Challenging Diagnosis of Streptococcus intermedius-Associated Empyema in an Immunocompetent Adult: A Case Report and Literature Review

The significance of Streptococcus intermedius in infectious diseases, especially pleural infections, is gaining recognition. While traditional risk factors like dental procedures and immunosuppression remain pivotal in differential diagnosis, there is an emerging recognition of unconventional clinical presentations and risk factors linked to infections by S. intermedius. This shift compels medical professionals to broaden their diagnostic and therapeutic strategies, underscoring the intricate and evolving nature of managing infections associated with this opportunistic bacterium. We describe the case of a 48-year-old immunocompetent woman with untreated hypertension who experienced a 15-day episode of right-sided chest pain, which worsened with a sudden onset of dyspnea, yet her daily activities remained unaffected. Physical examination suggested a pleuropulmonary syndrome due to significant pleural effusion, with a computed tomography (CT) scan of the lungs revealing about 50% effusion on the right side. Laboratory tests indicated elevated inflammatory markers. Ultrasound-guided thoracentesis extracted purulent fluid compatible with empyema, necessitating the placement of a pleural drain and multiple pleural cavity lavages using alteplase, which led to the removal of substantial infected fluid. Culture of the pleural fluid identified S. intermedius, which was pansusceptible. Treatment with intravenous ceftriaxone was administered, resulting in a favorable clinical outcome. This case highlights the critical nature of recognizing atypical clinical presentations and managing complex bacterial infections in the pleural space.