Coronavirus and Post-COVID-19 Syndrome: A Systematic Review

Coronavirus infectious Disease 2019 (COVID-19) was first reported in Wuhan, China, and with its rapidly mutating variants, it soon became a global concern. In response to the pandemic, intensive research and development efforts led to the development of six vaccines approved by the World Health Organization (WHO). Coronavirus is divided into four genera: alpha, beta, gamma and delta. Its unstable ssRNA resulted in multiple strains in a short period, which acted as a selection pressure for transmissibility. Sequelae of COVID-19 infection include multiple syndromes which have been reported at high incidence globally. Using the Cochrane guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we present a systematic review of the most common syndromes reported. A total of 12 eligible studies were included in this review. Syndromes reported in the literature include immune thrombocytopenic purpura (ITP), viral encephalomyelitis, hemophagocytic lymphohistiocytosis, thrombotic thrombocytopenic purpura (TTP), Guillain-Barrè syndrome (GBS) and postural orthostatic tachycardia syndrome (POTS). We cover the hypothesized pathophysiology, presenting symptoms and treatment for each respective syndrome. We aim to discuss coronavirus and its variants to provide a foundation on which to examine the syndromes manifested after COVID-19 infection (post-COVID-19 syndrome).