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1.
Cutaneous myiasis in sheep arising from the activity of Lucilia cuprina larvae can result in significant physiological changes in susceptible animals. The stress imposed on the pituitary-adrenal axis of the sheep in response to myiasis and acute restraint is the subject of this investigation. Merino wethers were exposed to handling restraint, and blood sampling, during examination for blowfly strike; where necessary, they were treated for cutaneous myiasis. Significant changes in the plasma concentrations of immunoreactive beta-endorphin (beta-EP), ACTH and cortisol were found in sheep with extensive myiasis, as compared with unstruck sheep or those with only localized myiasis. In five susceptible sheep with extensive cutaneous myiasis, mean plasma levels of beta-EP, ACTH and cortisol were 307 +/- 71 pg ml-1, 953 +/- 58 pg ml-1 and 232 +/- 46 nmol l-1 respectively, compared with 818 +/- 89 pg ml-1, 641 +/- 41 pg ml-1 and 107 +/- 17 nmol l-1 in six unstruck sheep handled similarly. Whereas significant increases in plasma ACTH and cortisol can result from pituitary-adrenal responses to acute emotional or surgical stress, and are usually accompanied by a concomitant release of beta-EP from the pituitary, the present findings indicate a marked reduction in beta-EP levels and a significant increase in ACTH and cortisol in sheep following blowfly strike and acute handling restraint. This result suggests that cutaneous myiasis in susceptible sheep can alter the pituitary-adrenal response to acute restraint stress, and this could occur either by an alteration of precursor processing in the pituitary or by the selective release of ACTH.  相似文献   

2.
We present the results of a study on myiasis in Panama during the first years of a Cochliomyia hominivorax eradication program (1998-2005), with the aim of investigating the behavior of the flies that produce myiasis in animals and human beings. The hosts that registered positive for myiasis were cattle (46.4%), dogs (15.3%), humans (14.7%), birds (12%), pigs (6%), horses (4%), and sheep (1%). Six fly species caused myiasis: Dermatobia hominis (58%), Phaenicia spp. (20%), Cochliomyia macellaria (19%), Chrysomya rufifacies (0.4%), and maggots of unidentified species belonging to the Sarcophagidae (3%) and Muscidae (0.3%). With the Dubois index, was no evidence that the absence of C. hominivorax allowed an increase in the cases of facultative myiasis.  相似文献   

3.
Whilst sheep myiasis caused by Lucilia sericata is a severe economic problem in Great Britain, it rarely reaches such proportions in countries bordering Western Europe. Possible reasons for this relative absence of myiasis were investigated in Denmark.
During the period 19 July-15 August 1948, trapping studies showed that blowflies normally associated with myiasis in Great Britain, and particularly L. sericata , occurred fairly abundantly in the Mols area of Jutland.
The reactions of Danish L. sericata to attractive materials placed on sheep were similar to those shown by the species under British conditions. The number of egg batches laid on sheep in response to chemical stimuli were fewer than would have been expected in Great Britain.
Studies on the fleece microclimate showed that relative humidities of 50 % or more frequently occurred on the skin surface. Humidities 3 cm. above the skin were markedly lower. Except during or immediately after rain, humidities high enough to ensure the hatching of blowfly eggs were never recorded.
It is concluded that the absence of myiasis in Denmark and its relatively low incidence in other countries is not due to the existence on the Continent of a strain of L. sericata differing in oviposition habits from the British species.  相似文献   

4.
Abstract. The orientation of adults of the myiasis species Wohlfahrtia magnified and Lucilia sericata to artificial visual stimuli (cloth targets) and olfactory stimuli ('swormlure-4', a potent screwworm attractant), was studied in sheep pastures near to Sarbogard in Hungary. Experiments with odour-baited cloth targets, enclosed in electrocuting grids, demonstrated that colour was an important factor influencing catches on targets: a black target caught most flies of both species, with other colours in the following order of effectiveness, blue > white > yellow. Wohlfahrtia magnified did not respond to swormlure-4 in the strong manner that L. sericata did. The sex ratios of W. magnifica caught on targets (67.2% males) and hand-netted from fence posts (68.8% males) were similar and biased towards males, whereas that of L. sericata on targets was strongly biased towards females (15.6% males), indicating a fundamental difference in the response of these two myiasis species towards the swormlure-baited targets. The orientation of these two species towards hosts was also recorded together with that of a third species, Phormia regina . Electric nets placed beside infested sheep caught significantly more flies of all three species than those placed beside uninfested sheep or in the absence of sheep. The sex ratio of W. magnified caught around infested sheep was the reverse of that on targets, with 68.5% females. Wohlfahrtia magnifica responded more strongly to healthy, uninfested sheep than did L. sericata and P. regina . The potential for use of targets both for population monitoring and control is discussed.  相似文献   

5.
OEstrosis is a very common myiasis of sheep and goats in mediterranean and tropical countries. Goats are suitable hosts for OEstrus ovis but the parasitic burden remain lower than in sheep. Cellular responses (mucous and serous mast cells, eosinophis and globules leucocytes) were measured in 30 infected and 30 non infected sheep and in 23 infected and 24 non infected goats. The presence of OEstrus ovis larvae led to an important inflammatory response in sheep and in goats as well. Furthermore, the intensity of the cellular response correlated with the larva burden, specially with globules leucocytes and eosinophils. Nevertheless, huge differences occurred between sheep and goats responses even in similar larval burden range. Infected sheep showed larger counts of mucous mast cells than goats, the differences were smaller in serous mast cells and eosinophils and no difference was detected in globules leucocytes (intraepithelial mast cells) counts between the two hosts species. These results were compared with those obtained in gastro-intestinal strongyles infections.  相似文献   

6.
Colonization by blowflies (Diptera: Calliphoridae) of mouse carcasses exposed in open agricultural land near Durham (54 45'N) changed from early spring monopolization by Calliphora vicina R.-D. to a summer pattern of multiple species exploitation by this species together with Lucilia caesar L., L. illustris Mg., L. silvarum Mg., L. sericata Mg. and L. richardsi Collin. In a garden at the edge of Durham, mouse carcasses were dominated by C. vicina from spring to autumn. Difference in mouse colonization between the agricultural and garden sites seemed to reflect differences in the blowfly species present, as measured by baited trap catches at the sites. In sets of C. vicina reared from mice under conditions of competition for larval food, it was found that resulting females were significantly larger than males, size being measured as mean wing length. Blowfly production from three sheep carcasses exposed successively at the agricultural site was dominated by C. vomitoria L. and L. caesar, but also produced other Lucilia species in small numbers, including L. sericata. These L. sericata females from sheep that had died from causes other than myiasis included full-sized specimens, in contrast to those produced from mouse carcasses that were all undersized individuals. As L. sericata females trapped on sheep pastures are predominantly full-sized, this suggests that large carcasses may, in part, be a source of the L. sericata population that attacks sheep as a myiasis agent. The nature of large carcasses as possible sources of L. sericata in lowland Britain is discussed.  相似文献   

7.
A serodiagnostic test for the diagnosis of infestation by the sheep nasal bot fly, Oestrus ovis (Linné) was examined. The enzyme-linked immunosorbent assay (ELISA) technique was used to analyze and compare the production of immunoglobulin G (IgG) antibodies against excretory-secretory products (ESP) and crude extract (CE) antigens from all the different larval stages of O. ovis in the sera of 276 adult sheep sampled in summer (n = 135) and winter (n = 141). ESP from first stage larvae was the most sensitive, coating antigen in winter and ESP from second stage larvae during summer. The most specific values were obtained by ESP against L1 in winter and by CE against L3 in summer. These results show that the stage of larval development has a significant impact on the humoral immune response over the course of a season. A significant correlation (P < 0.001) was found between the number of O. ovis larvae and the serum antibody levels using all differents antigens, except L3 CE. In Spain, where a long favourable period exists for the evolution and development of the different stage larvae between March and November, the ELISA test using L1 ESP antigen during winter and L2 ESP antigen in summer may be used for ovine oestrosis immunodiagnosis.  相似文献   

8.
A survey on the prevalence and geographical distribution of traumatic myiasis in sheep, and the risk factors for the disease, was carried out in a region of southern Italy. A total of 138 sheep flocks were selected and visited to acquire data on the presence or absence of traumatic myiasis using both a questionnaire for retrospective analysis and animal inspection. Prevalences registered at the farm and animal levels, respectively, were 8.7% and 6.3% in 2010, and 5.8% and 5.0% in 2011. Records of the occurrence of the parasitic disease in this region are recent: a statistically significant (P < 0.01) progressive increase in the number of farms affected (from 0.7% to 8.7%) has been registered since 2007. Wohlfahrtiosis was found in 11 of 95 (11.6%) geographical units sampled and three significant (P < 0.05) clusters of spatial farm aggregation were identified in the southern part of the study area. A total of 158 presently uninfested farms were considered to be at high risk for transmission as a result of their proximity to infested farms. The spreading of Wohlfahrtia magnifica (Diptera: Sarcophagidae) in southern regions of Italy represents a warning that the risk for infestation may become more significant in other Italian regions, as well as other European countries.  相似文献   

9.
Cutaneous myiasis is a common travel-associated dermatosis caused by fly larvae. We report an unusual case of furuncular myiasis caused by Dermatobia hominis that was associated with signs of systemic inflammation. In this case study, morphological and novel molecular approaches were used to identify and characterize the larvae responsible for human infestation.  相似文献   

10.
The blowfly, Lucilia cuprina Wiedemann (Diptera: Calliphoridae), is the primary myiasis (strike) fly of sheep in Australia. Most strike occurs in the anal-perineum area (crutch), but strike to the neck, shoulders, back and withers (body) is also important. Regression analysis was used to determine the extent to which the weekly incidence of flystrike can be explained by variations in fly abundance and/or recent changes in weather, pasture conditions or flock management. Strike and flock management data were collected by questionnaire surveys of 30-60 sheep properties in each of three major sheep-producing areas in southeastern Australia, namely, Gunning (southern New South Wales), Inverell (northern New South Wales) and Flinders Island (Bass Strait). After using simulation modelling to remove effects due to shearing, crutching and/or insecticide treatment, pasture growth index was found to be the most important explanatory variable affecting the incidence of all forms of myiasis. Others were average weekly air temperature, the amount and frequency of rainfall, relative humidity, dung quality index and a factor denoting seasonal effects. Together, these variables accounted for 48.4% of the variation in body strike, 56.8% of that in crutch strike and 51.9% of that in other forms of strike. Prediction was improved by the inclusion of additional lagged variables describing previous strike, fly abundance and fly activity. With these additions, the variation explained increased to 60.4% for body strike, 68.0% for crutch strike and 58.3% for other strikes.  相似文献   

11.
Myiasis is the infestation of live human and vertebrate animals with dipterous larvae which, at least for a short period, feed on the host's dead or living tissue, liquid body-substance, or ingested food. The objective of this study was to identify the flies producing myiasis in Bahía Blanca city, Argentina, from 01/03/2000 to 31/05/2005. Seventeen clinical cases were studied. The larvae obtained from lesions were forwarded from laboratories and from public and private hospitals. Part of the larvae were fixed in alcohol 70 masculine and processed according to the Mazza & J?rg technique (1939). The other part continued growing in flasks with meat in laboratory conditions to obtain the adults. The etiological agents of myiasis were identified by observing the diagnostic characteristics of the larvae III and of the adults, and by using taxonomic keys. Myiasis was produced by Cochlyiomia hominivorax (Coquerel) in thirteen of the cases and by Phaenicia sericata (= Lucila sericata) (Meigen) (Diptera: Calliphoridae) in the other four. The cases were traumatic and aural myiasis and happened from December to March. The ages of patients were four to eighty-six years and 76.5% of the cases occurred in male patients. Given the aggressiveness of these larvae, mainly C. hominivorax, in causing human myiasis, the importance of specific and quick diagnosis and of adequate treatment must be acknowledged.  相似文献   

12.
Abstract.  The geographical distribution and seasonality of the New World screwworm (NWS), Cochliomyia hominivorax Coquerel (Diptera: Calliphoridae), were monitored through the use of sentinel animals as part of a co-ordinated programme involving veterinarians and farmers, as well as undergraduate students and teachers from veterinary colleges in Venezuela. This surveillance activity made it possible to collect NWS egg masses or larvae from all 23 states in the country and to determine that the rainy season has a strong positive influence on the number of cases of myiasis caused by C. hominivorax in dogs. In addition, efforts were made to obtain the co-operation of the public health service in order to document the extent of human myiasis in the western–central region of Venezuela. Preliminary results revealed 241 cases over a 7-year period, with cases reported in infants as well as in elderly people. Larvae causing myiasis, other than C. hominivorax , were collected from primary myiasis in rabbit ( Lucilia eximia [Wiedemann]), dog (an unidentified sarcophagid species), birds ( Philornis sp.) and wild mice ( Cuterebra sp.). The economic impact of NWS in Venezuela has not been calculated in terms of loss of milk and meat production, damage to hides or death of animals. Control costs (e.g. cost of larvicides) have been estimated at US$ 2 m per year. Control of myiasis in animals is achieved through the use of chemical compounds, mainly organophosphorus (OP) compounds, macrocyclic lactones and, more recently, a foamy spray based on spinosad. Concerns about insecticide resistance to OP compounds have been raised.  相似文献   

13.
Prophylactic vaccines can be expected to be one of the major practical outputs of parasitology research. Various groups within Australia have pursued the vaccine objective for several years, with particular emphasis on blood-stage falciparum malaria in man, intestinal helminths of sheep and cattle, cutaneous myiasis (blowfly strike) in sheep, cysticercosis in sheep and cattle, bovine babesiosis, and cattle ticks. Other vaccine programmes are concerned with giardiasis, filariasis, toxoplasmosis, fascioliasis, coccidiosis in poultry, cutaneous leishmaniasis and schistosomiasis japonica. For many years, the only available vaccine against a parasite in Australia has been the attenuated Babesia bovis vaccine produced by the Tick Fever Research Centre of the Queensland Department of Primary Industries. Strategies for achieving molecular vaccines are generally similar within the various research groups. They involve analysis of the immunology and immunochemistry of a model or in-vitro system; development of functional monoclonal antibodies; analysis of antibody specificities in clinically and/or functionally defined polyclonal sera; screening of cDNA or genomic expression libraries; peptide synthesis; identification of an appropriate vaccination schedule involving adjuvants or new recombinant DNA-based antigen delivery systems. Outlined below are five of the major vaccine programmes.  相似文献   

14.
The Australian sheep blowfly Lucilia cuprina is the most important pest species involved in cutaneous myiasis (flystrike) of sheep in Australia and New Zealand. In New Zealand L. cuprina is primarily controlled through the application of insecticides. However, there is an increased interest in biological methods of control of this species. We have proposed to develop a genetically modified strain of L. cuprina that would be ideal for a male-only sterile release program. To that end we have developed a method for making transgenic L. cuprina using a piggyBac vector and an EGFP marker gene. We have also developed in Drosophila melanogaster a 2-component genetic system for controlling female viability. Females carrying both components of the system die unless fed a diet that contains tetracycline. We anticipate that the female-killing system will need to be optimised for L. cuprina in order to make a strain with the properties required for a male-only release program.  相似文献   

15.
Myiasis-causing Oestridae (bot flies) infect several animal species world-wide, from palaearctic to subtropical/tropical areas. Oestrids affect livestock production causing abortion, reduced milk production, losses in weight and fertility, poor hide quality and an impairment of the host's immune system. In the last few years much research has been carried out on the immunology of these infestations, in order to acquire efficient and reliable diagnostic serological tools; the genome of the different species of Oestridae has been studied to further their molecular identification, taxonomy and phylogenesis. The immunodiagnostic methods for many myiasis causing Oestrids have proven to be a viable alternative to the clinical parasitological examination or the post-mortem examination. Numerous serological tests have been developed for the diagnosis of bovine hypodermosis caused by Hypoderma bovis and Hypoderma lineatum, and ELISAs using larval hypodermin C as the antigen are currently used on serum, individual and pooled milk samples to detect the presence of circulating anti-Hypoderma antibodies. In Italy the best period to sample the animals is November-January, since it is in this period that the antibody kinetics of the animals reaches a peak. Recently the efficacy of the ELISA test on pasteurized milk samples has been demonstrated, allowing the diagnosis of bovine hypodermosis also in areas where there is no information on the presence of the disease and the sampling of the animals is laborious. The cross-reactivity between Przhevalskiana silenus antigens and anti-Hypoderma antibodies led to assessing the usefulness of a simple and cost-effective ELISA for the diagnosis of goat warble fly infection. In particular, it has been demonstrated that infected goats display an antibody peak in November-December in blood and milk, thus making this period suitable for sampling. Although no extensive data is available on the immunology of sheep and goat oestrosis caused by Oestrus ovis, the efficacy of ELISA has been demonstrated by correlating serological results with clinical post-mortem examinations. No immunological techniques are currently used to diagnose gasterophilosis of equids and only one study reports the efficacy of ELISA for detecting anti-Gasterophilus antibodies in infected equids. Several studies have been conducted into the molecular characterization of the mitochondrial DNA (mtDNA)--in particular of the gene encoding for the cytochrome oxidase I (COI)--for many free-living and parasitic arthropods for diagnostic, taxonomic and phylogenetic purposes. As regards Oestridae causing myiasis, the first study features a PCR-RFLP assay of the most common Italian species (i.e. H. bovis, H. lineatum, Gasterophilus intestinalis, P. silenus, O. ovis), which showed clear genetic differences among the genera examined, but no inter-specific variation between the two species of Hypoderma considered. The molecular characterization of the most variable region of the COI gene (encoding for the region from E4 to the terminal COOH) was able to clearly differentiate H. bovis and H. lineatum. The E4-COOH region of the COI gene has been characterized for 18 oestrid species and from a taxonomical point of view, molecular data confirm the morphological classification, with the examined species divided into four subfamilies. New insights have also been gained on the molecular differentiation of the most common species of Hypoderma (i.e. H. bovis, H. lineatum, Hypoderma actaeon, Hypoderma diana and Hypoderma tarandi) and, in particular, the restriction enzyme BfaI, provides a diagnostic profile that can be used to simultaneously differentiate all the species examined. The characterization of the E4-COOH COI gene and the hypervariable region of the gene encoding for the ribosomal Isu revealed the identity of Hypoderma sinense as a new species, infecting cattle and yaks in China. Finally, the molecular analysis of the same mitochondrial and ribosomal regions showed that P. silenus, Przhevalskiana aegagri and Przhevalskiana crossii are morphotypes of the same species.  相似文献   

16.
The larvae of the fly Lucilia cuprina cause a cutaneous myiasis in mammalian hosts, particularly sheep. The glycoprotein, peritrophin-95, isolated from Lucilia cuprina larval peritrophic matrix, is a candidate vaccine antigen. This protein induced an immune response in vaccinated sheep that inhibited larval growth. Recombinant forms of peritrophin-95 were produced in bacteria and baculovirus-infected insect cells. The bacterial protein was not glycosylated and incorrectly folded whereas the insect cell-expressed protein was glycosylated and probably correctly folded. Sheep immunised with purified native peritrophin-95 generated strong larval growth inhibitory activity in their sera, whereas sheep immunised with either recombinant form of peritrophin-95 generated only relatively weak inhibitory activity. Ingested ovine antibodies to native peritrophin-95 mediated the anti-larval growth activity and this was independent of the presence of ovine complement. The activity was associated with IgG(1) and IgG(2) but not IgM. There were strong antibody responses to both the correctly folded native peritrophin-95 polypeptide and the oligosaccharides present on this glycoprotein. Immuno-affinity isolation of antibody to the peritrophin-95 polypeptide and antibody to peritrophin-95 oligosaccharides demonstrated that the larval growth inhibitory activity resided with both antibodies. Lectin blots and ELISA data showed substantial differences between the oligosaccharides attached to native peritrophin-95 and insect cell-expressed recombinant peritrophin-95. It was concluded that the oligosaccharides attached to native peritrophin-95 and its unique polypeptide structure are essential for the induction of larval growth inhibitory activity in the sera of sheep vaccinated with this antigen.  相似文献   

17.
We describe here a rare case of traumatic myiasis occurred in August 2014, caused by an association of 2 Diptera species, Sarcophaga tibialis Macquart (Diptera: Sarcophagidae) and Lucilia sericata (Meigen) (Diptera: Calliphoridae), in a domestic cat in northern Italy. Species identification was based on adult male morphology. The present case is the first report of S. tibialis as an agent of myiasis in Italy, and also the first ever report of myiasis caused by an association of S. tibialis and L. sericata. The cat developed an extensive traumatic myiasis in a large wound on the rump, which was treated pharmacologically and surgically. The biology, ecology, and distribution of S. tibialis and L. sericata are also discussed. A literature review is provided on cases of myiasis caused by S. tibialis, and cases of myiasis by L. sericata involving cats worldwide and humans and animals in Italy.  相似文献   

18.
A third-stage larva of Dryomyza formosa (Wiedemann) (Diptera: Dryomyzidae) was found in the fresh stool of a 27-year-old Japanese woman resident of Shiobara, 150 km north of Tokyo, on 16 November 1998. This is the first record of myiasis due to Dryomyza. Detection of this maggot (2cm long) by the patient herself was associated with her longstanding delusion of abdominal parasitosis as a symptom of chronic schizophrenia. Circumstantial evidence agreed with this being a genuine case of intestinal myiasis, apparently due to accidental ingestion of the insect, with no signs that the patient had contrived the report, nor that the maggot had invaded the stool post-defaecation. This case draws attention to the likelihood that some personality states are predisposed to noticing and reporting myiasis, when it occurs. We review other conditions (mental and physical) that are more prone to myiasis.  相似文献   

19.
Abstract. Between 1920 and 1930, four species of parasitoid Hymenoptera (Tachinaephagus zealandicus, Alysia manducator, Nasonia vitripennis and Brachymeria ucalegon) were imported to New Zealand as an aid in the control of the blowflies causing myiasis in sheep (flystrike). Their long-term effects have never been investigated and the extent to which they were successful in establishing and enlarging their ranges has been given scant regard over the last 60 years. A long-term epidemiological study of flystrike in New Zealand between 1986 and 1996 obtained 4061 samples of blowfly larvae from flystruck sheep and carrion and overall 1.1% of these larval samples (most from the North Island) were found to be parasitized. Tachinaephagus zealandicus and A. manducator were present in field strikes, together with the endemic Aphaereta aotea recently found to be a parasite of calliphorids. The endemic species Phaenocarpa antipoda was found in association with carrion but not flystrike. Neither N.vitripennis nor B.ucalegon were isolated from larvae in field strikes, the former because it parasitizes only pupae and the latter may be extinct as it has not been sighted since its introduction in 1919.
It is concluded that if parasitoid wasps are able to locate and parasitize blowfly larvae on struck sheep, then their parasitism rate on more accessible larvae on carcases may be correspondingly greater. For this reason their scope for use in integrated management of flystrike could be increased by culturing and field release.  相似文献   

20.
Bacteremia induced by wound myiasis is uncommon and therefore rarely suspected by clinicians when treating patients with neglected wounds. We present a case of Ignatzschineria larvae bacteremia as a complication of Lucilia sp. maggot wound myiasis in a young male migrant. This is the first reported human case of Ignatzschineria bacteremia in Slovenia and one of the 2 described in the literature where the fly larvae infesting the wounds of the patient with Ignatzschineria bacteremia were not only suspected to be Lucilia sp. but also entomologically identified.  相似文献   

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