Eighteen Years of Human Rhinovirus Surveillance in the Republic of Korea (2007-2024): Age- and Season-Specific Trends from a Single-Center Study with Public Health Implications

Abstract

Human rhinovirus (HRV) is the most common cause of upper respiratory tract infections and can cause substantial morbidity in children. Because its clinical features are nonspecific, differentiation from influenza virus and respiratory syncytial virus is often difficult, underscoring the diagnostic importance of real-time reverse transcriptase polymerase chain reaction (Real-Time RT-PCR)-based detection. This study aimed to characterize long-term epidemiological patterns of HRV in the Republic of Korea and assess their clinical and public health implications. We retrospectively analyzed 23,284 nasopharyngeal swab specimens collected between 2007 and 2024 from outpatients and inpatients presenting with influenza-like illness at a tertiary care hospital. HRV RNA was detected by Real-Time RT-PCR, and positivity rates were compared by year, month, and age group. Annual detection peaked in 2015 (31.3%) and 2016 (28.6%), then dropped sharply during the COVID-19 pandemic (2020-2021, 4.2-11.0%) and remained low through 2024. Seasonally, rates were highest in July (24.4%) and September (24.1%) and lowest in January (6.9%). Age-specific analysis showed peak positivity in children (26.1%) and infants (20.3%), with lower rates in adults (3.9%) and older adults (3.3%). These findings underscore the diagnostic value of HRV detection and provide evidence for pediatric-focused prevention, outbreak preparedness, and climate-informed surveillance strategies.

Keywords: COVID-19 pandemic impact; age distribution; climate-responsive disease control; epidemiology; molecular surveillance; public health; rhinovirus; seasonality.

Figure 1

Annual number of total tested cases, HRV-positive cases, and corresponding positivity rates (%) from 2007 to 2024. Light blue bars indicate the total number of specimens tested each year, orange bars represent the number of HRV-positive cases, and the green line denotes the annual positivity rate (%). The figure illustrates distinct annual fluctuations in HRV detection, with a marked decline during the COVID-19 pandemic (2020–2021) followed by persistently reduced activity through 2024. Abbreviation: HRV, human rhinovirus.

Figure 2

Monthly variation in human rhinovirus (HRV) positivity rates from 2007 to 2024. Bars represent monthly HRV positivity rates (%) calculated from 2007 to 2024. Distinct color tones indicate seasonal groupings: blue for winter (December–February), light green for spring (March–May), red for summer (June–August), and golden brown for autumn (September–November). The figure highlights pronounced HRV activity during the late spring (May) to early autumn (September) months, peaking in July (24.4%).

Figure 3

Age-specific positivity rates of human rhinovirus (HRV). Bars represent HRV positivity rates (%) by age group, showing the highest rate in children (red bar) (26.1%), followed by infants (20.3%) and adolescents (15.7%), while adults (3.9%) and older adults (3.3%) exhibited markedly lower rates; significance is indicated as *** p < 0.001.