[Pneumocystis jiroveci: a new name for an old pathogen].

Pneumonia due to Pneumocystis is an important cause of morbidity-mortality among immunodepressed patients, above all with human immunodeficiency virus infection and finally in patients with transplants, oncology patients and those subjected to drug immunodepression. Its lack of capacity to grow in the usual culture mediums has hindered knowledge on many aspects of this infection (transmission, acquisition mode, infection sources). However, the incorporation of molecular biology tools in recent years has made it possible to go deeper into the understanding of the epidemiology, biology and characteristics of the infection by this pathogen. These advances have led to the modification of the taxonomic classification of this atypical fungus and change in the name of the Pneumocystis responsible for the infection in humans, which is now called Pneumocystis jirovecii. During this article, we will show some of the most recent advances in the knowledge of the human pneumocystosis.