Coinfection of Streptococcus agalactiae meningitis and cerebral toxoplasmosis in an HIV-immunocompromised patient: A case report

Abstract

Introduction: Human immunodeficiency virus (HIV) infection is a major predisposing factor for immunosuppression in untreated patients, increasing susceptibility to opportunistic infections. Among these, bacterial meningitis and cerebral toxoplasmosis are common, although they may present with atypical manifestations that delay diagnosis. Case presentation: We report a 38-year-old man who presented with neurological focalization and abnormal vital signs. The diagnosis of de novo HIV directed the evaluation toward neuroinfection. Cerebrospinal fluid analysis confirmed Streptococcus agalactiae, and brain magnetic resonance imaging revealed lesions consistent with cerebral toxoplasmosis, establishing a coinfection of exceptional rarity in the indexed literature. Discussion: Simultaneous coinfection by S. agalactiae and Toxoplasma gondii in the central nervous system of a patient with advanced HIV is exceptional. This case emphasizes the importance of integrating epidemiological context, clinical findings, and imaging to guide timely diagnosis. Magnetic resonance imaging played a decisive role by identifying lesions that were not detected on initial computed tomography. Conclusions: Early diagnosis and treatment in immunocompromised patients improve neurological prognosis and quality of life, even in unusual coinfection scenarios. To our knowledge, this coinfection has not been previously reported in the indexed literature, highlighting its clinical relevance.