Clinical analysis of Pneumocystis jiroveci pneumonia secondary to novel coronavirus infection：a case series

Background: Pneumocystis jiroveci pneumonia (PJP) is one of the common opportunistic infectious diseases of thelungs in immunosuppressed populations. With the global epidemic of the Delta variant of the novel coronavirus (SARS-CoV-2), it has been found that patients with novel coronavirus pneumonia can have concurrent or subsequent co-infection with Pneumocystis jiroveci. The purpose of this paper was to investigate the clinical characteristics and diagnosis and treatment of patients with Pneumocystis jiroveci pneumonia (PJP) secondary to novel coronavirus (COVID-19) infection. Methods: Clinical data of 14 patients with Pneumocystis jiroveci pneumonia secondary to novel coronavirus infection diagnosed in the First Hospital of Wenzhou Medical University from September 2022 to May 2023 were collected, and their general conditions, laboratory tests, imaging data, and treatments and regressions were analyzed. Result: Secondary PJP occurs more often in patients with severe novel coronavirus infection with immunocompromised patients and manifests itself as dyspnea and a significant decrease in arterial oxygen saturation higher than that of the average COVID-19 patients. Laboratory tests suggest a decrease in lymphocyte subset counts, absolute CD4+ T-cell counts, and elevated differential partial pressure of alveolar arterial blood oxygen, lactate dehydrogenase (LDH), and serum (1,3)-β-D-glucan (BDG). Metagenomic Next-Generation Sequencing (mNGS) combined with serum (1,3)-β-D-glucan (BDG) has a higher sensitivity for screening PJP. On chest imaging, it is mostly characterized by the crescent sign, pleural effusion, and enlarged hilar and mediastinal lymph nodes. Conclusions: It is difficult to identify PJP in the early stage of COVID-19 infection, and the combination of respiratory symptoms with BDG, mNGS and imaging examination is of great value for the early diagnosis of PJP. SMZCO and respiratory support are the most important treatments.