Background. COVID-19 predispose patients (pts) to secondary viral, bacterial and others infections that may have a worse outcome than COVID-19 on its own.
Aim: to evaluate the frequency of secondary infectious complications of the airways in pts with post-COVID-19 syndrome, who need hospital treatment in post-COVID-19 period.
Materials and Methods. 85 pts (54 (63.5%) men aged 19 to 81 (55.5±1.6) years who suffered pneumonia during the acute COVID-19 and need hospital treatment in the post-COVID period with pulmonary complications were examined. The main reason for hospitalization was respiratory failure due to the progression of the pathological process of the lungs, fibrotic changes or the "disappearing lung" syndrome, exacerbation of obstructive lung diseases. For all pts CT scan of the chest, sputum culture test, detection of Epstein-Barr virus (EBV) DNA load in nasopharyngeal scraping were performed.
Results. In 41 (48.2%) pts secondary infectious complications were detected, see table 1.
Table 1 ? Secondary infectious complications (n=85)
| Parameter | abs | % |
| EBV reactivation (EBVR)* | 27 | 31.8 |
| Bacterial complications (S. aureus, Klebsiella spp., Ps. aeruginosa, E. coli, Candida spp., S. pneumoniae, A. baumannii) ? in order of decreasing frequency | 14 | 16.5 |
| Mucormycosis** | 3 | 3.5 |
| Aspergillosis*** | 1 | 1.2 |
*? in 3 pts EBVR was combined with bacterial complications and in 1 patient ? with Aspergillosis;
** ? confirmed by histopathological examination of the lung tissue;
*** ? diagnosed on chest CT.
Conclusion. Secondary infectious complications of the airways in post-COVID-19 pts take place in the almost half of the pts. The most frequent are EBVR and bacterial complications, the most severe - mucormycosis.