Toxoplasma gondii is a zoonotic protozoan pathogen that infects many endothermic vertebrates, including humans; the domestic cat and other felids serve as the definitive host. Macropodids are considered highly susceptible to toxoplasmosis. Here, we describe the clinical, pathologic, and immunohistochemical findings of an outbreak of systemic toxoplasmosis in a mob of 11 red kangaroos (Macropus rufus), with high morbidity (73%) and mortality (100%) rates. Affected animals had either severe and rapidly deteriorating clinical conditions or sudden death, which was correlated with widespread necrotizing lesions in multiple organs and intralesional T. gondii organisms identified via MIC3-specific immunohistochemistry and confirmed by REP529-specific rtPCR. Quantification of parasites demonstrated the highest parasite density in pulmonary parenchyma compared with other tissues. Our study highlights the continued importance of this severe condition in Australian marsupials.

刚地弓形虫是一种人畜共患病原生动物病原体，可感染包括人类在内的许多吸热脊椎动物；家猫和其他猫科动物是最终宿主。大足类动物被认为对弓形虫病高度敏感。在这里，我们描述了 11 只红袋鼠 ( Macropus rufus ) 暴发全身性弓形虫病的临床、病理学和免疫组化结果，发病率 (73%) 和死亡率 (100%) 率都很高。受影响的动物要么有严重且迅速恶化的临床状况，要么是突然死亡，这与多器官和病灶内弓形虫的广泛坏死性病变有关通过 MIC3 特异性免疫组织化学鉴定并通过 REP529 特异性 rtPCR 确认的生物体。与其他组织相比，寄生虫的量化表明肺实质中的寄生虫密度最高。我们的研究强调了这种严重疾病在澳大利亚有袋动物中的持续重要性。