Ophthalmomyiasis Caused by Chrysomya bezziana after Periocular Carcinoma.
ABSTRACT: 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:BACKGROUND:Myiasis due to Old World screw-worm fly, Chrysomya bezziana, is an important obligate zoonotic disease in the OIE-list of diseases and is found throughout much of Africa, the Indian subcontinent, southeast and east Asia. C. bezziana myiasis causes not only morbidity and death to animals and humans, but also economic losses in the livestock industries. Because of the aggressive and destructive nature of this disease in hosts, we initiated this study to provide a comprehensive understanding of human myiasis caused by C. bezziana. METHODS:We searched the databases in English (PubMed, Embase and African Index Medicus) and Chinese (CNKI, Wanfang, and Duxiu), and international government online reports to 6th February, 2019, to identify studies concerning C. bezziana. Another ten human cases in China and Papua New Guinea that our team had recorded were also included. RESULTS:We retrieved 1,048 reports from which 202 studies were ultimately eligible for inclusion in the present descriptive analyses. Since the first human case due to C. bezziana was reported in 1909, we have summarized 291 cases and found that these cases often occurred in patients with poor hygiene, low socio-economic conditions, old age, and underlying diseases including infections, age-related diseases, and noninfectious chronic diseases. But C. bezziana myiasis appears largely neglected as a serious medical or veterinary condition, with human and animal cases only reported in 16 and 24 countries respectively, despite this fly species being recorded in 44 countries worldwide. CONCLUSION:Our findings indicate that cryptic myiasis cases due to the obligate parasite, C. bezziana, are under-recognized. Through this study on C. bezziana etiology, clinical features, diagnosis, treatment, epidemiology, prevention and control, we call for more vigilance and awareness of the disease from governments, health authorities, clinicians, veterinary workers, nursing homes, and also the general public.
Project description:In the last few years, significant changes in climate have had a disparate effect on biodiversity. The influences of these changes are random and unpredictable. The resurgence of insect pests, especially of medical and veterinary importance, often corresponds with climate changes. The Old World screwworm, Chrysomya bezziana, is one of the most important myiasis-causing flies that parasitize warm-blooded animals in the Eastern Hemisphere. We used a spatial distribution modeling approach to estimate the consequences of climatic changes on the potential geographic distribution of this insect throughout the world currently and in the future. A Maxent model used occurrence data from 104 localities and 19 climatic factors to predict the suitable habitat regions throughout the world. Two representative concentration pathways 2.6 and 8.5, were used to forecast the future distribution of C. bezziana in 2050 and 2070. The Maxent model for C. bezziana provided a satisfactory result, with a high value of the Area Under Curve equal to 0.855 (±0.001). Furthermore, the True Skilled Statistics value is equal to 0.67. These values indicate the significant influence on the model of the ecology of this fly species. Jackknife test indicated that temperature variables play a significant role in C. bezziana dynamics. The resultant models indicated the areas at risk of invasion by potential serious medical/veterinary issues, especially in countries with a large livestock production.
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: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: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:Purpose. External ophthalmomyiasis (EO) is caused by infesting larvae belonging to various species of flies. Most documented cases result from sheep (Oestrus ovis) and Russian (Rhinoestrus purpureus) botfly larvae, but we recently discovered a rare case of EO caused by flesh fly (Sarcophaga argyrostoma) larvae. Here, we report the case of a patient with EO who had been hospitalized and sedated for 1 week because of unrelated pneumonia. Methods. Case report. Results. A total of 32 larvae were removed from the adnexae of both eyes. Larvae identification was confirmed through DNA analysis. Treatment with topical tobramycin resulted in complete resolution of EO. Conclusion. EO can be caused by S. argyrostoma, and the elderly and debilitated may require extra ocular protection against flies during sedation.
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:Blow flies are the first insect group to colonize on a dead body and thus correct species identification is a crucial step in forensic investigations for estimating the minimum postmortem interval, as developmental times are species-specific. Due to the difficulty of traditional morphology-based identification such as the morphological similarity of closely related species and uncovered taxonomic keys for all developmental stages, DNA-based identification has been increasing in interest, especially in high biodiversity areas such as Thailand. In this study, the effectiveness of long mitochondrial cytochrome c oxidase subunit I and II (COI and COII) sequences (1247 and 635 bp, respectively) in identifying 16 species of forensically relevant blow flies in Thailand (Chrysomya bezziana, Chrysomya chani, Chrysomya megacephala, Chrysomya nigripes, Chrysomya pinguis, Chrysomya rufifacies, Chrysomya thanomthini, Chrysomya villeneuvi, Lucilia cuprina, Lucilia papuensis, Lucilia porphyrina, Lucilia sinensis, Hemipyrellia ligurriens, Hemipyrellia pulchra, Hypopygiopsis infumata, and Hypopygiopsis tumrasvini) was assessed using distance-based (Kimura two-parameter distances based on Best Match, Best Close Match, and All Species Barcodes criteria) and tree-based (grouping taxa by sequence similarity in the neighbor-joining tree) methods. Analyses of the obtained sequence data demonstrated that COI and COII genes were effective markers for accurate species identification of the Thai blow flies. This study has not only demonstrated the genetic diversity of Thai blow flies, but also provided a reliable DNA reference database for further use in forensic entomology within the country and other regions where these species exist.
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.