Epidemic and molecular evolution of human bocavirus in hospitalized children with acute respiratory tract infection

Abstract

Human bocavirus (HBoV) is a novel parvovirus, often associated with respiratory tract diseases in children. This study explored the epidemiological characteristics and molecular evolution of HBoV-1 in southeastern China. Nasopharyngeal aspirates were collected from children admitted to hospital with acute respiratory tract infections. HBoV-1 was detected using real-time reverse transcription polymerase chain reaction and further characterized by complete genome sequences analysis. Among the 3,022 recruited children, 386 (12.77%) were HBoV-1-positive and 300 (77.72%) had co-detection with other respiratory viruses. Seasonal prevalence peaked in summer. HBoV-1 presence was significantly associated with asthma attack [odds ratio = 1.74; 95 % confidence interval: 1.30, 2.31; p < 0.001]. Similar results were obtained when either single detection or co-detection of HBoV-1 was considered, demonstrating the minor impact of co-detection on the clinical characteristics or epidemic pattern. Phylogenetic analysis based on the complete genome sequences showed that all the HBoV-1 sequences clustered together and no branch was formed that was supported by bootstrap value ≥ 750. The overall evolutionary rate of the complete genome of HBoV-1 was estimated at 1.08 × 10(-4) nucleotide substitutions per site per year (s/s/y) [95% highest probability density: (0.40-1.86) × 10(-4) s/s/y]. Selective pressure analysis showed that all the ω-values were less than 1, suggesting that HBoV-1 was under negative selective pressure. Site-by-site analysis identified the codon site 40 of the VP1 gene under positive selection. In conclusion, our study disclosed the epidemiological and genetic dynamics of HBoV-1 epidemics in southeastern China in the most recent 3 years, the information of which might help to further improve our understanding of HBoV-1 infection and guide better surveillance and control strategies in the future.

Human bocavirus in hospitalized children under 5 years with acute respiratory infection, São Paulo, Brazil, 2010

“…Thus, the identification of HBoV genotypes, other than HBoV-1, associated with ARI might be lost. Together with previous reports from Asia [9,23], Europe [7], South America [10], Central America [33] and North America [34], our findings provide further evidence for a global distribution of HBoV-1, and its high association with respiratory infections. The genetic analysis of HBoV-1 strains showed minimal genomic variability (0.3-0.9% nt, HBoV-3 Fig.…”

“…The HBoV single-infection frequency detected (16.3%) was similar to that observed in another study carried out in the pediatric population (<5 years old) in Northeast Brazil (15.3%, 41/268) [13]. However, the prevalence of singleinfections was lower when compared to China (20.2%, 78/386) [9], and higher when compared to other studies in South Brazil (0.2%, 1/455 and 1.1%, 5/433) [12,15], Southeast Brazil (2.0%, 5/262) [10], Northeast Brazil (3.0%, 2/66) [11], Mexico (0.4%, 6/1404) [21], Argentina (3.7%, 18/488) [22], and India (6.6%, 20/305) [23]. This observed discrepancy may be explained by differences in the study design, recruitment criteria, settings, diagnostic methods or regional and temporal differences [8,24].…”

“…HBoV is increasingly being associated with acute respiratory infection (ARI) with unknown aetiology in young children, displaying global distribution and a prevalence varying from 1.5% to 45.7% [6][7][8][9]. In Brazil, HBoV has been detected in children with positive rates ranging from 2.4% to 23% [10][11][12][13][14][15]; however, its role as a causative agent of ARI diseases is questionable due to its concurrent detection with other respiratory pathogens.…”

Human Bocavirus Capsid Messenger RNA Detection in Children With Pneumonia

“…Studies linking HBoV with respiratory disease have been criticized for relying on cross-sectional designs, convenience samples, and inadequate control groups and for failing to confidently exclude alternate pathogens as the cause of symptoms [9,36]. Potential confounders include incomplete matching on age, sampling method and time of year/season, different protocols for testing of other respiratory pathogens, and selection of controls with increased risk for HBoV infection [6,9,10,39,40]. Much of the controversy is related to difficulties in identifying acute HBoV infections and excluding other potential etiologies.…”

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

“…Serological and nucleic acid test results are generally consistent [8][9][10][11], showing HBoV1 infection is very common. HBoV1 can cause both upper respiratory illness (URI) and lower respiratory illness (LRI) [12][13][14][15][16][17][18]. Infection with HBoV1 can lead to development of a cough, rhinitis, fever and other common clinical symptoms [15,19].…”