First known COVID-19 case and contact tracing efforts in Istanbul, Turkey

COVID-19 has now become a global pandemic. Understanding the routes of transmission is vital in the mitigation and suppression of the disease. Istanbul has become one of the disease's epicenters. This study aims to describe the first COVID-19 case and contact tracing efforts around it in Istanbul. The descriptive study was conducted in Istanbul, Turkey. First and associated COVID-19 cases were investigated with contact tracing and described primary and secondary cases. The source case was an individual who returned to Turkey from international travel at the beginning of March and tested PCR (-). The index case is the brother of the source case and is considered the first PCR (+) case diagnosed in Istanbul. Contact tracing revealed 23 PCR (+) cases, 14 of which resulted in hospitalization and three deaths. This study described cases of the first COVID-19 cluster in Istanbul. Also, contact tracing was used in this first cluster. This contributed to contact tracing algorithms in Turkey.