HBoV) has appeared as an emerging pathogen, with an increasing number of cases reported worldwide. HBoV is mainly associated with upper and lower respiratory tract infections in adults and children. However, its role as a respiratory pathogen is still not fully understood. It has been reported both as a co-infectious agent (predominantly with respiratory syncytial virus, rhinovirus, parainfluenza viruses, and adenovirus), and as an isolated viral pathogen during respiratory tract infections. It has also been found in asymptomatic subjects. The authors review the available literature on the epidemiology of HBoV, the underlying risk factors associated with infection, the virus's transmission, and its pathogenicity as a single pathogen and in co-infections, as well as the current hypothesis about the host's immune response. An update on different HBoV detection methods is provided, including the use of quantitative single or multiplex molecular methods (screening panels) on nasopharyngeal swabs or respiratory secretions, tissue biopsies, serum tests, and metagenomic next-generations sequencing in serum and respiratory secretions. The clinical features of infection, mainly regarding the respiratory tract but also, though rarely, the gastrointestinal one, are extensively described. Furthermore, a specific focus is dedicated to severe HBoV infections requiring hospitalization, oxygen therapy, and/or intensive care in the pediatric age; rare fatal cases have also been reported. Data on tissue viral persistence, reactivation, and reinfection are evaluated. A comparison of the clinical characteristics of single infection and viral or bacterial co-infections with high or low HBoV rates is carried out to establish the real burden of HBoV disease in the pediatric population.

Diagnosis and clinical significance of Human bocavirus 1 in children hospitalized for lower acute respiratory infection: molecular detection in respiratory secretions and serum

Introduction. Human bocavirus 1 (HBoV1) infection occurs with viral genome presence in respiratory secretions (RS) and serum, and therefore both samples can be used for diagnosis.

Gap statement. The diagnostic sensitivity of HBoV1 DNA detection in serum and the duration of DNAaemia in severe clinical cases have not been elucidated.

Aim. To determine HBoV1 DNA in serum and RS of paediatric patients hospitalized for lower acute respiratory infection (LARI) and to analyse the clinical–epidemiological features of positive cases.

Methodology. This was a prospective, transverse study. Physicians selected the clinical situations and obtained paired clinical samples (RS and serum) that were tested by PCR/qPCR for HBoV1. Positive cases were analysed considering time of specimen collection, co-detection, clinical manifestations and viral load; statistical significant level was set at α=0.05.

Results. HBoV1 was detected in 98 of 402 cases included (24 %); 18/98 (18 %) patients had the virus detectable in serum and 91/98 (93 %) in RS (P<0.001). Positivity rates were not significantly different in patients with RS and serum collected within or beyond 24 h of admission. Single HBoV1 infection was identified in 39/98 patients (40 %), three patients had HBoV1 in both clinical samples (3/39, 8 %) and 32 (32/39, 82 %) only in RS, 22 of them (69 %) with both clinical samples within 24 h of admission. Cough (P=0.001) and rhinitis (P=0.003) were significantly frequent among them and most patients were diagnosed with bronchiolitis (22/39, 56 %) and pneumonia (9/39, 23 %), which was more frequent compared to cases with co-infection (P=0.04). No significant differences were identified among patients with high, medium or low viral load of HBoV1 regarding rate of positivity in both clinical samples, the time of collection of RS and serum, co-detection, first episode of LARI, clinical manifestations, comorbidity or requirement for assisted ventilation. Intensive care unit (ICU) patients had a significantly higher frequency of detection (P<0.001) and co-detection (P=0.001) compared to patients on standard care.

Conclusions. HBoV1 is prevalent among infant patients hospitalized for LARI and including it in the standard testing can add to the aetiological diagnosis in these cases, especially for patients admitted to the ICU. HBoV1 detection in serum did not contribute significantly to the diagnosis as compared to detection in respiratory secretions.

Epidemiologic and clinical characteristics of human bocavirus infection in children hospitalized for acute respiratory tract infection in Qingdao, China

Persistent infection and prolonged shedding of human bocavirus 1 (HBoV1) in children have been reported, and the role of HBoV1 as a sole causative pathogen in acute respiratory infection (ARI) is yet to be established. While the reported prevalence of HBoV infection varies due to different detection methods and sampling criteria, determining the viral and bacterial etiology of HBoV infection using multiplex real-time PCR is yet to be reported. Herein, we aimed to further explore the pathogenicity of HBoV in patients with ARI by screening the viral and bacterial infections in children with ARI in Qingdao and comparing the epidemiological, clinical characteristics, and etiological results. Human bocavirus was identified in 28.1% of the samples, and further sequencing analysis of the detected HBoV confirmed 96.4% as HBoV1. The rate of HBoV as a single viral infection was 75%, and the rate of coinfection with bacteria was 66.1%, suggesting the need for continued monitoring of HBoV in children with ARIs. Clinical characterization suggested that HBoV infection may affect the function of organs, such as the liver, kidney, and heart, and the blood acid–base balance. Additionally, it is essential to promote awareness about the importance of disinfection and sterilization of the hospital environment and standardizing operations. The interactions between HBoV and other pathogens remain to be investigated in further detail in the future.