The genus Plasmodium (Plasmodiidae) ranks among the most widespread intracellular protozoan parasites affecting a wide range of mammals, birds, and reptiles. Little information is available about lizard malaria parasites in South America, and the pathological features of the resulting parasitoses remain unknown or poorly understood. To partially fill in these gaps, we conducted blood smear analysis, molecular detection, and phylogenetic and pathological investigations in lizards inhabiting an Atlantic Forest fragment in Paraiba, Brazil. From 104 striped forest whiptails (Kentropyx calcarata) screened for the presence of haemosporidian parasites, 67 (64.4%) were positive. Four of five Amazon lava lizards (Strobilurus torquatus) we collected from this same area were also positive. A total of 27 forest whiptails were infected with a new genetic lineage of Plasmodium kentropyxi and other Plasmodium lineages were also detected. Histopathological analysis in infected forest whiptails revealed systemic intraerythrocytic Plasmodium stages, mainly gametocytes, in the liver, lung, and heart. Also, the liver of infected lizards had mild to moderate levels of Kupffer cell and melanomacrophage hypertrophy/hyperplasia with sinusoid leukocytosis. Overall, our findings suggest that an endemic Plasmodium species causes histological alterations that are not related to major pathological processes in striped forest whiptails.

疟原虫属（Plasmodiidae）属于影响广泛的哺乳动物，鸟类和爬行动物的最广泛的细胞内原生动物寄生虫。关于南美蜥蜴疟疾寄生虫的信息很少，并且由此产生的寄生虫的病理特征仍然未知或了解甚少。为了部分填补这些空白，我们对居住在巴西帕拉伊巴州大西洋森林碎片上的蜥蜴进行了血液涂片分析，分子检测以及系统发育和病理学调查。从104个条纹林尾wh（Kentropyx calcarata）中筛选出有血孢病寄生虫，其中67株（64.4％）呈阳性。五个亚马逊熔岩蜥蜴（Strobilurus torquatus）我们从同一地区收集的信息也很乐观。总共有27种森林燕尾被新的疟原虫kentropyxi遗传谱系感染，还检测到其他疟原虫谱系。在受感染的森林尾巴中进行的组织病理学分析显示，肝脏，肺部和心脏的系统性红细胞内疟原虫阶段，主要是配子体细胞。而且，被感染的蜥蜴的肝脏具有中等至中等水平的库普弗细胞和黑色素巨噬细胞肥大/增生，并伴有窦性白细胞增多症。总体而言，我们的发现表明，疟原虫是一种地方病，引起的组织学改变与条纹森林wh的主要病理过程无关。