[HIV infection : risks of late diagnosis].

Pneumocystis jirovecii pneumonia is an opportunistic infection defining AIDS in advanced HIV disease. We report the case of a 64-year-old man with no known immunosuppression who presented with progressive dyspnea, dry cough, and severe hypoxemia. The patient developed severe acute respiratory distress syndrome requiring invasive mechanical ventilation. Bronchoalveolar lavage polymerase chain reaction revealed a high burden of Pneumocystis jirovecii. HIV testing was positive, with a viral load of 8,000,000 copies/mL and a CD4 count of 9 cells/mm³. The clinical course was complicated by immune reconstitution inflammatory syndrome. This case highlights the severe consequences of late HIV diagnosis in patients outside traditional risk groups and underlines the importance of broader HIV screening strategies.