Post-COVID-19 syndrome: a discussion of onset timing

Introduction. Post-COVID syndrome (alternatively: chronic COVID syndrome, post-acute sequelae of COVID-19, long-haul COVID, long COVID, PASC, CCS) is a state of permanent or permanent presence of symptoms of a pathological process after COVID-19. Currently, there is no consensus on the timing of the onset of post-COVID-19 syndrome. The purpose of this study was to analyze the appearance of some post-COVID symptoms 1, 2 and 3 months after infection with the SARS-CoV-2 virus. Materials and methods. The analysis of clinical and laboratory data of 59 medical workers who had a mild or moderate form of COVID-19 was carried out. Three groups were formed: with the assessment of post-COVID-19 changes 1 month after the onset of the disease; with the detection of changes after 2 months; and with the detection of dysfunctions after 3 months. Results and discussion. It was found that 57.7% of respondents complained of fatigue, weakness, sleep disorders in the first month of observation. After 2 months, the frequency of complaints decreased by 42.3%, and by 3 months it increased again by 15.6%. A month after COVID-19, several cases were recorded when employees were unable to perform any, even very light, work. However, by 3 months of follow-up, 96.2% of the surveyed declared full recovery of efficiency. The appearance of muscle, joint, and spinal pain was reported more often in the first month after COVID-19, then the number of complaints decreased by half to 23–25% of the total number of observations. The assessment of the severity of the infection among the respondents of the three groups did not reveal significant differences between the data in 1, 2 and 3 months after COVID-19. Conclusion. An analysis of some post-COVID symptoms showed that in mild and moderate COVID-19, manifestations are observed 1, 2 and 3 months after infection with the SARS-CoV-2 virus. Multidirectional change dynamics were revealed, more often accompanied by a decrease in the manifestation of post-COVID syndrome 2 months after coronavirus infection, which may create a false impression of an absence of signs of post-COVID syndrome during this period.