Parasitological surveys of non-human primates provides an important opportunity to better understand the epidemiology, transmission dynamics and emergence risk of anthropozoonoses such as leishmaniasis, which affect human populations in several regions accross South America. Our study area, in northeastern Argentina, can be considered a southern marginal region for the presence of leishmaniases and includes the habitat of black and gold howler monkeys, Alouatta caraya. To evaluate if A. caraya serve as potential hosts in the Leishmania cycle, we used molecular methods to examine infection by Leishmania spp. in 109 howler monkeys of different ages captured between July and August 2010. External ear tissue samples were subjected to PCR amplification for the Leishmania ribosomal internal transcribed spacer (ITS-1) and a RFLP assay with the Hae III restriction enzyme, and finally confirmed by sequencing. Nine howler monkeys (8.3%) were infected with Le. braziliensis (2.8%), Le. amazonensis (2.8%) and/or Le. infantum (3.7%). The results also suggest a case of co-infection between Le. braziliensis and Le. amazonensis. Further, we report the first observation of Le. amazonensis in the northeastern region of Argentina. The detection of Leishmania spp. in free-ranging howler monkeys gives rise to questions about the actual prevalence of the parasite in the wild, as well as if the number of infected wild monkeys detected may present a risk of leishmaniasis emergence in surronding human populations. Anyway, the presence of Leishmania spp. in A. caraya suggests the possible importance of these monkeys in the sylvatic and periurban transmission.

非人类灵长类动物的寄生虫学调查提供了一个重要的机会，可以更好地了解诸如利什曼病等人为动物的流行病学，传播动态和出现风险，这些疾病会影响整个南美多个地区的人口。我们的研究区位于阿根廷东北部，被认为是利什曼病的南部边缘地区，其中包括黑吼和金吼猴（Alouatta caraya）的栖息地。为了评估Caraya caraya是否在Leishmania周期中充当潜在宿主，我们使用分子方法检查了Leishmania spp的感染。在2010年7月至2010年8月之间捕获了109只不同年龄的how叫猴子。将外耳组织样品进行利什曼原虫核糖体内部转录间隔子（ITS-1）的PCR扩增，并使用Hae III限制性内切酶进行RFLP分析，最后通过测序进行确认。Le感染了九只吼猴（8.3％）。巴西（2.8％），勒。亚马逊（2.8％）和/或Le。婴儿（3.7％）。该结果还表明Le之间存在共同感染的情况。巴西和勒。亚马孙。此外，我们报告了Le的第一个观察结果。亚马逊东北地区的亚马逊。利什曼原虫的检测spp。在自由范围内鸣叫的猴子引起了关于该寄生虫在野外的实际患病率以及所检测到的被感染野猴的数量是否可能在周围人群中出现利什曼病的风险的疑问。无论如何，利什曼原虫属的存在。在A. caraya表明在sylvatic和城郊传输这些猴子可能的重要性。