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Pneumocystis pneumonia
What's new
Updated 2024 NIH/CDC/IDSA/HIVMA and 2024 BHIVA guidelines for the prevention and management of pneumocystis pneumonia .
Background
Overview
Definition
PCP is a severe opportunistic fungal infection caused by P. jirovecii, primarily affecting immunocompromised individuals.
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Pathophysiology
The pathophysiology of PCP involves airborne transmission of the fungus, which then invades lung tissue and adheres to type 1 epithelial cells. The attachment of Pneumocystis to the alveolar epithelium promotes the transition of the organism from the trophic to the cyst form, leading to the production of inflammatory mediators, lung injury, and impaired gas exchange.
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Epidemiology
The incidence of PCP is estimated at 2.2-4.5 per 100,000, with more than 80% occurring in patients without HIV. In the US, approximately 10,500 hospitalizations and 400 deaths are reported annually due to PCP.
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Risk factors
Risk factors for PCP include HIV infection with a low CD4+ T-cell count, malignancies, solid organ transplantation, hematologic stem cell transplantation, prolonged use of corticosteroids and other immunosuppressive agents, such as chemotherapy (especially purine analogs), T-cell-depleting agents, TNF-α inhibitors, anti-interleukin 6, anti-CD26, and calcineurin inhibitors.
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Disease course
Clinically, PCP often presents with a progressive nonproductive cough, exertional dyspnea, chest pain, and fever. Patients with HIV may have an indolent course, while patients without HIV usually present with rapidly progressive onset.
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Prognosis and risk of recurrence
The mortality rate of PCP in patients with and without HIV is estimated at 25% and 33-69%, respectively.
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Guidelines
Key sources
The following summarized guidelines for the evaluation and management of pneumocystis pneumonia are prepared by our editorial team based on guidelines from the British HIV Association (BHIVA 2024), the British Society for Haematology (BSH 2024,2022,2018), the European League Against Rheumatism (EULAR 2024), the European Respiratory Society (ERS/EBMT 2024), the Infectious Diseases Society of America (IDSA/CDC/NIH/HIVMA 2024), the Consensus Expert Panel ...
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