臺灣北部西部地區野生食肉目動物及共域犬貓焦蟲壁蝨感染調查

人類活動導致野生動物棲地破碎化、氣候變遷使疾病的分佈改變，人類、家畜動物和野生動物有更多機會接觸彼此的疾病。其中壁蝨媒介疾病（tick-borned disease）在新興傳染病中相當重要，是許多人畜共通傳染病及家畜動物疾病媒介，因此近年來越來越受重視。臺灣野生動物壁蝨種類、媒介疾病資料有限，然而陽明山地區白鼻心發現焦蟲（Babesia spp.）感染，且共域的流浪貓有感染相同焦蟲情形。臺灣淺山地區食肉目動物和人類、家畜動物生活棲地接近，壁蝨媒介疾病也是新興傳染病的重點，因此本研究目的在於調查臺灣野生食肉目動物及共域流浪狗貓焦蟲壁蝨感染情形。此外，野生動物焦蟲可能和其他疾病共通感染而有更嚴重的臨床症狀，因此同時調查犬瘟熱、冠狀病毒、小病毒、弓蟲等犬貓傳染病，以更全面了解疾病動態。本研究中主要調查臺灣北部陽明山國家公園及西部大安溪南北兩岸的食肉目動物及共域流浪犬貓，於2016年秋至2019年春季主動捕捉及採樣，並配合2013-2015年保存之檢體，共計檢驗246隻個體，包含105隻鼬獾、33隻白鼻心、7隻麝香貓、23隻食蟹獴、41隻狗及37隻貓。採集全血、口腔拭子、結膜拭子、肛門拭子及血清進行焦蟲、犬瘟熱、冠狀病毒、小病毒核酸診斷、弓蟲血清抗體試驗、血液學檢查。另外，從野生動物身上採集共232隻壁蝨進行鑑種，並完成150隻壁蝨、3壁蝨卵焦蟲核酸診斷。結果顯示鼬獾有新種焦蟲，北部盛行率27.3%，西部18.0%，兩區無顯著差異。西部地區有1鼬獾感染犬焦蟲（B. gibsoni）。北部白鼻心及流浪貓有同種焦蟲，盛行率分別為75.0%及10.8%，西部則無檢出。北部犬隻有39%感染B. gibsoni，食蟹獴、麝香貓皆無檢出焦蟲。血檢方面可見焦蟲陽性鼬獾有低白蛋白、總蛋白、血鈣；陽性白鼻心有大球正色性貧血、低白蛋白等。壁蝨鑑種結果顯示有4種壁蝨，Ixodes ovatus 154隻、Haemaphysalis hystricus 37隻、Ixodes granulatus 17隻、Rhiphcephalus sanuineus 4隻。焦蟲核酸診斷結果雖有4 Haemaphysalis hystricus陽性，然無定序結果。傳染病檢驗發現臺灣野生食肉目動物有檢出冠狀病毒、小病毒、弓蟲。感染犬焦蟲（B. gibsoni）鼬獾有小病毒感染，然焦蟲、壁蝨感染皆和上述傳染病無統計上顯著相關。本研究顯示臺灣鼬獾、白鼻心有焦蟲感染，且可能和共域流浪動物有交互傳染。野生食肉目動物和流浪動物有相同壁蝨，且有攜帶人畜共通傳染病風險品系。未來對於野生食肉目動物壁蝨疾病持續監控有助於野生動物、家畜動物及人類健康福祉。

關鍵字

焦蟲；壁蝨；壁蝨媒介疾病；血液學；共通感染

並列摘要

Anthropogenic fragmentation of wildlife habitats and climate change are likely to increase transmission of infectious agent among human, livestocks and wildlife, especially arthropod-borne disease. Tick-borned disease draws more and more attention due to its threat to both human and livestock health. Despite that infection of Babesia spp in masked palm civets and a sympatric cat had been reported, the knowledge about tick and tick-borne disease in wildlife of Taiwan is still in its infancy. The small carnivores which live in low elevation mountains may share same habitats with human and stray dogs and cats. Thus, the aim of this study is to investigate the infection of Babesia spp. and tick in small carnivores from northern and western Taiwan. In addition, since co-infection of other diseases may promote the clinical sign of babesiosis, investigation of canine and feline diseases including canine distemper, canine parvoviral enteritis, feline infectious enteritis, and Toxoplasmosis in small carnivores were also performed. The survey was conducted in Yangmingshan National park and Da-an river area which located in northern and western Taiwan, respectively. Total 246 animals were included in the study, including animals trapped and sampled from 2016 October to 2019 April and samples collected from 2013 to 2015. There were 105 ferret badgers, 33 masked palm civets, 7 small Indian civets, 23 crab eating mongrooses, 41 dogs and 37 cats. Whole blood and oral/conjunctiva/rectal swab were collected for molecular detection of Babesia spp., canine morbillivirus, coronavirus and canine/feline parvovirus, and serum was collected for detection of antibody to Toxoplasma gondii. 232 ticks were also collected from animals for morphological identification and molecular detection. The results showed that ferret badgers were infected by novel B. spp., with prevalence 27.3% and 18.0% in northern and western Taiwan respectively. The masked palm civets and stray cats in northern Taiwan shared same B. spp, with prevalence 75.0% an 10.8% respectively. The stray dogs were infected by B. gibsoni with prevalence 39.0%. No Babesia spp was detected in small Indian civets nor crab eating mongrooses. Clinical pathology results showed that lower albumin, total protein and calcium vale in Babesia PCR positive ferret badgers than negative group. Babesia positive masked palm civets showed normochromic macrocytic anemia and lower albumin value. Ticks identification showed that 4 species of ticks were found, including 154 Ixodes ovatus, 37 Haemaphysalis hystricus, 17 Ixodes granulatus, and 4 Rhiphcephalus sanuineus. 150 ticks and 3 tick eggs were screaned with PCR for Babesia spp., and 4 H. hystricus were PCR positive without DNA sequence. 5 major pathogen screening showed that wild carnivores in Taiwan may infected with coronavirus, parvovirus, and Toxoplasma gondii. The ferret badger, which infected by B. gibsoni, was also infected by parvovirus. There were not any statically evidence whether coinfection will promote babesia infection. Our results showed that B. spp infection of ferret badger and masked palm civets may be associated with sympatric stray dogs and cats. Wild carnivores and sympatric stray dogs and cats shared same tick species, which may carry zoonotic disease. Keep monitoring tick-borne disease of wild carnivores may help wildlife, livestock and human health.