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Enzyme-linked immunosorbent assay for detection of antibodies against Mycobacterium paratuberculosis in goats
1991
Molina, A. | Morera, L. | Llanes, D.
Using a heat and sonicated Mycobacteriumparatuberculosis Cordoba antigen (COA1) and the commercial protoplasmic-antigen (PPA-3) as antigens, an ELISA for detecting goat antibodies was standardized. When 2 reference populations, 1 positive (17 goats) and the other negative (63 goats) to disease, were used, this test showed 87.5% sensitivity and 93.6% specificity for COA1, and 88.2 and 95.2%, respectively for PPA-3. Absorption with M phlei was performed; no significant differences were found for COA1, but a lower sensitivity was found with PPA-3. This test was not especially affected by cross-reactivity with other mycobacterial disease because when 9 goats with M bovis infection were included in the M paratuberculosis control group, the specificity was only slightly different for absorbed (94.4%) and nonabsorbed sera (91.7%) for COA1, and (93.1 and 94.4%, respectively) for PPA-3. This test was used to study the percentage of seropositive goats for M paratuberculosis in 3 herds with different prevalences. Among 251 goats in southern Spain (Huelva), 40% were found positive for COA1, and 41% for PPA-3. Among 242 goats studied in southern Spain (Cordoba), 10.0% were positive for COA1 and 13.0% for PPA-3. In the Canary Island population of 176 goats, 3% were positive for COA1 and 0.5% for PPA-3. According to the accuracies of both positive and negative predictions, our test could be applied to populations with high prevalence to prevent additions to the herd and to cull infected animals (with 40% prevalence, the positive and negative predictive values are 90%), and to prevent adding infected animals to populations with moderate or low prevalence.
Показать больше [+] Меньше [-]Frequency and severity of osteochondrosis in horses with cervical stenotic myelopathy
1991
Stewart, R.H. | Reed, S.M. | Weisbrode, S.E.
We compared the frequency and severity of osteochondrosis lesions in young Thoroughbred horses with cervical stenotic myelopathy (CSM) vs that in clinically normal Thoroughbreds of the same age. All lesions of the cervical vertebrae and appendicular skeleton were classifiedhistologically as osteochondrosis or nonosteochondrosis and were measured for severity. Minimal sagittal diameter was significantly smaller in horses with CSM from C2 through C6; no difference was detected at C7. Severity of cervical vertebral osteochondrosis was greater in the horses with CSM, however frequency was not different. Frequency and severity of nonosteochondrosis lesions were not different in cervical vertebrae or appendicular skeleton. Frequency and severity of appendicular skeleton osteochondrosis lesions were both greater in horses with CSM. Osteochondrosis and nonosteochondrosis lesions were more severe on facets at sites of compression than on facets at noncompressed sites in horses with CSM. However, compression was also observed at sites with no articular facet lesions. The association of widespread osteochondrosis and spinal canal narrowing with CSM suggests CSM may represent a systemic failure in the development or maturation of cartilage and bone.
Показать больше [+] Меньше [-]Fasciola and Paramphistomum infections in small ruminants (sheep and goat) in Terengganu
2017
Mursyidah A. K. | Khadijah S. | Rita N.
A study was conducted to identify the current status of Fasciolaand Paramphistomum infections in small ruminants in Terengganu. A total of 267 faecal samples from small ruminants were collected and subjected to sedimentation technique. Serum samples were diagnosed for detection of IgG antibody for Fasciola infection using sELISA method. Results showed that there were 4% of the goats positive with Paramphistomum eggs whereas Fasciola egg was not observed in any of the faecal samples. However, it was found that 89% of the serum samples from goats were positive with IgG antibody for Fasciola infection. Small ruminants in Terengganu were not infected with severe Fasciola and Paramphistomum infections yet the results obtained from this study will update the current status of the infections. This information will help the farmers and the Department of Veterinary Services to plan on management to maintain the animals’ health.
Показать больше [+] Меньше [-]Antigen detection of foot-and-mouth disease and serotypes from samples submitted to the Regional Veterinary Laboratory Kota Bharu from 2012 to 2016
2017
Zubaidah M. A. | Tariq J. | Mohd Daud Z. | Mahazan M. S.
In Peninsular Malaysia, footand-mouth disease (FMD) has been reported since early 1860 which then became sporadic, causing outbreaks every year. Since then, Peninsular Malaysia has become endemic with FMD. The aim of this study is to provide findings of the current FMD occurrence and its serotyping in Peninsular Malaysia. An identification of Foot and Mouth Disease serotype was carried out in Peninsular Malaysia by the Regional Veterinary Laboratory Kota Bharu (RVLKB) only. Epithelial tissue samples were received from 10 states throughout Peninsular Malaysia from 2012 until 2016. Indirect sandwich ELISA was performed using ELISA kit for FMDV antigen detection supplied from the Institute for Animal Health, Pirbright Laboratory. All findings and results in this paper were based on samples received by RVLKB and does not reflect overall cases reported to State DVS or to DVS Malaysia. From the results, 2013 had the highest samples positive for FMDV (35% from 43 samples), followed by 2014 (31% from 80 samples), 2012 (24% from 122 samples), 2015 (21% from 39 samples) and the lowest is 2016 (17% from 194 samples). The FMDV serotypes detected throughout 2012 to 2016 from 110 positive samples were Serotype O (80%), followed by Serotype A (20%) and none from Serotype Asia 1. Strict regulation, FMD vaccine evaluation by LPB ELISA and strict animal movement shall be considered to achieve FMD free for upcoming Year 2020.
Показать больше [+] Меньше [-]Ignorance as a factor influencing the prevalence of onchocerciasis in some villages in Oyo State, Nigeria
2017
Akinboade, O. A. | Anong, C. I. N. | Uwalaka, E. C.
Most studies on Simulum damnosum in Nigeria has focused mainly on the problem of onchocerciasis from the ecological standpoint. However, this study is aimed at viewing it from the human angle, with focus placed on the ignorance of the rural dwellers about the influences of their environment on the increasing incidences of onchocerciasis in their population. The premise is that, as the government and the scientists are working towards finding a lasting solution to the epidemic, the rural dwellers need to wake up to the realities of their own destiny. They need to come out and collaborate with other good efforts to form a strong united force that will rid their society of this menace. A study on the level of ignorance was carried out. It is assumed that their ignorance has kept the villagers relatively inactive and passive about freeing themselves. A descriptive method was used for this research and about 450 villagers were randomly selected and verbally interviewed. A questionnaire was designed and used as the instrument of the research. The research was carried out in two different villages of Asejire and Asepari. Findings were encouraging. Some of the villagers did not know about the existence of the disease even when some of their close relatives showed the symptoms. This high level of ignorance shows that it will be difficult to attain any cooperation from them in any attempt to make their environment unfavourable for the vector.
Показать больше [+] Меньше [-]Seroprevalence of Mycoplasma suis infection in pigs in eastern China as estimated by a blocking enzyme-linked immunosorbent assay
2017
Zhongyang, Liang | Jiansong, Zhang | Yijuan, Shen | Yuting, Xia | Yufeng, Li | Jiarong, Xu
Porcine infectious anemia caused by Mycoplasma suis is a global disease and results in serious economic losses. To determine the prevalence of M. suis infection in eastern China, a cross-sectional serologic study was conducted with 3458 porcine serum samples randomly obtained from January 2014 to August 2016. The samples were tested with a blocking enzyme-linked immunosorbent assay developed in our laboratory. The seroprevalence was 33.3% in the complete sample set and was 25.9%, 37.8%, and 37.8% in 2014, 2015, and 2016, respectively. The seroprevalence was distinctly higher in summer (39.9%) and autumn (42.0%) than in spring (28.9%) and winter (23.3%). Shanghai was the region with the highest seroprevalence (54.2%) and Jiangsu the region with the lowest (23.0%). The seroprevalence was markedly higher in boars (47.1%), multiparous sows (47.0%), and replacement gilts (39.2%) than in piglets (24.2%), fattening pigs (17.2%), and nursery pigs (12.5%). These data demonstrate that the prevalence of M. suis infection is increasing yearly in eastern China.
Показать больше [+] Меньше [-]Evaluation of an alternative method of herd classification for infection with paratuberculosis in cattle herds in the United States
2012
Tavornpanich, Saraya | Wells, Scott J. | Fossler, Charles P. | Roussel, Allen J. | Gardner, Ian A.
Objective: To develop a better system for classification of herd infection status for paratuberculosis (Johne's disease [JD]) in US cattle herds on the basis of the risk of potential transmission of Mycobacterium avium subsp paratubeculosis. Sample: Simulated data for herd size and within-herd prevalence; sensitivity and specificity for test methods obtained from consensus-based estimates. Procedures: Interrelationships among variables influencing interpretation and classification of herd infection status for JD were evaluated by use of simulated data for various herd sizes, true within-herd prevalences, and sampling and testing methods. The probability of finding ≥ 1 infected animal in herds was estimated for various testing methods and sample sizes by use of hypergeometric random sampling. Results: 2 main components were required for the new herd JD classification system: the probability of detection of infection determined on the basis of test results from a sample of animals and the maximum detected number of animals with positive test results. Tables were constructed of the estimated probability of detection of infection, and the maximum number of cattle with positive test results or fecal pools with positive culture results with 95% confidence for classification of herd JD infection status were plotted. Herd risk for JD was categorized on the basis of 95% confidence that the true within-herd prevalence was ≤ 15%, ≤ 10%, ≤ 5%, or ≤ 2%. Conclusions and Clinical Relevance: Analysis of the findings indicated that a scientifically rigorous and transparent herd classification system for JD in cattle is feasible.
Показать больше [+] Меньше [-]Effect of intensity of fecal pat sampling on estimates of Escherichia coli O157 prevalence
2005
Echeverry, A. | Loneragan, G.H. | Wagner, B.A. | Brashears, M.M.
To evaluate site-to-site variation within fecal pats from cattle with regard to detection of Escherichia coli O157 and determine the effect on the accuracy of prevalence estimates of assay of multiple samples collected from the same fecal pat. 120 freshly voided fecal pats collected from 2 beef feedlots. Procedures-5 samples were systematically collected from each fecal pat and analyzed for E coli O157 via selective preenrichment techniques, immunomagnetic separation, and biochemical tests. Presumptive isolates were definitively identified via agglutination assays and polymerase chain reaction techniques. Best estimators of prevalence were calculated from the distribution of E coli O157-positive samples per pat. Of the 120 fecal pats, 96, 13, 4, 2, 3, and 2 fecal pats had 0, 1, 2, 3, 4, and 5 E coli O157-positive samples, respectively. The greatest estimate of E coli O157 prevalence (20%) was achieved when all 5 samples were assessed; this estimate represented a 2.4- fold increase in prevalence, compared with that provided via analysis of 1 sample/pat (8.2%). Compared with assessment of 5 sites/pat, the relative sensitivity of detecting an E coli O157-positive fecal pat via analysis of 1 site/pat was 40.1%. Results suggest that estimates of E coli O157 prevalence derived from sampling of 1 location/pat are likely underestimates of the true prevalence of this pathogen in fecal pats (and by extension, cattle). Additional research is warranted to confirm these results in situations of high and low prevalence and across different feedlots.
Показать больше [+] Меньше [-]Seroepidemiologic survey of Borrelia burgdorferi exposure of dairy cattle in Wisconsin
1994
Ji, B. | Collins, M.T.
An ELISA, using purified flagellin of Borrelia burgdorferi as the solid-phase antigen, was used to measure antibody concentrations to B burgdorferi in dairy cattle in Wisconsin. Serum obtained from 5,060 cows in 160 randomly selected herds in the state were tested. Serum from an additional 2,600 cattle in Barron County, Wis, a county with a high annual incidence of B burgdorferi infections in human beings, was also tested. Only 7% of the cows that were tested, but 66% of the herds that were tested, were seropositive for B burgdorferi. Sixteen percent of the herds had a prevalence of 15% seropositive cows, whereas 50% of the herds had a prevalence of 1 to 14% seropositive cows. Seropositive herds were concentrated in the west-central part of Wisconsin. An association existed between the geographic location of seropositive herds and counties in which B burgdorferi infection of human beings was acquired (P < 0.05) as well as the geographic location of seropositive herds and the geographic distribution of Ixodes scapularis (P < 0.05). Barron County, in which B burgdorferi infection is endemic, had a significantly (P < 0.05) higher percentage of seropositive cows (17%) than did the state of Wisconsin (7%).
Показать больше [+] Меньше [-]Predicting the number of herds infected with pseudorabies virus in the United States
1994
Miller, G.Y. | Forster, D.L. | Tsai, J. | Bech-Nielsen, S.
Epidemiologic modeling of the likely herd-to-herd transmission of pseudorabies virus (PRV) was developed to assess the progress and potential for the PRV-eradication program in the United States. The herd-to-herd transmission of PRV over a 20-year period (1993 to 2012) in the United States was simulated under various scenarios, which included variable program-funding levels and variable prevalences. A transition model (Markov process model) was used to predict yearly changes in herd prevalence of PRV infection. Five mutually exclusive states of nature for herds were assumed: uninfected and not vaccinated; uninfected and vaccinated; known to be infected and not vaccinated; known to be infected and vaccinated; and infected, but not known to be infected. Three prevalences for states in the United States were assumed: higher prevalence, moderate prevalence, and lower prevalence. Three funding levels were assumed: no eradication program, continued funding at the current level, and increased funding of 25%. Estimates made by an expert panel for determining probabilities in the state-transition matrices were used. A model also was developed, and was considered to be the most optimistic scenario likely under increased funding of 25%. The most optimistic estimates of the probabilities that still lay within the range of estimates made by the expert panel were used for this model. Only the optimistic transmission matrices allowed for total eradication of PRV. Using the optimistic matrices, all states in the United States of America had moved into the moderate- or low-level risk status by the year 2000. The longest time taken to achieve eradication was for the state of Iowa, where eradication was not achieved until 2012.
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