Introduction. Since 2019, more than 600 million cases of the new coronavirus infection Covid-19 have been reported worldwide. According to various studies, the development of a systemic inflammatory response and «cytokine storm» play an important role in the pathogenesis of kidney damage, which leads to impaired microcirculation, increased thrombus formation and the development of ischemic areas in the parenchyma.
Aim. To study the frequency and possible causes of purulent forms of pyelonephritis in patients who have had a new coronavirus infection Covid-19.
Materials and methods. The prospective and retrospective study included the results of 403 patients with acute non-obstructive pyelonephritis in the pre-Covid period and those with a history of a new coronavirus infection.
Results. In patients with acute non-obstructive pyelonephritis without past urological history who had a new coronavirus infection, an increase in purulent-destructive forms from 5.0 to 17.0% was noted. One of the reasons is increased antibiotic resistance and the emergence of pan-resistant uropathogens due to irrational use of antibacterial drugs.
Conclusion. The use of reserve antibacterial drugs in patients with acute pyelonephritis as empirical therapy and anticoagulants in order to improve microcirculation and prevent thrombosis is pathogenetically justified.

Keywords: apostematous pyelonephritis, kidney abscess, purulent-destructive pyelonephritis, COVID-19, coronavirus infection, antibiotic resistance, urinary tract infection