Presumptive Neurocysticercosis with Concurrent Bacterial Infection: A Diagnostic Challenge.

Background: Neurocysticercosis is a parasitic infection of the central nervous system caused by the larval stage of Taenia solium. This disease is endemic in some countries in Central and South America, South and South-East Asia, and sub-Saharan Africa. In North America, Europe, Japan, and Australia, only sporadic cases are documented. Moreover, reports of bacterial superinfection arising within neurocysticercotic lesions remain exceptionally scarce. Methods: We report a clinically severe and diagnostically challenging case of suspected neurocysticercosis with cerebral streptococcal superinfection in a 17-year-old Italian patient with Down syndrome and no history of travel to endemic regions. Results: The patient, with pre-existing epileptic encephalopathy, presented with progressive drowsiness and altered mental status, rapidly deteriorating to cardiorespiratory arrest. Neuroimaging demonstrated multiple ring-enhancing lesions, in conjunction with positive Taenia solium serology. Streptococcus spp. was identified in one neurosurgically drained lesion, consistent with secondary bacterial involvement in association with concurrent pneumonia. Combined antiparasitic therapy and targeted antimicrobial treatment resulted in sustained clinical and radiological improvement. Conclusions: In non-endemic settings, neurocysticercosis should remain within the differential diagnosis of unexplained epilepsy and multifocal CNS lesions. Although rare, bacterial superinfection warrants consideration in atypical presentations, particularly in individuals with concomitant infectious foci and underlying immune dysfunction such as that associated with Down syndrome.