Laboratory of Parasitology, Federal University of the Agreste of Pernambuco, Garanhuns, Brazil.
Graduate Program in Animal Biosciences, Federal Rural University of Pernambuco, Recife, Brazil.
Acta Parasitol. 2024 Jun;69(2):1115-1121. doi: 10.1007/s11686-024-00834-x. Epub 2024 Mar 27.
Medical and veterinary filarial nematodes are transmitted by blood-feeding vectors. In dogs, these parasites are mainly represented by nematodes in which microfilariae dwell in the blood (Dirofilaria spp. and Acanthocheilonema spp.) or skin (Cercopithifilaria spp. and Onchocerca lupi). The aim of this study was to determine the prevalence of these filarial infections in dogs residing in a touristic, heavily populated location in the northeastern region of Brazil.
Blood samples (n = 245) were assessed by a modified Knott test, followed by a qualitative ELISA test (SNAP® 4Dx® Plus, IDEXX Laboratory, Westbrook, Maine, USA) for the detection of antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato, Ehrlichia spp. and antigens of Dirofilaria immitis. Skin samples (n = 71) were microscopically examined and molecularly assessed through a PCR targeting the 12 S rRNA gene.
Microfilariae and antigen of D. immitis were detected simultaneously in 15 (6.1%; 95% CI = 3.7-9.8) animals. Nine animals (3.6%; 95% CI = 1.9-6.8) were D. immitis antigen positive but microfilariae negative and nine other animals (3.6%; 95% CI = 1.9-6.8) were microfilariae positive but D. immitis antigen negative. D. immitis positive dogs were found in four different municipalities. No filarioids were detected in the skin after microscopical and molecular analyses.
Data from this study demonstrate that D. immitis is the main filarial nematode infecting dogs in coastal areas in northeastern Brazil. Based on the potential risk of infection in which animals are submitted, it is essential to perform tests to detect microfilariae and D. immitis antigen. Preventive measures must be adopted by using microfilaricidal compounds and anti-feeding insecticides to prevent canine infection.
医学和兽医丝虫通过吸血媒介传播。在狗中，这些寄生虫主要代表居住在血液中的微丝蚴（Dirofilaria spp. 和 Acanthocheilonema spp.）或皮肤中的微丝蚴（Cercopithifilaria spp. 和 Onchocerca lupi）的线虫。本研究的目的是确定在巴西东北部旅游胜地居住的狗中这些丝虫感染的流行情况。
对 245 份血液样本进行改良 Knott 试验检测，然后使用定性 ELISA 试验（SNAP® 4Dx® Plus，IDEXX Laboratory，缅因州 Westbrook，美国）检测针对 Anaplasma spp.、Borrelia burgdorferi sensu lato、Ehrlichia spp. 和 Dirofilaria immitis 抗原的抗体。对 71 份皮肤样本进行显微镜检查，并通过针对 12S rRNA 基因的 PCR 进行分子评估。
15 只（6.1%；95%CI=3.7-9.8）动物同时检测到微丝蚴和 D. immitis 抗原。9 只（3.6%；95%CI=1.9-6.8）动物 D. immitis 抗原阳性但微丝蚴阴性，9 只（3.6%；95%CI=1.9-6.8）动物微丝蚴阳性但 D. immitis 抗原阴性。在四个不同的城市发现了 D. immitis 阳性的狗。经显微镜和分子分析后，未在皮肤中发现丝状原虫。
本研究数据表明，D. immitis 是感染巴西东北部沿海地区狗的主要丝虫线虫。基于动物感染的潜在风险，有必要进行检测以检测微丝蚴和 D. immitis 抗原。必须采取预防措施，使用杀微丝蚴化合物和驱虫杀虫剂来预防犬感染。
