Fibrous subcutaneous nodule caused by Dirofilaria repens

Systematic Review of Lesser Known Parasitoses: Maxillofacial Dirofilariasis

BACKGROUND

Dirofilariasis is an endemic disease in tropical and subtropical countries caused by about 40 different species of dirofilari. Dirofilariasis of the oral cavity is extremely rare and is usually seen as mucosal or submucosal nodules. We also present a case of dirofilariasis of the mandibular third molar region submucosally in a 26 year old male patient.

PURPOSE

To identify, enlist and analyze the cases of dirofilariasis in maxillofacial region reported worldwide so as to understand the clinical presentation and encourage the consideration of helminthic infections as a possible differential diagnosis in maxillofacial swellings.

METHODS

Two authors KC and SK independently searched the electronic database of PUBMED, OVID, Google Scholar and manual search from other sources. A general search strategy was planned and anatomic areas of interest identified. The search was made within a bracket of 1 month by the independent authors KC and SK who assessed titles, abstracts and full texts of articles based on the decided keywords. The final selection of articles was screened for the cases that were reported in the maxillofacial region including the age, gender, site of occurrence and region of the world reported in. A geographic distribution of the reported cases was tabulated.

RESULTS

A total number of 265, 97, 1327, 3 articles were identified by PubMed, Ovid, GoogleScholar and manual search respectively. The final articles were manually searched for duplicates and filtered according to the inclusion/exclusion criteria which led to a final list of 58 unique articles that were included in the study. In total 99 cases were identified.

CONCLUSION

Although intraoral dirofilarial infections are extremely uncommon, it should be considered in the differential diagnosis of an intraoral or facial swelling that does not completely respond to routine therapy especially in patients from endemic areas.

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.

Canine and human Dirofilaria infections in the Balkan Peninsula

Dirofilaria immitis and Dirofilaria repens infections are mosquito-borne diseases, mainly of dogs. Both parasites are zoonotic, and they sometimes cause serious infections in humans. The aim of this short review was to examine the situation in the Balkan Peninsula, from where it is not always easy to obtain suitable data, often reported in journals and other publications difficult to be retrieved and with poor or no visibility. The review included data from international and regional literature, doctoral theses, and conference proceedings.

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.

Human Pulmonary Dirofilariasis: One More Case in Greece Suggests That Dirofilaria is a Rather Common Cause of Coin Lesions in the Lungs in Endemic Areas of Europe

Herein we describe a case of a 52 year-old male from Greece who presented with a coin lesion in the right lung, which proved to be an infection from Dirofilaria immitis. A careful review of the literature shows that, contrary to the common perception, humans may be frequently infected by Dirofilaria species. For this reason the authors suggest that in every case which presents with a coin lesion in the lung in endemic areas, dirofilariasis should always be considered, and excluded before any other intervention is decided.