Examination of SARS-CoV-2 RNA in joint synovial fluid of patients with COVID-19 and acute knee arthritis.

It has not yet been fully established that there is coronavirus disease 2019 (COVID-19) involvement in the synovial fluid and it remains a topic of debate. The aim of this study was to evaluate the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in knee joint synovial fluid of patients with COVID-19. This retrospective study was conducted with an initial screening of patients who were admitted to a tertiary pandemic hospital due to COVID-19 symptoms, and underwent treatment for COVID-19 between March and June 2020. A total of 2476 patients were hospitalized or received treatment for a possible diagnosis of COVID-19. While the RT-PCR test was positive in 318 patients (12.8%), 2158 (87.2%) were computed tomography positive but reverse transcription-polymerase chain reaction (RT-PCR) negative. Twelve patients were consulted due to acute joint effusion. Of five patients with knee joint effusion and a positive RT-PCR test, the synovial tissue RT-PCR test was positive in only one patient. This paper is the first to show the presence of SARS-CoV-2 in synovial fluid. This can be considered of importance for the determination and elimination of the route of transmission, thereby preventing further development and spread of the disease. [ABSTRACT FROM AUTHOR]