Human ophthalmomyiasis interna caused by Hypoderma tarandi, Northern Canada.
ABSTRACT: Human myiasis caused by bot flies of nonhuman animals is rare but may be increasing. The treatment of choice is laser photocoagulation or vitrectomy with larva removal and intraocular steroids. Ophthalmomyiasis caused by Hypoderma spp. should be recognized as a potentially reversible cause of vision loss.
Project description:Purpose:To discuss two striking cases of ophthalmomyiasis interna posterior, in which the larval stage of a botfly is found in the posterior segment. Observations:In the first case, the subretinal maggot is alive and found to be migrating under the retina. The maggot was lasered in the office and killed. In the second case, a dead maggot was discovered in the subretinal space in a child, after it had caused significant subretinal scarring and permanent vision loss. Conclusions and Importance:Ophthalmomyiasis is a rare condition that can often be unrecognized and result in permanent vision loss. Early diagnosis and photocoagulation of the larva (if alive) can halt progression of vision loss in these cases.
Project description:Ophthalmomyiasis externa refers to the infestation of ocular surface by dipterous larvae. The term ophthalmomyiasis interna refers to the infestation of the anterior or posterior segment of the eyeball. Oestrus ovis is the most common aetiological agent for ophthalmomyiasis externa, and external disease is the most common form of ocular myiasis correspondingly. The larva is an obligate parasite of sheep. However, humans are accidentally infested. This article is related to the case series of three patients with the diagnosis of ophthalmomyiasis externa who were treated in Hakkari State Hospital in June 2013.
Project description:Hypoderma tarandi causes myiasis in reindeer and caribou (Rangifer tarandus spp.) in most northern hemisphere regions where these animals live. We report a series of 39 human myiasis cases caused by H. tarandi in Norway from 2011 to 2016. Thirty-two were residents of Finnmark, the northernmost county of Norway, one a visitor to Finnmark, and six lived in other counties of Norway where reindeer live. Clinical manifestations involved migratory dermal swellings of the face and head, enlargement of regional lymph nodes, and periorbital oedema, with or without eosinophilia. Most cases of human myiasis are seen in tropical and subtropical countries, and in tourists returning from such areas. Our findings demonstrate that myiasis caused by H. tarandi is more common than previously thought. Healthcare professionals in regions where there is a likelihood of human infestation with H. tarandi (regions populated by reindeer), or treating returning travellers, should be aware of the condition. All clinicians are advised to obtain a detailed travel history when assessing patients with migratory dermal swellings. On clinical suspicion, ivermectin should be given to prevent larval invasion of the eye (ophthalmomyiasis). Since H. tarandi oviposits on hair, we suggest wearing a hat as a prevention measure.
Project description:Purpose:To describe a case of concurrent ophthalmomyiasis externa and aural myiasis in a patient presenting with headache, right eye pain and blurred vision in an urban hospital in Philadelphia, PA. Observations:Myiasis is the parasitic infestation of a live mammal with fly larvae that feed and grow on host tissue. Predominantly described in the Middle East, Africa and Asia, it is rarely reported in the United States. We describe a case of concurrent ophthalmomyiasis externa and aural myiasis in a 44-year-old man who presented with headache, right eye pain and blurred vision in an urban hospital in Philadelphia, PA. After complete extraction and examination at bedside and in the operating room, the patient improved without complications after treatment with topical antibiotics and steroids. Conclusions:Although rare in urban settings in the United States, in certain demographic populations, it is important to consider myiasis in the setting of eye and ear pain and to perform a complete eye and ear examination.
Project description:Hypoderma spp. larvae cause subcutaneous myiasis in several animal species. The objective of the present investigation was to identify and characterize morphologically and molecularly the larvae of Hypoderma spp. collected from cattle (Bos taurus taurus) and red deer (Cervus elaphus) in the district of Castelo Branco, Portugal. For this purpose, a total of 8 larvae were collected from cattle (n=2) and red deer (n=6). After morphological identification of Hypoderma spp. larvae, molecular characterization was based on PCR-RFLP and mitochondrial CO1 gene sequence analysis. All larvae were morphologically characterized as the third instar larvae (L3) of H. actaeon. Two restriction enzymes were used for molecular identification of the larvae. TaqI restriction enzyme was not able to cut H. actaeon. However, MboII restriction enzyme differentiated Hypoderma species showing 210 and 450 bp bands in H. actaeon. Furthermore, according to the alignment of the mt-CO1 gene sequences of Hypoderma species and to PCR-RFLP findings, all the identified Hypoderma larvae were confirmed as H. actaeon. This is the first report of identification of Hypoderma spp. (Diptera; Oestridae) from cattle and red deer in Portugal, based on morphological and molecular analyses.
Project description:We report a case of human cutaneous myiasis by Hypoderma lineatum, contracted by a farmer who never traveled outside Italy. Identification at species level has been performed by both morphological examination and sequencing of cytochrome c oxidase subunit I gene. This is the first description of human hypodermosis by H. lineatum contracted in Europe.
Project description:We treated a homeless man in Iran with a history of squamous cell carcinoma who had ophthalmomyiasis caused by Chrysomya bezziana parasites. This case highlights a much-neglected condition and describes measures to prevent it.
Project description:Purpose:Orbital myiasis is a rare condition. We report a case of massive orbital myiasis (ophthalmomyiasis profunda) arising from nasal myiasis and caused by Chrysomya bezziana in a patient with diabetes. Observations:A 55-year-old woman presented with massive orbital myiasis from larvae invading the entire orbit, with only a small part of sclera and bulbar conjunctiva left of the ocular structures left unaffected. The patient complained of breathing difficulty and drooping of the left eyelid with no other significant complaints. Computed tomography of paranasal sinuses was performed to determine the extent of intraocular invasion of larvae and the surrounding area that might be involved. The larvae filled the nasal and orbital cavity with bony destruction. The patient had a history of diabetes mellitus with uncontrolled blood sugar. Conclusions and importance:Orbital myiasis is an infestation of any anatomical structure of the orbit with larvae from the order Diptera. To our knowledge, this is the first reported case of massive orbital myiasis arising from nasal myiasis caused by C. bezziana in a patient with diabetes. Eliminating the causative larvae and topical treatment with antibiotics eye ointment therapy improved the patient's symptoms. Epidemiological data are required to improve documentation of the incidence rate of myiasis.
Project description:BACKGROUND:Hypoderma bovis and H. sinense (Diptera: Oestridae) mainly parasitise cattle and yaks. The two parasites are pathogenic and cause economic losses that result from reduced amounts of livestock products, including milk, meat, and skin. Genetic diversity and population genetic structure of H. bovis and H. sinense have not been evaluated, but could be used to inform appropriate strategies to control these parasites. METHODS:We cloned and sequenced part of the mitochondrial cytochrome c oxidase subunit I (COI) gene from 60?H. bovis isolates and 52?H. sinense isolates from five locations in Qinghai Province, China, to identify polymorphisms, and infer their phylogenetic relationships, historical population expansions, and divergence time. RESULTS:We identified 17 COI haplotypes from the H. bovis samples, and 23 COI haplotypes from the H. sinense samples. The haplotype and nucleotide diversities were 0.738 and 0.00202 for H. bovis, and 0.867 and 0.00300 for H. sinense, respectively, which indicates rich genetic diversity in H. bovis and H. sinense populations. Bayesian phylogenetic analysis revealed that the two species are monophyletic, and geographical structuring of haplotypes was significantly different in H. sinense (P?<?0.05), but not H. bovis. Neutrality tests and mismatch distribution statistical analysis revealed that populations of the two species have undergone demographic expansions. The divergence three Hypoderma spp. (H. bovis, H. lineatum, and H. sinense) was estimated to have occurred approximately 4.5 million years ago (Mya), which indicates that the rapid uplift of the Qinghai-Tibetan Plateau during the late Miocene-Pliocene was associated with divergence of Hypoderma species. CONCLUSIONS:Results of the present study revealed that both H. bovis and H. sinense displayed high genetic diversity and widespread population genetic differentiation within and among populations; these data, along with the molecular phylogeny, demographic history, and divergence time estimation, provide new insight into evolutionary history of these species. These findings will help elucidate speciation in Hypoderma and provide theoretical basis for epidemiological surveillance and control of these species on the Qinghai-Tibetan Plateau.