von Dohlen Alexa Rosypal, Scott David, Dubey J P, Lindsay David S
1 Department of Natural Sciences and Mathematics, Johnson C. Smith University, Charlotte, North Carolina 28216.
2 Carolina Raptor Center, 6000 Sample Road, Huntersville, North Carolina 28078.
J Parasitol. 2019 Feb;105(1):11-16.
The life cycle of Sarcocystis species is heteroxenous (2-host), with carnivores being the definitive host and herbivores serving as intermediate hosts in predator-prey relationships. Raptors (eagles, hawks, falcons, and owls) are apex predators and are not consumed routinely by other carnivores, making the occurrence of sarcocysts in their muscles unusual. Recent reports of sarcocysts in eagles and owls with Sarcocystis encephalitis suggests that this condition may be becoming more frequent, and Sarcocystis falcatula has been implicated as the agent of encephalitis in golden ( Aquila chrysaetos) and bald eagles ( Haliaeetus leucocephalus) as well as great horned owls ( Bubo virginianus). The present study was done to determine the prevalence of sarcocysts of Sarcocystis species in the muscles of raptors from the southeastern United States. Pectoral and heart muscle from 204 raptor patients from the Carolina Raptor Center, Huntersville, North Carolina were tested for the presence of Sarcocystis species using histology. Only a few sarcocysts were seen in sections of pectoral muscle from 39 of 204 raptors (19.1%) and heart muscle from 9 that also had sarcocysts in their pectoral muscle. Two structural types of sarcocysts, thin-walled (1 μm; 62%) or thick-walled (>2 μm, 38%), were seen. Statistical analysis of raptor age and gender was done by Fisher's exact test on samples from raptors with 20 or more samples per group. The prevalence of sarcocysts by age (2 yr or more) was significant for red-shouldered hawks ( Buteo lineatus) ( P = 0.022) and Cooper's hawks ( Accipiter cooperii) ( P = 0.028). Sarcocyst prevalence in male raptors from these groups evaluated statistically were always less than in females. Prevalence in female red-tailed hawks ( Buteo jamaicensis) (42.1%) was significantly greater than in males (6.7%) using Fisher's exact test ( P = 0.047). Examination of case histories from the 39 sarcocyst-positive raptors did not reveal an association with sarcocysts in raptor pectoral or heart muscle and in a diagnosis of encephalitis. Additional studies are needed to determine the epidemiology and relationships of Sarcocystis spp. that use raptors as intermediate hosts and the importance of Sarcocystis spp. in the overall wellbeing of raptors in their natural environments.
肉孢子虫属的生命周期是异宿主的（双宿主），在捕食者 - 猎物关系中，食肉动物是终末宿主，食草动物作为中间宿主。猛禽（鹰、隼、猎鹰和猫头鹰）是顶级捕食者，通常不会被其他食肉动物捕食，因此它们肌肉中出现肉孢子囊的情况并不常见。最近有关于患有肉孢子虫性脑炎的鹰和猫头鹰体内出现肉孢子囊的报道，这表明这种情况可能越来越频繁，而且镰状肉孢子虫被认为是金雕（Aquila chrysaetos）、白头海雕（Haliaeetus leucocephalus）以及大角鸮（Bubo virginianus）脑炎的病原体。本研究旨在确定美国东南部猛禽肌肉中肉孢子虫属肉孢子囊的患病率。使用组织学方法对来自北卡罗来纳州亨特斯维尔市卡罗来纳猛禽中心的204只猛禽患者的胸肌和心肌进行了肉孢子虫属检测。在204只猛禽中，有39只（19.1%）的胸肌切片中仅发现了少数肉孢子囊，在胸肌中也有肉孢子囊的9只猛禽的心肌中也发现了肉孢子囊。观察到两种结构类型的肉孢子囊，薄壁的（1μm；62%）或厚壁的（>2μm，38%）。对每组样本量为20个或更多的猛禽样本，通过Fisher精确检验对猛禽的年龄和性别进行了统计分析。红肩鹰（Buteo lineatus）（P = 0.022）和库珀鹰（Accipiter cooperii）（P = 0.028）的肉孢子囊患病率在年龄（2岁及以上）方面具有统计学意义。对这些组中雄性猛禽的肉孢子囊患病率进行统计学评估时，其患病率总是低于雌性。使用Fisher精确检验（P = 0.047），雌性红尾鹰（Buteo jamaicensis）的患病率（42.1%）显著高于雄性（6.7%）。对39只肉孢子囊阳性猛禽的病历检查未发现猛禽胸肌或心肌中的肉孢子囊与脑炎诊断之间存在关联。需要进一步的研究来确定以猛禽作为中间宿主的肉孢子虫属的流行病学和关系，以及肉孢子虫属在猛禽自然环境中的整体健康状况中的重要性。
