Past Achievements, Present Gaps, and Future Priorities in Pneumocystis jirovecii Research: A Global Bibliometric Analysis.

Pneumocystis jirovecii is an opportunistic fungal pathogen responsible for Pneumocystis pneumonia (PCP), a severe infection that remains a major cause of morbidity and mortality among immunocompromised patients, particularly in non-HIV immunosuppressed populations. Despite its recognized clinical relevance and inclusion in the World Health Organization's Fungal Priority Pathogens List, important gaps persist in its diagnosis, epidemiology, and therapeutic management. This study provides a comprehensive bibliometric analysis of global scientific production on P. jirovecii using Scopus as the primary data source. Publications were evaluated for temporal trends, document types, authorship patterns, institutional productivity, collaboration networks, funding sources, thematic evolution, and journal distribution, with additional comparison against other major pneumonia-associated pathogens. A total of 27,396 articles published between 1916 and 2025 were identified. Over the last 50 years, scientific output increased from 10,382 publications in 1975-2000 to 16,496 in 2001-2025, representing an overall growth of 58.9%. Early research expansion was strongly shaped by the HIV/AIDS epidemic, whereas the post-2000 period reflected advances in molecular diagnostics, taxonomic clarification, and broader attention to non-HIV immunosuppressed populations. Although the field has become more diversified and clinically integrated, persistent structural inequities and underinvestment continue to limit progress, particularly in low- and middle-income settings.