<i>Cysticercus tenuicollis</i> in selected locations in Poland: genetic diversity, prevalence and epidemiological patterns in roe deer <i>(Capreolus capreolus)</i> and moose <i>(Alces alces)</i>

Abstract Introduction Taenia hydatigena is a widespread tapeworm. The predilection site of the adult form is the small intestine of its carnivore definitive hosts, and this site of the larval form, Cysticercus tenuicollis , is the abdominal visceral organs of its ungulate intermediate hosts. Cysticercal lesions are of food safety and economic importance, as they may condemn carcasses or internal organs of slaughtered animals and hunted game. The study aimed to evaluate the prevalence, intensity of infection and species composition of metacestodes from Polish roe deer and moose, and analyse the genetic diversity of the isolates. Material and Methods Altogether, 167 roe deer (from the Mazowieckie and Łódzkie voivodeships) and 36 moose (from the Mazowieckie, Lubelskie and Podlaskie voivodeships) were studied. Metacestodes were collected post mortem and used for molecular investigations based on the partial cox 1 (cytochrome c oxidase subunit 1) gene. Results The prevalence and the general intensity of infection were 9.6% and 1–6 cysts for roe deer, and 8.3% and 1–9 cysts for moose. Exclusively T. hydatigena infections were noted. Intraspecific genetic diversity of 1.42% was observed. The omentum and the mesentery were the most prevalent locations of metacestodes. Conclusion Taenia hydatigena isolates from roe deer and moose varied genetically. Assuming national prevalence at the level observed in this study, the number of infected roe deer in Poland could exceed 18,000. Although T. hydatigena is not a zoonotic agent, its spread should be monitored and limited. Dogs should not be fed raw game meat in order to prevent parasitosis from spreading to farm animals.