Interrupted circulation and re-emergence of human bocavirus following COVID-19: A 10-year retrospective analysis from a tertiary hospital in the Republic of Korea

Abstract

In pediatric respiratory infections, human bocavirus (HBoV), a DNA virus in the Parvoviridae family, is increasingly being recognized as a major pathogen. However, the long-term epidemiological patterns of HBoV, particularly under the ecological shifts induced by the 2019 coronavirus (COVID-19) pandemic, remain unclear. In this retrospective study, we analyzed 11,643 specimens obtained from patients with respiratory symptoms at Dankook University Hospital, Korea, between 2015 and 2024, encompassing both inpatients and outpatients. We evaluated the distribution of HBoV positivity with respect to age, sex, season, and year, and accordingly identified 415 HBoV-positive cases. Notably, during 2020, the peak pandemic year, there was a marked decline in positivity to <1 %, followed by a partial resurgence in 2022. Statistically significant differences were observed in HBoV detection regarding year and season, with peak activity occurring primarily in spring and early summer. The highest positivity was observed in infants aged 0-1 year (7.7 %), followed by children aged 2-11 years (4.6 %), whereas there were near-zero detection rates for adolescents and adults. In a majority of the assessed years, infants were consistently characterized by the highest positivity, with minor fluctuations observed during low-prevalence periods. Our findings indicate that HBoV is characterized by non-random epidemiological patterns influenced by age and season, and sensitively responds to ecological disruptions, such as the COVID-19 pandemic. These findings provide strong evidence supporting the inclusion of HBoV in routine respiratory virus surveillance and emphasize the importance of implementing age- and season-specific diagnostic and preventive strategies, particularly targeting infants and young children.

Keywords: Human bocavirus; Infant; Pandemic; Pediatric patients; Respiratory infection; Seasonality.