van Elk C E, van de Bildt M W G, Jauniaux T, Hiemstra S, van Run P R W A, Foster G, Meerbeek J, Osterhaus A D M E, Kuiken T
Dolfinarium Harderwijk, Strandboulevard Oost 1, Harderwijk, Netherlands
Erasmus Medical Center, Dr. Molewaterplein 50, Netherlands.
Vet Pathol. 2014 Nov;51(6):1174-82. doi: 10.1177/0300985813516643. Epub 2014 Jan 7.
The virulence of morbilliviruses for toothed whales (odontocetes) appears to differ according to host species. In 4 species of odontocetes, morbilliviruses are highly virulent, causing large-scale epizootics with high mortality. In 8 other species of odontocetes, including white-beaked dolphins (Lagenorhynchus albirostris), morbilliviruses have been found as an incidental infection. In these species, the virulence of morbilliviruses is not clear. Therefore, the admission of 2 white-beaked dolphins with morbillivirus infection into a rehabilitation center provided a unique opportunity to investigate the virulence of morbillivirus in this species. By phylogenetic analysis, the morbilliviruses in both animals were identified as a dolphin morbillivirus (DMV) most closely related to that detected in a white-beaked dolphin in Germany in 2007. Both animals were examined clinically and pathologically. Case No. 1 had a chronic neural DMV infection, characterized by polioencephalitis in the cerebrum and morbillivirus antigen expression limited to neurons and glial cells. Surprisingly, no nervous signs were observed in this animal during the 6 months before death. Case No. 2 had a subacute systemic DMV infection, characterized by interstitial pneumonia, leucopenia, lymphoid depletion, and DMV antigen expression in mononuclear cells and syncytia in the lung and in mononuclear cells in multiple lymphoid organs. Cause of death was not attributed to DMV infection in either animal. DMV was not detected in 2 contemporaneously stranded white-beaked dolphins. Stranding rate did not increase in the region. These results suggest that DMV is not highly virulent for white-beaked dolphins.
麻疹病毒对齿鲸的致病性似乎因宿主物种而异。在4种齿鲸中，麻疹病毒具有高致病性，可引发大规模 epizootics，死亡率很高。在包括白喙斑纹海豚（Lagenorhynchus albirostris）在内的其他8种齿鲸中，麻疹病毒被发现为偶然感染。在这些物种中，麻疹病毒的致病性尚不清楚。因此，将2只感染麻疹病毒的白喙斑纹海豚收治到康复中心，为研究该物种中麻疹病毒的致病性提供了独特的机会。通过系统发育分析，两只动物体内的麻疹病毒均被鉴定为海豚麻疹病毒（DMV），与2007年在德国一只白喙斑纹海豚中检测到的病毒最为密切相关。对两只动物都进行了临床和病理检查。病例1患有慢性神经性DMV感染，其特征为大脑灰质炎脑炎，麻疹病毒抗原表达仅限于神经元和神经胶质细胞。令人惊讶的是，这只动物在死亡前6个月没有观察到神经症状。病例2患有亚急性全身性DMV感染，其特征为间质性肺炎、白细胞减少、淋巴组织耗竭，以及肺和多个淋巴器官中的单核细胞和多核巨细胞中有DMV抗原表达。两只动物的死亡原因均未归因于DMV感染。在同时搁浅的2只白喙斑纹海豚中未检测到DMV。该地区的搁浅率没有增加。这些结果表明，DMV对白喙斑纹海豚的致病性不高。
