The dwarf tapeworm Hymenolepis nana in pet rodents in Slovakia-epidemiological survey and genetic analysis.

Rodents are popular companion animals and are often kept as pets for children. However, they can be reservoirs of a variety of zoonotic pathogens. As little attention is being paid to the possibility of acquiring parasitic infections from pet rodents, the occurrence of Hymenolepis nana in rodents from pet shops and breeding clubs of Slovakia was surveyed, with parallel genetic analyses to type isolates from rodent species. In 2016-2018, pooled faecal samples from 119 boxes with 228 mice, 191 rats, 124 hamsters and 25 Mongolian gerbils were collected from 12 pet shops and 3 breeding clubs in five cities of eastern Slovakia. H. nana eggs were detected in 25 (21.0%) boxes. Animals from pet shops were infected more frequently (24.6% positive boxes) than those from breeding clubs (17.2%), without statistical significance. The highest prevalence was recorded in rats from pet shops, where 41.7% of boxes contained parasite eggs. Hamsters and mice in pet shops were also frequently infected; in 23.8% and 25% of boxes, respectively, H. nana eggs were observed. Prevalence in rats and hamsters from breeding clubs was lower, but in mice surpassed 40%. Nine samples with positive PCR products in any of the four DNA regions, mitochondrial cox1 and nuclear pmy, ITS1 and ITS2 targets, gave profiles characteristic of H. nana. The results imply the risk of zoonotic transmission of hymenolepiasis in Slovakia. Particular attention should be given to hygiene level maintained while keeping rodents. Furthermore, rodents intended for sale should be tested for parasites and then dewormed.