Mitochondrial DNA analysis strongly suggested that the patient became infected with the parasite in Nepal at least 10 years before the onset of the disease. The pork tapeworm Taenia solium is one of the most
important human parasites because of its pathogenicity. It causes two types of human infection: (1) teniasis, intestinal infection of adult worms, caused by eating undercooked pork contaminated with cysticerci (larval stage) and (2) cysticercosis, tissue infection of cysticerci throughout the body, Selleck Pexidartinib acquired by ingesting the eggs. Neurocysticercosis (NCC), cysticercosis in the central nervous system, is a lethal and rather common parasitic disease in many developing countries where pork is consumed. However, the recent increase in the number of immigrants and tourists is spreading the disease into the more developed countries and the communities where eating pork is forbidden.1–3 Thus, it is important to ascertain the origin of the infection to assess the risk factors in nonendemic areas.4 In August 1996, a 46-year-old Japanese man complained of a dull headache during his stay in Jakarta, Indonesia, and he had NVP-BEZ235 purchase a medical examination at the local hospital in Manila, Philippines on the way back to Japan. Cerebral computer tomography (CT) showed a putative brain tumor in the left temporal lobe.
Then he came back to Japan and was admitted to Kitasato University Hospital. By CT scanning, a small solitary cystic lesion with ring enhancement was observed at the cerebral surface of the left temporal lobe. He showed no other neurological abnormalities, and his blood/stool tests were within the normal range. In September, the patient was operated and a well-encapsulated cyst of about 1 cm in diameter was surgically resected. PAK6 Histopathological
examination revealed it to be a viable cysticercus of T. solium.5 He recovered well and came back to his job 19 days after the operation. NCC with solitary cyst was later confirmed serologically using highly specific antigens at Asahikawa Medical College.6 Where did the patient become infected? Because teniasis/cysticercosis is not endemic in Japan, it was assumed that he acquired the parasite outside of Japan. He had been an overseas technical advisor for 12 years since 1970s, and visited Indonesia, Nigeria, Nepal, and Malaysia, where NCC cases have been reported.7 Because the patient had lived in Indonesia for 6 years just before the onset of the disease (1990–1996), we suspected that he had been infected with the parasite there. To solve the puzzle, we retrospectively analyzed cytochrome c oxidase I (cox1) of mitochondrial DNA (mtDNA) using the formalin-fixed and paraffin-embedded histological specimen prepared from the patient. Based on the phylogenetic analysis using mtDNA sequences, T. solium can be divided into two genotypes, Asian and African/Latin American.