The objective of our study is to investigate the prevalence of viral respiratory infections in inpatients following the end of the pandemic. Additionally, the prevalence of patients co-infected with multiple viruses simultaneously will be assessed.

In the secondary part of the study, the development of respiratory tract infections, the need for intensive care, and mortality rates within seven days will also be evaluated, and risk factors for patients with a more severe clinical course will be statistically calculated.

This study aims to determine the prevalence of viral respiratory agents in hospitalized patients post-COVID-19 and to examine the clinical course of respiratory viral co-infections, which are expected to be more severe.

This study will be conducted retrospectively at Kocaeli University Hospital between May 2023, considered the end date of the pandemic, and January 2024. Patients over 18 years of age will be included, and data will be accessed through the hospital automation system. Patients with SARS-CoV-2 PCR-positive symptoms and those expected to use molnupiravir due to the need for treatment will be considered as COVID-19. Respiratory tract agents will be detected by multiplex PCR from symptomatic inpatients. All patients with influenza will also receive oseltamivir. The distribution of viruses, the need for intensive care hospitalization, and whether they cause death within seven days, as well as the prevalence, clinical course, and risk factors of viral co-infections expected to be clinically more severe in the literature, will also be examined

Inclusion Criteria:

• Patients over 18 years of age
• Patients admitted to our clinic or consulted to infectious diseases from other inpatient services.
• Patients diagnosed with upper or lower respiratory tract infections due to viral agents

Exclusion Criteria:

• Patients infected with bacterial agents will not be included in the study.
• Patients admitted from the outpatient clinic were not included in the study plan.

The study population includes patients over 18 years of age who are hospitalized, have symptoms of respiratory tract infection, and have a positive result for a respiratory tract virus detected by PCR. Patients with SARS-CoV-2 PCR-positive symptoms who require antiviral treatment will be classified as cases of COVID-19.