Pneumocystis Jirovecii Pneumonia in Patients Without HIV: A UK 5-Year Retrospective Study

Pneumocystis jirovecii pneumonia (PCP) is an opportunistic fungal infection that affects patients who are immunocompromised, which commonly includes people with HIV, haematological malignancies, a history of organ transplantation, and patients on long-term immunosuppressive therapies. England, as well as other countries, has seen a steady increase in the incidence of PCP. The authors’ study aimed to understand which medical conditions were predominant in their patient population diagnosed with PCP. The authors conducted a retrospective and observational study in adult patients with a diagnosis of PCP from January 2019–December 2023, a 5-year period, in a District General Hospital in the UK. The results showed that the majority (55%) of patients diagnosed with PCP did not have any malignancy, and that these patients were mainly individuals with rheumatological or autoimmune disease. Among patients with a prior diagnosis of neoplasia, 71% and 29% had solid organ tumours and haematological malignancies, respectively. The in-hospital fatality rate was 27% among all patients with PCP. There is a rising incidence of PCP among patients on long-term immunomodulating drugs, such as people with autoimmune disorders. A high index of suspicion is required for early disease identification and treatment to reduce mortality.