Bocavirus Infection in Otherwise Healthy Children with Respiratory Disease

Abstract

To evaluate the role of human bocavirus (hBoV) as a causative agent of respiratory disease, the importance of the viral load in respiratory disease type and severity and the pathogenicity of the different hBoV species, we studied all hBoV-positive nasopharyngeal samples collected from children who attended an emergency room for a respiratory tract infection during three winters (2009–2010, 2011–2012, and 2013–2014). Human bocavirus was detected using the respiratory virus panel fast assay and real-time PCR. Of the 1,823 nasopharyngeal samples, 104 (5.7%) were positive for hBoV; a similar prevalence was observed in all three periods studied. Among hBoV-infected children, 53.8% were between 1–2 years old, and hBoV was detected alone in 57/104 (54.8%) cases. All of the detected hBoV strains belonged to genotype 1. The median hBoV load was significantly higher in samples containing strains with both the N546H and T590S mutations compared to other samples (p<0.05). Children with a single hBoV-1 infection more frequently had upper respiratory tract infections (URTIs) than those who were co-infected (37.0% vs 17.8%, respectively, p = 0.04). The duration of hospitalization was longer among children with high viral loads than that observed among children with low viral loads (8.0 ±2.2 days vs 5.0 ±1.5 days, respectively, p = 0.03), and the use of aerosol therapy was more frequent among children with high viral loads than among those with low viral loads (77.1% vs 55.7%, respectively, p = 0.04). This study shows that hBoV is a relatively uncommon but stable infectious agent in children and that hBoV1 seems to be the only strain detected in Italy in respiratory samples. From a clinical point of view, hBoV1 seems to have in the majority of healthy children relatively low clinical relevance. Moreover, the viral load influences only the duration of hospitalization and the use of aerosol therapy without any association with the site of the respiratory disease.

Comparison of rates of hospitalization between single and dual virus detection in a Mexican cohort of children and adults with influenza-like illness

“…Because HBoV infection is very common and frequently found in asymptomatic participants, the pathogenic role of this virus has been questioned [31,32]. Children with higher viral loads tend to have more severe infections [33], longer hospitalization duration [34,35], and are found to have co-infection by other viruses [36,37] less frequently than those with lower viral loads. However, in children in daycare, viral load had no apparent association with severity of illness [31], which also might reflect challenges in reproducibly measuring viral load in secretions.…”

Frequent Detection and Genetic Diversity of Human Bocavirus in Urban Sewage Samples

“…However, few data are available from some clinical studies, where low percentages of positivity for HBoV were found in different types of clinical specimens. Principi and coworkers detected HBoV in 104 (5.7 %) nasopharyngeal samples collected from children attending an emergency room for a respiratory tract infection, all belonging to species 1 (Principi et al 2015). In a study on the prevalence of viral infections in children with community-acquired pneumonia, HBoV was detected in 10 % of samples, mainly in association with other viruses (particularly Respiratory Syncytial virus and rhinovirus) (Mameli and Zuccotti 2013).…”

Clinical and Virus Surveillance After the First Wheezing Episode

“…RV infections are reported to be most common after 9–12 months of age (30), which is consistent with our findings. The second most common virus was HBoV, a recently discovered pathogen that is detected in 5.7% – 20% of hospitalized children with respiratory illnesses and episodes of wheezing (24, 31). The third most common pathogen during the one-year follow-up was RSV, which was detected in 2% – 15% of children with mean age 12 months at the study entry.…”