Dirofilaria tenuis infection of the oral mucosa and cheek

Zoonotic dirofilariases: one, no one, or more than one parasite

Dirofilaria spp. are vector-borne filarial nematodes that affect a variety of animal species, including humans. Dirofilaria immitis and Dirofilaria repens are the two main zoonotic species, but also other wildlife-associated Dirofilaria species are occasionally reported as causative agents of human dirofilariasis, including Dirofilaria striata, Dirofilaria tenuis, Dirofilaria ursi, Dirofilaria spectans, and Dirofilaria magnilarvata. Since the etiological identity of most of the species mentioned here is arguable, we summarized and critically discussed data concerning infections in humans, focusing on the reliability of Dirofilaria species identification. We advocate the importance of combined morphological and genomic approaches to provide unequivocal evidence for their zoonotic potential and pathogenicity.

Human dirofilariosis of buccal mucosa - First molecularly confirmed case and literature review

When presented in unusual manner, human dirofilariosis is hard to recognize and often leads to misdiagnosis and unjustified use of various medications. Herein, we report a rare case of Dirofilaria infection localized in buccal mucosa. A 45-year-old male, residing in the Central Serbia, developed striking edema of buccal mucosa followed by leucocytosis, with both neutrophylia and eosinophylia. Thirty days after first symptoms occurred, nodule was formed along the lateral edge of right maxilla. Therefore, patient underwent surgical extirpation and subsequent histopathological analysis of the specimen revealed the presence of a nematode. Based on morphological characteristics of detected parasite, the diagnosis of submucosal Dirofilaria repens-like infection was made. The diagnosis was confirmed, being the first case in the world analyzed by molecular methods. So far, only 13 such cases have been reported worldwide and our paper brings attention to rare form of this zoonosis and updates the data about human dirofilariosis in buccal mucosa.

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.

Dirofilariasis Presenting as an Infiltrative Mass in the Right Buccal Space

Dirofilariasis is caused by filarial nematodes (roundworms) of the genus Dirofilaria. Dirofilariasis of the oral mucosa is very rare. Herein, we report a case of a 79-year-old man who had a slowly growing infiltrative mass in the right buccal space. Histopathologic examination showed an inflammatory infiltrate with eosinophilia, histiocytes, and small organisms (0.2-0.3 mm). Digital images were sent to the Centers for Disease Control and Prevention, which identified the parasite as a nematode in the genus Dirofilaria. It appeared to be dead and degenerating, but external, fine longitudinal cuticular ridges and the presence of tall muscle cells were diagnostic. Thus, Dirofilaria, despite its rarity, should be considered in the differential diagnosis of tumor-like lesions in the buccal mucosa.

Oral helminthic infestations

Oral infections caused by helminths (worms) are rarely encountered in clinical practice, and consequently, there is a paucity of information in the medical and dental literature about these conditions. In the present article, we review the English literature related to oral helminthic infestations. The main oral infections caused by helminths include four roundworm (trichinosis, trichuriasis, filariasis, and larva migrans) and three tapeworm infections (cysticercosis, sparganosis, and echinococcosis). Cases are mainly encountered in endemic areas and mainly present a benign clinical picture. The diagnosis of oral helminthic infections is mostly established after histopathological examination, which shows parasitic larvae lined by fibrous tissue and inflammatory cells. Surgical excision is the preferred treatment of isolated oral lesions caused by helminths; however, patients should undergo thorough medical evaluation to exclude the possible involvement of other body systems.

Dirofilarial infection presenting as a facial mass: case report of an emerging zoonosis

Dirofilariasis is a parasitic infection caused by nematodes. Human infection remains rare but is increasing in scope, particularly in endemic areas. Dirofilariasis typically presents as a subcutaneous mass or with pulmonary nodules. Here, we present the case of a 73-year-old woman whose asymptomatic facial mass was caused by dirofilarial infection. The pathophysiology, diagnosis, and treatment of dirofilariasis of the head and neck will be discussed. In endemic areas, dirofilariasis must be considered in the differential diagnosis of facial masses.

Intra-oral Dirofilaria repens infection: report of seven cases

Cutaneous dirofilariasis usually affects animals such as cats and dogs which are known to be the natural host of Dirofilaria. Dirofilariasis displays a worldwide distribution. Certain geographic regions account for the majority of reported cases. South-eastern United States, Australia and Europe have been identified as endemic regions (1, 2). However, new endemic areas are arising with increased awareness in African and Asian regions. Out of about 40 different species of Dirofilaria only a few species are commonly known to infect man, namely Dirofilaria immitus, D. tenices and D. repens. Human infection occurs when a human becomes a blood meal of an infected arthropod vector and on accidental entering of the worm. Rarely this zoonotic infection affects the oral mucosa (3). Man is the dead end of this parasite. Since the human body is an abnormal environment for the parasite, the development of the larvae is inhibited by means of retardation of sexual maturity. Lesions are presented as single non-tender subcutaneous nodules, and most patients are asymptomatic. Diagnosis is established by H&E sections prepared from excised nodules. In a majority of the cases, only a single worm either a male or a female could be identified. The worm is usually dead and degenerated with a massive inflammatory cell infiltration. Seven new cases presented as intra-oral nodules with their clinicopathological correlation are discussed.

Human dirofilariasis of the buccal mucosa: a case report

Human dirofilariasis is a helminthic zoonosis that is common in some parts of the world. A sporadic case of dirofilariasis affecting the buccal mucosa has been reported in a non-endemic area of southern China. Clinical findings, diagnosis, pathogenesis and management are discussed. This is the fourth case of human dirofilariasis involving the oral mucosa reported in world literature.

Dirofilaria repens presenting as a premasseteric nodule

Dirofilariasis is a rare zoonosis that is mainly seen with subcutaneous or pulmonary involvement. Natural hosts are dogs, cats, jackals, and raccoons; however, humans can rarely become an accidental host for the parasite. In the reported case, infection manifested as a subcutaneous nodule, representing a significant diagnostic challenge for both the surgeon and the pathologist. A case of a 62-year-old man with a premasseteric soft tissue mass caused by Dirofilaria repens is presented with histopathologic confirmation.