Investigation of Respiratory Pathogens Responsible for Coinfection in COVID-19 Patients

Objective: This study aims to determine the coinfection rate of hospitalized COVID-19 patients, investigate the etiological agents causing coinfection, and reveal the clinical characteristics of patients with coinfection. In addition, by identifying coinfections accompanying viral infections, we aim to prevent unnecessary antibiotic use and antimicrobial resistance. Methods: This study analyzed 76 hospitalized patients with prediagnoses of COVID-19 between Sep 2021 and Feb 2022. They had a positive RT-PCR test for SARS-CoV-2, compatible thoracic Computed Tomography findings, and biochemical parameters indicating coinfection. Patients’ respiratory samples were tested for other respiratory pathogens by multiplex PCR. Results: Out of 76 patients, 54 (71.1%) were found to have one or more pathogens along with SARS-CoV-2. Among these patients, 35 had a single pathogen, while 19 had multiple pathogens. The most common pathogens were Staphylococcus aureus in 24 (31.6%) patients, influenza viruses in 18 patients (23.7%), and Streptococcus pneumoniae in 15 (17.1%) patients. There was no significant difference between mortality rates, length of hospital stay, hospitalization site, biochemical parameters (C-reactive protein, procalcitonin, lactate dehydrogenase, D-dimer, lymphocyte count, ferritin level) between patients with and without coinfection. Conclusion: Although no significant difference was found in parameters such as mortality rates and length of hospital stay in patients with comorbid pathogens in our study, we think that clinicians should take the risk of coinfection into account in the follow-up and treatment of hospitalized patients and perform appropriate tests in suspected cases. Our study showed that the viral and bacterial pathogens accompanying SARS-CoV-2 are significant and that more specific and large-scale studies are needed to examine the clinical effects of these factors. We also believe that influenza, pneumococcal, and COVID-19 vaccines should not be ignored, especially in risk groups, during the pandemic.