Pneumocystis pneumonia mimicking COVID-19

Background. The new coronavirus infection COVID-19 caused by a SARS-CoV-2 zoonotic beta-coronavirus has radically transformed the conventional concept of the immune system’s participation in an infectious process. The successful application of anti-interleukin monoclonal antibodies and inhibitors of Janus kinases in COVID-19, traditionally contraindicated in infections, testifies that the immune response to the pathogen may be more dangerous than the infection itself. However, when prescribing the immunosuppressive therapy to COVID-19 patients, one should not forget that some interstitial pneumonias caused by opportunistic microflora, such as Pneumocystis Jirovecii, have similar clinical and radiological manifestations. Clinical case description. A 29-year old female patient was admitted to the infectious disease hospital with complaints of a febrile temperature, shortness of breath at rest, low-productive cough, pronounced weakness. She had been ill for 14 days, the SARS-CoV-2 RNA was detected at the pre-hospital stage. After the admission, a chest CT scan was performed showing a subtotal lung damage with the characteristic radiological manifestations of interstitial pneumonia in the form of ground glass opacity regions, presence of “air traps”, that was initially attributed to bilateral viral pneumonia (СТ-3/4). The subsequent examination confirming primary HIV infection and a sputum analysis positive for P. Jirovecii allowed us to establish a correct clinical diagnosis of pneumocystis pneumonia against the background of HIV infection and a mild COVID-19 course, administer a co-trimoxazole therapy and obtain a favorable outcome. Conclusion. This observation demonstrates the necessity of applying an individual approach to each patient admitted to a COVID hospital and performing a differential diagnosis, even when COVID-19 is confirmed by the laboratory work, in order not to miss other interstitial pneumonias, in particular, pneumocystis pneumonia appearing against the background on immunodeficiency.