Coenurosis of Yak, Bos grunniens, caused by Taenia multiceps: A Case Report with Molecular Identification in Qinghai Tibetan Plateau Area, China

Abstract

Coenurosis is an important zoonotic helminthic disease caused by the larval stage of the tapeworm Taenia multiceps. This parasite typically infects the brain of the intermediate hosts, including sheep, goat, cattle and even humans. We report a case of T. multiceps infection in a yak confirmed by clinical symptoms, morphological characteristics, and molecular and phylogenetic analyses. The coenurus was thin-walled, whitish, and spherical in shape with a diameter of 10 cm. The parasite species was identified as T. multiceps by PCR amplification and sequencing of the 18S rRNA, cox1 and nad1 genes. Three gene sequences all showed high homology (all above 97%) with the reference sequences from different hosts. Moreover, phylogenetic reconstructions with the 3 published Taenia gene sequences confirmed that the Qinghai yak isolate was closely related to T. multiceps. Although there are advanced diagnosis and treatment methods for coenurosis, early infection is difficult to diagnose. Importantly, the findings of yak infection case should not be ignored due to its zoonotic potential.

Taenia multiceps coenurosis: a review

“…The disease has also been reported in animals other than small ruminants, including cattle [ 37 , 48 , 74 , 75 ], mouflon [ 76 , 77 ], buffalo, horses [ 78 , 79 ] and yak [ 80 , 81 ]. Coenurosis in rarely seen in the tissues of small ruminants other than those of the brain or spinal cord, and has been described mainly in Asian countries, and never in Europe or the Americas.…”

“…Limited data have been published on the molecular characterization of T. multiceps in cattle, which mostly indicated similar genetic variants of T. multiceps to those found in sheep and goats [ 17 , 74 ]. Likewise, phylogenetic reconstructions based on 18S rRNA, cox1 and nad1 gene sequences showed that a T. multiceps yak isolate from China was closely related to T. multiceps isolates from other hosts and geographic locations [ 80 ].…”

Improved Dot-ELISA Assay Using Purified Sheep Coenurus cerebralis Antigenic Fractions for the Diagnosis of Zoonotic Coenurosis

“…Moreover, C. cerebralis causes sheep coenurosis, which is common in Egypt, in which the metacestodes develop in the brain and spinal cord mainly, causing nervous signs, depression, circling, convulsions, head deviation, blindness, and ataxia leading to animals' death and severe economic DOI: https://dx.doi.org/10. 54203/scil.2022.wvj30 losses (Zhang, 2019). Dogs are a definitive host for Taenia species; a high incidence of infection by this metacestode in sheep should be reflected in humans in the same localities (Rostami et al, 2013).…”