Temporal dynamics and forecasting of respiratory viral infections during and after the SARS-CoV-2 pandemic (2020-2027): a multiplex PCR and ARIMA-based study.

Abstract

Introduction: Respiratory viruses are the leading cause of acute respiratory tract infections in both children and adults, with significant morbidity and healthcare burden. Before the COVID-19 pandemic, these pathogens typically exhibited predictable seasonal circulation patterns. However, the pandemic markedly disrupted this seasonality, leading to reduced viral detection during lockdowns and unusual peaks in subsequent periods.

Objective: This study aimed to identify respiratory pathogens in LRTI patients using multiplex PCR and to assess changes in virus distribution during and after the COVID-19 pandemic across age groups.

Methods: A total of 748 nasopharyngeal swab samples (one per patient) collected between March 2020 and November 2024 were retrospectively analyzed using the QIAstat-Dx Respiratory Panel, a multiplex PCR assay de tecting 19 respiratory viruses including SARS-CoV-2, influenza viruses, respiratory syncytial virus (RSV), and Rhinovirus/Enterovirus. Statistical analyses, including multivariate logistic regression, assessed viral positivity predictors. Additionally, the Autoregressive Integrated Moving Average (ARIMA) time-series model was used to evaluate trends and predict respiratory virus activity through 2027.

Results: The cohort comprised 60.4% males and 39.6% females, with 14.4% pediatric (0-18 years) and 85.6% adult patients. Respiratory viruses were detected in 43.6% of samples, with significantly higher positivity in children (71.5%) compared to adults (40%) (p < 0.01). SARS-CoV-2 dominated during the pandemic (65.5% of positive cases), whereas post-pandemic viral circulation shifted toward other pathogens, notably Rhinovirus/Enterovirus (71.5%). Co-infections occurred more frequently in children (14.1%) than adults (2.7%) (p < 0.001). RSV re-emerged in late 2022 but was undetected in 2024, while influenza activity increased notably in early 2024. Multivariate analysis identified pediatric age as a strong independent predictor of viral positivity (OR: 3.68; 95% CI: 2.25-6.03).

Discussion: Following the relaxation of public health measures, there was a marked resurgence of non- SARS-CoV-2 respiratory viruses, particularly in children, indicating a possible shift in viral epidemiology. These findings emphasize the critical need for ongoing surveillance and targeted interventions, especially in pediatric populations, to mitigate future respiratory viral disease burdens.