Introduction: Coronaviruses are the agents of viral respiratory infections and cause severe respiratory infections, especially in the elderly, those with chronic disease and immunocompromised patients. The aim of this study was to determine the positive and common types of Coronaviridae family in patients admitted to our hospital in the four-year period before the COVID 19 pandemic (2016-2020) and to investigate the distribution of coronavirus positivity by age groups, months, seasons and years. Materials and Methods: Between February 2016 and January 2020, clinical samples of 1164 female (45%) and 1428 (55%) male patients were sent to the molecular virology laboratory from the various clinics of Gazi University, Faculty of Medicine Hospital due to symptoms of acute respiratory tract infection. Coronaviridae family positivity was investigated retrospectively in clinical samples of 2592 patients aged 0-101 years. Nucleic acid extraction from the clinical samples was performed with the ‘EZ1 Virus Mini Kit’. For viral DNA amplification, it was performed by multiplex Real-Time PCR method using ‘FTD Respiratory Pathogen 21’ test. Statistical analysis of the distribution of coronavirus positivity by age groups, months, seasons and years was done by SPSS 20.0 computer program. Results: Two hundred and twenty-nine (8.8%) of the clinical samples were found to be positive for any Coronavirus type. The most common type of Coronavirus was found to be CoV-229E with 52% (119/229). The distribution of other coronavirus types including CoV-HKU1, CoV-OC43 and CoV-NL63 was determined as 19.2% (44/229), 17.4% (40/229) and 14% (32/229) respectively, and the most common type of Coronavirus changed from year to year. Single Coronavirus positivity was found to be 48.1%, its association with other viruses was 51.9%. The highest coinfection of Coronavirus was found in Rhinovirus (35.3%) and influenza A virus (19.3%). Patients over 60 years of age were found to have a higher rate (30.6%) positivity compared to other age groups (p< 0.05). The highest rate of Coronavirus positivity was observed in January (17.4%) and the lowest rate in June (1.7%). It was observed that the highest rate of positivity (44.2%) was in winter and the lowest rate (8.2%) was in summer (p< 0.05). Coronaviruses were found to be detected at higher rates in winter with seasonal variation (p< 0.05). Conclusion: Since it is not possible to diagnose viral respiratory tract infections based on clinical findings, viral respiratory panel and Multiplex real time PCR test is a fast and useful method in routine diagnosis for early diagnosis and treatment and to prevent unnecessary use of antibiotics. Coronaviridae family positivity is seen in patients over 60 years of age and in seasonal variation, with higher rates in winter.
A two year surveillance for influenza and RSV using Real-time PCR among children with acute respiratory infections in Kolkata reveals distinct seasonality of infection
