Serological and molecular investigation of Leishmania spp. infection in cats from an area endemic for canine and human leishmaniasis in Northeast Brazil

Abstract The aim of this study was to investigate the occurrence of Leishmania spp. antibodies, and its association with feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV), in domestic cats from an area endemic for canine and human leishmaniasis in Rio Grande do Norte State, Brazil. Ninety-one cats were subjected to a complete clinical exam, and blood samples were collected. An epidemiological questionnaire was used to investigate the risk factors. IgG anti-Leishmania spp. antibodies were detected by immunofluorescence antibody test (IFAT), with a cut-off value of 1:40. Polymerase chain reaction (PCR) was performed to detect genetic material of Leishmania spp. in the blood samples. The presence of antibodies against FIV and antigens of FeLV was evaluated using an immunochromatographic test. Seropositivity for Leishmania spp., FIV, and FeLV was observed in 14/91 (15.38%), 26/91 (28.57%), and 3/91 (3.29%) cats, respectively. All samples gave negative results on PCR analysis. Based on these data, no significant statistical association was observed between seropositivity for Leishmania spp., and sex, age, presence of clinical signs, evaluated risk factors, and positivity for retroviruses. These findings demonstrated for the first time that cats from Mossoró, Rio Grande do Norte, are being exposed to this zoonosis and might be part of the epidemiological chain of transmission of visceral leishmaniasis.

摘要 本研究旨在调查巴西北里奥格兰德州犬与人利什曼病流行区内家猫的利什曼原虫属（Leishmania spp.）抗体检出情况，及其与猫免疫缺陷病毒（FIV）、猫白血病病毒（FeLV）的相关性。本研究共纳入91只家猫，对其开展全面临床检查并采集血液样本；同时通过流行病学问卷调研相关危险因素。采用临界值为1:40的免疫荧光抗体试验（IFAT）检测抗利什曼原虫属IgG抗体，通过聚合酶链式反应（PCR）检测血液样本中的利什曼原虫属遗传物质，另采用免疫层析试验检测猫抗FIV抗体及FeLV抗原。结果显示，利什曼原虫属、FIV及FeLV的血清阳性率分别为14/91（15.38%）、26/91（28.57%）及3/91（3.29%）；所有样本的PCR检测结果均为阴性。基于上述数据，未观察到利什曼原虫属血清阳性与性别、年龄、临床症状表现、评估的危险因素以及逆转录病毒阳性之间存在显著统计学关联。本研究首次证实，巴西北里奥格兰德州莫索罗市的家猫已暴露于该人畜共患病，且可能参与内脏利什曼病的流行病学传播链条。