Clinical characterization of human bocavirus 1 infection in infants hospitalized in an intensive care unit for severe acute respiratory tract disease

Acute respiratory infections represent the leading cause of morbimortality in children and viruses are the main etiological agents. Here we describe the clinical characteristics and evolution of infants admitted to intensive care unit with severe acute respiratory infection (SARI) due to Human Bocavirus 1 mono-infection in patients without previous comorbidity. We also compared them with respiratory syncytial virus (RSV) cases. Of 141 cases included (age 5.43 ± 4.54 months, 52% male), 80% had at least 1 virus detected. RSV was the most frequent in the series (71.6%) followed by HBoV1 (28%). Five cases of HBoV1 mono-detection were identified. Pediatric acute respiratory distress syndrome was present in both groups, HBoV1 and RSV. The clinical presentation and evolution of HBoV1 single infection was similar to RSV. HBoV1 should be included among the agents investigated in cases of SARI in infants.

Acute human bocavirus 1 infection in child with life-threatening bilateral bronchiolitis and right-sided pneumonia: a case report

Background

Human bocavirus 1 is a commonly detected human parvovirus. Many studies have shown human bocavirus 1 as a pathogen in association with acute respiratory tract infections in children. However, because human bocavirus 1 persists in the upper airways for extensive time periods after acute infection, the definition and diagnostics of acute human bocavirus 1 infection is challenging. Until now, detection of human bocavirus 1 exclusively, high viral load in respiratory samples, and viremia have been associated with a clinical picture of acute respiratory illness. There are no studies showing detection of human bocavirus 1 messenger ribonucleic acid in the peripheral blood mononuclear cells as a diagnostic marker for acute lower respiratory tract infection.

Case presentation

We report the case of a 17-month-old Latvian boy who presented in intensive care unit with acute bilateral bronchiolitis, with a history of rhinorrhea and cough for 6 days and fever for the last 2 days prior to admission, followed by severe respiratory distress and tracheal intubation. Human bocavirus 1 was the only respiratory virus detected by a qualitative multiplex polymerase chain reaction panel. For the diagnosis of acute human bocavirus 1 infection, both molecular and serological approaches were used. Human bocavirus 1 deoxyribonucleic acid (DNA) was detected simultaneously in nasopharyngeal aspirate, stool, and blood, as well as in the corresponding cell-free blood plasma by qualitative and quantitative polymerase chain reaction, revealing high DNA-copy numbers in nasopharyngeal aspirate and stool. Despite a low-load viremia, human bocavirus 1 messenger ribonucleic acid was found in the peripheral blood mononuclear cells. For detection of human bocavirus 1-specific antibodies, non-competitive immunoglobulin M and competitive immunoglobulin G enzyme immunoassays were used. The plasma was positive for both human bocavirus 1-specific immunoglobulin M and immunoglobulin G antibodies.

Conclusions

The presence of human bocavirus 1 genomic DNA in blood plasma and human bocavirus 1 messenger ribonucleic acid in peripheral blood mononuclear cells together with human bocavirus 1-specific immunoglobulin M are markers of acute human bocavirus 1 infection that may cause life-threatening acute bronchiolitis.

Comparison of phenotypic and genotypic diagnosis of acute human bocavirus 1 infection in children

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Diagnosis of HBoV1 has been based on detection of DNA or mRNA.

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Rapid HBoV1 antigen detection is beneficial for diagnosing acute HBoV1 infections.

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HBoV1 antigen detection is attractive for point-of-care use.

Background

Diagnosis of human bocavirus 1 (HBoV1) has been based on qualitative PCRs detecting HBoV1 DNA or detection of HBoV1 mRNA.

Objective

This study aims to assess whether a rapid and automated HBoV1 antigen test is suitable for diagnosis of acute HBoV1 infection.

Study design

HBoV1 antigen detection has been compared with quantitative HBoV1 DNA PCR and HBoV1 mRNA RT-PCR.

Results and conclusion

We conclude that HBoV1 antigen detection has higher clinical specificity and positive predictive value than HBoV1 DNA qualitative PCRs, yet a lower sensitivity than HBoV1 mRNA detection. Additionally, HBoV1 antigen detection is beneficial in its rapidity and availability as a point-of-care test.

Epidemiology of HBoV1 infection and relationship with meteorological conditions in hospitalized pediatric patients with acute respiratory illness: a 7-year study in a subtropical region

BACKGROUND

Human bocavirus 1 (HBoV1) is an important cause of acute respiratory illness (ARI), yet the epidemiology and effect of meteorological conditions on infection is not fully understood. To investigate the distribution of HBoV1 and determine the effect of meteorological conditions, hospitalized pediatric patients were studied in a subtropical region of China.

METHODS

Samples from 11,399 hospitalized pediatric patients (≤14 years old), with ARI were tested for HBoV1 and other common respiratory pathogens using real-time PCR, between July 2009 and June 2016. In addition, local meteorological data were collected.

RESULTS

Of the 11,399 patients tested, 5606 (49.2%) were positive for at least one respiratory pathogen. Two hundred forty-eight of 11,399 (2.2%) were positive for HBoV1 infection. Co-infection was common in HBoV1-positive patients (45.2%, 112/248). A significant difference in the prevalence of HBoV1 was found in patients in different age groups (p < 0.001), and the peak prevalence was found in patients aged 7-12 months (4.7%, 56/1203). Two HBoV1 prevalence peaks were found in summer (between June and September) and winter (between November and December). The prevalence of HBoV1 was significantly positively correlated with mean temperature and negatively correlated with mean relative humidity, and the mean temperature in the preceding month had better explanatory power than the current monthly temperature.

CONCLUSIONS

This study provides a better understanding of the characteristics of HBoV1 infection in children in subtropical regions. Data from this study provide useful information for the future control and prevention of HBoV1 infections.