Cytomegalovirus Encephalitis and Cerebral Toxoplasmosis in an Immunocompetent Patient: A Rare Case Report

Abstract

Cytomegalovirus (CMV) and Toxoplasma gondii infections are typically associated with immunocompromised individuals, in whom they can cause severe central nervous system (CNS) complications. However, their concurrent manifestation in immunocompetent hosts (IMCh) is exceptionally rare and underreported. We present the case of a 51-year-old immunocompetent male with a three-month history of progressive headache, nausea, and intermittent joint pain, without neurological deficits. Imaging revealed chronic infarcts in the basal ganglia and frontal lobe, as well as multifocal lesions in the periventricular area. Serological testing indicated high-avidity IgG for both CMV and T. gondii, consistent with chronic latent infections. Despite being HIV-negative and without prior immunosuppressive therapy, the patient exhibited hematologic abnormalities, including thrombocytopenia, lymphopenia, and eosinophilia. Treatment with valganciclovir, cotrimoxazole, and clindamycin led to symptomatic improvement. This case underscores the diagnostic challenges of CMV encephalitis and cerebral toxoplasmosis in IMCh, where nonspecific symptoms and overlapping radiological findings may mimic other etiologies such as stroke. Given the neurotropic nature of T. gondii and the hematologic impact of CMV, coinfection—though rare—should be considered in patients with atypical CNS symptoms and hematological abnormalities, even in the absence of immunodeficiency. This report showed the need for heightened clinical suspicion and thorough evaluation to avoid misdiagnosis and ensure timely intervention. Clinicians should recognize that serious manifestations of CMV and toxoplasmosis are possible in IMCh and may present subtly, necessitating comprehensive serologic and imaging workups for accurate diagnosis and management.