Mallick et al: video report

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Excision of subcutaneous Dirofilariasis of the eyelid

D Mallick and TP Ittyerah

CBM Ophthalmic Institute, Kerala, India

Correspondence to: Dr D Mallick, CBM Ophthalmic Institute, Little Flower Hospital, Angamaly-683572, Kerala, India. Email: debjoymallick{at}indiatimes.com

Accepted for publication: 15th January 2003

Still from video showing worm removalDirofilariasis of the subcutaneous tissue of the eyelids: After careful incision, the coiled worm was seen immediately beneath the skin. It was gently extracted from the surgical wound with a pair of forceps, revealing a 10 cm white slender actively moving on removal.

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Background

Dirofilariasis, a disease commonly found in carnivorous mammals, is uncommon in humans. Of the genus Dirofilaria, two important species that have been reported to involve the eye include D.tenuis and D.repens1. D.tenuis is the most common Dirofilaria species causing human dirofilariasis in the United States2 while D.repens has been reported from Malaysia3, Sri Lanka (formerly known as Ceylon)4 and Thailand. The only 2 reports on dirofilariasis of the eye from India6,7 describe involvement of the subconjuntival space. We report for the first time in India on dirofilariasis of the subcutaneous tissue of the eyelids.

  

Case Report

A 14 year old female patient presented with a vermiform swelling of the left upper eyelid, which she had noticed for several days. She also reported occasional movements within the swelling. The skin overlying the swelling was intact and showed no blister. Both eyes were otherwise normal and had a vision of 6/6. No swelling was noted on any other part of the body. An examination of the patient�s stool did not reveal any ova parasites or cysts and peripheral blood did not show any eosinophilia. The patient was a resident of the town of Angamaly in Kerala in South India.

The skin over the vermiform swelling was carefully incised after administering a subcutaneous injection of a local anaesthetic agent. The coiled up worm was seen immediately beneath the skin. The worm was gently extracted from the surgical wound with a pair of forceps (figure1b). It had a white slender body measuring 10 cm in length and 0.41 mm in its widest diameter and showed active movements on removal. The specimen was examined by parasitologists at the Liverpool School of Tropical Medicine. Subsequent investigations there concluded that the worm was a sexually immature female filarial worm belonging to the genus Dirofilaria, most probably D.repens. The worm showed a prominent cuticle and a short segment of the body removed at the level of the uterus showed oocytes but no microfilariae.

  

Discussion

Dirofilariasis commonly affects domestic and wild animals. Zoonotic dirofiloarial infestations following incidental infection of humans are uncommon and may be caused by several species of dirofilaria. Subcutaneous dirofilariasis has been reported to be caused by D.tenuis in Southeastern United States2 and by D.repens in Malaysia3, Srilanka (Ceylon)4, and Thailand5. Subconjunctival dirofilariasis has been reported less frequently1. The only 2 existing reports from India6,7 on diroflariasis describe subconjunctival involvement. D.immitis, which usually causes pulmonary lesions in humans has rarely been reported to involve the subcutaneous tissues8.

D.tenuis is a natural parasite of raccoons. D.tenuis has not been reported from the state of Kerala probably as there are no raccoons here. D.repens is found in cats dogs and foxes. The source and route of infection is not known definitely. The black salt marsh mosquito Aedes taeniorhyncus has been described as a possible vector for D.tenuis infection2. Probably a similar mosquito vector is also responsible for the spread of D.repens. The South Indian state of Kerala is studded with a network of backwaters which could serve as breeding grounds for mosquitoes. A reservoir of D.repens may exist in the cat and dog population of the state.

Humans are a suboptimal host for Dirofilaria and many of the worms recovered are either immature or dead. The worm we recovered was a female worm whose uterus contained only oocytes showing that the worm was sexually immature.

Dirofilarial worms are identified by their thick laminated cuticle, broad lateral chords and large muscle cells9. Accurate species identification is best accomplished by examination of mature worms. Surgical removal of the worms is the treatment of choice and generally no further treatment is recommended

 The authors would like to express their gratitude to Dr J.W Bailey of the Clinical Diagnostic Parasitology Laboratory at the Liverpool School of Tropical Medicine,UK, for her help in getting the worm identified

 

References

  1. Soylu M, Ozcan K, Yalaz M, Varinli S, Slem G Dirofilariasis: an uncommon parasitosis of the eye. Br J Ophthalmol 1993;77:602-603.
  2. Heurle D, Kwa BH, Vickery AC. Ophthalmic dirofilariasis Ann Ophthalmol 1990;22:273-275.
  3. Dissanaike AS, Ramalingam S, Fong A, et al: Filaria in the vitreous of the eye of man in peninsular Malaysia. Am J Trop Med Hyg 1977;26:1143-1147.
  4. Dissanaike AS, Lykov VP, Sivayoham ISSR et al, Four more cases of human infection with dirofilaria (nochtiella). Ceylon Med J 1972;17:105-112.
  5. Jariya P, Sucharit S:Dirofilaria repens from the eyelid of a woman in Thailand Am J Trop Med Hyg 1983;32:1456-1457.
  6. Nadgir S, Talur SS, Mangoli V, Halesh LH, Krishna BV. Subconjunctival dirofilariasis in India Southeast Asian J Trop Med Public Health 2001;32(2):244-246
  7. George M, Kurian C. Conjunctival abscess due to dirofilaria conjunctivae J Indian Med Assoc 1978;71(5):123-124.
  8. Nishimura T, Kondo K, Shoho C.Human infection with subcutaneous Dirofilaria immitis Biken J 1964;7:1-8.
  9. Font RL, Neafie RC, Perry HD, Subcutaneous dirofilariasis of the eyelid and ocular adnexa: report of six cases Arch Ophthalmol 1980;98:1079-1082.