Identification of Taenia asiatica in China: molecular, morphological, and epidemiological analysis of a Luzhai...

Multiple analysis has characterized a recently described tapeworm of people, Taenia asiatica, in mainland China. Six adult tapeworms collected from people of the Zhuang minority residing in the southern part of China (Luzhai isolate) were comparatively analyzed with other tapeworms from people: T. asiatica (n = 2, South Korea), T. saginata (n = 1, Poland; n = 1, Korea), and T. solium (n = 1, People's Republic of China). Experimental infections with eggs from the Luzhai isolate in pigs and cattle produced cysticerci, each with a hookletless scolex and with wartlike formations on the external surface of the bladder wall. There were rostellar protrusions in the scolices of adult worms. Random amplified polymorphic DNA analysis using 3 arbitrary primers produced bands identical to those of the Korean T. asiatica. Conversely, T. saginata and T. solium exhibited different banding patterns. Phylogenetic relationships inferred from the complete nucleotide sequences of the internal transcribed spacer 2 placed the Chinese tapeworms consistently within the T. asiatica clade by 96% bootstrapping value in the maximum likelihood analysis, 96% in maximum parsimony, and 100% in neighbor joining. These collective data demonstrate that T. asiatica is sympatrically distributed with the other 2 species of Taenia in the human host in mainland China.