Objectives: We aimed to describe recent epidemiological trends of SARS-CoV-2, influenza virus (A/B), and respiratory syncytial virus (RSV) in the canton of Geneva, Switzerland, using data from the Sentinella network for primary care consultations, hospital-based surveillance at Geneva University Hospitals and municipal wastewater surveillance conducted by Eawag, the Swiss Federal Institute of Aquatic Science and Technology.

Methods: We described the temporal trends in weekly SARS-CoV-2, influenza virus (A/B), and RSV infections among primary care consultations, hospitalized patients and the mean normalized viral load per week for SARS-CoV-2, influenza virus (A/B), and RSV from wastewater samples between 1 July 2022 and 30 April 2025. We used Kendall’s rank correlation (τ) to assess the correlation between the viral RNA loads in wastewater and SARS-CoV-2, influenza A, and RSV infections among hospitalized patients between 1 September 2024 and 30 April 2025.

Results: The period from September 2024 to April 2025 was the first extended winter season since the beginning of the COVID-19 pandemic, during which SARS-CoV-2 activity remained consistently lower than previous seasons across all surveillance systems. In contrast, influenza activity was higher than in recent prior winter seasons. There was a decrease in the number of RSV hospitalizations during the 2024–2025 winter season. The associations between wastewater loads and infections were significant and positive for SARS-CoV-2 (τ = 0.75; p <0.01), influenza A (τ = 0.80; p <0.01), and RSV (τ = 0.68; p <0.01).

Conclusions: Our findings contribute to understanding the evolving epidemiology of COVID-19 in relation to the two other respiratory viruses (influenza and RSV) across complementary surveillance systems.