Animal Biology Division, Institute of Biological Sciences, University of the Philippines Los, Baños, 4031, Los Baños, Laguna, Philippines.
Department of Biological Sciences and Environmental Studies, University of the Philippines Mindanao, Tugbok District, Mintal, 8000, Davao City, Philippines.
Malar J. 2019 Apr 24;18(1):147. doi: 10.1186/s12936-019-2780-4.
Macaca fascicularis (long-tailed macaque) is the most widespread species of macaque in Southeast Asia and the only species of monkey found naturally in the Philippines. The species is the natural host for the zoonotic malaria species, Plasmodium knowlesi and Plasmodium cynomolgi and for the potentially zoonotic species, Plasmodium inui. Moreover, other Plasmodium species such as Plasmodium coatneyi and Plasmodium fieldi are also natural parasites of M. fascicularis. The aims of this study were to identify and determine the prevalence of Plasmodium species infecting wild and captive long-tailed macaques from the Philippines.
A total of 95 blood samples from long-tailed macaques in the Philippines were collected from three locations; 30 were from captive macaques at the National Wildlife Rescue and Rehabilitation Center (NWRRC) in Luzon, 25 were from captive macaques at the Palawan Wildlife Rescue and Conservation Center (PWRCC) in Palawan and 40 were from wild macaques from Puerto Princesa Subterranean River National Park (PPSRNP) in Palawan. The Plasmodium spp. infecting the macaques were identified using nested PCR assays on DNA extracted from these blood samples.
All 40 of the wild macaques from PPSRNP in Palawan and 5 of 25 captive macaques from PWRCC in Palawan were Plasmodium-positive; while none of the 30 captive macaques from the NWRRC in Luzon had any malaria parasites. Overall, P. inui was the most prevalent malaria parasite (44.2%), followed by P. fieldi (41.1%), P. cynomolgi (23.2%), P. coatneyi (21.1%), and P. knowlesi (19%). Mixed species infections were also observed in 39 of the 45 Plasmodium-positive macaques. There was a significant difference in the prevalence of P. knowlesi among the troops of wild macaques from PPSRNP.
Wild long-tailed macaques from the island of Palawan, the Philippines are infected with P. knowlesi, P. inui, P. coatneyi, P. fieldi and P. cynomolgi. The prevalence of these Plasmodium spp. varied among the sites of collection and among troops of wild macaques at one site. The presence of these simian Plasmodium parasites, especially P. knowlesi and P. cynomolgi in the long-tailed macaques in Palawan presents risks for zoonotic transmission in the area.
猕猴（长尾猕猴）是东南亚分布最广的猕猴物种，也是菲律宾唯一自然存在的猴种。该物种是动物源疟疾病原种间日疟原虫（Plasmodium knowlesi）和猕猴疟原虫（Plasmodium cynomolgi）以及潜在的动物源疟疾病原种间日疟原虫（Plasmodium inui）的天然宿主。此外，其他疟原虫，如疟原虫（Plasmodium coatneyi）和疟原虫（Plasmodium fieldi）也是长尾猕猴的天然寄生虫。本研究的目的是鉴定和确定感染菲律宾野生和圈养长尾猕猴的疟原虫种类和流行率。
从菲律宾三个地点共采集了 95 份长尾猕猴血样；其中 30 份来自吕宋岛国家野生动物救援和康复中心（NWRRC）的圈养猕猴，25 份来自巴拉望岛野生动物救援和保护中心（PWRCC）的圈养猕猴，40 份来自巴拉望岛普林塞萨港地下河国家公园（PPSRNP）的野生猕猴。使用巢式 PCR 检测从这些血样中提取的 DNA 来鉴定感染猕猴的疟原虫种类。
来自巴拉望岛普林塞萨港地下河国家公园的 40 只野生猕猴和来自巴拉望岛野生动物救援和保护中心的 25 只圈养猕猴中的 5 只均为疟原虫阳性；而来自吕宋岛国家野生动物救援和康复中心的 30 只圈养猕猴均无疟原虫。总体而言，间日疟原虫（Plasmodium inui）是最常见的疟原虫（44.2%），其次是疟原虫（Plasmodium fieldi）（41.1%）、猕猴疟原虫（Plasmodium cynomolgi）（23.2%）、疟原虫（Plasmodium coatneyi）（21.1%）和间日疟原虫（Plasmodium knowlesi）（19%）。在 45 只疟原虫阳性猕猴中还观察到混合种感染。来自普林塞萨港地下河国家公园的野生猕猴群中，间日疟原虫的流行率存在显著差异。
来自菲律宾巴拉望岛的野生长尾猕猴感染间日疟原虫（Plasmodium knowlesi）、间日疟原虫（Plasmodium inui）、疟原虫（Plasmodium coatneyi）、疟原虫（Plasmodium fieldi）和猕猴疟原虫（Plasmodium cynomolgi）。这些疟原虫的流行率在采集地点和同一地点的野生猕猴群之间存在差异。在巴拉望岛的长尾猕猴中存在这些灵长类疟原虫，特别是间日疟原虫和猕猴疟原虫，这给该地区的人畜共患传播带来了风险。
