Trichinellosis dissemination among wild carnivores in the Republic of Kazakhstan: A 10-year study

Vet World. 2023 Sep;16(9):1840-1848. doi: 10.14202/vetworld.2023.1840-1848. Epub 2023 Sep 14.

Abstract

Background and aim: Trichinellosis is caused by a species of roundworm called Trichinella and is an invasive disease causing severe medical, veterinary, and socioeconomic problems worldwide. More than 100 mammalian species are Trichinella hosts. Among domestic animals, pigs and dogs are prone to trichinellosis. An essential aspect of controlling the spread of infection is to identify the number and level of infections in wild carnivores in the country. However, the number, habitats, and movements of wild animal Trichinella hosts in Kazakhstan have not been reported yet. This study aimed to monitor the wild animal habitat nearby the settlements for tracking the trichinellosis speading among carnivores.

Materials and methods: Wild carnivorous animals were captured in seven regions of the Republic of Kazakhstan. The carcasses of corsacs, wolves, foxes, wild boars, and badgers were studied. Muscle tissue samples from spontaneously infected wild animals were collected. The digestion method in "GASTROS-2M" was used to isolate Trichinella spp. from animal muscles. The species of the parasite was determined by a polymerase chain reaction for 5S spacer of Trichinella ribosomal DNA with subsequent sequencing by Senger. Statistical analysis methods were performed for average value in Microsoft Excel 2010.

Results: The results of the research showed that among 155 animals wolves (20.4%) and foxes (26.7%) were the most infected with invasive Trichinella larvae. The invasion intensity was 503.6% in foxes and 289.7% in wolves. However, badgers (164%), wild boars (0%), and corsacs (0%) presented lower invasion levels. Using specific primers, larvae samples were identified as Trichinella nativa.

Conclusion: The results of monitoring revealed the spread of trichinosis among wild animals: wolves, foxes, badgers. The Karaganda, Kostanay, Western Kazakhstan, and Akmola regions had the largest distribution of wild animals infected with trichinellosis. In total, 20% of the 155 studied animals were infected. The greatest invasion intensity was typical for wolves, foxes and badgers. It is necessary to monitor the spread of trichinellosis among wild carnivores to control the epidemiological situation and reduce the level of spontaneous infection among animals. Regular monitoring of habitats and carnivores must be conducted within the country and in the border areas.

Keywords: distribution; intensity of infection; trichinellosis; wild carnivores.