Abstract: Objective To describe the morphological characteristics of Porocephalus taiwana sp. nov., discuss its pathogenic features and the method of etiological diagnosis of the new disease. Methods Fecal sedimentation concentration was used to collect nymphs from the patient’s watery stool for species identification. Clinical information was collected for determining the pathogenic features of the new infection. Results A new pathogenic pentastomid Porocephalus taiwana sp. nov. is discovered and a new disease-porocephaliasis taiwana-is nominated. With the findings from this case it is proposed that the traditional visceral pentastomiasis should be divided into two subtypes, Encystic and Excystic. According to the pathological features, this case belongs to the excystic visceral pentastomiasis. Conclusion Porocephalus taiwana sp. nov. is a new pathogenic pentastomid infecting humans. Porocephaliais taiwana belongs to a novel type (excystic) of visceral pentastomiasis.

Key words: Pentastomid, Porocephalus taiwana sp. nov., Pathogenicity, Taiwan, China