Updating Taenia asiatica in humans and pigs

Abstract

An epidemiological study on taeniasis and cysticercosis in northern India has recently updated the epidemiology of Taenia asiatica. Practically, all the detected cases of taeniasis were caused by T. asiatica, cited for the first time in humans in that country. The finding widens the geographical distribution of T. asiatica, a species wrongly considered an exclusive South-Eastern Asian parasite. Due to the introduction of molecular techniques in Taenia diagnosis, the species is slowly showing its true distribution. A human Taenia species with cosmopolitan hosts (the same as the other two Taenia species) but limited to a specific geographical area and not affected by globalisation would certainly be hard to believe. Regarding cysticercosis, there is a remarkable finding concerning T. asiatica pig cysticercosis, specifically the presence of the cysticercus of T. asiatica not only in the liver (its preferential infection site) but also in muscle. This is the first time that the cysticercus of T. asiatica has been found in muscle in a naturally infected pig. This fact is actually relevant since people are at a greater risk of becoming infected by T. asiatica than previously expected since the liver is no longer the only site of pig infection. The Taenia species causing Taenia saginata-like taeniasis around the world, as well as pig and human cysticercosis, should always be molecularly confirmed since T. asiatica could be involved.