INTRODUCTION
In December 2019, a series of 41 severe viral pneumonia cases were reported in Wuhan city, Hubei Province, China, whose cause could not be identified (1). Subsequent full genome sequencing and phylogenic analysis showed that SARS-CoV-2 belongs to the betacoronavirus 2b lineage, which belongs to the same group as Severe Acute Respiratory Syndrome coronavirus (SARS CoV), a highly virulent pathogen in humans (2,3). SARS-CoV-2 infection (COVID-19) was reported as a global public health emergency by the World Health Organization (WHO) in January 2020 and was declared a pandemic on March 11 (4,5).
The disease is transmitted by inhalation or contact with infected droplets, and the incubation period varies between 2-14 days. Symptoms are usually fever, cough, sore throat, dyspnoea. Symptoms are mild in most of the asymptomatic cases. However, in some patients (usually the elderly and those with comorbidities), it can progress to pneumonia, acute respiratory distress syndrome, and multiple organ dysfunction. It is estimated that the case mortality rate varies between 2-3% (6). However, most people infected with SARS-CoV-2 do not have symptoms (7,8). The potential for patients with no symptoms to spread COVID-19; It confirms the importance of early diagnosis, monitoring and isolation.
Accurate and rapid diagnosis of COVID-19 infection is very important to provide appropriate medical support to patients and to prevent disease spread by quarantine. The current recommendation for the diagnosis of active infection is to detect viral RNA from respiratory tract samples by real-time reverse transcription-polymerase chain reaction (RT-PCR). (9–12). RT-PCR test for COVID-19 is thought to have high specificity, but its sensitivity has been reported to be as low as 59-71% (13,14).
Alternative protocols with similar sensitivity were needed in SARS-CoV-2 screening due to the increasing rapidity of the COVID-19 pandemic, the difficulty of detecting asymptomatic cases, low sensitivity and time-consuming results of the RT-PCR test, and the inability of thorax CT (15-17). Recently, test methods have been developed for the rapid detection of combined SARS-CoV-2 IgG and IgM antibodies in human serum / plasma (19). In our study, we aimed to evaluate the results of simultaneous thorax CT and ELISA-based IgM / IgG tests in COVID-19 patients diagnosed with RT-PCR in our emergency department and to demonstrate the value of serological tests in the diagnosis of COVID-19.