Probable Tiger-to-Tiger Transmission of Avian Influenza H5N1

During the second outbreak of avian influenza H5N1 in Thailand, probable horizontal transmission among tigers was demonstrated in the tiger zoo. Sequencing and phylogenetic analysis of those viruses showed no differences from the first isolate obtained in January 2004. This finding has implications for influenza virus epidemiology and pathogenicity in mammals

鞘内免疫による狂犬病の治療と狂犬病発症ウサギに見られた心筋症の病理発生

狂犬病は致死的な人獣共通感染症で、現在もなお有効な治療法がない。本研究室ではこれまでに鞘内免疫の前に皮下免疫を施すと鞘内免疫単独よりも高い抗体価をより迅速に脳脊髄液に誘導すること、脳からの狂犬病ウイルス排除に重要な脳脊髄液中和抗体は末梢血中抗体および中枢神経組織で産生された抗体の２つの起源を持つことを報告してきた。これらの結果に基づき、私は、鞘内免疫を用いて狂犬病を治療できるのではないかと考えた。第１章では、固定毒狂犬病ウイルス接種4～8日後に神経筋症状を呈した10羽のウサギを用いて実験を行った。皮下免疫のみを行った3羽中1羽および皮下免疫後鞘内免疫を行った4羽中4羽はウイルス接種後11～18日後から重篤な神経症状から回復し、外部刺激への反応と飲食を再開し、実験終了後まで生残したが、それらの5例を除く全例がウイルス接種後8～12日以内に斃死した。生残したウサギの中枢神経組織ではウイルスが排除されており、それには液性および細胞性免疫が関与していると推測された。本実験では、完全な回復には至らなかったものの、鞘内免疫によって狂犬病発症個体の延命が可能であることが証明され、この知見は新規狂犬病治療法開発の礎になると思われた。第2章では、固定毒狂犬病ウイルス接種に起因する脳病変を有するウサギは、カテコールアミン過分泌に特徴的な収縮帯壊死を伴う心筋壊死に陥ることを発見し、その発生機序を検討した。各ウサギの心筋病変の程度は脳病変のそれにほぼ比例しており、どの症例においても心筋への狂犬病ウイルス感染は認められなかった。さらに、心筋病変の発生は麻酔薬の投与回数および投与量と無関係であった。これらの所見から、狂犬病罹患ウサギの心筋壊死は神経原性心筋症であると結論された。結論として、本研究では、鞘内免疫によって狂犬病を治療出来る可能性があるが、現在のプロトコールでは不完全であり、更なる改善を要すること、狂犬病の併発症として神経原性心筋症が発生することを明らかにした

Anticoagulant rodenticide poisoning in farmed Patagonian mara (Dolichotis patagonum)

Abstract Background Anticoagulant rodenticide (AR) poisoning was diagnosed in 3 Patagonian maras (Dolichotis patagonum) raised in the mara farm in Thailand. To date, there have been no reports of maras with diagnosed AR poisoning. Case presentation The first clinical sign of the sickening maras was anorexia. Fifteen from 50 maras were dead over a 3–5 day period after the clinical signs had occurred. Positive results to AR were detected in all of the maras’ liver specimens by screening test using thin layer chromatography and spectrophotometry methods. Supportive therapy was selected for the treatment of the 35 surviving maras. During the follow – up observation period of 12 months, all of the surviving maras were healthy and no reproductive loss. Conclusions This is the first report on suspected AR poisoning in maras in Thailand based on history taking, clinical signs, gross pathology lesions and chemical analysis. AR poisoning in the present report is possibly from contaminated animal food. Therefore, quality control of food should be fastidious when feeding maras

Successful management of colonic pythiosis in two dogs in Thailand using antifungal therapy

Abstract Gastrointestinal pythiosis is a severe, progressive and often a fatal disease, which is caused by the aquatic pathogen Pythium insidiosum. Treatment is challenging due to the disease's resistance to antifungal drugs. Surgical resection is frequently attempted in cases of pythiosis; however, it can be technically challenging. This report presents two dogs with decreased appetite, abdominal pain, progressive haematochezia, tenesmus and significant weight loss. With the medical histories of both being young canines, living in areas with access to natural water resources and with the main chronic gastrointestinal symptoms having not responded to symptomatic treatment, pythiosis was taken into consideration. Abdominal ultrasound revealed severe, diffuse thickening and loss of normal layering of the colonic wall. These findings led to a differential diagnosis between intestinal neoplasia and fungal disease. Full‐thickness biopsies were later performed, and immunohistochemistry staining was suggested for colonic pythiosis. Medical treatment for pythiosis was successful with a combination of oral terbinafine and prednisolone. However, therapy with itraconazole in case 1 did not improve the clinical signs, and in case 2, itraconazole was used after all clinical signs have improved for clinical control. Since then, there has been no recurrence of clinical signs until the time of preparing this report (19 months for case 1, 11 months for case 2 since the cessation of treatment). The treatment was successful based on clinical signs and ultrasonographic data, and the disease remission was not confirmed by advance imaging, monitoring of pythiosis enzyme‐linked immunosorbent essay concentration or repeat sampling