Epidemiological surveillance and incidence of respiratory viruses in Chile: Before and after COVID 19

Objective: During the COVID 19 pandemic, various measures, such as lockdowns and travel restrictions, were implemented to curb the spread of SARS CoV 2, significantly impacting case numbers. These interventions also influenced the incidence of other respiratory viruses, including respiratory syncytial virus (RSV) and influenza A (InfA). Materials and methods: This study examines the effect of SARS CoV 2 on the circulation of major respiratory viruses by analyzing epidemiological data from Chile between 2015 and 2023. Results: Data analysis revealed that during the pandemic, RSV, InfA, adenoviruses (ADV), and human metapneumovirus (HMPV) reached historically low levels. However, the relaxation of restrictions in 2021 led to a surge in respiratory virus infections, with RSV cases approaching pre-pandemic levels by 2022. Notably, in 2022 and 2023, infections caused by these viruses exceeded pre pandemic numbers. Conclusions: These findings align with epidemiological predictions regarding shifts in infection patterns due to preventive measures. Understanding these trends, particularly during lockdowns, is crucial for planning future outbreak response strategies. The insights gained from this analysis have recently informed proactive measures for Chile’s upcoming winter season, helping mitigate an anticipated rise in respiratory emergencies, especially among children in regions with high humidity and low temperatures.