The vast majority of COVID-19 patients are currently receiving antibiotics. But only about 10% of COVID-19 patients actually have bacterial co-infection [1, 2]. In an effort to reduce unnecessary antibiotic treatment for COVID-19, the American Thoracic Society and the Infectious Disease Society of America have endorsed the use of procalcitonin testing (PCT) as a way to reduce COVID-19 antibiotic use [3]. Most patients with COVID-19 are mildly ill and have very low PCT levels at the time of admission (<0.25 ?g / L or even <0.1 ?g / L). However, in some cases, an increase in the PCT level is observed [4,5].

The aim of our study was to assess the role of procalcitonin in the choice of antibiotics in hospitalized patients with COVID-19. In the period from March 2020 to March 2021, the level of procalcitonin was determined in 101 hospitalized patients diagnosed with COVID-19, pneumonia, including 34 patients in the department of intensive care. All patients tested positive for SARS-CoV-2 using real-time polymerase chain reaction from combined nasopharyngeal swabs. The PCT level was determined using a Cobas e 411 immunochemical analyzer (Roche Diagnostics). For comparison, we selected two more understandable groups of adult patients: the group of patients admitted to the intensive care unit (n = 34) and the group with a moderate course of the disease (n = 67). For patients randomized to procalcitonin-controlled therapy, the use of antibiotics was more or less strongly discouraged (procalcitonin levels ? 0.1 or ? 0.25 ?g / L, respectively) or recommended (procalcitonin levels> 0.25 ?g / L) [6,7]. Sixty-seven patients were tested for PCT on admission to the COVID-19 pneumonia patient unit, and thirty-four on admission to the intensive care unit. In the first group of patients, the average PCT value was 0.086 ?g / L (a group with a low PCT level) and in the second group, the average PCT value was 0.471 ?g / L (the group with a higher level). In addition, there was a greater number of patients requiring invasive ventilation in the higher PCT group than in the low PCT group, and a better trend toward survival in the low PCT group. This was not statistically significant.

Thus, current evidence suggests that the likelihood of an adverse course of pneumonitis and/or bacterial infection in COVID-19 increases with increasing serum procalcitonin levels. PCT testing can help reduce unnecessary antibiotic use and associated side effects.

Keywords: antibiotic therapy; antimicrobial stewardship; procalcitonin