Massey University, Institute of Natural and Mathematical Sciences, Massey University, Private Bag 102904, North Shore Mail Centre, Auckland, 0745, New Zealand.
International Zoo Veterinary Group, Station House, Parkwood Street, Keighley, BD21 4NQ, UK.
Parasit Vectors. 2019 Jan 17;12(1):40. doi: 10.1186/s13071-018-3255-0.
Haemoproteus and Plasmodium species are widespread avian blood parasites. Several Plasmodium species are known for their high virulence and have caused significant declines in naïve bird populations. The impact of closely related Haemoproteus parasites is largely unknown. Recently we reported a lethal disease in two parrot aviaries caused by Haemoproteus parasites.
Here we show that the causative pathogen Haemoproteus minutus is responsible for further 17 lethal outbreaks in parrot aviaries in Denmark, Germany and Great Britain. All affected parrots are endemic to Australasia and South America. We sequenced the cytochrome b gene from megalomeront-infected muscle tissue of 21 parrots and identified the two lineages TUPHI01 and TURDUS2 as causative agents, commonly naturally infecting the common blackbird (Turdus merula) and the song thrush (Turdus philomelos), respectively, in the Palaearctic. No intraerythrocytic parasite stages were found in any of the parrots. We failed to detect H. minutus in invasive Indian ring-necked parakeets (Psittacula krameri) in Germany. Together this suggests that abortive infections with two virulent lineages of H. minutus are lethal for naïve parrot species from Australasia and South America. We asked whether we could detect H. minutus in New Zealand, where its Turdus hosts were introduced in the 1800s. We therefore tested invasive blackbirds and song thrushes, and the co-existing endemic red-fronted parakeet (Cyanoramphus novaezelandiae) population on three New Zealand islands. No Haemoproteus spp. DNA was detected in all blood samples, indicating absence of transmission.
The results of this study show that captive parrots in Europe are threatened by two lineages of an otherwise benign parasite of Turdus spp. Aviary collections of parrots should be protected from Culicoides spp. vectors in Europe. Animal trade and climate changes extending the current vector and parasite distribution have to be considered as potential risk factors for the introduction of the disease in naïve parrot populations.
疟原虫和血巴尔通体属是广泛存在于鸟类中的血液寄生虫。一些疟原虫因其高致病性而闻名，它们导致了许多雏鸟种群的大量减少。密切相关的血巴尔通体寄生虫的影响在很大程度上尚不清楚。最近，我们报道了在两个鹦鹉养殖场中由血巴尔通体寄生虫引起的致命疾病。
在这里，我们表明，致病病原体小血巴尔通体是导致丹麦、德国和英国的鹦鹉养殖场中另外 17 次致命爆发的原因。所有受影响的鹦鹉都分布在澳大拉西亚和南美洲。我们从 21 只鹦鹉的肌肉组织中的巨殖体感染组织中测序了细胞色素 b 基因，并确定了两个谱系 TUPHI01 和 TURDUS2 是致病因子，它们通常分别自然感染古北界的普通乌鸫（Turdus merula）和歌鸫（Turdus philomelos）。在任何一只鹦鹉中都没有发现红细胞内寄生虫阶段。我们在德国没有检测到入侵的印度环颈鹦鹉（Psittacula krameri）中的小血巴尔通体。综上所述，这表明对来自澳大拉西亚和南美洲的雏鸟物种的两种具有致命性的小血巴尔通体的无效感染是致命的。我们想知道我们是否可以在新西兰检测到小血巴尔通体，因为其 Turdus 宿主在 19 世纪被引入新西兰。因此，我们在新西兰的三个岛屿上测试了入侵的乌鸫和歌鸫以及共存的本土红额鹦鹉（Cyanoramphus novaezelandiae）种群。在所有血液样本中均未检测到血巴尔通体属的 DNA，表明没有传播。
本研究结果表明，欧洲的圈养鹦鹉受到两种原本良性的 Turdus spp. 寄生虫的威胁。在欧洲，应保护鹦鹉养殖场免受库蠓属媒介的侵害。应考虑动物贸易和气候变化，因为这些因素可能会导致疾病在雏鸟种群中传播。
