Subconjunctival dirofilariasis caused by Dirofilaria repens: A case report with short review

Subconjunctival dirofilariasis: a case report from the United Arab Emirates and review of literature from the Arabian Gulf region

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Cases of dirofilariasis have been increasingly reported in non-endemic areas.

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This is the second case of ocular dirofilariasis to be reported in the United Arab Emirates.

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Prompt surgical intervention in the parasite results in favourable outcomes.

We report the second case of ocular dirofilariasis from the United Arab Emirates in a 53-year-old Indian male. In this case, the patient had no travel history and presented with severe ocular pain and redness. Clinical examination raised the suspicion of a parasitic infection, and a microscopic examination confirmed the diagnosis of Dirofilaria repens. Surgical intervention was performed, and the patient had good postoperative outcomes. To our knowledge, this was the fifth case of human dirofilariasis and the third of ocular dirofilariasis to be reported from an area where the parasite is not known to be endemic – the Arabian Gulf region.

Whether Dirofilaria repens parasites from South India belong to zoonotic Candidatus Dirofilaria hongkongensis (Dirofilaria sp. hongkongensis)?

The canine and zoonotic dirofilarioses are arthropod-borne parasitic infections caused by nematodes of the genus Dirofilaria, infecting canines, felines and humans throughout the world. Dirofilaria repens was considered as the most common cause of human dirofilariosis in Kerala. In the present study, molecular characterization of Dirofilaria isolates causing dirofilariosis in humans, dogs and jackal from Kerala, South India was undertaken by performing sequence and phylogenetic analysis based on cytochrome oxidase subunit I (COI) gene. The live worms from swellings/ nodules in subconjunctiva or subcutaneous tissue or scrotum were recovered from humans (n = 3), dogs (n = 4) and one jackal. The PCRs targeting a repetitive fragment, 18S rRNA and COI genes yielded products of ~246 bp, ~875 bp and ~350 bp respectively in all the samples. The sequence analysis of 18S rRNA gene revealed the closest identity (98 to 99%) with an already published sequence of D. repens isolated from a human in Japan. However, based on the sequence and phylogenetic analysis of partial sequences of COI gene, the Dirofilaria infecting both animals (dogs, jackal) and humans native to Kerala, South India were identified as genetically conserved and closely related to Dirofilaria sp. hongkongensis. Hence, the results of the present study suggested the existence of Candidatus Dirofilaria hongkongensis (Dirofilaria sp. hongkongensis) in Kerala, South India causing zoonotic filariosis in canines and humans.

Ocular Dirofilariasis: A Rare case from Mumbai, India

Dirofilariasis is a worldwide zoonotic filariasis. Human dirofilariasis is a zoonotic infection most commonly caused by Dirofilariarepens. Dirofilariasis, caused by Dirofilaria repens, has been reported to occur widely throughout Asia, Europe, and Africa. It has not been widely recognized in India; however, several cases have been reported in the last few years. Ease and frequency of international travel has probably contributed to the increase in the number of cases. There is probably a focus of human infection with D. repens in Kerala, India. We report a case of ocular dirofilariasis, from the Western part of India. Among the Indian case reports of human dirofilariasis caused by D. repens, majority had ocular infections and few had subcutaneous involvement of the face.