Torres-Chable Oswaldo M, Baak-Baak Carlos M, Cigarroa-Toledo Nohemi, Blitvich Bradley J, Brito-Argaez Ligia G, Alvarado-Kantun Yessenia N, Zaragoza-Vera Claudia V, Arjona-Jimenez Guadalupe, Moreno-Perez Lluvia G, Medina-Perez Pablo, Machain-Williams Carlos I, Garcia-Rejon Julian E
Laboratorio de Enfermedades Tropicales y Transmitidas por Vector, División Académica de Ciencias Agropecuarias, Universidad Juárez Autónoma de Tabasco, Villahermosa, Tabasco, México.
Laboratorio de Arbovirologia, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, México.
J Vector Borne Dis. 2018 Apr-Jun;55(2):151-158. doi: 10.4103/0972-9062.242563.
BACKGROUND & OBJECTIVES: Dirofilaria immitis is a filarial nematode that causes heartworm disease in domestic as well as wild canines and felines; and cutaneous or pulmonary infections in humans. The purpose of the study was to estimate the prevalence of D. immitis in domestic dogs in Tabasco, Mexico and to assay mosquitoes temporally and spatially associated with dogs for evidence of infection.
Blood was collected from 1050 dogs in 1039 houses during a random household survey performed in 2016 and 2017. Genomic DNA was extracted and assayed by polymerase chain reaction (PCR) using pan-filarial primers and various species-specific primers. Dog owners were interviewed using a structured questionnaire designed to collect information on factors that may impact the occurrence of filarial infection. The association between canine dirofilariasis prevalence and factors likely to impact infection was determined by univariate logistic regression analysis, followed by multivariate binomial logistic regression analysis. Indoor and outdoor resting mosquitoes were collected from houses by manual aspiration. Mosquitoes were identified according to species, homogenized and tested by PCR for filarial nematodes.
A total of 84 (8%) dogs were positive for D. immitis DNA, while 3 (0.3%) dogs contained Acanthocheilonema reconditum DNA. Several factors were significantly associated with D. immitis infection. For example, dogs that lived <100 m from a large source of open standing water were significantly more likely (p = 0.002) to become infected with D. immitis than other dogs. Additionally, dogs with infrequent or no anthelmintic treatment were significantly more likely (p = 0.0) to become infected than dogs that were regularly treated. The entomologic investigation yielded 2618 female mosquitoes from 14 species. Four pools of Culex quinquefasciatus were positive for D. immitis DNA and the minimum infection rate, calculated as the number of positive pools per 1000 mosquitoes tested, was 2.9.
INTERPRETATION & CONCLUSION: The study identified several factors positively associated with an increased risk of D. immitis infection in domestic dogs in Tabasco and provides evidence that Cx. quinquefasciatus is potentially an important vector in this region. This information can be used by local veterinarians and dog owners to reduce the burden of D. immitis on canine health.
犬恶丝虫是一种丝虫线虫，可导致家犬、野生犬科动物和猫科动物患心丝虫病，也可引起人类皮肤或肺部感染。本研究的目的是估计墨西哥塔巴斯科州家犬中犬恶丝虫的流行率，并检测与犬在时间和空间上相关的蚊子是否有感染迹象。
在2016年和2017年进行的一项随机家庭调查中，从1039户家庭的1050只犬采集血液。提取基因组DNA，使用泛丝虫引物和各种物种特异性引物通过聚合酶链反应（PCR）进行检测。使用结构化问卷对犬主人进行访谈，以收集可能影响丝虫感染发生的因素的信息。通过单因素逻辑回归分析确定犬恶丝虫病流行率与可能影响感染的因素之间的关联，随后进行多因素二项逻辑回归分析。通过手动抽吸从房屋中收集室内和室外静息蚊子。根据物种对蚊子进行鉴定，匀浆后通过PCR检测丝虫线虫。
共有84只（8%）犬的犬恶丝虫DNA呈阳性，而3只（0.3%）犬含有隐匿棘唇线虫DNA。几个因素与犬恶丝虫感染显著相关。例如，生活在距离大型露天积水水源不到100米的犬比其他犬感染犬恶丝虫的可能性显著更高（p = 0.002）。此外，很少或未进行驱虫治疗的犬比定期治疗的犬感染的可能性显著更高（p = 0.0）。昆虫学调查共捕获了来自14个物种的2618只雌蚊。四组致倦库蚊的犬恶丝虫DNA呈阳性，以每1000只检测蚊子中的阳性组数计算的最低感染率为2.9。
该研究确定了几个与塔巴斯科州家犬感染犬恶丝虫风险增加呈正相关的因素，并提供证据表明致倦库蚊可能是该地区的重要传播媒介。当地兽医和犬主人可利用这些信息减轻犬恶丝虫对犬类健康的负担。
