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An apparently pharyngeal myiasis in a patient caused by Oestrus ovis (Oestridae: Diptera)
Acta Tropica 68 (1997) 361 – 363
Short communication
An apparently pharyngeal myiasis in a patient caused by Oestrus o6is (Oestridae: Diptera) I. Yeruham a,*, S. Malnick b, D. Bass b, S. Rosen a a
The Koret School of Veterinary Medicine, The Hebrew Uni6ersity of Jerusalem, P.O.B. 12, Reho6ot 76100, Israel b Kaplan Medical Center, P.O.B. 1, Reho6ot 76100, Israel Received 5 May 1997; received in revised form 30 June 1997; accepted 4 July 1997
Keywords: Myiasis; Oestrus o6is
Oestrus o6is, (Linnaeus, 1758) the sheep nasal bot, is a cosmopolitan myiasis-producing fly whose larvae are well recognized parasites in the nasal cavities and sinuses of sheep and goats (Zumpt, 1965), whereas infestation in man is rare (Amr et al., 1993). Myiasis in an incidental host may have biological significance and can also be of medical and public health importance if the incidental host is man. The females are larviparous, depositing a number of first-instar larvae on the edge of, or just inside the nostrils of sheep and goats. The peculiar feature of the O. o6is female is that it may larviposit while still in flight. In their normal development in sheep, the larvae migrate at once to the nasal mucosa and nasal and frontal sinuses where they undergo 2 moults. After 2 to 12 months, the fully grown third instar larvae are expelled and pupate on the ground. The imagos emerge three to four weeks later. The ophthalmomyaisis produced in man by O. o6is larvae is restricted to conjunctivae, sclera, eyelids, and lachrymal duct (external ophthalmomyiasis) or the * Corresponding author. Present address: 4 Hagoren St., 70700 Gedera, Israel. 0001-706X/97/$17.00 © 1997 Elsevier Science B.V. All rights reserved. PII S 0 0 0 1 - 7 0 6 X ( 9 7 ) 0 0 0 9 9 - 5
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I. Yeruham et al. / Acta Tropica 68 (1997) 361–363
eye ball (internal ophthalmomyiasis) (Hadani et al., 1975; Dar et al., 1980; Stulting and Meyer, 1981; Omar et al., 1988; Amr et al., 1993). We report an unique case of an apparently pharyngeal myiasis in a patient caused by O. o6is. A 82 year old man presented with a complaint of a white mass appearing in his mouth after sneezing or coughing. This had happened on several occasions and he had noted that a fly was appearing from one of these masses on one of the occasions. His previous medical history included progressive systemic sclerosis which had resulted in esophageal reflux and skin changes on the hands. He was known to have a 1 cm diameter diverticulum at the lower end of the esophagus which had been shown on an upper GI series. An upper GI endoscopy was normal with no evidence of larvae in the stomach and repeat barium swallow showed the diverticulum with no contents inside it. A CT scan of the chest showed the esophageal diverticulum. A CT scan of the nasal sinuses and eyes was normal and an examination by an ear, nose and throat consultant was unremarkable. After having produced a total of six larvae there were no further episodes. Larvae were collected and preserved in 70% alcohol. Larvae were examined under a stereoscopic microscope for confirmatory identification using the keys of Zumpt (1965) and Wetzel and Bauristhene (1970). The collected larvae were identified as the third larval stage of O. o6is. We believe that the patient suffered from an apparently pharyngeal myiasis. Our patient lives in a urban area far away from the breeding places of sheep and goats, and has never had any direct contact with these species. Although there was no direct observation of expulsion of larvae from the patient, his history was consistent on each occasion, he is a reliable witness and there is no reason to doubt the accuracy of his history. Larvae of specific myiasis-producing flies, i.e. their larvae are obligatory parasites requiring at least some period of development in living tissues in specific hosts, may occasionally infest human; O. o6is, (Omar et al., 1988; Amr et al., 1993), Hypoderma lineatum (Al-Dabagh et al., 1980); H. bo6is (Jurko, 1957); Rhinooestrus purpureus (Le Fichoux et al., 1981), and Gastrophilus spp. (Zumpt, 1965). In addition to the described case, there are only two reports on myiasis in human due to O. o6is involving not only the eye but also the ear, nose and throat (Pampiglione, 1958; Al-Dabagh et al., 1980). Myiasis caused by O. o6is may be considered as an occupational disease of shepherds or farmers who usually keep sheep and goats in close proximity to their dwellings (Amr et al., 1993). Zumpt (1963) stated that man is most commonly infested in those geographical areas where the density of sheep and goats is low compared with that of man, so that the flies larviposit on people. This might explain the infestation of the patient in our case. Larvae of O. o6is can not usually progress beyond the first stage in the eye tissues (Hadani et al., 1975; Al-Dabagh et al., 1980). This is the first report in which the third instar larvae were found in a human, and shows that the O. o6is fly can
I. Yeruham et al. / Acta Tropica 68 (1997) 361–363
363
complete its life cycle even in an non-specific host like man. It is possible that the esophageal disturbance that is linked with progressive systemic sclerosis was related to the probable pharyngeal myiasis in our patient. Progressive systemic sclerosis commonly causes motility disturbances of the esophagus including a markedly lower esophageal sphincter pressure and aperistalsis (Gilliland, 1994). The combination of these two factors results in a marked gastroesophageal reflux and it is possible that this facilitated the expulsion of the larvae. There were no further episodes after esophagogastroduodenoscopy was performed. The patient received acid-suppressive therapy with omeprazole 20 mg bid and thus it is possible that swallowed larvae, which would not be exposed to gastric acid, were regurgitated.
References Al-Dabagh, M., Al-Mufti, N., et al., 1980. A second record from Iraq of human myiasis caused by larvae of the sheep botfly Oestrus o6is. L. Ann. Trop. Med. Parasitol. 74, 73 – 77. Amr, Z.S., Amr, B.A., Abo-Shehada, M.N., 1993. Ophthalmomyiasis externa caused by Oestrus o6is L. in the Ajloun area of northern Jordan. Ann. Trop. Med. Parasitol. 87, 259 – 262. Dar, M.S., Ben Amer, M., Dar, F.K., et al., 1980. Ophthalmomyiasis caused by the sheep nasal bot, Oestrus o6is (Oestridae) larvae, in the Benghazi area of Eastern Libya. Trans. R. Soc. Trop. Med. Hyg. 74, 303–306. Gilliland, B.C., 1994. Systemic sclerosis (Scleroderma). In: Isselbacher, K.J., Braunwald, E., Wilson, J., Martin, J.B., Fauci, A.S., Kasper, D.L. (Eds.), Harrison’s Principles of Internal Medicine, 13th ed. McGraw Hill, New York, pp. 1655–1661. Hadani, A., Rauchbach, K., Ilsar, M., 1975. Ophthalmomyiasis in a man caused by larvae of the sheep nasal bot fly (Oestrus o6is Linnaeus, 1785). Refu. Vet. 32, 157 – 158. Jurko, S., 1957. Ophthalmomyiasis interna anterior.. Med. Arch. 11, 57. LeFichoux, Y., Marty, P., Denis, G., et al., 1981. Un cas d’ophtalmomyiase externe a’ Oestrus o6is, Linn’e 1758 contract’ee sur la plage de Nice. Acta Trop. 38, 461 – 468. Omar, M.S., Das, A.B., Osman, N.I., 1988. External ophthalmomyiasis due to the sheep nostril bot fly larva Oestrus o6is in Saudi Arabia. Ann. Trop. Med. Parasitol. 82, 221 – 223. Pampiglione, S., 1958. Indagine epidemiologica sulla miasi congiuntivale umana da Oesturs o6is in Italia I. Pensiero/scuebtufuci 9, 242–244. Stulting, A.A., Meyer, H., 1981. External ophthalmomyiasis caused by Oestrus o6is.. South Afr. Med. J. 60, 709–710. Wetzel, H., Bauristhene, E., 1970. The identity of the third larval stage of Oestrus o6is Linnaeus (1758) (Diptera: Oestridae). Zool. Anz. 184, 87 – 94. Zumpt, F., 1963. Ophthalmomyiasis in man with special reference to the situation in Southern Africa. South Afr. Med. J. 37, 425–428. Zumpt, F., 1965. Myiasis in Man and Animals in the Old World. Butterworth, London, p. 257.
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Short communication
An apparently pharyngeal myiasis in a patient caused by Oestrus o6is (Oestridae: Diptera) I. Yeruham a,*, S. Malnick b, D. Bass b, S. Rosen a a
The Koret School of Veterinary Medicine, The Hebrew Uni6ersity of Jerusalem, P.O.B. 12, Reho6ot 76100, Israel b Kaplan Medical Center, P.O.B. 1, Reho6ot 76100, Israel Received 5 May 1997; received in revised form 30 June 1997; accepted 4 July 1997
Keywords: Myiasis; Oestrus o6is
Oestrus o6is, (Linnaeus, 1758) the sheep nasal bot, is a cosmopolitan myiasis-producing fly whose larvae are well recognized parasites in the nasal cavities and sinuses of sheep and goats (Zumpt, 1965), whereas infestation in man is rare (Amr et al., 1993). Myiasis in an incidental host may have biological significance and can also be of medical and public health importance if the incidental host is man. The females are larviparous, depositing a number of first-instar larvae on the edge of, or just inside the nostrils of sheep and goats. The peculiar feature of the O. o6is female is that it may larviposit while still in flight. In their normal development in sheep, the larvae migrate at once to the nasal mucosa and nasal and frontal sinuses where they undergo 2 moults. After 2 to 12 months, the fully grown third instar larvae are expelled and pupate on the ground. The imagos emerge three to four weeks later. The ophthalmomyaisis produced in man by O. o6is larvae is restricted to conjunctivae, sclera, eyelids, and lachrymal duct (external ophthalmomyiasis) or the * Corresponding author. Present address: 4 Hagoren St., 70700 Gedera, Israel. 0001-706X/97/$17.00 © 1997 Elsevier Science B.V. All rights reserved. PII S 0 0 0 1 - 7 0 6 X ( 9 7 ) 0 0 0 9 9 - 5
362
I. Yeruham et al. / Acta Tropica 68 (1997) 361–363
eye ball (internal ophthalmomyiasis) (Hadani et al., 1975; Dar et al., 1980; Stulting and Meyer, 1981; Omar et al., 1988; Amr et al., 1993). We report an unique case of an apparently pharyngeal myiasis in a patient caused by O. o6is. A 82 year old man presented with a complaint of a white mass appearing in his mouth after sneezing or coughing. This had happened on several occasions and he had noted that a fly was appearing from one of these masses on one of the occasions. His previous medical history included progressive systemic sclerosis which had resulted in esophageal reflux and skin changes on the hands. He was known to have a 1 cm diameter diverticulum at the lower end of the esophagus which had been shown on an upper GI series. An upper GI endoscopy was normal with no evidence of larvae in the stomach and repeat barium swallow showed the diverticulum with no contents inside it. A CT scan of the chest showed the esophageal diverticulum. A CT scan of the nasal sinuses and eyes was normal and an examination by an ear, nose and throat consultant was unremarkable. After having produced a total of six larvae there were no further episodes. Larvae were collected and preserved in 70% alcohol. Larvae were examined under a stereoscopic microscope for confirmatory identification using the keys of Zumpt (1965) and Wetzel and Bauristhene (1970). The collected larvae were identified as the third larval stage of O. o6is. We believe that the patient suffered from an apparently pharyngeal myiasis. Our patient lives in a urban area far away from the breeding places of sheep and goats, and has never had any direct contact with these species. Although there was no direct observation of expulsion of larvae from the patient, his history was consistent on each occasion, he is a reliable witness and there is no reason to doubt the accuracy of his history. Larvae of specific myiasis-producing flies, i.e. their larvae are obligatory parasites requiring at least some period of development in living tissues in specific hosts, may occasionally infest human; O. o6is, (Omar et al., 1988; Amr et al., 1993), Hypoderma lineatum (Al-Dabagh et al., 1980); H. bo6is (Jurko, 1957); Rhinooestrus purpureus (Le Fichoux et al., 1981), and Gastrophilus spp. (Zumpt, 1965). In addition to the described case, there are only two reports on myiasis in human due to O. o6is involving not only the eye but also the ear, nose and throat (Pampiglione, 1958; Al-Dabagh et al., 1980). Myiasis caused by O. o6is may be considered as an occupational disease of shepherds or farmers who usually keep sheep and goats in close proximity to their dwellings (Amr et al., 1993). Zumpt (1963) stated that man is most commonly infested in those geographical areas where the density of sheep and goats is low compared with that of man, so that the flies larviposit on people. This might explain the infestation of the patient in our case. Larvae of O. o6is can not usually progress beyond the first stage in the eye tissues (Hadani et al., 1975; Al-Dabagh et al., 1980). This is the first report in which the third instar larvae were found in a human, and shows that the O. o6is fly can
I. Yeruham et al. / Acta Tropica 68 (1997) 361–363
363
complete its life cycle even in an non-specific host like man. It is possible that the esophageal disturbance that is linked with progressive systemic sclerosis was related to the probable pharyngeal myiasis in our patient. Progressive systemic sclerosis commonly causes motility disturbances of the esophagus including a markedly lower esophageal sphincter pressure and aperistalsis (Gilliland, 1994). The combination of these two factors results in a marked gastroesophageal reflux and it is possible that this facilitated the expulsion of the larvae. There were no further episodes after esophagogastroduodenoscopy was performed. The patient received acid-suppressive therapy with omeprazole 20 mg bid and thus it is possible that swallowed larvae, which would not be exposed to gastric acid, were regurgitated.
References Al-Dabagh, M., Al-Mufti, N., et al., 1980. A second record from Iraq of human myiasis caused by larvae of the sheep botfly Oestrus o6is. L. Ann. Trop. Med. Parasitol. 74, 73 – 77. Amr, Z.S., Amr, B.A., Abo-Shehada, M.N., 1993. Ophthalmomyiasis externa caused by Oestrus o6is L. in the Ajloun area of northern Jordan. Ann. Trop. Med. Parasitol. 87, 259 – 262. Dar, M.S., Ben Amer, M., Dar, F.K., et al., 1980. Ophthalmomyiasis caused by the sheep nasal bot, Oestrus o6is (Oestridae) larvae, in the Benghazi area of Eastern Libya. Trans. R. Soc. Trop. Med. Hyg. 74, 303–306. Gilliland, B.C., 1994. Systemic sclerosis (Scleroderma). In: Isselbacher, K.J., Braunwald, E., Wilson, J., Martin, J.B., Fauci, A.S., Kasper, D.L. (Eds.), Harrison’s Principles of Internal Medicine, 13th ed. McGraw Hill, New York, pp. 1655–1661. Hadani, A., Rauchbach, K., Ilsar, M., 1975. Ophthalmomyiasis in a man caused by larvae of the sheep nasal bot fly (Oestrus o6is Linnaeus, 1785). Refu. Vet. 32, 157 – 158. Jurko, S., 1957. Ophthalmomyiasis interna anterior.. Med. Arch. 11, 57. LeFichoux, Y., Marty, P., Denis, G., et al., 1981. Un cas d’ophtalmomyiase externe a’ Oestrus o6is, Linn’e 1758 contract’ee sur la plage de Nice. Acta Trop. 38, 461 – 468. Omar, M.S., Das, A.B., Osman, N.I., 1988. External ophthalmomyiasis due to the sheep nostril bot fly larva Oestrus o6is in Saudi Arabia. Ann. Trop. Med. Parasitol. 82, 221 – 223. Pampiglione, S., 1958. Indagine epidemiologica sulla miasi congiuntivale umana da Oesturs o6is in Italia I. Pensiero/scuebtufuci 9, 242–244. Stulting, A.A., Meyer, H., 1981. External ophthalmomyiasis caused by Oestrus o6is.. South Afr. Med. J. 60, 709–710. Wetzel, H., Bauristhene, E., 1970. The identity of the third larval stage of Oestrus o6is Linnaeus (1758) (Diptera: Oestridae). Zool. Anz. 184, 87 – 94. Zumpt, F., 1963. Ophthalmomyiasis in man with special reference to the situation in Southern Africa. South Afr. Med. J. 37, 425–428. Zumpt, F., 1965. Myiasis in Man and Animals in the Old World. Butterworth, London, p. 257.
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