Gizzarelli Manuela, Bosco Antonio, Foglia Manzillo Valentina, Bongiorno Gioia, Bianchi Riccardo, Giaquinto Daniela, Ben Fayala Nour El Houda, Varloud Marie, Crippa Alessia, Gradoni Luigi, Cringoli Giuseppe, Maurelli Maria Paola, Rinaldi Laura, Oliva Gaetano
Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy.
Unit of Vector-Borne Diseases, Istituto Superiore di Sanità, Rome, Italy.
Front Vet Sci. 2021 May 4;8:667290. doi: 10.3389/fvets.2021.667290. eCollection 2021.
Infected dogs are considered the main domestic animal reservoirs for parasite. Infectiousness to competent phlebotomine vectors has been associated with many factors, the main being the severity of the disease exhibited by infected dogs. This study examines the relationship between different clinical parameters and the infectiousness to colonized sand flies having a blood meal on dogs. Data obtained in the present study come from an untreated group of sick dogs submitted to xenodiagnosis for the evaluation of a spot on insecticide solution. Seventeen dogs were diagnosed as affected by leishmaniasis through clinical examination, immunofluorescence antibody test (IFAT) serology, and loop-mediated isothermal amplification (LAMP). The disease severity (clinical score) was staged by using a numeric value derived from eight clinical and parasitological parameters. Xenodiagnosis was performed on caged dogs exposed for 1.5 h to sand-fly bites. The following parameters related to sand flies were examined: blood feeding (% of blood engorged females), promastigote detection (% of promastigote-positive sand flies), promastigote burden, and the promastigote stage maturation (potential transmissibility rate). Statistical relationship between the clinical score and entomological parameters was investigated, as well as the possible correlation between each clinical and laboratory parameters and sand fly infection/infectivity. The severity of clinical score may influence the blood feeding by, and the probability of promastigote detection in, sand flies; skin lesions seem to be the main factor that influences the rate of blood feeding. Promastigote burden is related to IFAT titer, skin lesions, and clinical score. All entomological parameters are strongly related among them. This study confirms that both infection and infectivity are influenced by a dog's clinical condition.
感染犬被认为是该寄生虫的主要家畜宿主。对有能力的白蛉传播媒介的传染性与许多因素有关，其中主要因素是感染犬所表现出疾病的严重程度。本研究考察了不同临床参数与以犬为血餐的定殖沙蝇传染性之间的关系。本研究获得的数据来自一组未经治疗的患病犬，这些犬接受了异种诊断以评估杀虫剂溶液斑点。通过临床检查、免疫荧光抗体试验（IFAT）血清学和环介导等温扩增（LAMP），17只犬被诊断为感染利什曼病。疾病严重程度（临床评分）通过从八个临床和寄生虫学参数得出的数值进行分期。对关在笼中的犬进行异种诊断，使其暴露于沙蝇叮咬1.5小时。检查了与沙蝇相关的以下参数：吸血情况（饱腹雌蝇的百分比）、前鞭毛体检测（前鞭毛体阳性沙蝇的百分比）、前鞭毛体负荷以及前鞭毛体阶段成熟度（潜在传播率）。研究了临床评分与昆虫学参数之间的统计关系，以及每个临床和实验室参数与沙蝇感染/传染性之间的可能相关性。临床评分的严重程度可能会影响沙蝇的吸血情况以及在前鞭毛体检测中的概率；皮肤病变似乎是影响吸血率的主要因素。前鞭毛体负荷与IFAT滴度、皮肤病变和临床评分有关。所有昆虫学参数之间都密切相关。本研究证实，感染和传染性均受犬临床状况的影响。
