Prevalence of Gastrointestinal Parasites in Zoo Animals and Phylogenetic Characterization of Toxascaris leonina (Linstow, 1902) and Baylisascaris transfuga (Rudolphi, 1819) in Jiangsu Province, Eastern China

TL;DR

Over 40% of zoo animals in eastern China are infected with gastrointestinal parasites, including new reports of certain species in zoo animals, highlighting the need for better control measures.

Contribution

The study reports the first detection of Paramphistomum and Fasciola spp. in specific zoo animals in China and provides molecular characterization of Toxascaris leonina and Baylisascaris transfuga.

Findings

42.3% of zoo animals in Zhuyuwan Zoo were infected with gastrointestinal parasites.

Paramphistomum spp. and Fasciola spp. were first reported in Père David’s deer and sika deer in Chinese zoos.

Molecular analysis confirmed Toxascaris leonina in African lions and Baylisascaris transfuga in brown bears.

Abstract

A study in eastern China has found that over 40% of zoo animals are infected with gastrointestinal parasites, which pose a threat to their welfare and the health of visitors and veterinarians. More than 11 parasite species were identified in the study conducted at Zhuyuwan Zoo, including two species of Ascaris, and they detected Paramphistomum spp. eggs in the captive Père David’s deer and Fasciola spp. eggs in sika deer, which had not been previously reported in Chinese zoos. The study highlights the need for prevention and control measures to be implemented to tackle parasitic diseases in zoo animals.

The burden of gastrointestinal parasites in zoo animals has serious implications for their welfare and the health of veterinarians and visitors. Zhuyuwan Zoo is located in the eastern suburb of Yangzhou city in eastern China, in which over 40 species of zoo animals are kept. In order to understand the infection status of GI parasites in Zhuyuwan Zoo, a total of 104 fresh fecal samples collected randomly from birds (n = 19), primates (n = 19), and non-primate mammals (n = 66) were analyzed using the saturated saline flotation technique and nylon sifter elutriation and sieving method for eggs/oocysts, respectively. Two Ascaris species were molecularly characterized. The results showed that the overall prevalence of parasitic infection was 42.3% (44/104). The parasitic infection rate in birds, primates, and non-primate mammals were 26.3% (5/19), 31.6% (6/19), and 50.0% (33/66), respectively. A total of 11 species of parasites were identified, namely, Trichostrongylidae, Capillaria sp., Trichuris spp., Strongyloides spp., Amidostomum sp., Toxascaris leonina, Baylisascaris transfuga, Parascaris equorum, Paramphistomum spp., Fasciola spp., and Eimeria spp. Paramphistomum spp. eggs were first detected from the captive Père David’s deer, and Fasciola spp. eggs were first reported from sika deer in zoo in China. A sequence analysis of ITS-2 and cox1 showed that the eggs isolated from the African lion (Panthera leo Linnaeus, 1758) were T. leonina, and the eggs from the brown bear (Ursus arctos Linnaeus, 1758) were B. transfuga. The public health threat posed by these potential zoonotic parasitic agents requires attention. These results lay a theoretical foundation for prevention and control of wild animal parasitic diseases at zoos in China.

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