Department of Animal Health, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain.
Department of Veterinary Medicine, University of Bari, Valenzano, Bari, Italy.
Parasit Vectors. 2018 Mar 20;11(1):195. doi: 10.1186/s13071-018-2773-0.
The fruit fly Phortica variegata (Drosophilidae: Steganinae) feeds on the ocular secretions of animals and humans, and has been described as an intermediate host of the eye worm Thelazia callipaeda (Spirurida: Thelaziidae) in Italy. Despite the increased detection of T. callipaeda in many European countries, information about its vector role in natural conditions is still limited. In the Iberian Peninsula, thelaziosis caused by T. callipaeda has been reported in dogs, cats, red foxes, wild rabbits and humans.
In the last seven years, we have detected increased numbers of cases of canine thelaziosis at three locations in mainland Spain: Site 1, La Vera region (Cáceres Province, central-western Spain; 51 cases); Site 2, El Escorial municipality (Madrid Community, central Spain; 23 cases); and Site 3, Miraflores de la Sierra municipality (Madrid Community, central Spain; 41 cases). Site 1 is considered endemic for T. callipaeda while the other two sites have been recently recognised as risk zones for T. callipaeda infection.
From June 2016 to September 2017, 2162 flies were collected and morphologically identified as Phortica spp. (Site 1, n = 395; Site 2, n = 1544; and Site 3, n = 223). Upon dissection, third-stage T. callipaeda larvae were found in two out of 155 flies examined from Site 1, and both these larvae tested molecularly positive for the eye worm. Of the 395 flies collected from Site 1, 371 were molecularly processed for arthropod species identification and T. callipaeda detection. All 371 flies were identified as P. variegata and 28 (7.5%; 95% CI: 4.8-10%) tested positive for T. callipaeda DNA haplotype 1.
Our findings indicate that T. callipaeda circulates among dogs and P. variegata in Spain, where zoonotic cases have been also reported. The co-existence of canine thelaziosis and Phortica spp. in geographical areas previously considered free of the eye worm indicates a risk of infection for both animals and humans living in this region.
花蝇 Phortica variegata（双翅目：Steganinae）以动物和人类的眼部分泌物为食，在意大利被描述为眼虫 Thelazia callipaeda（旋尾目：Thelaziidae）的中间宿主。尽管在许多欧洲国家越来越多地发现 T. callipaeda，但有关其自然条件下媒介作用的信息仍然有限。在伊比利亚半岛，T. callipaeda 引起的嗜眼线虫病已在狗、猫、红狐、野兔和人类中报告。
在过去的七年中，我们在西班牙大陆的三个地点检测到犬嗜眼线虫病的病例数量增加：地点 1，拉维拉地区（卡塞雷斯省，西班牙中西部；51 例）；地点 2，埃尔埃斯科里亚尔市（马德里社区，西班牙中部；23 例）；和地点 3，米拉弗洛雷斯德拉萨里市（马德里社区，西班牙中部；41 例）。地点 1 被认为是 T. callipaeda 的地方病疫区，而另外两个地点最近被确认为 T. callipaeda 感染的风险区。
2016 年 6 月至 2017 年 9 月，共收集并形态鉴定了 2162 只蝇类，鉴定为 Phortica spp.（地点 1，n = 395；地点 2，n = 1544；地点 3，n = 223）。在解剖检查中，从地点 1 检查的 155 只蝇类中有 2 只发现了第三期 T. callipaeda 幼虫，这两条幼虫的分子检测均对眼虫呈阳性。从地点 1 收集的 395 只蝇类中，有 371 只进行了分子处理以鉴定节肢动物种类和 T. callipaeda 检测。所有 371 只蝇类均鉴定为 P. variegata，28 只（7.5%；95%CI：4.8-10%）对 T. callipaeda DNA 单倍型 1 呈阳性。
我们的研究结果表明，T. callipaeda 在西班牙的狗和 Phortica variegata 中传播，并且在该地区也报告了人感染病例。在以前被认为没有眼虫的地理区域中同时存在犬嗜眼线虫病和 Phortica spp.，表明该地区的动物和人类都有感染的风险。
