[Circulation dynamics of respiratory syncytial virus and its relationship with ambient temperature. 25-year series in Buenos Aires].

Objective: To evaluate changes in RSV seasonality in the last 25 years and their correlation with the mean annual temperature.

Methods: Cross-sectional study, based on RSV and temperature data from the City of Buenos Aires (1995-2019). For each year, we describe the beginning, end, and duration of the RSV season and the correlation with the mean annual temperature.

Results: We identified 10,183 RSV infections. The duration of the RSV season decreased significantly (1995: 29 weeks vs. 2019: 18 weeks; R: 0.6 (p< 0.001)), due to an earlier ending (1995: week 45 vs. 2019: week 34; 0.6 (p<0.001)). No correlation was observed between mean annual temperature and the duration, start, or end of the RSV season.

Conclusion: In the last 25 years, the duration of the RSV season has been significantly shortened due to an earlier ending, without correlation with temperature.