tailieunhanh - Báo cáo khoa học: "Transport of Babesia venatorum-infected Ixodes ricinus to Norway by northward migrating passerine birds"

Tuyển tập các báo cáo nghiên cứu về bệnh học thý y được đăng trên tạp chí Acta Veterinaria Scandinavica cung cấp cho các bạn kiến thức về bệnh thú yđề tài: Transport of Babesia venatorum-infected Ixodes ricinus to Norway by northward migrating passerine birds. | Hasle et al. Acta Veterinaria Scandinavica 2011 53 41 http content 53 1 41 AVS ACTAVETERINARIA SCANDINAVICA RESEARCH Open Access Transport of Babesia venatorum-infected Ixodes ricinus to Norway by northward migrating passerine birds Gunnar Hasle1 Hans P Leinaas2 Knut H R0ed3 and 0ivind 0ines4 Abstract Background Bovine babesiosis is regarded as a limited health problem for Norwegian cows and the incidence has decreased markedly since the 1930s. Rare cases of babesiosis in splenectomised humans from infection with Babesia divergens and have been described. The objective of this study was to determine whether birds can introduce Babesia-infected ticks. There are between 30 and 85 million passerine birds that migrate to Norway every spring. Methods Passerine birds were examined for ticks at four bird observatories along the southern Norwegian coast during the spring migrations of 2003 2004 and 2005. The presence of Babesia was detected in the nymphs of Ixodes ricinus by real-time PCR. Positive samples were confirmed using PCR cloning and phylogenetic analyses. Results Of 512 ticks examined real-time PCR revealed five to be positive . Of these four generated products that indicated the presence of Babesia spp. each of these were confirmed to be from Babesia venatorum EU1 . Two of the four B. venatorum-positive ticks were caught from birds having an eastern migratory route P . Conclusions Birds transport millions of ticks across the North Sea the Skagerrak and the Kattegat every year. Thus even with the low prevalence of Babesia-infected ticks a substantial number of infected ticks will be transported into Norway each year. Therefore there is a continuous risk for introduction of new Babesia spp. into areas where I. ricinus can survive. Background Ticks have limited mobility 1 but can be transported over long distances when feeding on their vertebrate hosts. In particular avian hosts can efficiently transport ticks across .