Clinical Manifestations and Diagnostic Challenges of Human Taeniasis in a Low-Prevalence Setting: An Eight-Case Series from South Korea, 2019–2025

ABSTRACT. In South Korea, a low-prevalence setting for taeniasis, the clinical recognition of this infection remains challenging. Eight patients diagnosed with taeniasis at Chosun University Hospital between January 2019 and July 2025 were retrospectively reviewed. Clinical characteristics, exposure history, and results from stool microscopy, serologic testing, and molecular analyses, including multiplex polymerase chain reaction and 18S ribosomal RNA (rRNA) sequencing, were analyzed to evaluate clinical presentation and diagnostic performance in routine clinical practice. Clinical manifestations were generally mild and nonspecific, and most patients sought medical attention only after spontaneously passing proglottids. A history of consuming raw or undercooked beef was the most common route of exposure. Conventional diagnostic methods, including stool microscopy and serological testing, had limited utility, with stool microscopy successfully used to detect Taenia eggs in only two of six tested patients. Additional molecular analyses in the present study, including multiplex polymerase chain reaction and 18S rRNA sequencing, improved diagnostic confirmation and provided supportive phylogenetic evidence for species relatedness within the genus Taenia , including clustering of seven isolates near Taenia saginata reference sequences and one isolate near Taenia asiatica reference sequences. However, these approaches still lacked sufficient resolution for reliable species-level differentiation. These findings highlight that in low-prevalence settings, the major diagnostic challenge is no longer detecting taeniasis itself but reliably differentiating species, particularly excluding Taenia solium , which may affect decisions regarding further evaluation for cysticercosis or neurocysticercosis.