[Co-infection of Severe Acute Respiratory Syndrome Coronavirus 2 and Other Viral Respiratory Pathogens in the Republic of Korea].

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), is co-infection with other respiratory viruses can negatively affect the patient's clinical condition and cause difficulty in breathing, comorbidities, and increased mortality risk. Hence, the Korea Centers for Disease Control and Prevention Agency analyzed the co-infection rate of respiratory viruses, such as influenza, and the distribution by age groups in domestic COVID-19 patients. Co-infection with one or more respiratory viruses was confirmed in 104 (2.0%) of 5,171 COVID-19-positive samples collected from January to December 2022. The detection rate of co-infection with respiratory pathogens was highest at 15.8% in the age group of 0-6 years. The immature immune system of children and environmental resistance of non-enveloped viruses may have contributed to the high co-infection detection rate. As the spread of respiratory viruses is increasing due to relaxation of the COVID-19 restrictions and co-infections are expected to increase, we will continue to monitor co-infections of SARS-CoV-2 and other respiratory viruses closely.