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1.
Musella V Catelan D Rinaldi L Lagazio C Cringoli G Biggeri A 《Preventive veterinary medicine》2011,99(2-4):69-77
Gastrointestinal (GI) strongyle and fluke infections remain one of the main constraints on health and productivity in sheep dairy production. A cross-sectional survey was conducted in 2004-2005 on ovine farms in the Campania region of southern Italy in order to evaluate the prevalence of Haemonchus contortus, Fasciola hepatica, Dicrocoelium dendriticum and Calicophoron daubneyi from among other parasitic infections. In the present work, we focused on the role of the ecological characteristics of the pasture environment while accounting for the underlying long range geographical risk pattern. Bayesian multivariate spatial statistical analysis was used. A systematic grid (10 km×10 km) sampling approach was used. Laboratory procedures were based on the FLOTAC technique to detect and count eggs of helminths. A Geographical Information System (GIS) was constructed by using environmental data layers. Data on each of these layers were then extracted for pasturing areas that were previously digitalized aerial images of the ovine farms. Bayesian multivariate statistical analyses, including improper multivariate conditional autoregressive models, were used to select covariates on a multivariate spatially structured risk surface. Out of the 121 tested farms, 109 were positive for H. contortus, 81 for D. dendriticum, 17 for C. daubneyi and 15 for F. hepatica. The statistical analysis highlighted a north-south long range spatially structured pattern. This geographical pattern is treated here as a confounder, because the main interest was in the causal role of ecological covariates at the level of each pasturing area. A high percentage of pasture and impermeable soil were strong predictors of F. hepatica risk and a high percentage of wood was a strong predictor of C. daubneyi. A high percentage of wood, rocks and arable soil with sparse trees explained the spatial distribution of D. dendriticum. Sparse vegetation, river, mixed soil and permeable soil explained the spatial distribution of the H. contortus. Bayesian multivariate spatial analysis of parasitic infections with covariates from remote sensing at a very small geographical level allowed us to identify relevant risk predictors. All the covariates selected are consistent with the life cycles of the helminths investigated. This research showed the utility of appropriate GIS-driven surveillance systems. Moreover, spatial features can be used to tailor sampling design where the sampling fraction can be a function of remote sensing covariables. 相似文献
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Katsoulos PD Christodoulopoulos G Karatzia MA Pourliotis K Minas A 《Veterinary parasitology》2011,179(1-3):262-265
The main objective of this study was to investigate whether cholelithiasis in sheep is related to parasitism or other commonly observed disorders such as liver abscesses. Additionally, the features of the observed biliary calculi are described. The livers of 254 randomly selected clinically healthy adult dairy sheep were used. All visible concretions in the bile were considered as stones. Based on the macroscopical examination, 60 livers were normal, 40 were parasitized with Fasciola hepatica, 42 were parasitized with Dicrocoelium dendriticum, 28 were parasitized with both D. dendriticum and F. hepatica, 40 livers had abscesses and 44 had hydatid cysts. Biliary calculi were detected in 40 livers. Twenty livers had pigment stones and 20 livers had cholesterol stones. The percentage of cholelithiasis was significantly higher in livers parasitized with flukes compared with the others (P<0.05) and the parasitoses with F. hepatica and D. dendriticum were proven to be significant risk factors (P<0.05) for the presence of cholelithiasis in sheep. 相似文献
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This study investigated the immunoglobulin isotype responses of sheep and cattle chronically infected with Fasciola hepatica and Fasciola gigantica to adult F. hepatica excretory/secretory products (Fh-ES) or F. gigantica excretory/secretory products (Fg-ES), respectively. An antibody enzyme-linked immunosorbent assay (Ab-ELISA) was used to determine serum antibody (total Ig, IgG(1), IgM, IgG(2) and IgA) responses. At necropsy, the mean number of flukes recovered was lower in cattle than in sheep. All F. hepatica and F. gigantica infected sheep and cattle showed an increased total Ig levels from 3 to 4 weeks post-infection (wpi). Among isotypes IgG(1) was most dominant while IgM was the earliest (2 wpi) to be detected in both sheep and cattle infected with both F. hepatica and F. gigantica animals. IgG(2) response was early (2 wpi) in sheep infected by F. hepatica but there was no response in sheep infected with F. gigantica. There was a late and strong IgG(2) response in cattle infected with both flukes. The IgA isotype showed an early and a clear biphasic response in sheep with F. hepatica but was less pronounced in F. gigantica infected sheep. While IgA response to Fh-ES was noticed 5 wpi in F. hepatica infected cattle, it appeared much later (21 wpi) in those infected with F. gigantica. The dominance of IgG(1) isotype in infected sheep and cattle suggest an associated Th2 response. This early response to adult Fasciola spp. ES antigen suggests an early exposure to the antigen presumably through the cross-reacting ES products of juvenile flukes. There is clearly difference in IgG(2) isotype response in cattle (resistant) compared to sheep (susceptible). The late IgG(2) response in cattle may suggest late Th1 involvement in bovine cellular responses to adult Fh-ES/Fg-ES. 相似文献
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Reichel MP 《Veterinary parasitology》2002,107(1-2):65-72
AIM: To validate an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against liver fluke (Fasciola hepatica) in sheep and cattle sera. METHODS: Gold-standard sera from sheep and cattle of known infection status, i.e. sera from non-infected animals and from animals known to be infected with F. hepatica were assayed with a commercially available ELISA and results analysed by ROC analysis. RESULTS: The ROC analysis suggested cut-offs that were considerably lower than those suggested by the manufacturer, yet the ELISA performed with high sensitivity and specificity, 98 to 100%, respectively for sheep and cattle sera. For bovine sera, particularly good discrimination between positive and negative sera was observed. Infection in experimentally infested animals could be demonstrated 7-8 weeks earlier than with classical parasitological techniques. CONCLUSIONS: The analysis of the ELISA's performance demonstrated high sensitivity and specificity. ROC analyses optimised the cut-off point suggested by the manufacturer of the commercial diagnostic assay. Diagnosis of infection with F. hepatica was achieved much earlier than is possible with current parasitological techniques. This could help with the control of fasciolosis, enabling treatment before clinical manifestation of the disease. 相似文献
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Theodoropoulos G Theodoropoulou E Petrakos G Kantzoura V Kostopoulos J 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2002,49(6):281-284
The prevalence of parasitic infections responsible for the condemnation of carcasses and viscera during meat inspection, and their economic implication, was estimated in a year long abattoir survey of 10 277 slaughtered farm animals in the region of Trikala, Greece. The organs examined for the presence of parasitic lesions during meat inspection were: liver and lungs of all animals, rumen of cattle, small intestine of lambs and kids, and muscles of cattle and swine. The parasitic lesions observed in the lungs of cattle, sheep and goats were caused only by hydatid cysts. No hydatid cysts were observed in the lungs of swine. The parasitic lesions observed in the liver of cattle, sheep and goats were as a result of hydatid cysts and flukes of Fasciola hepatica and Dicrocoelium dendriticum, while those of swine were due to milk spots only. Moniezia sp. proglottids were found in the small intestine of lambs only. The prevalence of parasites responsible for the condemnation of marketable organs was low (0.26%). Parasites were responsible for 22% of the total of condemned organs, and their annual cost was 99, 00 GDR (approximately 292 Euros). The parasites most contributing to marketable organ condemnation were hydatid cysts (26%) and D. dendriticum flukes (26%). 相似文献
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Following several clinical cases of suspected bovine virus diarrhoea (BVD) on three Namibian cattle farms, a serological survey was conducted on bovine, ovine, caprine and wild ruminant sera originating from different regions of the country. Neutralizing antibodies to BVD virus (BVDV) were detected in 58% of 1,014 cattle sera, 14% of 618 sheep sera and 4.6% of 1,118 goat sera. Sera from seven of ten wildlife species were positive with kudu, eland and giraffe having prevalence rates greater than 40%. BVDV was isolated from six clinically affected bovines and three healthy heifers persistently infected with BVDV. The survey demonstrated that pestivirus infections are widespread in Namibia in both domestic and wild ruminants. 相似文献
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Kuerpick B Fiedor C von Samson-Himmelstjerna G Schnieder T Strube C 《Berliner und Münchener tier?rztliche Wochenschrift》2012,125(7-8):345-350
The liver fluke Fasciola (F) hepatica is one of the most important trematodes in cattle farming worldwide. Fasciolosis in dairy cows is leading to production losses due to decreased milk yield, liver condemnation and impaired reproduction. The treatment of dairy cows is unsatisfactory, because available drugs are either effective against adult flukes only or have long withdrawal times or in some countries may not be used at all. In the present study the prevalence of F. hepatica in dairy farms located in East Frisia, which is part of the federal state Lower Saxony, was investigated. East Frisia is considered a high risk area for Fasciola hepatica infections, because of its coastal location, high precipitation and moist pastures. About 750 bulk milk samples were collected in January and November 2006 and analysed for F. hepatica antibodies using the Pourquier ELISA. In addition, questionnaires, which were answered by 260 of the participating farmers, were evaluated to analyse management-related factors associated with fasciolosis. In January and November, 52.1% and 53.6% of the bulk milk samples, respectively, showed positive results. Thereby, 88.1% of the examined farms showed an unchanged infection status, whereas 6.2% of the farms became seropositive during the grazing season and 5.8% of the dairy herds turned seronegative. Statistical analysis revealed a significant negative association between average annual milk production and the frequency of infections with F. hepatica. 相似文献
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Rinaldi L Fusco G Musella V Veneziano V Guarino A Taddei R Cringoli G 《Veterinary parasitology》2005,128(3-4):219-230
A cross-sectional serological survey was conducted on cattle pasturing in an area of the southern Italian Apennines to evaluate the seroprevalence to Neospora caninum, and to investigate the climatic, environmental, farm management, and individual animal factors that influence the distribution of this protozoan. Blood samples were collected from 864 pastured cattle raised on 81 farms. Serum samples were tested for antibodies to N. caninum using an ELISA assay (HerdCheck), IDEXX). A geographical information system (GIS) for the study area was constructed using the following remote sensing (RS) and landscape feature data: autumn-winter, spring and summer normalized difference vegetation index (NDVI), land cover, elevation, slope, aspect, mean rainfall and minimum, mean, and maximum temperature in spring, summer, autumn and winter. Data on each of these features were then extracted for "buffer zones" consisting of the area included in a circle of 3 km diameter centered on the 81 geo-referenced centroids of the main cattle pastures. Climatic and environmental data obtained from RS and GIS and individual animal characteristics and farm management data obtained from a questionnaire were analyzed in relation to N. caninum seropositivity and antibody titres both by linear and logistic regression models. Out of the 81 farms sampled, 63 (77.8%) had at least one tested animal positive for N. caninum. Out of the 864 bovine sera samples, 266 (30.8%) were found to have antibodies to N. caninum. The results of the logistic regression model show that significantly high seroprevalence to N. caninum was found in heifers/steers and adults, in cattle raised on farms having a large number of dogs, and in cattle raised in buffer zones having high minimum temperatures in the spring, and a narrow extension of summer NDVI. In addition, positive linear correlations were found between N. caninum antibody titres and the number of dogs on farm, and the minimum temperature in spring. All the above determined risk factors for N. caninum seroprevalence indicate that horizontal infection resulting from the ingestion of oocysts shed by dogs is the most probable route of N. caninum infection in pastured cattle of the southern Italian Apennines. 相似文献
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Cringoli G Taddei R Rinaldi L Veneziano V Musella V Cascone C Sibilio G Malone JB 《Veterinary parasitology》2004,122(1):15-26
A geographic information system (GIS) was constructed using remote sensing (RS) and landscape feature data together with Calicophoron daubneyi positive survey records from 197 georeferenced ovine farms with animals pasturing in a 3971 km(2) area of the southern Italian Apennines. The objective was to study the spatial distribution of this rumen fluke, identify environmental features that influence its distribution, and develop a preliminary risk assessment model. The GIS for the study area was constructed utilizing the following environmental variables: normalized difference vegetation index (NDVI), land cover, elevation, slope, aspect, and total length of rivers. These variables were then calculated for "buffer zones" consisting of the areas included in a circle of 3 km diameter centered on 197 farms. The environmental data obtained from GIS and RS and from data taken by the veterinarians on the field (stocking rate and presence of streams, springs and brooks on pasture) were analyzed by univariate (Spearman and ANOVA) and multivariate (discriminant) statistical analyses using the farm coprological status (positive/negative) as the dependent variable. Sheep on 32 of the 197 (16.2%) farms, were positive for C. daubneyi, with an average intensity of 52 epg. A multivariate stepwise discriminant analysis model was developed that included moors and heathland, sclerophyllous and coniferous forest vegetation, autumn-winter NDVI and presence of streams, springs and brooks on pasture. The variables entered in the model were also correlated with C. daubneyi positive farms in the univariate tests and are consistent with the environmental requirements of C. daubneyi and its snail intermediate host. 相似文献
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Enzyme-linked immunosorbent assays (ELISA) for the detection of Fusobacterium necrophorum antibody in the sera of rabbits, cattle, and sheep were developed, using a ribosome-rich extract (RRE) from F necrophorum as the antigen. Test character, including optimal antigen dilution and substrate incubation periods, was established, using rabbit, bovine, and ovine antisera produced against RRE from isolates of F necrophorum. Rabbit antisera produced against 7 other species of bacteria were used to test the specificity of the F necrophorum RRE antigen. Cross-reactivity was not detected. Sera from 50 feedlot cattle were examined with the bovine ELISA. Of the 50 samples, 43 (88%) were positive for F necrophorum antibody. The ELISA developed in this study were sensitive and specific and appear to be readily adaptable to serologic investigations of F necrophorum. 相似文献
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Fourteen isolates of Bacteroides nodosus were cultured from cattle on six farms and examined for colony morphology, pilation, agglutinability, proteolytic activity and pathogenicity for sheep. Where sheep were also present on the farms, isolates from these were compared with those from cattle.Colonies of the bovine isolates were moderately fimbriate. Cells from these colonies were pilated, but not to the extent observed on virulent sheep isolates. The proteolytic activity of the isolates was also less than that described for virulent ovine isolates. When inoculated into sheep, B. nodosus from cattle produced only mild interdigital inflammation. There was no separation of horn characteristic of virulent foot-rot. Preliminary studies, based on agglutination tests, suggest that B. nodosus with different surface antigens may occur in cattle in the same herd and in cattle and sheep on the same farm. On one of six farms isolates from cattle and sheep were indistinguishable by the agglutination test. 相似文献
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Natural infection of Lymnaea glabra and Lymnaea truncatula by Fasciola hepatica and/or Paramphistomum daubneyi was studied at two periods of risk (June-July and September-October) in 11 French farms known for their high prevalences of F. hepatica infection in ruminants. A total of 1,778 L. truncatula and 2,396 L. glabra measuring 6 mm or more in height were collected to determine the prevalence of natural infection with F. hepatica and P. daubneyi. The role of four factors, i.e. season, snail co-infection (F. hepatica-P. daubneyi), ruminant host and the existence of single or mixed intermediate host communities, was investigated. There were no differences in prevalences between the two risk periods. Co-infections in L. glabra were more frequent than expected. The prevalences of infection with F. hepatica or P. daubneyi in L. glabra were higher in farms rearing sheep than in farms rearing cattle. A similar finding was also noted for L. truncatula infected with P. daubneyi only. L. glabra was a much better intermediate host for F. hepatica and P. daubneyi when it was the only available snail, possibly indicating an adaptation of parasites to their less usual host in local conditions. The two trematodes preferably developed in L. truncatula rather than in L. glabra when both host species lived in the same places. 相似文献
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绵羊源爱知病毒D型(ovine Aichivirus D)是在国内绵羊中新发现的病毒,本研究根据绵羊源Aichivirus D 3D基因序列设计检测引物,通过反应体系和条件优化,成功建立了检测绵羊源Aichivirus D的TB Green染料法荧光RT-PCR方法,该方法特异性和稳定性良好,灵敏度高。对2020年4月―2021年5月采集自四川6个场253份绵羊粪便样本(健康羊的133份,腹泻羊的120份)进行检测,结果该病毒的平均检出率为8.7％,场阳性率为66.7％。其中,腹泻粪便样本中绵羊源Aichivirus D阳性率(17.5%)显著高于非腹泻粪便样本中绵羊源Aichivirus D阳性率(0.75%,P<0.001)。表明绵羊源Aichivirus D可能是引起以上地区绵羊腹泻的病原。从绵羊源Aichivirus D的阳性样本中成功克隆出大小为1 422 bp的13个完整的绵羊源Aichivirus D 3D基因,其核苷酸相似性为99.4％～100.0％。遗传演化分析发现这13株绵羊源Aichivirus D 3D基因与本实验室前期研究上传的绵羊源Aichivirus D 3D基因共同聚为单独的一个大支。本研究为绵羊源Aichivirus D的分子检测提供了一种新的方法和基础流行病学数据。 相似文献
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G Froyd 《The Veterinary record》1975,97(25-26):492-495
Over a period of 15 months data were collected from abattoirs in Great Britain on 213,082 cattle and 362,838 sheep livers to determine the distribution and prevalence of damage by Fasciola hepatica. The stock came from 8239 farms, and from livestock markets in 81 counties. 53 per cent of the farms had sent affected stock, with significant percentages in eastern as well as the western counties of England and Scotland. 21 per cent of all cattle and 7 per cent of all sheep livers examined were affected. In both species, the percentage of adult stock affected was more than double that of young stock. The condemnation rate in cattle was relatively constant throughout the year. The effects of infestation are more widely distributed than has been generally recognised. Greater emphasis should be placed on the control of chronic fascioliasis in cattle. 相似文献
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The highest prevalences and intensities of human fasciolosis by Fasciola hepatica are found in the northern Bolivian Altiplano, where sheep and cattle are the main reservoir host species and pigs and donkeys the secondary ones. Morphometric comparisons of many linear measurements, areas and ratios of F. hepatica adults (from sheep, cattle and pigs) and eggs (from sheep, cattle, pigs and donkeys) in natural liver fluke populations of the Bolivian Altiplano, as well as of F. hepatica adults and eggs experimentally obtained in Wistar rats infected with Altiplanic sheep, cattle and pig isolates, were made using computer image analysis and an allometric model. Although morphometric values of adult flukes from natural populations of sheep, cattle, and pigs showed great overlap, there were clear differences in allometric growth. The allometries analyzed were: body area (BA) versus body length (BL), BA versus body width (BW), BA versus perimeter (Pe), BA versus distance between posterior end of body and ventral sucker (P-VS), BL versus BW, BL versus Pe, and BL versus P-VS. These allometries show a good fit in the seven pairs of variables in all the populations examined. Comparative statistical analysis of the allometries shows that fluke adult populations from sheep, cattle and pigs significantly differ in BL versus BW and BL versus P-VS functions. Statistical analysis of F. hepatica egg size shows characteristic morphometric traits in each definitive host species. In experimentally infected rats, fluke adult allometry and egg morphometry do not vary depending on the Altiplanic definitive host species isolate. Our study reveals that the definitive host species decisively influences the size of F. hepatica adults and eggs, and these influences do not persist in a rodent definitive host model. 相似文献
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Salimi-Bejestani MR McGarry JW Felstead S Ortiz P Akca A Williams DJ 《Research in veterinary science》2005,78(2):177-181
An ELISA was developed for the detection of Fasciola hepatica antibody in serum of cattle. The assay was applied to sera from 258 naturally infected cattle, 256 non-infected cattle and six calves experimentally infected with F. hepatica. The diagnostic sensitivity and specificity of the ELISA test was 98% (95% confidence intervals, 96-100%) and 96% (95% confidence intervals, 93-98%) respectively at a cut-off value of 15% positivity. The results using sera from the experimentally infected calves showed that antibodies were first detected 2-4 weeks after infection. The ELISA test was also compared to the commercially available Bio-X bovine F. hepatica ELISA kit. A subset of 39 positive sera and 47 negative sera were selected from the samples used to evaluate the in-house test. The results indicated that the agreement between the two tests was almost perfect (k statistic=0.82). 相似文献