Estimated BVDV-prevalence, -contact and -vaccine use in dairy herds in Northern Portugal

Niza-Ribeiro, João; Pereira, Ana Cláudia Costa; Souza, J. A. A.; Madeira, Helena; Barbosa, Abigaíl; Afonso, Carla

doi:10.1016/j.prevetmed.2005.06.005

Cited by 11 publications

(8 citation statements)

References 3 publications

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“…Excluding herds where no vaccination history was available, herd-level prevalence was 98.7% (95% CI – 97.9-99.4%) in non-vaccinating herds. While vaccination affected individual animal prevalence in a previous study, a lack of a significant effect of vaccination on herd-level prevalence was also found in that study [32]. Herd level prevalence was only calculated in non-vaccinating herds in this study.…”

Section: Discussionsupporting

confidence: 52%

Bovine viral diarrhoea virus seroprevalence and vaccination usage in dairy and beef herds in the Republic of Ireland

et al. 2012

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BackgroundBovine viral diarrhoea (BVD) is an infectious disease of cattle with a worldwide distribution. Herd-level prevalence varies among European Union (EU) member states, and prevalence information facilitates decision-making and monitoring of progress in control and eradication programmes. The primary objective of the present study was to address significant knowledge gaps regarding herd BVD seroprevalence (based on pooled sera) and control on Irish farms, including vaccine usage.MethodsPreliminary validation of an indirect BVD antibody ELISA test (Svanova, Biotech AB, Uppsala, Sweden) using pooled sera was a novel and important aspect of the present study. Serum pools were constructed from serum samples of known seropositivity and pools were analysed using the same test in laboratory replicates. The output from this indirect ELISA was expressed as a percentage positivity (PP) value. Results were used to guide selection of a proposed cut-off (PCO) PP. This indirect ELISA was applied to randomly constructed within-herd serum pools, in a cross-sectional study of a stratified random sample of 1,171 Irish dairy and beef cow herds in 2009, for which vaccination status was determined by telephone survey. The herd-level prevalence of BVD in Ireland (percentage positive herds) was estimated in non-vaccinating herds, where herds were classified positive when herd pool result exceeded PCO PP. Vaccinated herds were excluded because of the potential impact of vaccination on herd classification status. Comparison of herd-level classification was conducted in a subset of 111 non-vaccinating dairy herds using the same ELISA on bulk milk tank (BMT) samples. Associations between possible risk factors (herd size (quartiles)) and herd-level prevalence were determined using chi-squared analysis.ResultsReceiver Operating Characteristics Analysis of replicate results in the preliminary validation study yielded an optimal cut-off PP (Proposed Cut-off percentage positivity - PCO PP) of 7.58%. This PCO PP gave a relative sensitivity (Se) and specificity (Sp) of 98.57% and 100% respectively, relative to the use of the ELISA on individual sera, and was chosen as the optimal cut-off since it resulted in maximization of the prevalence independent Youden’s Index.The herd-level BVD prevalence in non-vaccinating herds was 98.7% (95% CI - 98.3-99.5%) in the cross-sectional study with no significant difference between dairy and beef herds (98.3% vs 98.8%, respectively, p = 0.595).An agreement of 95.4% was found on Kappa analysis of herd serological classification when bulk milk and serum pool results were compared in non-vaccinating herds. 19.2 percent of farmers used BVDV vaccine; 81% of vaccinated herds were dairy. A significant association was found between seroprevalence (quartiles) and herd size (quartiles) (p < 0.01), though no association was found between herd size (quartiles) and herd-level classification based on PCO (p = 0.548).ConclusionsThe results from this study indicate that the true herd-level seroprevalence to Bovine Virus ...

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Section: Discussionsupporting

confidence: 52%

Bovine viral diarrhoea virus seroprevalence and vaccination usage in dairy and beef herds in the Republic of Ireland

et al. 2012

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“…Several BVDV control strategies have been proposed and launched in many countries based on information about prevalence, incidence and associated risk factors, which is the baseline knowledge required for designing and implementing effective regional control actions [3]. …”

Section: Introductionmentioning

confidence: 99%

What variables are important in predicting bovine viral diarrhea virus? A random forest approach

Machado

Recamonde‐Mendoza

Corbellini

2015

Vet Res

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Bovine viral diarrhea virus (BVDV) causes one of the most economically important diseases in cattle, and the virus is found worldwide. A better understanding of the disease associated factors is a crucial step towards the definition of strategies for control and eradication. In this study we trained a random forest (RF) prediction model and performed variable importance analysis to identify factors associated with BVDV occurrence. In addition, we assessed the influence of features selection on RF performance and evaluated its predictive power relative to other popular classifiers and to logistic regression. We found that RF classification model resulted in an average error rate of 32.03% for the negative class (negative for BVDV) and 36.78% for the positive class (positive for BVDV).The RF model presented area under the ROC curve equal to 0.702. Variable importance analysis revealed that important predictors of BVDV occurrence were: a) who inseminates the animals, b) number of neighboring farms that have cattle and c) rectal palpation performed routinely. Our results suggest that the use of machine learning algorithms, especially RF, is a promising methodology for the analysis of cross-sectional studies, presenting a satisfactory predictive power and the ability to identify predictors that represent potential risk factors for BVDV investigation. We examined classical predictors and found some new and hard to control practices that may lead to the spread of this disease within and among farms, mainly regarding poor or neglected reproduction management, which should be considered for disease control and eradication.Electronic supplementary materialThe online version of this article (doi:10.1186/s13567-015-0219-7) contains supplementary material, which is available to authorized users.

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“…The prevalence of BVDV in Bovine of Iran (20.48%) is higher than Argentina (1.69%) (Campero et al 2003), Greek (14%) (Billinis et al 2005) And India (17.31%%) (Sudharshana et al 1999) But is lower than Northern Portugal (35%) (Niza-Ribeiro et al 2005) and Turkey (23.07%) (Seyyal et al 2002). …”

Section: Discussionmentioning

confidence: 99%

Prevalence study of Bovine viral diarrhea virus by evaluation of antigen capture ELISA and RT-PCR assay in Bovine, Ovine, Caprine, Buffalo and Camel aborted fetuses in Iran

Dehkordi

2011

AMB Expr

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Bovine viral diarrhea virus is a pestivirus in the family Flaviviridae that cause abortions and stillbirths in livestock and its traditional diagnosis is based on cell culture and virus neutralization test. In this study, for more sensitive, specific detection and determined the prevalence of virus in aborted Bovine, Ovine, Caprine, Buffalo and Camel fetuses the antigen capture ELISA and RT-PCR were recommended. From the total of 2173 aborted fetuses, 347 (15.96%) and 402 (18.49%) were positive for presence of Bovine viral diarrhea virus by antigen capture ELISA and RT-PCR respectively. Statistical analysis of data showed significant differences between ELISA and RT-PCR for detection of virus in aborted fetuses.These results indicate a high presence of this pathogen in Iran and that RT- PCR is considerably faster and more accurate than ELISA for identification of Bovine viral diarrhea virus.To our knowledge the Camels and Bovine are the most resistant and sensitive to Bovine viral diarrhea's abortions respectively and the prevalence of virus in Caprine is more than Ovine aborted fetuses. This study is the first prevalence report of Bovine viral diarrhea virus in aborted Bovine, Ovine, Caprine, Buffalo and Camel fetuses by evaluation of ELISA and RT-PCR in Iran.

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Estimated BVDV-prevalence, -contact and -vaccine use in dairy herds in Northern Portugal

Cited by 11 publications

References 3 publications

Bovine viral diarrhoea virus seroprevalence and vaccination usage in dairy and beef herds in the Republic of Ireland

Bovine viral diarrhoea virus seroprevalence and vaccination usage in dairy and beef herds in the Republic of Ireland

What variables are important in predicting bovine viral diarrhea virus? A random forest approach

Prevalence study of Bovine viral diarrhea virus by evaluation of antigen capture ELISA and RT-PCR assay in Bovine, Ovine, Caprine, Buffalo and Camel aborted fetuses in Iran

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