Oestrus Ovis Research Articles

Oestrosis: Parasitism by Oestrus ovis

Abstract Oestrus ovis (Linnaeus 1761) is a parasite of sheep and goats, in which the fly larvae are obligatory parasites of nasal and sinus cavities. Oestrosis is endemic in hot and dry regions, especially in Mediterranean areas of Europe, Africa and America. Infected animals firstly suffer from fly strike, when adult flies inject first stage larvae on their nostrils and secondly, hosts will suffer from nasal-sinus myiasis with varying clinical respiratory signs. The disturbance caused to small ruminants while grazing and the effects during development of larvae can have severe consequences on livestock production. The evolution of O. ovis depends on the weather; the parasite is very well-adapted to their environment, being able to undergo hypobiosis either inside or outside the host, according to the climatic environmental conditions and seasonality. Understanding the epidemiology and life cycle of O. ovis is crucial to design effective control measures of this myiasis. Moreover, O. ovis infestation is considered a zoonosis; it causes ophthalmomyiasis in man in many parts of the world. The present article focuses on describing the main information about this parasite gathered in the last 20 years.

Diagnosis of ophthalmomyiasis externa by dermatoscopy.

Ophthalmomyiasis in humans caused by the larvae of the sheep nasal botfly (Oestrus ovis) and is a rare phenomenon in Israel. We describe the utilization of the dermatoscope as a diagnostic tool for the facilitation of early diagnosis of conjunctivitis due to the infestation of the eyes by the sheep nasal botfly in two patients. After the physical removal of the larvae with the help of a cotton swab applicator under a slit lamp examination and the topical use of antibiotics, the clinical symptoms improved within 1–2 days. Undoubtedly the dermatoscope played a crucial role leading to the definitive diagnosis and immediate therapeutic intervention.

Oestrus ovis in Ecuador: Importance in the Andean sheep farming.

Aim:This study aimed to determine the prevalence of Oestrus ovis in sheep meant for meat commercialization in the main slaughterhouse of the country.Materials and Methods:Between October 2015 and December 2015, we assessed the occurrence of Oestrus myiasis in the main slaughterhouse localized in Quito. In total, 80 sheep heads were randomly inspected and necropsied. Larvae were removed from nasal cavities and paranasal sinuses and cleaned. ANOVA (generalized linear model) was used to estimate the relationship between sex, age, and place of origin and presence or absence of parasite larvae.Results:Morphological identification confirmed that 19% (15/80) of the examined animals were positive for Oestrus ovis; from the positive cases, 21% were young animals <12 months old. We found that statistical differences by animal sex, males, were most infested 93% (14/15) than females 7% (1/15). Larvae’s L2 were more abundant than other stages (62 of the total 149). 14 of the infested animals were from the Andean places at > 2500 meters above sea level (m.a.s.l.), and only one case from the coastal region at 250 m.a.s.l. with tropical environmental conditions.Conclusions:Our results showed evidence of the presence of myiasis caused by O. ovis in Andean and coastal places in Ecuador and its adaptation to different environmental conditions from that reported previously in temperate regions from Europe and Africa.

Oestrus ovis external ophtalmomyiasis: a case report in Burgundy France

BackgroundExternal ophtalmomyiasis (EOM) is a zoonosis related to the presence of Oestrus ovis larvae at the ocular level in small ruminants (i.e. ovine, caprine). In humans, EOM is a rare cosmopolitan disorder, mostly described in warm and dry rural areas in patients living close to livestock areas. In metropolitan France (excluding Corsica), EOM is an exceptional disease with less than 25 cases recorded since 1917.Case presentationWe report a case of EOM in a 19-years old man in the last week of September 2016 in Burgundy.ConclusionThe diagnosis of an EOM in Burgundy, a French region described as cold and humid, is surprising and could be due to a more marked climatic warming during the vegetative season in Burgundy resulting in the implantation of Diptera of the genus Oestrus sp. in this region.

Ocular external myiasis. A series of cases due to larvae Oestrus ovis in Navarra, Spain

Abstract Objective To report a case series of external ophthalmomyiasis in a region of Spain together with its common epidemiological factors and treatment. Material and methods A presentation is made of four clinical cases of patients with external ocular myiasis caused by Oestrus ovis larvae. Results Ocular myiasis is a parasitic infection by larval stages of flies. It can affect the ocular globe externally and/or internally, with the former being the most frequently found condition. The organism that mainly affects the eyes is the O. ovis larvae. Conclusion Ocular external myiasis is a rare condition that occasionally can occur in humans. In this case series, a common risk factor for infection is established: the previous exposure to livestock and/or agricultural activity. An adequate diagnosis and treatment could avoid the transition from external to internal form, as well as its complications.

Immune humoral response of young lambs naturally infested by Oestrus ovis (Diptera: Oestridae).

Twenty-six newborn lambs were evaluated for 21 weeks, from birth to slaughter, to assess their plasma anti-Oestrus ovis immunoglobulin (IgG) using the ELISA technique. On the last day of sampling, all the lambs were slaughtered and O. ovis larvae were recovered, quantified and identified according to the larval stage. High levels of IgG were observed over the first three weeks of life, thus indicating that antibodies are transferred via colostrum from ewes to lambs. Afterwards, the antibody levels declined progressively until the lambs were 11 weeks of age and subsequently started to increase again when they were around 13 weeks of age, reaching the apex on the last week of sampling. All the lambs were parasitized with different larval stages of O. ovis, with an average of 39 larvae per lamb, and the intensity of the infestation ranged from 10 to 97 larvae. However, there was non-significant correlation coefficients between IgG levels and O. ovis larval burden (P > 0.05). In conclusion, although the lambs became infested with O. ovis at an early age, the larval burden was not associated with specific IgG levels.

Miasis ocular externa. Serie de casos por larvas Oestrus ovis en Navarra

ObjectiveTo report a case series of external ophthalmomyiasis in a region of Spain together with its common epidemiological factors and treatment. Material and methodsA presentation is made of four clinical cases of patients with external ocular myiasis caused by Oestrus ovis larvae. ResultsOcular myiasis is a parasitic infection by larval stages of flies. It can affect the ocular globe externally and / or internally, with the former being the most frequently found condition. The organism that mainly affects the eyes is the Oestrus ovis larvae. ConclusionOcular external myiasis is a rare condition that occasionally can occur in humans. In this case series, a common risk factor for infection is established: the previous exposure to livestock and / or agricultural activity. An adequate diagnosis and treatment could avoid the transition from external to internal form, as well as its complications.

Rearing and measurements of Oestrus ovis larvae and pupae (Diptera: Oestridae) from slaughtered sheep heads in Mosul abattoir -Iraq

Rearing and measurements of Oestrus ovis larvae and pupae (Diptera: Oestridae) from slaughtered sheep heads in Mosul abattoir -Iraq

Spatial modeling of oestrosis in sheep in Guantánamo province, Cuba

Oestrosis is a myiasis caused by larvae of the fly Oestrus ovis (Linné 1761, Diptera: Oestridae) that occurs worldwide. Oestrosis was first reported in Cuba in the middle of the 1990s in the municipality of Imías, Guantánamo province. Determining the spatial pattern and risk factors for the disease might be useful to help explain the disease occurrence and select options for disease surveillance and control. In the present study, the number and distribution of affected premises was shown to have been similar throughout the period studied (2006–2010). The disease was found to occur mostly in the southern and western parts of the province with high dispersion in an east-west direction over the period of study. Three “hotspots” (Getis-Ord Gi*) were identified in the province in which there was an increased risk of disease occurrence. Geographically Weighted Logistic Regression was used to test associations between environmental variables and disease occurrence. Results demonstrated that areas with lower mean annual rainfall, higher mean temperature, and higher sheep density had the highest risk of disease occurrence. High risk areas are mostly located in the western zone (El Salvador, Niceto Pérez and Guantánamo municipalities) and also in the central zone (coast of San Antonio del Sur and Imías). The associations between oestrosis cases and local environmental characteristics varied geographically within the study area. These results might be useful to improve disease surveillance and control. Treatment of animals in these “hotspots”, as well as in other places where the risk is higher should be prioritized to more efficiently reduce the harmful impact of this disease.

Micro-computed tomography visualization of the vestigial alimentary canal in adult oestrid flies.

Oestrid flies (Diptera: Oestridae) do not feed during the adult stage as they acquire all necessary nutrients during the parasitic larval stage. The adult mouthparts and digestive tract are therefore frequently vestigial; however, morphological data on the alimentary canal in adult oestrid flies are scarce and a proper visualization of this organ system within the adult body is lacking. The present work visualizes the morphology of the alimentary canal in adults of two oestrid species, Oestrus ovis L. and Hypoderma lineatum (de Villiers), with the use of non-invasive micro-computed tomography (micro-CT) and compares it with the highly developed alimentary canal of the blow fly Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). Both O.ovis and H.lineatum adults showed significant reductions of the cardia and the diameter of the digestive tract, an absence of the helicoidal portion of the midgut typical of other cyclorrhaphous flies, and a lack of crop and salivary glands. Given the current interest in the alimentary canal in adult dipterans in biomedical and developmental biology studies, further understanding of the morphology and development of this organ system in adult oestrids may provide valuable new insights in several areas of research.

Dipteran species in agricultural region of eastern Thessaloniki

In an agricultural region of Thessaloniki province, fly traps were placed, which contained substances in order to attract flies with the purpose to trap and identify them. The substances were, pieces offish, meat and feta cheese, sugar and faeces of small ruminants. Fifteen different flies species were trapped, of which, thirteen are mentioned in the international bibliography, as parasites, such as, Musca domestica, Muscina sp, Fannia sp, Phormia regina, Lucilia (Phaenicia) sericata, Calliphora erythrocephala (vicina), Sarcophaga sp, Oestrus ovis, Gasterophillus sp, Stomoxys calcitrans, Haematobia (Shiphona) irritans, Chrysops sp and Hydrotaea (Ophyra) spp and two, as no parasites, such as Drosophilla melanogaster and Apis mellifera. From the trapped flies, Hydrotaea sp, Muscina sp, Fannia sp and Phormia regina, were identified for the first time in Greece. From the substances which were used in order to attract the flies, the fish was the one that all flies showed preference to, in the greater number, while the rest of the substances they chose descending order, was meat, sugar and feta cheese. Finally, only one fly was found in the excrement of small ruminants.

Report of a Case of Human Nasal Myiasis Caused By Second Instar Larvae of Oestrus Ovis in CHU Oran: Review of Literature

Myiasis is the invasion of human and animal organs and tissues by dipteran larvae. This is a case report of a human nasal myiasis caused by the second instar larvae of the sheep bot fly, Oestrusovis. The cases of human myiasis at Oestrusovis are accidental and rare, mainly affecting the eyes. In the literature, there are only sporadic reports of nasal myiasis. We present a new case of nasal myiasis caused by the second instar larvae of Oestrusovis in a 29-year-old male patient, originally from OuedRhiou in the west of Algeria, whois a medical doctor suffering from signs of rhinosinusitis.

S10 Plastination Technique for Preservation of Parasites: the case of Oestrus ovis larvae

S10 Plastination Technique for Preservation of Parasites: the case of Oestrus ovis larvae

Parasite prevalence in Mycobacterium spp. infected dairy goats in the region of Murcia (south-east Spain).

Eighty-four Murciano-Granadina dairy goats slaughtered in the region of Murcia (South-East Spain) were necropsied to evaluate parasitic infections. The majority of the animals (94.0%) were parasitised and multiple infections were present. Twenty-one parasite species were found, including 18 nematode species (Muellerius capillaris, Dictyocaulus filaria, Neostrongylus linearis, Cystocaulus ocreatus, Teladorsagia circumcincta, T. occidentalis, T. trifurcata, Marshallagia marshalli, Camelostrongylus mentulatus, Trichostrongylus capricola, Nematodirus abnormalis, N. filicollis, N. spathiger, T. vitrinus, T. colubriformis, Trichuris spp., Chabertia ovina and Skrjabinema ovis); one trematode species (Dicrocoelium dendriticum); one arthropod species (Oestrus ovis); and one protozoa genus (Eimeria spp.). Additionally, 17.85% of the animals were Mycobacterium spp. positive. Therefore, comparison between parasite prevalence, intensity and abundance in tuberculosis-positive and -negative animals was performed. Statistically significant differences between the prevalence of lungworms and gastrointestinal nematodes in Mycobacterium spp. infected and free goats were found. The paper discusses this co-infection between Mycobacteriaceae and endoparasites.

Ophthalmomyiasis externa: A case report from Alkharj, Saudi Arabia

Ophthalmomyiasis is an infestation of mammalian eyes with larvae or maggots of certain flies. Oestrus ovis is the most common cause of human myiasis. This article reports a case of ophthalmomyiasis externa caused by Oestrus ovis (sheep nasal botfly) in a young healthy male, living in Al Kharj, Kingdom of Saudi Arabia. Patient presented with acute symptoms in left eye in April, mimicking as unilateral conjunctivitis/keratitis/external ocular foreign body/uveitis. Prompt diagnosis and mechanical removal of five live larvae from conjunctival fornices of the left eye under topical anaesthesia and cyclopentolate 1% eyedrops, not only relieved patient’s severe symptoms in a single day but also prevented rare yet sight threatening complications.

Prevalence and intensity of Oestrus ovis in sheep and goats in south-eastern part of Turkey

Oestrosis is a parasitic disease which is prevalent among sheep and goats in Mediterranean region. Slaughter house surveys to determine the prevalence and intensity of infestation by Oestrus ovis Linnaeus (Diptera: Oestridae) in sheep and goats, were conducted monthly for one year in south-eastern region of Turkey. A total of 804 heads belonging to 724 sheep and 80 goats were examined for Oestrus ovis larvae between May 2014 and April 2015. 72.75% of sheep heads and 50% of goat heads were seen to be infested with Oestrus ovis larvae. Of a total of 4723 larvae found in sheep heads, 2245 were detected to be first instars larva, 1231 second instars larva, 1247 third instars larva. Of a total of 259 larvae detected in goats, 150 were first instars larva, 79 second instars larva, 30 third instars larva. The mean of larval burden per infested animal was significantly higher in sheep (8.8±5.9) than in goat (6.5±5.0) (P less than 0.05). Monthly distribution of first, second and third instars larvae indicate that adult flies are active between April and end of September, first instars larvae enter hypobiotic period in October. In conclusion, it was revealed that to use an effective drug against Oestrus ovis that will be done during reproductive period of flies should start in April and continue until the end of summer due to high rates of oestrosis, parasite treatment that will be done when reproductive period ends should be done in October and November in the southeast part of Turkey.

Ultramorphological and molecular characteristics of the larval stages of the horse nasal-myiasis fly, Rhinoestrus sp. (Diptera: Oestridae) from Mongolian horse in China.

Rhinoestrus sp. (Diptera: Oestridae) is an economically important parasite that can cause severe nasal myiasis in equids and can also affect humans. The ultrastructure of all Rhinoestrus sp. larval instars from Mongolian horse was examined by light and scanning electron microscopy to characterize the features of Rhinoestrus. The structure of the anterior region, posterior region, and the spines of the third segment was analyzed for 10 specimens in each larval stage. Additionally, 34 third-instar (L3) larvae of Rhinoestrus sp. from Mongolian horse were subjected to molecular characterization by polymerase chain reaction (PCR). Partial sequencing of the mitochondrial cytochrome oxidase subunit I gene (COXI) was performed. Phylogenetic relationships for Rhinoestrus sp. from Mongolian horse were reconstructed based on COXI sequences and COXI homologs from 12 oestrid species available in GenBank, and inter- and intraspecies variations in nucleotide sequences were analyzed. The cephalopharyngeal skeleton of Rhinoestrus sp. from Mongolian horse at immature stages was composed of "H"-shaped hypopharyngeal sclerites and "Y"-shaped pharyngeal sclerites. Pairs of papillary sensillae in the cephalic region maintained the same number and location in all three instars, but the third instar additionally included two pairs of verruciform sensillae. COXI sequences of Rhinoestrus sp. larvae collected from Mongolian horses were separated from those of Cephenemyia sp. and other species of Rhinoestrus (R. phacochoeri and R. usbekistanicus). Our sequence analyses demonstrate that all samples greatly resembled Rhinoestrus purpureus but were not R. purpureus. Further studies will be needed to confirm the existence of a new species. The pairs of papillary sensilla in the cephalic region retained the same number and location in all three instars, but included two pairs of verruciform sensilla in the third-instar larvae collected from Mongolian horses were more closely related to those of Oestrus ovis and Pharyngomyia picta.

External ophthalmomyiasis caused by Oestrus ovis in east China

External ophthalmomyiasis is a superficial infestation of the eye tissues by the larvae or maggots of flies. External ophthalmomyiasis, caused by Oestrus ovis, is found occasionally in shepherding areas, but is rare in the cities of eastern China. We present a case of a 30-year-old man with complaints of a foreign body sensation, lacrimation and itching in the right eye, with uncorrected visual acuity of 20/20 in each eye. Six larvae were removed from the conjunctival sac and were ultimately authenticated as the first instar larvae of Oestrus ovis. He responded well after prompt appropriate therapy.

Identificación de larvas productoras de miasis obtenidas del cepario de la Universidad Colegio Mayor de Cundinamarca con importancia en salud pública

Las miasis son infestaciones parasitarias en humanos y animales causadas por estadios larvarios de moscas; son de distribución mundial y son una enfermedad frecuente en nuestro medio. En la literatura solo existen algunos casos reportados; por lo cual, su verdadera incidencia es difícil de establecer debido al sub-registro y ausencia de tipificación de larvas. Objetivo. Identificar, clasificary caracterizar morfológicamente las larvas causantes de miasis como base para futuras aplicaciones e intervenciones en salud pública. Materiales y métodos. Se analizaron 262 larvas obtenidas del cepario de la Universidad Colegio Mayor de Cundinamarca que se encontraban almacenadas sin ningún tipo de identificación, organización e historia. Resultados. Se realizó la identificacióncon estereoscopio y claves dicotómicas de las familias Cuterebridae, Oestridae y Calliphoridae. Las especies encontradas son asociadas a diferentes tipos de miasis humana y animal, entre ellas; Dermatobia hominis, Dermatobia cyaniventris, Oestrus ovis, Cochliomyia hominivorax y Lucilia sp. Discusión. Las formas más comunes de este parasitismo son cavitarias y forunculares; causadas por Dermatobia hominis y Cochliomyia hominivorax, sin embargo, éstas no son de reporte obligatorio ante los servicios médicos humanos. Por lo tanto, es indispensable la información y capacitación de profesionales de la salud para la correcta conservación, identificación y reporte de las larvas extirpadas en pacientes con miasis, hasta el punto de ser considerada una práctica derutina en el diagnóstico clínico.

An analysis of matrix metalloproteinases (MMPs) activity in excretory/secretory antigens of Oestrus ovis larvae from sheep

The present study was carried out to ascertain the presence of matrix metalloproteinases activity in excretory/secretory (E/S) antigens of larvae of Oestrus ovis by gelatin zymography. The larvae of O. ovis were collected from sheep slaughtered at local abattoirs in Orathanadu and Thanjavur. Live, intact larvae were washed thoroughly with phosphate buffered saline (PBS, pH 7.4) and suspended in PBS at 37°C in an incubator for 16 h. After incubation, the fluid was collected, centrifuged at 10,000 rpm for 15 min at 4°C and the supernatant was used as E/S antigen. On gelatin zymographic analysis, presence of 220 kDa MMP-9 (pro form) and 210 kDa (active form) homodimeric forms was observed as a fainter band at the top of the gelatin zymogram. A clear, bright gelatinolytic activity was observed at 20 kDa level at the bottom of the zymogram. The other forms of MMP-9, viz. 135 heterodimeric form was observed at 125 kDa size (active form) as a fainter band and the 72 kDa MMP-2 was detected as a fainter bands at 72 kDa (pro form) and 62 kDa (active form). The strong gelatinolytic activity detected at 20 kDa level of E/S antigens of O. ovis was the catalytic breakdown products of the MMPs found in the fluid. It was concluded that the activity of the MMPs in the E/S antigens of O. ovis was very strong, helping in the migration of the larvae from one site to the other.