臺灣野生鳥類弓蟲抗體盛行率調查

Seroprevalence of Toxoplasma gondii antibodies in wild birds in Taiwan

陳儒頎(Ju-Chi Chen)

指導教授 ： 吳應寧

國立臺灣大學/獸醫專業學院/臨床動物醫學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.02455

摘要

弓蟲(Toxoplasma gondii)為一能感染人類以及野生動物的人畜共通病原。本研究於2013年四月至2014年八月期間，於台灣北中南共五處野生動物救傷站或收容單位，採集了來自台灣15個鄉鎮、37種鳥種，共394隻野生鳥類的樣本。以改良凝集試驗(modified agglutination test, MAT)檢驗弓蟲抗體，總體血清盛行率為23.35% (CI 95%= 19.17%-27.53%)。其中在猛禽(25.73%; CI 95%= 19.76%-31.70%, 鴞形Strigiformes, n=111; 鷹形目Accipitriformes, n=93; 隼形Falconiformes, n=2 ;)、水棲性鳥類(34.29%; CI 95%= 18.56%-50.01%, 鶴形目Gruiformes, n=1; 鴴形目Charadriiformes, n=2; 雁型目Anseriformes, n=1; 鵜形目Pelecaniformes, n=30 ;佛法僧目Coraciiformes, n=1 ;)、地棲性鳥類(18.12%; CI 95%= 11.94%-24.31%, 鴿形目Columbiformes, n=102, 雀形目Passeriformes, n=45; 雞形目Galliformes, n=2)都有一定陽性率。在鵑形目Cuculiformes (n=2)以及鴷形目Piciformes (n=2)樣本中都沒有發現抗體。血清陽性率與鳥類年齡、臨床有無異常表現有顯著相關，與食性、樣本來源地區沒有相關。在15個鄉鎮中，13個發現有血清陽性結果，顯示此一人畜共通病原已經廣泛存在於台灣許多地區。此結果顯示在台灣都會區以及郊區、從水域到陸域都有機會接觸到弓蟲。野生鳥類可能無症狀感染，但同時此一病原在野生鳥類的致病力還需要更進一步探討。本研究中同時使用過去常用以調查弓蟲抗體盛行率的乳膠凝集試驗(Latex agglutination test, LAT)檢驗383個樣本，結果顯示比起改良凝集試驗有較低的陽性率。此研究為台灣第一個野生鳥類的弓蟲抗體盛行率調查。

關鍵字

弓蟲 ； 野生動物 ； 鳥類 ； 臺灣 ； 改良凝集試驗

並列摘要

Toxoplasma gondii is a zoonotic protozoon which is well known for infecting humans and wild animals. In the present study, antibodies to T. gondii were evaluated in 394 wild birds, belonging to 37 species, from 17 different counties or cities in Taiwan. Serum samples were collected from five wild bird rehabilitation centers between April 2013 and August 2014. Using a modified agglutination test (MAT), the overall seroprevalence of infection was 23.35% (CI 95%= 19.17%-27.53%). Antibodies were detected in birds of prey (25.73%; CI 95%= 19.76%-31.70%, Strigiformes, n=111; Accipitriformes, n=93; Falconiformes, n=2), birds living in freshwater or marine systems (34.29%; CI 95%= 18.56%-50.01%, Gruiformes, n=1; Charadriiformes, n=2; Anseriformes, n=1; Pelecaniformes, n=30; Coraciiformes, n=1) and ground-feeding birds (18.12%; CI 95%= 11.94%-24.31%, Columbiformes, n=102, Passeriformes, n=45; Galliformes, n=2). No antibodies were detected in birds of the order Cuculiformes (n=2) and Piciformes (n=2). The latex agglutination test, which has been used to evaluate the prevalence of the disease in Taiwan in past decades, was performed on 383 sera and showed lower sensitivity than the MAT. Age category and the presence of clinical abnormalities were associated with T. gondii seropositivity. No statistically significant associations were observed between seropositivity and the species, the geographic area of the sample and feeding behavior. The results showed that this zoonotic pathogen has spread widely in Taiwan: seropositivity in birds was detected in 13 of 22 administrative regions of Taiwan. This suggests the zoonotic potential of the disease, with transmission from urban to rural regions, and from terrestrial to aquatic systems. Antibodies were detected in birds with or without clinical abnormalities, which indicates that wild birds can be infected asymptomatically. The pathogenicity of T. gondii infection in wild birds in Taiwan needs further investigation. This is the first study of the seroprevalence of T. gondii in wild birds in Taiwan.

並列關鍵字

Toxoplasma gondii ； wild animals ； avian species ； Taiwan ； modified agglutination test

參考文獻

17. Lin DS, Sung NC , Fei AC. Prevalences of antibodies to Toxoplasma gondii in Taipei Zoo animals. Taiwan Veterinary Journal 35(1)43-48, 2009.

26. Lin DS, Sung NC, Fei CY. Prevalences of Antibodies to Toxoplasma gondii in Taipei Zoo Animals. Taiwan Veterinary Journal 35(1):43-48, 2008.

28. Lin DS, Fei CY, Chow HM, Mo KM, Pong YM. Prevalences of Antibodies to Toxoplasma gondii in Cats and Humans in Taipe, Taiwan. Bio Bull NTNU. 33(2):95-103, 1998.

1. Cenci-Goga BT, Rossitto PV, Sechi P, McCrindle CM, Cullor JS. Toxoplasma in Animals, Food, and Humans: An Old Parasite of New Concern. Foodborne pathogens and disease 8:751-762, 2011.

2. Dubey JP. A review of toxoplasmosis in wild birds. Veterinay Parasitology. 106:121-153, 2002.