Virus-virus Interactions Among Patients Admitted to the Hospices Civils de Lyon, During 2022 to 2025 Winters Seasons

Condition(s) studied

Investigational drug(s) / intervention(s)

Virologic results: Virologic results for biological samples collected as part of the diagnosis of respiratory viral infections in patients of all ages receiving routine care, regardless of their department of origin, during the winter periods from 2022 to 2025.

Study summary

Respiratory viruses circulate throughout the year, and particularly during the winter. Consequently, co-infections involving two or more viruses can occur. The study of virus-virus interactions at the population level is necessary to understand the dynamics of co-infections. Viruses such as IAV (influenza A virus) and rhinoviruses (common cold viruses) are known to have a negative interaction, mutually excluding one another, which results in a reduced likelihood of co-infection. The study of virus-virus interactions at the population level constitutes an essential first step towards understanding and characterising these phenomena at the individual level, and subsequently at the cellular level. Using integrative approaches combining epidemiological data, clinical observations and in vitro models, it has been shown that IAV and SARS-CoV-2 have a negative interaction, whilst potentially contributing to the severity of respiratory infections. This research also suggests that prior vaccination against IAV reduces the risk of severe forms of the disease.

Furthermore, viral co-infections appear to influence the severity of respiratory infections, particularly in children. Children appear to be more susceptible to these co-infections, with around 35% of cases reported, compared with 6% in adults. In this context, the study and characterisation of virus-virus interactions appear essential to better understand the pathophysiology of respiratory infections and improve the management of co-infected patients.

Every week, Dr Jean-Sébastien Casalegno publishes the Hospices Civils' epidemiological bulletin, which considers the prevalence of respiratory viruses detected at the Centre de Biologie et Pathologie Nord. This local dataset reports on the co-circulation of respiratory viruses and is of interest for the study of virus-virus interactions at a population level.

The impact of viral co-infections on the severity of respiratory infections remains a subject of debate in the literature. Understanding the dynamics of interaction between respiratory viruses at a population level, in order to identify preferential associations or exclusions, is essential for assessing the clinical impact of co-infections.

Eligibility

Primary outcome measure(s)

• Virus-virus interactions over three consecutive winters — Baseline
  To characterize virus-virus interactions from 2022 to 2025 by assessing a co-infection exclusion score in order to identify, based on PCR results from respiratory samples collected over specific time periods (months/years), the preferred (positive) associations and exclusion (negative) relationships between respiratory viruses.

Trial sites (1)

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