On duodenal stump leakage caused by adult human Taenia

To the editor: Shao Xinxin and colleagues recently described a case of duodenal stump leakage caused by Taenia saginata (T. saginata).1 Apparently, they did not identify the discharged adult tapeworm recovered after the treatment neither morphologically nor molecularly. The authors concluded that the species responsible for the symptoms was T. saginata based on the fact that the patient mentioned that he had been infected by T. saginata two years ago.1 We assumed that if the patient was diagnosed two years ago, he was also treated to eliminate the worm. However, previous parasitation did not prevent re-infection with the same or with other Taenia species. The patient came from Tibet where the three human Taenia species co-exist, i.e. Taenia solium, T. saginata and Taenia asiatica.2,3 In Tibet, people do have the habit not only of eating raw or undercooked beef but also pork,2,3 therefore, the species causing the stump leakage could be any of the three species. Taenia saginata, acquired by the consumption of infected beef, is the least dangerous species since it only causes human taeniosis. On the other hand, human cysticercosis is a disorder caused by the extraintestinal larval stage of Taenia solium that can be fatal when the cysticerci are located in the central nervous system (neurocysticercosis). Taenia solium, as well as Taenia asiatica, are species transmitted to humans by the ingestion of infected pork, and there is a relevant knowledge gap about the third human Taenia, Taenia asiatica, of which it is still not known whether it is able to produce human cysticercosis or not.4 In addition to the fact that taeniasis can be a cause of complications in other gastrointestinal disorders (as the case published by Shao et al1) in human Taenia cases, it is crucial to establish which are the species responsible for the infection at least for three reasons: (1) to properly treat Taenia solium patients to avoid human cysticercosis; (2) to establish adequate control measures depending on the species identified; and (3) to investigate the possible presence of cysticercosis in Taenia asiatica patients.