A Case of Orbital Dirofilariasis in Northern Turkey

First time identification of subconjunctival Dirofilaria immitis in Turkey: giant episcleral granuloma mimicking scleritis

Dirofilariasis is a vector-borne disease that is present worldwide. This report describes a giant subconjunctival granuloma which mimics scleritis, caused by D. immitis. A 60-year-old man was referred with the complaints of irritation, redness, and swelling at the medial part of the right eye. He was living in Izmir province located in western Turkey. Slit-lamp examination showed a firm, immobile mass measuring 13.0 × 5.0 × 5.0 mm with yellowish creamy color. The mass was completely removed surgically under local anesthesia mainly for diagnosis. Histopathology revealed typical morphological features of a filarioid nematode in favor of Dirofilaria as characterized by the external smooth cuticular surface, cuticular layer, muscle layer, and intestinal tubule. Molecular study was performed using DNA isolated from paraffin-embedded tissue sections of the worm. PCR amplification and then DNA sequence analysis of cytochrome c oxidase subunit 1 (cox1) gene fragment confirmed that the worm was D. immitis. It is suggested that this may represent the first human case of D. immitis occurring in subconjunctival granuloma in Turkey. Although rare, D. immitis caused by ocular dirofilariasis in humans should be considered.

Potential Mosquito Vectors of Dirofilaria immitis and Dirofilaira repens (Spirurida: Onchocercidae) in Aras Valley, Turkey

Dirofilaria immitis (Leidy, 1856) and Dirofilaria repens (Railliet & Henry, 1911) are mosquito-borne filarial nematodes that primarily affect dogs, causing heartworm disease and subcutaneous dirofilariosis. The canine heartworm is reported in different provinces in Turkey. However, studies about the transmitting mosquito species are limited. Hence, this study aimed to investigate potential vectors of D. immitis and D. repens in Aras Valley, Turkey. In total, 17,995 female mosquitoes were collected from eight villages during three mosquito seasons (2012-2014) in Aras Valley, located in north-eastern Turkey. A total of 1,054 DNA pools (527 abdomen and 527 head-thorax) were tested with Dirofilaria primers by multiplex-polymerase chain reaction (PCR). Aedes caspius was the most abundant species in collection sites with 90%; this was followed by Culex theileri Theobald, 1903 (Diptera: Culicidae) (7.31%), Anopheles maculipennis Meigen 1818 (Diptera: Culicidae) (1.28%), Culex pipiens Linnaeus, 1758 (Diptera: Culicidae) (0.43%), (Anopheles) hyrcanus (Pallas, 1771) (Diptera: Culicidae) (0.37%), Aedes vexans (Meigen, 1830) (Diptera: Culicidae) (0.25%), and Culiseta annulata Schrank, 1776 (Diptera:Culicidae) (0.02%). Dirofilaria immitis and D. repens were detected in mosquito pools from five villages. The total Dirofilaria spp. estimated infection rate was 1.33%. The highest estimated infection rate was found in Ae. vexans (6.66%) and the lowest was in Ae. caspius (1.26%). The results show that An. maculipennis sl, Ae. caspius, Ae. vexans, Cx. theileri and Cx. pipiens are potential vectors of D. immitis and D. repens with DNA in head-thorax pools; An. hyrcanus is also a likely vector, but Dirofilaria DNA was found only in abdomen pools for the study area. This study revealed new potential vector species for D. immitis. Mosquitoes with natural infections of D. repens were reported for the first time in Turkey.

Recent advances on Dirofilaria repens in dogs and humans in Europe

Dirofilaria repens is a nematode affecting domestic and wild canids, transmitted by several species of mosquitoes. It usually causes a non-pathogenic subcutaneous infection in dogs and is the principal agent of human dirofilariosis in the Old World. In the last decades, D. repens has increased in prevalence in areas where it has already been reported and its distribution range has expanded into new areas of Europe, representing a paradigmatic example of an emergent pathogen. Despite its emergence and zoonotic impact, D. repens has received less attention by scientists compared to Dirofilaria immitis. In this review we report the recent advances of D. repens infection in dogs and humans, and transmission by vectors, and discuss possible factors that influence the spread and increase of this zoonotic parasite in Europe. There is evidence that D. repens has spread faster than D. immitis from the endemic areas of southern Europe to northern Europe. Climate change affecting mosquito vectors and the facilitation of pet travel seem to have contributed to this expansion; however, in the authors' opinion, the major factor is likely the rate of undiagnosed dogs continuing to perpetuate the life-cycle of D. repens. Many infected dogs remain undetected due to the subclinical nature of the disease, the lack of rapid and reliable diagnostic tools and the poor knowledge and still low awareness of D. repens in non-endemic areas. Improved diagnostic tools are warranted to bring D. repens diagnosis to the state of D. immitis diagnosis, as well as improved screening of imported dogs and promotion of preventative measures among veterinarians and dog owners. For vector-borne diseases involving pets, veterinarians play a significant role in prevention and should be more aware of their responsibility in reducing the impact of the zoonotic agents. In addition, they should enhance multisectorial collaboration with medical entomologists and the public health experts, under the concept and the actions of One Health-One Medicine.

Differential diagnosis of dirofilariasis of the lower lid: a clinical case from Ophthalmological diagnostic center no. 7 for children and adults, Saint Petersburg

We present a brief literature review on dirofilariasis and its incidence in Russia. The diagnosis and operative treatment of a patient with dirofilariasis caused by infection with Dirofilaria repens is described. The diagnostic criteria (epidemiological analysis, ultrasonographic, and laboratory-based and parasitological work-up) are presented. Ultrasonography plays an important role in the differential diagnosis of dirofilariasis and cavernous hemangiomas. Different non-surgical and surgical treatment approaches are discussed.

Ocular and subcutaneous dirofilariasis in a Sri Lankan infant: an environmental hazard caused by dogs and mosquitoes

An 11-month-old infant presented with a subcutaneous nodule in the right cheek which was found by ultrasonography to be a worm. Following treatment with di-ethylcarbamazine, a worm emerged from the left upper eyelid which was confirmed to be Dirofilaria repens. Dirofilariasis usually manifests as a single lesion and is rare in infants.

Orbital parasitosis

Orbital parasitoses are uncommon diseases. Due to specific characteristics of orbital space, many different diseases, such as tumors and inflammatory disease, can present with similar clinical manifestations. The aim of this study is to review the most important clinical, epidemiological, and treatment aspects of orbital parasitoses described worldwide.

Discrete eyelid swelling caused by live subconjunctival Dirofilaria repens

We present a case concerning a 48 year-old man, who had complaints about ocular pains and an unpleasant feeling, which had started two days before admission. It was as if there was “something moving in his left eye.” The examination showed an extremely motile white worm, which was wrapped in concentric circles around the limb in the subconjunctival space of the patient’s left eye. It was identified as the adult female form of Dirofilaria repens. The patient had a normal clinical finding, except eosinophilia. Ocular filariasis is as a possibility to think about, even when the cases are not in a typically endemic area and with no specific subjective complains.