Regional Training on Rabies Diagnosis / OIE Tokyo/Yokohama, Japan, 5-8 August 2014 Rabies Infection on Ferret-badger in Taiwan Yangchang Tu, D.V.M., MS Assistant Researcher, Epidemiology Research Division, AHRI, Council of Agriculture 1
Content Background Diagnosis of Rabies Phylogenetic Analysis of Rabies Virus in Ferretbadger in Taiwan Control measures Summary and Conclusions 2
Veterinary Service in Taiwan AHRI BAPHIQ the Bureau of Animal and Plant Health Inspection and Quarantine Livestock Disease Control Center (LDCC) Investigation on suspected cases send samples to AHRI report to BAPHIQ prevention and control 3
Background Since 1961, Taiwan had been recognized as one of the ten rabies-free countries. The Council of Agriculture has implemented rabies surveillance programs on dogs and bats and no rabies was found. - 7,391 dog samples since 1999-361 bat samples since 2008 Species Samples from 1999 to 2012 Samples in 2013 (Jan.~Aug.) Rabies case/total sample size Dog 6,841 550 0/7,391 Bat 322 39 0/361 4
Background (cont.) Wildlife disease surveillance programs Considering that many emerging diseases have been found in wild animals, the OIE has called on Member Countries to conduct wildlife disease surveillance programs. Since 2012, BAPHIQ has supported National Taiwan University (NTU) and National Pingtung University of Science and Technology (NPUST) to conduct disease surveillance in wildlife. In 2013, the target wildlife pathogen surveillance was launched to obtain information about rabies and other epidemic diseases. 5
Background (cont.) - Rabies in ferret-badger NTU received a case from Nantou. encephalitis was diagnosed; Canine distemper (CD) was suspected but tested negative. RT-PCR for Rabies shown positive result. Samples were sent to AHRI for diagnosis, including Impression Smear, RT-PCR, & FAT, etc. Rabies specific Ag and RNA was found. Jan., 2013 Jun. Jun. 24 Jun. 26 Jul. 16 Case found 接獲案例反覆檢測 Re-test RT-PCR 檢驗 Case 通報 Re-test 送檢 reported 會議與 Case confirmation 通報 In combination of previous two cases found in May. and Nov. of 2012, all 3 cases were negative for CD & pseudorabies. NTU reported to BAPHIQ. Rabies was confirmed in all 3 cases by Rabies Diagnostic Group and relevant report was sent to the OIE on Jul. 17. 6
Current situation (cont.) Test results of animals Updated: June. 26, 2014 Animals No. of tests 1999-2013 No. of Positive No. of tests 2013 No. of Positive No. of tests 2014-06 No. of Positive 2014-06 Dogs 6,841 0 1,553 1 a 496 0 Cats 5 0 112 0 8 0 Bats 322 0 64 0 47 0 Carnivores -- -- 1,019 276 190 103 Other wildlife -- -- 341 1 b 14 0 Total 7,168 0 3,098 278 755 103 a. : bit by rabid ferret badger b.: shrew case in July-30-2013. 7
Current situation (cont.) Test results of carnivores Total: 1,029 Updated: June. 26, 2014 Animals No. of testing No. of positive Animals No. of testing No. of positive Ferret-badger (Melogale moschate subaurantiaca) 984 379 Formosan gemfaced civet (Paguma larvata ) 196 0 Small Chinese civet (Viverricula indica pallida) 3 0 Golden Weasel (Mustela sibirica taivana 4 0 Crab-eating mongoose (Herpestes urva) 19 0 Ferret (Mustela putorius furo) 3 0 8
Current situation (cont.) Ferret-badger (Melogale moschate subaurantiaca) Common Carnivores in Taiwan Formosan gem-faced civet (Paguma larvata) 鼬獾白鼻心麝香貓 Small Chinese civet (Viverricula indica pallida) 黃鼠狼食蟹檬石虎 Golden Weasel (Mustela sibirica taivana) Crab-eating mongoose (Herpestes urva) Leopard cat (Prionailurus bengalensis chinensis) 9
Current situation Distribution of confirmed rabid ferret-badgers in Taiwan Updated: June. 26, 2014 Taichung City (46/379; 12.1%) Nantou County (60/379; 15.8%) Yunlin County (20/379; 5.2%) Chiayi County (13/379; 3.4%) Tainan City (21/379; 5.5%) Kaohsiung City (14/379; 3.6%) Hualien County (9/379; 2.3%) Taitung County (182/379; 48.0%) 1 rabid shrew 1 rabid dog Pingtung County (14/379; 3.7%) Confirmed by fluorescent antibody test 10
Flow of Rabies Diagnosis in AHRI Brain sample Sampling: brain stem cerebral cortex cerebellum hippocampus + Positive Histopathology Fluorescent antibody test (FAT) - Negative Immunohistochemistry (IHC) Need to confirm ( ± ) Virus isolation MNA cell culture Inoculation of mice + - Positive Negative - Negative + Positive Other Methods RT-PCR + - Positive Negative 1. Strip 2. Electron microscope (EM) 11
Phylogenetic analysis of rabies virus in ferret badger in Taiwan 12
Phylogenetic relationships of RABV N gene G gene The most recent common ancestor of RABV of Formosan ferretbadger originated 91-113 years (Chiou et al., 2014) ago. 13
Phylogenetic tree of Taiwan RABV: N gene 嘉義番路 台中霧峰 南投仁愛台中新社南投仁愛台中新社 台中和平南投國姓台中新社 南投魚池台中太平台中東勢台中和平 南投埔里南投魚池南投信義南投魚池南投魚池南投溪頭南投信義南投竹山雲林古坑 嘉義番路 嘉義阿里山嘉義竹崎雲林古坑雲林古坑 高雄田寮台南左鎮台南南化高雄旗山高雄旗山高雄六龜 花蓮卓溪花蓮卓溪 屏東霧台台東延平 台東東河台東海瑞台東成功台東卑南 台東卑南 台東東河 Two clusters Ia-Central: Nantou, Taichung Ib-South: Yunlin, Chiayi, Tainan, Kaohsiung II-East: Hualien, Taitung, Pingtung 14
Phylogenetic tree of Taiwan RABV : G gene 高雄六龜雲林古坑台東卑南 台中東勢台中和平南投國姓台中和平南投仁愛 南投信義台中新社台中新社 南投魚池台中霧峰南投魚池南投埔里台中新社南投魚池南投魚池台中太平南投仁愛 南投溪頭南投信義南投竹山 嘉義阿里山嘉義竹崎 雲林古坑雲林古坑台南南化嘉義番路嘉義番路 高雄田寮台南左鎮高雄旗山高雄旗山 屏東霧台花蓮卓溪 花蓮卓溪台東海瑞 台東東河台東延平 台東成功 台東卑南 Two clusters Ia-Central: Nantou, Taichung Ib-South: Yunlin, Chiayi, Tainan, Kaohsiung II-East: Hualien, Taitung, Pingtung 15
Geographic location of RABV infection in ferret badger in Taiwan Three subgroups: Central: Nantou, Taichung South: Yunlin, Chiayi, Tainan, Kaohsiung East: Hualien, Taitung, Pingtung 16
Regional Training on Rabies Diagnosis / OIE Tokyo/Yokohama, Japan, 5-8 August 2014 Control measures: Rabies in Ferret-badgers in Taiwan Yangchang Tu, D.V.M., MS Assistant Researcher, Epidemiology Research Division, AHRI, Council of Agriculture
Goal: no rabies cases in dogs and cats Support laboratory Emergency vaccine storage Study & research Safeguard of human Dogs&Cats management Rabies prevention International coopration Improve vaccination coverage Animal surveillance Public communication &awareness 18
Vaccination coverage in dogs and cats High risk areas (rabies-positive mountainous areas): 90% of the population Other areas: 70% of the population Starting from 2014, the owner whose dogs and cats have no rabies vaccination shall be fined (US$ 350-1,700). 19
Stockpile rabies vaccine: 250,000 doses for emergency response. These vaccines will be given to dogs & cats in high risk areas & animal shelters free of charge. 20
Encourage owners to sterilize & to register their dogs & cats. Assist animal protection NGOs to establish shelters for stray dogs. Work with veterinary practitioners to improve rabies vaccination coverage in dogs & cats. 21
Set up animal rabies notification hotline. Monitor wild animals downers or those with abnormal behavior. Continue the rabies surveillance on dogs, cats, bats, and those animals had a history of bitten human. Formosan gem-faced civet Yellow Ferret badgers Crab-eating mongroose 22
Feasibility study on oral rabies vaccines for ferret badgers Epidemiological studies on ferret badger rabies Pathogenicity of RABV-TWFB 23
Invite international experts to provide prevention strategies and oral vaccination for wildlife. 24
Summary and Conclusions In total, 1,564 wild animals were tested with 381 rabies positive including 379 ferret badgers, 1 house shrew and 1 puppy. The infected ferret-badgers, the major affected species in Taiwan, may show neurological signs or attacking human or pets. RABV in Taiwan belong to Lyssavirus genotype I. There are three subgroups of RABV among ferret-badger due to geographical barrier in Taiwan. 25
Conclusion The most recent common ancestor of RABV of Formosan ferret-badger originated 91-113 years ago. The rabies virus could be cryptically circulating in ferret badgers in Taiwan for a long time. The rabies epidemic is under control and the disease is restricted only in ferret badgers. 26
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