1
|
Nielsen LR, Houe H, Nielsen SS. Narrative Review Comparing Principles and Instruments Used in Three Active Surveillance and Control Programmes for Non-EU-regulated Diseases in the Danish Cattle Population. Front Vet Sci 2021; 8:685857. [PMID: 34350228 PMCID: PMC8326568 DOI: 10.3389/fvets.2021.685857] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/24/2021] [Indexed: 11/30/2022] Open
Abstract
The objective of this paper is to provide a comparative review of three active surveillance and control programmes in the Danish cattle sector to highlight important differences for decision makers to develop successful programmes. The focus is on differences in purpose, principles, design and instruments applied to achieve the goals stated for each programme for bovine viral diarrhoea (BVDV), paratuberculosis and Salmonella Dublin. The purposes of the programmes are to reduce economic consequences and improve animal welfare, and for S. Dublin also to prevent zoonotic risk, with varying importance as motivation for the programmes over time. The targets of the BVDV and S. Dublin programmes have been to eradicate the diseases from the Danish cattle population. This goal was successfully reached for BVDV in 2006 where the programme was changed to a surveillance programme after 12 years with an active control programme. The S. Dublin dairy herd-level prevalence decreased from 25% in 2003 to 6% in 2015, just before the milk quota system was abandoned. Over the last 5 years, the prevalence has increased to 8–9% test-positive dairy herds. It is mandatory to participate, and frequent updates of legislative orders were used over two decades as critical instruments in those two programmes. In contrast, participation in the paratuberculosis programme is voluntary and the goals are to promote participation and reduce the prevalence and economic and welfare consequences of the disease. The daily administration of all three programmes is carried out by the major farmers' organisation, who organise surveillance, IT-solutions and other control tools, projects and communication in collaboration with researchers from the universities, laboratories and, for BVDV and S. Dublin, the veterinary authorities. Differences among the programme designs and instruments are mainly due to the environmental component of paratuberculosis and S. Dublin, as the bacteria able to survive for extended periods outside the host. This extra diffuse source of infection increases the demand for persistent and daily hygiene and management efforts. The lower test sensitivities (than for BVDV) lead to a requirement to perform repeated testing of herds and animals over longer time periods calling for withstanding motivation among farmers.
Collapse
Affiliation(s)
- Liza Rosenbaum Nielsen
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Hans Houe
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Søren Saxmose Nielsen
- Section for Animal Welfare and Disease Control, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| |
Collapse
|
2
|
Mechanisms linking bovine viral diarrhea virus (BVDV) infection with infertility in cattle. Anim Health Res Rev 2019; 20:72-85. [PMID: 31895016 DOI: 10.1017/s1466252319000057] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Bovine viral diarrhea virus (BVDV) is an important infectious disease agent that causes significant reproductive and economic losses in the cattle industry worldwide. Although BVDV infection is known to cause poor fertility in cattle, a greater part of the underlying mechanisms particularly associated with early reproductive losses are not clearly understood. Previous studies reported viral compromise of reproductive function in infected bulls. In females, BVDV infection is thought to be capable of killing the oocyte, embryo or fetus directly, or to induce lesions that result in fetal abortion or malformation. BVDV infections may also induce immune dysfunction, and predispose cattle to other diseases that cause poor health and fertility. Other reports also suggested BVDV-induced disruption of the reproductive endocrine system, and a disruption of leukocyte and cytokine functions in the reproductive organs. More recent studies have provided evidence of viral-induced suppression of endometrial innate immunity that may predispose to uterine disease. Furthermore, there is new evidence that BVDV may potentially disrupt the maternal recognition of pregnancy or the immune protection of the conceptus. This review brings together the previous reports with the more recent findings, and attempts to explain some of the mechanisms linking this important virus to infertility in cattle.
Collapse
|
3
|
Effect of Bovine Viral Diarrhea Virus on the ovarian functionality and in vitro reproductive performance of persistently infected heifers. Vet Microbiol 2013; 165:326-32. [DOI: 10.1016/j.vetmic.2013.04.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/27/2013] [Accepted: 04/07/2013] [Indexed: 11/21/2022]
|
4
|
Galuppo AG, Junior NB, Arruda NS, Corbellini AO, Chiappetta CM, Pavão DL, D'Angelo M, Canal CW, Rodrigues JL. Evaluation of the effectiveness of semen processing techniques to remove bovine viral diarrhea virus from experimentally contaminated semen samples. J Virol Methods 2012; 187:443-8. [PMID: 23219984 DOI: 10.1016/j.jviromet.2012.11.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 11/20/2012] [Accepted: 11/21/2012] [Indexed: 11/16/2022]
Abstract
The aim of this study was to evaluate the capacity of three semen processing techniques, Percoll gradient centrifugation, Swim-up and a combination of Swim-up and Percoll gradient centrifugation, to reduce the viral load of bovine viral diarrhea virus (BVDV) in experimentally infected semen samples. The evaluation was performed using two approaches: first, searching for the presence of virus in the processed samples (via virus titration and RT-PCR) and second, ascertaining the possible interference on in vitro embryo production. The sperm count and DNA integrity (Comet assay) of the processed samples were analyzed (Experiment 1). The amount of virus in the processed samples was determined by titration in cell culture (Experiment 2). The samples processed by Swim up/Percoll gradient centrifugation were utilized for in vitro embryo production, and the embryos produced were tested for BVDV by RT-PCR (Experiment 3). Sperm concentration, Comet assay and embryo production were analyzed by chi-squared tests (P<0.05). There was a significant difference between sperm separation techniques when the sperm count and Comet assay were analyzed. The sperm count obtained from the Swim up/Percoll gradient centrifugation group was lower than that obtained in either of the two other groups (Swim up and Percoll gradient centrifugation), and the Comet assay showed that the combination of the two semen processing techniques (Swim up/Percoll gradient) produced a 1.1% prevalence of Comet level 2, which was not observed in the other groups. The BVDV titer (10(6.68)TCID(50)/mL) added to experimentally infected semen samples decreased after Percoll gradient centrifugation to 10(2.3)-10(1)TCID(50)/mL; for the Swim up group, the titer range was 10(3.3)-10(1.87)TCID(50)/mL, and in the Swim up/Percoll gradient centrifugation group, BVDV was undetectable. The decreases in titer varied from 99.9% in the Swim up-processed group to 100% in the Swim up/Percoll gradient centrifugation group. In vitro embryo production displayed similar blastocyst development rates among all groups, and RT-PCR was negative for the produced embryos. The data showed that the combination of Swim up/Percoll gradient centrifugation promoted the elimination of BVDV from the semen samples without damaging spermatozoa cells and also allowed successful in vitro embryo production free of BVDV. Hence, the risk of BVDV contamination is negligible for the embryo recipient.
Collapse
Affiliation(s)
- Andrea G Galuppo
- Laboratory of Embryology and Reproductive Biotechniques-FAVET-UFRGS, Porto Alegre (RS), Brazil.
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Negrón ME, Pogranichniy RM, Van Alstine W, Hilton WM, Lévy M, Raizman EA. Evaluation of horizontal transmission of bovine viral diarrhea virus type 1a from experimentally infected white-tailed deer fawns (Odocoileus virginianus) to colostrum-deprived calves. Am J Vet Res 2012; 73:257-62. [DOI: 10.2460/ajvr.73.2.257] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
6
|
Newcomer BW, Marley MS, Galik PK, Walz PH, Zhang Y, Riddell KP, Dykstra CC, Boykin DW, Kumar A, Cruz-Espindola C, Boothe DM, Joiner KS, Givens MD. Antiviral treatment of calves persistently infected with bovine viral diarrhoea virus. Antivir Chem Chemother 2012; 22:171-9. [PMID: 22182713 DOI: 10.3851/imp1903] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2011] [Indexed: 10/17/2022] Open
Abstract
BACKGROUND Animals persistently infected (PI) with bovine viral diarrhoea virus (BVDV) are a key source of viral propagation within and among herds. Currently, no specific therapy exists to treat PI animals. The purpose of this research was to initiate evaluation of the pharmacokinetic and safety data of a novel antiviral agent in BVDV-free calves and to assess the antiviral efficacy of the same agent in PI calves. METHODS One BVDV-free calf was treated with 2-(2-benzimidazolyl)-5-[4-(2-imidazolino)phenyl]furan dihydrochloride (DB772) once at a dose of 1.6 mg/kg intravenously and one BVDV-free calf was treated three times a day for 6 days at 9.5 mg/kg intravenously. Subsequently, four PI calves were treated intravenously with 12 mg/kg DB772 three times a day for 6 days and two PI control calves were treated with an equivalent volume of diluent only. RESULTS Prior to antiviral treatment, the virus isolated from each calf was susceptible to DB772 in vitro. The antiviral treatment effectively inhibited virus for 14 days in one calf and at least 3 days in three calves. Subsequent virus isolated from the three calves was resistant to DB772 in vitro. No adverse effects of DB772 administration were detected. CONCLUSIONS Results demonstrate that DB772 administration is safe and exhibits antiviral properties in PI calves while facilitating the rapid development of viral resistance to this novel therapeutic agent.
Collapse
Affiliation(s)
- Benjamin W Newcomer
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Barrett DJ, More SJ, Graham DA, O'Flaherty J, Doherty ML, Gunn HM. Considerations on BVD eradication for the Irish livestock industry. Ir Vet J 2011; 64:12. [PMID: 21967764 PMCID: PMC3199273 DOI: 10.1186/2046-0481-64-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 10/03/2011] [Indexed: 11/21/2022] Open
Abstract
Animal Health Ireland has produced clear guidelines for the control of Bovine Viral Diarrhoea (BVD) infection in Irish cattle herds. In the course of developing these guidelines it was clear that a framework for regional and/or national BVD control would be required to increase the uptake of BVD control at farm level and reduce the overall prevalence of the disease. This paper assessed the economic impact of BVD, epidemiological aspects of the disease to its control, models of BVD control, international experiences of BVD control programmes. The technical knowledge and test technology exists to eradicate BVD. Indeed, many countries have successfully and others are embarking on control of the disease. The identification and prompt elimination of PI cattle will form the basis of any control programme. The trade of such animals must be curtailed. Pregnant and potentially pregnant carrying PI foetuses pose a significant threat. International experience indicates systematic, well coordinated programmes have the most success, while voluntary programmes can make good initial progress but ultimately fail. The farming community must buy into any proposed programme, and without their support, failure is likely. To buy into the programme and create such a demand for BVD control, farmers must first be well informed. It is likely that stemming economic loss and improving productivity will be the primary motivator at individual farm level.
Collapse
Affiliation(s)
- Damien J Barrett
- Dept Agriculture, Fisheries and Food, Sligo Regional Veterinary Laboratory, Doonally, Sligo, Ireland.
| | | | | | | | | | | |
Collapse
|
8
|
Studies on BVD involving establishment of sentinel calves and assessment of herd immunity in a large dairy farm in Saudi Arabia. Trop Anim Health Prod 2011; 44:413-7. [PMID: 21667324 DOI: 10.1007/s11250-011-9912-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2011] [Indexed: 10/18/2022]
Abstract
Little information is published, so far, regarding bovine viral diarrhea (BVD) in Saudi Arabia and the Gulf region. This study is the first of its kind in the country. Its aim was to explore the BVD situation in a large dairy farm, which has been experiencing reproduction problems suggestive of BVD virus infection, albeit the practice of routine vaccination. The study took two pathways; the first involved establishment of a cohort of sentinel calves so as: (a) to note the BVD virus activity in the farm by following the time lapse and pattern for waning of the maternally derived antibodies and detection of any subsequent seroconversion and (b) to look for any clinical signs suggestive of BVD virus infection in these calves. The second pathway was to assess the level of herd immunity in the different age groups of lactating cows and maiden heifers. The obtained results were discussed, and control strategies were outlined.
Collapse
|
9
|
Nickell JS, White BJ, Larson RL, Renter DG, Sanderson MW. A Simulation Model to Quantify the Value of Implementing Whole-Herd Bovine Viral Diarrhea Virus Testing Strategies in Beef Cow–Calf Herds. J Vet Diagn Invest 2011; 23:194-205. [DOI: 10.1177/104063871102300202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Although numerous diagnostic tests are available to identify cattle persistently infected (PI) with Bovine viral diarrhea virus (BVDV) in cow–calf herds, data are sparse when evaluating the economic viability of individual tests or diagnostic strategies. Multiple factors influence BVDV testing in determining if testing should be performed and which strategy to use. A stochastic model was constructed to estimate the value of implementing various whole-herd BVDV cow–calf testing protocols. Three common BVDV tests (immunohistochemistry, antigen-capture enzyme-linked immunosorbent assay, and polymerase chain reaction) performed on skin tissue were evaluated as single- or two-test strategies. The estimated testing value was calculated for each strategy at 3 herd sizes that reflect typical farm sizes in the United States (50, 100, and 500 cows) and 3 probabilities of BVDV-positive herd status (0.077, 0.19, 0.47) based upon the literature. The economic value of testing was the difference in estimated gross revenue between simulated cow–calf herds that either did or did not apply the specific testing strategy. Beneficial economic outcomes were more frequently observed when the probability of a herd being BVDV positive was 0.47. Although the relative value ranking of many testing strategies varied by each scenario, the two-test strategy composed of immunohistochemistry had the highest estimated value in all but one herd size–herd prevalence permutation. These data indicate that the estimated value of applying BVDV whole-herd testing strategies is influenced by the selected strategy, herd size, and the probability of herd BVDV-positive status; therefore, these factors should be considered when designing optimum testing strategies for cow–calf herds.
Collapse
Affiliation(s)
- Jason S. Nickell
- Departments of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS
| | - Brad J. White
- Clinical Sciences, Kansas State University, Manhattan, KS
| | | | - David G. Renter
- Departments of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS
| | | |
Collapse
|
10
|
Arenhart S, Bauermann FV, Oliveira SA, Weiblen R, Flores EF. Excreção e transmissão do vírus da diarréia viral bovina por bezerros persistentemente infectados. PESQUISA VETERINARIA BRASILEIRA 2009. [DOI: 10.1590/s0100-736x2009000900010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bezerros persistentemente infectados (PI) nascidos de vacas infectadas com amostras não-citopáticas do vírus da diarréia viral bovina (BVDV) se constituem nos principais reservatórios do vírus na natureza. Este trabalho relata uma investigação do padrão de excreção e transmissão viral por cinco bezerros PI produzidos experimentalmente pela inoculação de vacas prenhes com isolados brasileiros do BVDV. Cinco bezerros que sobreviveram a infecção intrauterina nasceram saudáveis, soronegativos e com a presença de vírus no sangue. Após o desmame - e desaparecimento dos anticorpos colostrais - os bezerros PI foram monitorados semanalmente durante 150 dias para a presença de vírus e títulos virais no soro e em secreções (ocular, oral, nasal e genital). Os títulos virais no soro de cada animal apresentaram pequenas variações durante o período (com exceção de um animal que apresentou um aumento de título tardiamente), mas os títulos variaram amplamente entre os animais (entre 10² e 10(6)TCID50/ml). O vírus também foi excretado continuamente nas secreções de todos os animais, com pequenas variações de título entre as coletas. Os maiores títulos virais foram geralmente detectados nas secreções nasais e oculares (títulos de 10(4) a 10(6)TCID50/mL), enquanto as secreções orais e genitais usualmente continham títulos virais baixos (10² a 10³TCID50/mL). Com o objetivo de avaliar a dinâmica de transmissão viral, um bezerro PI foi introduzido em um grupo de 10 bezerros soronegativos, mantido com uma alta densidade animal e submetido a manejo diário para simular as condições de manejo semi-intensivo. Após 30 dias de convívio com o bezerro PI, todos os demais animais haviam soroconvertido ao BVDV. Para investigar a transmissão viral sob condições extensivas, outro bezerro PI foi incorporado a um rebanho de 48 animais mantido a campo, com baixa densidade animal e submetido a manejo extensivo. Dentre estes animais, 8/48 (16,6%) foram soropositivos para anticorpos no dia 10, 26/48 (54,1%) no dia 40 e 37/48 (77%) haviam soroconvertido no dia 100, quando encerrou-se o monitoramento. Estes resultados demonstram que a viremia e excreção viral contínua em altos títulos por animais PI assegura a transmissão rápida do BVDV a animais mantidos em contato, sendo a transmissão notadamente mais rápida em condições intensivas e de alta densidade animal.
Collapse
|
11
|
|
12
|
Arenhart S, Silva LFD, Henzel A, Ferreira R, Weiblen R, Flores EF. Proteção fetal contra o vírus da diarréia viral bovina (BVDV) em vacas prenhes previamente imunizadas com uma vacina experimental atenuada. PESQUISA VETERINARIA BRASILEIRA 2008. [DOI: 10.1590/s0100-736x2008001000004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Esse artigo relata a avaliação da resposta sorológica e proteção fetal conferida por uma vacina experimental contendo duas amostras atenuadas do vírus da diarréia viral bovina tipos 1 (BVDV-1) e 2 (BVDV-2). Vacas foram imunizadas com a vacina experimental (n=19) e juntamente com controles não-vacinadas (n=18) foram colocadas em cobertura e desafiadas, entre os dias 60 e 90 de gestação, pela inoculação intranasal de quatro amostras heterólogas de BVDV-1 e BVDV-2. A resposta sorológica foi avaliada por testes de soro-neutralização realizados a diferentes intervalos após a vacinação (dias 34, 78 e 138 pós-vacinação [pv]). A proteção fetal foi monitorada por exames ultra-sonográficos e clínicos realizados durante o restante da gestação; e pela pesquisa de vírus e anticorpos no sangue pré-colostral coletado dos fetos abortados e/ou dos bezerros recém nascidos. No dia do desafio (dia 138 pv), todas as vacas vacinadas apresentavam anticorpos neutralizantes em títulos altos contra o BVDV-1 (1.280- >10.240) e, com exceção de uma vaca (título 20), todas apresentavam títulos médios a altos contra o BVDV-2 (80-1.280). O monitoramento da gestação revelou que, dentre as 18 vacas não-vacinadas, apenas três (16,6%) pariram bezerros saudáveis e livres de vírus. As 15 restantes (83,3%) apresentaram indicativos de infecção fetal e/ou falhas reprodutivas. Sete dessas vacas (38,8%) pariram bezerros positivos para o vírus, sendo que cinco eram saudáveis e sobreviveram (27,7%); e dois apresentavam sinais de prematuridade ou fraqueza e morreram três e 15 dias após o nascimento, respectivamente. As oito vacas controle restantes (44,4%) abortaram entre o dia 30 pós-desafio e às proximidades do parto, ou deram à luz bezerros prematuros, inviáveis ou natimortos. Por outro lado, 17 de 19 (89,4%) vacas vacinadas deram à luz bezerros saudáveis e livres de vírus. Uma vaca vacinada abortou 130 dias pós-desafio, mas o produto não pôde ser examinado para a presença de vírus. Outra vaca vacinada pariu um bezerro positivo para o vírus (5,2%). Em resumo, a vacina experimental induziu títulos adequados de anticorpos na maioria dos animais; e a resposta imunológica induzida pela vacinação foi capaz de conferir proteção fetal e prevenir as perdas reprodutivas frente ao desafio com um pool de amostras heterólogas de BVDV. Assim, essa vacina experimental pode representar uma boa alternativa para a redução das perdas reprodutivas associadas com a infecção pelo BVDV.
Collapse
|
13
|
Elam NA, Thomson DU, Gleghorn JF. Effects of long- or short-term exposure to a calf identified as persistently infected with bovine viral diarrhea virus on feedlot performance of freshly weaned, transport-stressed beef heifers. J Anim Sci 2008; 86:1917-24. [PMID: 18344295 DOI: 10.2527/jas.2007-0535] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A single experiment with a completely randomized design was conducted to evaluate the effects of long- or short-term exposure to a calf identified as persistently infected with bovine viral diarrhea virus (PI-BVD) on feedlot performance and carcass characteristics of freshly weaned, transport-stressed beef heifers. Two hundred eighty-eight heifers that had been vaccinated for BVD before weaning and transport were processed and given a metaphylactic antibiotic treatment at arrival and were fed common receiving, growing, and finishing diets for a 215-d period. Treatments were designed to directly or adjacently expose the cattle to a PI-BVD heifer. Directly exposed treatments were 1) negative control with no PI-BVD calf exposure (control), 2) PI-BVD calf commingled in the pen for 60 h and then removed (short-term exposure), and 3) PI-BVD calf commingled in the pen for the duration of the study (long-term exposure); and spatially exposed treatments were 1) negative control with no PI-BVD calf exposure (adjacent pen control), 2) PI-BVD calf commingled in the adjacent pen for 60 h and then removed (adjacent pen short-term exposure), and 3) PI-BVD calf commingled in the adjacent pen for the duration of the study (adjacent pen long-term exposure). Exposure to a PI calf transiently (60 h) or for the duration of the feeding period (215 d) did not affect (P > or = 0.25) final BW compared with heifers that were not exposed. Neither period nor overall DMI was affected (P > or = 0.37) by PI-BVD calf exposure, and no differences (P > or = 0.44) were observed between short- and long-term exposed heifers in the direct or spatially exposed groups. Likewise, total trial ADG was not affected (P > or = 0.36) and overall efficiency of gain (P > or = 0.19) was unaffected by PI-BVD calf exposure in the direct or spatially exposed groups. The results from this study suggest that exposing previously vaccinated, freshly weaned, transport- stressed beef calves to a calf that is persistently infected with bovine viral diarrhea virus has little, if any, marked effects on health, performance, or carcass characteristics.
Collapse
Affiliation(s)
- N A Elam
- New Mexico State University Clayton Livestock Research Center, Clayton 88415, USA.
| | | | | |
Collapse
|
14
|
Uttenthal A, Hoyer MJ, Grøndahl C, Houe H, van Maanen C, Rasmussen TB, Larsen LE. Vertical transmission of bovine viral diarrhoea virus (BVDV) in mousedeer (Tragulus javanicus) and spread to domestic cattle. Arch Virol 2006; 151:2377-87. [PMID: 16835699 DOI: 10.1007/s00705-006-0818-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2006] [Accepted: 06/07/2006] [Indexed: 11/25/2022]
Abstract
This study investigates the transmission of bovine viral diarrhoea virus (BVDV) 1f from a persistently infected (PI) lesser Malayan mousedeer to two bovine calves. Different contact routes to two calves were analysed: 1) aerosol contact between two adjacent pens without physical contact; 2) indirect contact by use of common utensils; 3) direct nose-to-nose contact for 30 seconds. One of the calves was infected either by aerosol or indirect contact. The virus sequence in 247 nucleotides in the 5'-UTR was 100% identical in mousedeer and calf. To elucidate the distribution of BVDV within the affected mousedeer family the captive population in a Zoo was analysed. The maternal line of PI animals was maintained, whereas a PI male was able to reproduce and have a non-PI calf. As a consequence of this, six female PI mousedeer were killed; subsequent autopsies did not reveal any lesions. Sequencing mousedeer BVD virus in the E2 region (420 nucleotides) through 4 generations showed only 7 mutations, which were maintained from mother to offspring.
Collapse
Affiliation(s)
- A Uttenthal
- Department of Virology, Danish Institute for Food and Veterinary Research, Lindholm, Kalvehave, Denmark.
| | | | | | | | | | | | | |
Collapse
|
15
|
Fulton RW, Hessman B, Johnson BJ, Ridpath JF, Saliki JT, Burge LJ, Sjeklocha D, Confer AW, Funk RA, Payton ME. Evaluation of diagnostic tests used for detection of bovine viral diarrhea virus and prevalence of subtypes 1a, 1b, and 2a in persistently infected cattle entering a feedlot. J Am Vet Med Assoc 2006; 228:578-84. [PMID: 16478438 DOI: 10.2460/javma.228.4.578] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate diagnostic tests used for detection of bovine viral diarrhea virus (BVDV) and determine the prevalence of BVDV subtypes 1a, 1b, and 2a in persistently infected (PI) cattle entering a feedlot. DESIGN Prospective study. ANIMALS 21,743 calves. PROCEDURES Samples were obtained from calves initially testing positive via antigen capture ELISA (ACE) performed on fresh skin (ear notch) specimens, and ACE was repeated. Additionally, immunohistochemistry (IHC) was performed on skin specimens fixed in neutral-buffered 10% formalin, and reverse transcriptase PCR (RT-PCR) assay and virus isolation were performed on serum samples. Virus was subtyped via sequencing of the 5' untranslated region of the viral genome. RESULTS Initial ACE results were positive for BVDV in 88 calves. After subsequent testing, results of ACE, IHC, RT-PCR assay, and viral isolation were positive in 86 of 88 calves; results of all subsequent tests were negative in 2 calves. Those 2 calves had false-positive test results. On the basis of IHC results, 86 of 21,743 calves were PI with BVDV, resulting in a prevalence of 0.4%. Distribution of BVDV subtypes was BVDV1b (77.9%), BVDV1a (11.6%), and BVDV2a (10.5%). CONCLUSIONS AND CLINICAL RELEVANCE Rapid tests such as ACE permit identification and segregation of PI cattle pending results of further tests, thus reducing their contact with the rest of the feedlot population. Although vaccines with BVDV1a and 2a components are given to cattle entering feedlots, these vaccines may not provide adequate protection against BVDV1b.
Collapse
Affiliation(s)
- Robert W Fulton
- Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK 74078, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Givens MD, Stringfellow DA, Riddell KP, Galik PK, Carson RL, Riddell MG, Navarre CB. Normal calves produced after transfer of in vitro fertilized embryos cultured with an antiviral compound. Theriogenology 2006; 65:344-55. [PMID: 15955552 DOI: 10.1016/j.theriogenology.2005.04.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Accepted: 04/13/2005] [Indexed: 10/25/2022]
Abstract
Bovine viral diarrhea virus (BVDV) replicates in embryo co-culture systems and remains associated with developing IVF bovine embryos, despite washing and trypsin treatment. Previous research demonstrated that 2-(4-[2-imidazolinyl]phenyl)-5-(4-methoxyphenyl)furan (DB606) inhibits replication of BVDV in cultured cells. The objective of this study was to evaluate the capability of IVF embryos to develop into normal, weaned calves after exposure to antiviral concentrations of DB606 during IVC. Oocytes were obtained from cows via transvaginal, ultrasound-guided follicular aspiration. Presumptive zygotes (n = 849) that resulted from fertilization of these oocytes were cultured for 7 d in medium supplemented with 0.4 microM DB606 or medium lacking antiviral agent. All blastocysts (n = 110) were transferred individually into the uterus of a synchronized recipient. The pregnancy status of recipients was determined using transrectal ultrasonography at 21-23 d after embryo transfer. Additional pregnancies as controls (n = 21) were initiated by natural breeding. Developing fetuses and resulting calves were evaluated every 27-34 d. Blastocyst development, pregnancies per transferred embryo, pregnancies maintained per pregnancies established, gestation length, gender ratio, birth weights, viability of neonates, complete blood counts, and serum chemistry profiles at 3 mo of age and adjusted 205 d weaning weights were compared for research treatments. Development to weaning after exposure to DB606 did not differ significantly from controls. In conclusion, bovine embryo cultures can be safely supplemented with antiviral concentrations of DB606; addition of DB606 agent might prevent viral transmission if BVDV were inadvertently introduced into the embryo culture system.
Collapse
Affiliation(s)
- M D Givens
- 127 Sugg Laboratory, College of Veterinary Medicine, Auburn University, AL 36849-5516, USA.
| | | | | | | | | | | | | |
Collapse
|
17
|
Givens MD, Galik PK, Riddell KP, Dykstra CC, Brock KV, Stringfellow DA. Effects of aromatic cationic molecules on bovine viral diarrhea virus and embryonic development. Theriogenology 2005; 63:1984-94. [PMID: 15823354 DOI: 10.1016/j.theriogenology.2004.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Indexed: 11/24/2022]
Abstract
Bovine viral diarrhea virus (BVDV) has been shown to replicate in embryo culture systems and remain associated with bovine embryos developing in vitro. In this study, novel antiviral agents were evaluated for capability to inhibit replication of BVDV without affecting embryonic development. Serial concentrations of 2-[5(6)-{2-imidazolinyl}-2-benzimidazolyl]-5-(4-aminophenyl)furan (DB456) or 2-(4-[2-imidazolinyl]phenyl)-5-(4-methoxyphenyl)furan (DB606) were prepared in IVC medium. Then, bovine uterine tubal epithelial cells (UTC) were placed in IVC media with varying concentrations of DB456 or DB606. Within 1h, a genotype I or II strain of BVDV was added to the cultures. Cultures were maintained for 7 days. Infectious virus was quantitated in IVC media collected on days 3 and 7 and in UTC lysates harvested on day 7. The effective antiviral concentrations of DB606 were much lower than effective antiviral concentrations of DB456. In subsequent experiments, IVF presumptive zygotes were cultured in IVC medium with or without DB456 or DB606 at multiple concentrations for 7 days to evaluate effect of the compound on conceptus development. On day 7, stage of embryonic development was observed, and blastocysts were harvested and stained using Hoechst 33342 to enumerate embryonic cells. While DB456 inhibited blastocyst development, DB606 at 20 times the effective antiviral concentration did not hinder blastocyst development or reduce the mean number of cells per blastocyst. These preliminary results indicated that bovine embryo cultures might be safely supplemented with effective concentrations of an antiviral agent.
Collapse
Affiliation(s)
- M D Givens
- Department of Pathobiology, Clinical Sciences, College of Veterinary Medicine, Auburn University, 127 Sugg Laboratory Building, Auburn, AL 36849-5516, USA.
| | | | | | | | | | | |
Collapse
|
18
|
Larson RL, Miller RB, Kleiboeker SB, Miller MA, White BJ. Economic costs associated with two testing strategies for screening feeder calves for persistent infection with bovine viral diarrhea virus. J Am Vet Med Assoc 2005; 226:249-54. [PMID: 15706977 DOI: 10.2460/javma.2005.226.249] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To develop partial budgets of the economic costs of 2 test strategies for screening cattle for persistent infection with bovine viral diarrhea virus (BVDV). DESIGN Partial budget analysis. ANIMALS 938 calves arriving at 2 stocker operations. PROCEDURE Calves were tested to determine prevalence of persistent BVDV infection. Test strategies that were evaluated included a single-test strategy consisting of immunohistochemical staining of skin biopsy specimens from all animals and a 2-test strategy consisting of polymerase chain reaction (PCR) assaying of pooled blood samples followed by immunohistochemical staining of skin biopsy specimens from animals in pools for which assay results were positive. Break-even costs (i.e., cost of persistent BVDV infection per animal necessary to justify whole-herd diagnostic testing) associated with each test strategy were calculated as a function of disease prevalence and test cost. RESULTS Apparent prevalence of persistent BVDV infection was 0.32%. Sensitivity and specificity of the PCR assay for pooled samples were 100% and 89.7%, respectively. Regardless of the prevalence of persistent BVDV infection, the break-even cost for the 2-test strategy was lower than the break-even cost for the single-test strategy. However, the economic advantage was greatest when prevalence was low. CONCLUSIONS AND CLINICAL RELEVANCE Results suggest that using a 2-test strategy to screen cattle for persistent BVDV infection, whereby the first test involves PCR assaying of pooled samples and the second involves immunohistochemical testing only of those animals represented in pooled samples with positive assay results, will reduce the cost of screening incoming feedlot cattle, compared with immunohistochemical testing of all animals.
Collapse
Affiliation(s)
- Robert L Larson
- Department of Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | | | | | | | | |
Collapse
|
19
|
Loneragan GH, Thomson DU, Montgomery DL, Mason GL, Larson RL. Prevalence, outcome, and health consequences associated with persistent infection with bovine viral diarrhea virus in feedlot cattle. J Am Vet Med Assoc 2005; 226:595-601. [PMID: 15742703 DOI: 10.2460/javma.2005.226.595] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To estimate prevalence of cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) at arrival at a feedlot, prevalence of chronically ill and dead PI cattle, and the magnitude of excess disease attributable to a PI animal. DESIGN Cross-sectional and cohort studies. ANIMALS 2,000 cattle at the time they arrived at a feedlot, 1,383 chronically ill cattle from 7 feedlots, and 1,585 dead cattle from a single feedlot. PROCEDURE Skin biopsy specimens were collected and evaluated via immunohistochemistry. Cattle were characterized as either PI or not PI with BVDV on the basis of characteristic immunostaining. Follow-up was obtained for the 2,000 cattle from which samples were collected at arrival, and health outcomes were determined for cattle exposed and not exposed to a PI animal. RESULTS Prevalence of PI cattle was 0.3% at arrival, 2.6% in chronically ill cattle, and 2.5% in dead cattle. Risk of initial treatment for respiratory tract disease was 43% greater in cattle exposed to a PI animal, compared with those not exposed to a PI animal. Overall, 15.9% of initial respiratory tract disease events were attributable to exposure to a PI animal. CONCLUSIONS AND CLINICAL RELEVANCE Relatively few PI cattle arrive at feedlots. However, those cattle are more likely to require treatment for respiratory tract disease and either become chronically ill or die than cattle that are not PI. In addition, they are associated with an increase in the incidence of respiratory tract disease of in-contact cattle.
Collapse
Affiliation(s)
- Guy H Loneragan
- Feedlot Research Group, Division of Agriculture, College of Agriculture, Nursing, and Natural Sciences, West Texas A&M University, Canyon, TX 79016, USA
| | | | | | | | | |
Collapse
|
20
|
Givens MD, Waldrop JG. Bovine viral diarrhea virus in embryo and semen production systems. Vet Clin North Am Food Anim Pract 2004; 20:21-38. [PMID: 15062472 DOI: 10.1016/j.cvfa.2003.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Although BVDV-free offspring have been produced from persistently infected bulls and heifers via advanced reproductive techniques, embryos and semen can potentially transmit the virus. Due to this potential for transmission, appropriate testing is necessary to ensure freedom of semen and embryos from BVDV. In the future, less constraining quality control measures may ensure freedom of embryos and semen from BVDV. These quality control measures require additional research to be validated.
Collapse
Affiliation(s)
- M Daniel Givens
- Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, 129 Sugg Laboratory, Auburn, AL 36849-5516, USA.
| | | |
Collapse
|
21
|
Smith DR, Grotelueschen DM. Biosecurity and biocontainment of bovine viral diarrhea virus. Vet Clin North Am Food Anim Pract 2004; 20:131-49. [PMID: 15062479 DOI: 10.1016/j.cvfa.2003.11.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Infection of cattle with BVDV results in a variety of clinical illnesses costly to the cattle industry worldwide. The reservoir and primary source of transmission is cattle born PI with BVDV after transplacental infection in early gestation. It is a challenge to determine with certainty whether or not BVDV is circulating among a herd of cattle. If the virus is present in a herd,then biocontainment strategies are used to eliminate the virus by testing to removing PI cattle, preventing exposure of pregnant cattle to the virus, and increasing resistance to infection using vaccination. If it is clear that the virus is not present in a herd then, biosecurity actions must be taken to prevent introducing the virus into the herd.
Collapse
Affiliation(s)
- David R Smith
- Department of Veterinary and Biomedical Sciences, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln, P.O. Box 830907, 124 VDC, Fair St. and E. Campus Loop, Lincoln, NE 68583-0907, USA.
| | | |
Collapse
|
22
|
Stokstad M, Niskanen R, Lindberg A, Thorén P, Belák S, Alenius S, Løken T. Experimental Infection of Cows with Bovine Viral Diarrhoea Virus in Early Pregnancy - Findings in Serum and Foetal Fluids. ACTA ACUST UNITED AC 2003; 50:424-9. [PMID: 14633195 DOI: 10.1046/j.0931-1793.2003.00699.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nineteen pregnant cows were experimentally infected with bovine viral diarrhoea virus (BVDV) between day 74 and 81 of pregnancy. All cows became infected and developed serum antibodies. Sixteen of the cows delivered persistently infected (PI) offspring, whereas the remaining three gave birth to calves with detectable serum antibodies and free from BVDV. The 16 cows with PI foetuses developed higher levels of antibodies in serum during pregnancy than did their three peers carrying non-PI calves. Multivariate analysis showed that the antibody levels in these two groups of cows were significantly different from day 135 of pregnancy. Foetal fluid was successfully collected from 18 of the 19 infected cows and from five uninfected control cows between 10 and 24 days before delivery by use of a percutaneous, blind puncture technique. No negative effects were observed in the cows or their offspring. BVDV was isolated and detected with an immunoperoxidase test in foetal fluid from 13 of the 16 cows carrying PI foetuses, and from 15 of the cows when a quantitative fluorescent polymerase chain reaction (PCR) technique was used. The negative sample in the PCR assay was positive for BVDV antibodies. The number of viral copies per microlitre in foetal fluids varied between 103 and 1080 in the positive samples. All samples taken from the cows carrying non-PI foetuses were negative for BVDV in both assays. In this experiment, examination of either serum or foetal fluids could identify the cows carrying a PI foetus. Examination of serum for BVDV antibodies was a reliable indicator of a PI foetus if the serum was collected during the last 2 months of pregnancy. For examination of foetal fluids, both viral and serological analyses should be performed. For viral analysis, PCR should be the test of choice. High levels of BVDV antibodies in conjunction with a negative result in the PCR may be indicative of a false-negative virus result. Further experience with the method of collection of foetal fluids is necessary for evaluation of its safety. Investigation of pregnant cows in order to discover a PI offspring before it is born could be a useful tool in control and eradication of BVDV.
Collapse
MESH Headings
- Animals
- Antibodies, Viral/analysis
- Antibodies, Viral/blood
- Bovine Virus Diarrhea-Mucosal Disease/diagnosis
- Bovine Virus Diarrhea-Mucosal Disease/transmission
- Cattle
- DNA, Viral/analysis
- DNA, Viral/blood
- Diarrhea Viruses, Bovine Viral/genetics
- Diarrhea Viruses, Bovine Viral/immunology
- Diarrhea Viruses, Bovine Viral/isolation & purification
- Diarrhea Viruses, Bovine Viral/pathogenicity
- Enzyme-Linked Immunosorbent Assay/veterinary
- Female
- Fetus/virology
- Infectious Disease Transmission, Vertical/veterinary
- Polymerase Chain Reaction/veterinary
- Predictive Value of Tests
- Pregnancy
- Pregnancy Complications, Infectious/diagnosis
- Pregnancy Complications, Infectious/veterinary
Collapse
Affiliation(s)
- M Stokstad
- Norwegian School of Veterinary Science, Department of Production Animal Clinical Sciences, PO Box 8146 Dep, N-0033 Oslo, Norway.
| | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
Infections with bovine viral diarrhoea virus continue to plague the cattle industry worldwide. The wish to control the negative effects of the virus has lead to the development of numerous vaccines, but also of eradication schemes. In this paper, a comprehensive overview on BVDV is given: the virus and its clinical manifestations, its occurrence and economic impact, the different routes of transmission, as well as diagnostic methods and objectives. Furthermore, the two major options for BVDV control--eradication and vaccination--are discussed as well as the risk for reintroduction of BVDV after eradication.
Collapse
|
24
|
Given MD, Riddell KP, Galik PK, Stringfellow DA, Brock KV, Loskutoff NM. Diagnostic dilemma encountered when detecting bovine viral diarrhea virus in IVF embryo production. Theriogenology 2002; 58:1399-407. [PMID: 12387352 DOI: 10.1016/s0093-691x(02)01033-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Routine quality controls in production of bovine embryos by in vitro fertilization (IVF) should include screening all materials of animal origin for the presence of bovine viral diarrhea virus (BVDV). Using a reverse transcription nested polymerase chain reaction (RT-nPCR) assay, we detected BVDV in primary cultures of uterine tubal cells (UTC) that had been used during IVF procedures. The goal of our ensuing investigation was to determine its source and assess risks associated with the identified contaminant. Sequencing of the amplified 5' nontranslated region (NTR) of the viral genome confirmed a Genotype I BVDV contaminant. This viral contaminant was also identified by RT-nPCR in multiple samples of the same lot of fetal bovine serum (FBS) that was used in transport media by the laboratory that harvested the UTC. Both routine and enhanced roller bottle methods for virus isolation failed to detect BVDV in the FBS. Furthermore, virus neutralization assays did identify antibodies to Genotype I strains of BVDV in the FBS. After 7 days of co-incubation, neither cultured, washed UTC nor exposed, washed embryos were RT-nPCR positive for BVDV. Eight embryos produced in the contaminated system were nonsurgically transferred into eight seronegative cows. None of the embryo recipients seroconverted to BVDV. Thus, contamination of cell culture medium with BVDV did not result in transmission of the virus when IVF embryos were transferred. Failure to transmit disease was likely aided by serendipitous control from anti-BVDV antibodies in the FBS. However, a diagnostic dilemma was created when the RT-nPCR assays used to screen for BVDV were positive, yet attempts to isolate the virus were negative. This case study illustrates that if molecular assays are to be used to confirm the pathogen-free status of IVF embryo production systems, media components of animal origin (e.g. FBS) should be screened with molecular assays for BVDV as well as traditional virus isolation techniques.
Collapse
Affiliation(s)
- M Daniel Given
- Sugg Laboratory, College of Veterinary Medicine, Auburn University, AL 36849-5519, USA.
| | | | | | | | | | | |
Collapse
|
25
|
Givens MD, Galik PK, Riddell KP, Stringfellow DA, Brock KV, Bishop MD, Eilertsen KJ, Loskutoff NM. Validation of a reverse transcription nested polymerase chain reaction (RT-nPCR) to detect bovine viral diarrhea virus (BVDV) associated with in vitro-derived bovine embryos and co-cultured cells. Theriogenology 2001; 56:787-99. [PMID: 11665882 DOI: 10.1016/s0093-691x(01)00608-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Sensitive RT-nPCR assays can be used for the rapid detection of viruses. The objective of this research was to validate an RT-nPCR assay for detection of BVDV associated with various samples collected from an IVF system. In 12 research replicates, we maintained matured COCs as negative controls or exposed them to 1 of 4 noncytopathic strains (SD-1, NY-1, CD-87, or PA-131) of BVDV for 1 h immediately before IVF. After 4 d of IVC, we harvested groups of 5 nonfertile ova or degenerated embryos (NFD) and some associated cumulus cells and transferred developing embryos and the remaining cumulus cells into secondary IVC drops. On the seventh d of IVC, cumulus cells, groups of 5 washed NFD and groups of 5 developed, washed embryos were harvested. We also collected single developed embryos after washing, washing with trypsin, washing and cryopreservation in ethylene glycol, or washing with trypsin and cryopreservation in ethylene glycol. All washes were performed according to International Embryo Transfer Society standards. Developed embryos and NFD were sonicated prior to assay. All samples were assayed for BVDV using virus isolation and RT-nPCR. The virus isolation and RT-nPCR assays determined that all negative control samples were BVDV-free. Virus was detected in association with all exposed cumulus cells and groups of developed embryos using both virus isolation and RT-nPCR. Results from viral assays of other exposed samples indicate enhanced sensitivity of the RT-nPCR assay. The RT-nPCR assay used in this research exhibited acceptable sensitivity, specificity, predictive value and repeatability for rapid detection of BVDV associated with the various samples obtained from an IVF system.
Collapse
|
26
|
Givens MD, Galik PK, Riddell KP, Brock KV, Stringfellow DA. Replication and persistence of different strains of bovine viral diarrhea virus in an in vitro embryo production system. Theriogenology 2000; 54:1093-107. [PMID: 11131328 DOI: 10.1016/s0093-691x(00)00418-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Recent studies have shown that exposed, in vitro-derived embryos remain contaminated with bovine viral diarrhea virus (BVDV) after washing. However, introduction of a Genotype II versus Genotype I strain of BVDV into an IVF system was reported to provide greater potential for transmission of disease. The primary objective of this study was to compare the potentials for different strains of noncytopathic BVDV to replicate in an IVF system, associate with IVF embryos and infect co-cultured cells via association with washed embryos. The secondary objective was to compare the effect of different strains of BVDV on embryonic development. Two Genotype I (SD-1 and NY-1) and 2 Genotype II (CD-87 and PA-131) strains of BVDV were evaluated. After IVM and IVF of oocytes, presumptive zygotes were washed and transferred into in vitro cultures containing uterine tubal cells (UTC) and medium that was free of BVDV-neutralizing activity. Immediately before addition of zygotes, the cultures were inoculated with 10(5) cell culture infective doses (50%, CCID50) of a strain of BVDV or maintained as a negative control. Cultures of zygotes were then incubated for 7 d. Embryonic development was observed on Days 3 and 7, and attempts were made to isolate BVDV from UTC and medium on Day 7. Also on Day 7, groups of intact, washed blastocysts were either transferred into virus-free secondary cultures containing UTC or sonicated with sonicate fluid assayed by both virus isolation and single-closed-tube reverse transcription nested polymerase chain reaction (RT-nPCR). After 3 d in secondary culture, hatched embryos were enumerated, and medium from the cultures, washed UTC and embryos were tested for BVDV by virus isolation. In addition, washed UTC and embryos were tested for BVDV using RT-nPCR. All strains of BVDV persisted and replicated in the embryo culture environment, but cleavage beyond the 4-cell stage, blastocyst development and hatching varied among cultures contaminated with different strains of virus. Further, the quantity of BVDV associated with washed embryos from both initial and secondary cultures varied among strains, but the variation was unrelated to difference in genotype (SD-1 and PA-131 greater than NY-1 and CD-87). Although all strains of BVDV replicated in UTC in the initial in vitro cultures and remained associated with washed blastocysts, susceptible UTC in the secondary in vitro cultures were seldom infected by any strain of virus.
Collapse
Affiliation(s)
- M D Givens
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849, USA.
| | | | | | | | | |
Collapse
|
27
|
Fray MD, Paton DJ, Alenius S. The effects of bovine viral diarrhoea virus on cattle reproduction in relation to disease control. Anim Reprod Sci 2000; 60-61:615-27. [PMID: 10844229 DOI: 10.1016/s0378-4320(00)00082-8] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Bovine viral diarrhoea virus (BVDV) is a major reproductive pathogen in cattle. Infection of the bull can lead to a fall in semen quality and the isolation of infectious virus in the ejaculate, while infection in the cow leads to poor conception rates, abortions and congenital defects. BVDV also reduces the animal's resistance to other respiratory and enteric pathogens. The prevalence of BVDV is primarily due to the efficiency with which the virus crosses the placenta of susceptible females. Calves that survive infection during the first trimester of pregnancy are born with a persistent and lifelong infection. These persistently infected (PI) animals represent between 1.0% and 2.0% of the cattle population and continuously shed infectious virus. The availability of reliable diagnostic ELISA and PCR techniques, which can test milk or serum samples for virus or antibodies, has simplified BVDV surveillance and improved the prospects for control. Although PI animals are the principal vectors within and between herds, they can be readily identified and removed. By contrast, cows carrying a PI foetus are particularly problematic. These animals have been compared to 'Trojan Horses' because they are virus-negative and antibody-positive but they deliver PI calves. In general, acutely infected cattle are much less efficient vectors but infections at the onset of puberty have resulted in a localised and persistent infection within the testes. Under these circumstances, virus shedding into the semen may remain undetected. Transmission of BVDV can be controlled through vaccination or eradication. BVDV vaccine technology has been developing over the past 30 years, but currently available vaccines are still of the conventional inactivated or attenuated sort. In general, vaccination has not been applied with sufficient rigor to make a significant impact on the level of circulating virus, unlike the national and regional eradication programmes established in areas such as Scandinavia, Austria, the Netherlands and Scotland. Eradication confers the added advantage of improved herd health; however, it also creates a susceptible cattle population that needs to be protected by stringent biosecurity. In this article, we discuss how BVDV influences reproductive function, the potential for viral transmission during breeding and the measures that must be taken to avoid the spread of infection to susceptible cattle populations via semen, embryos, culture fluids and infected cows.
Collapse
Affiliation(s)
- M D Fray
- Institute for Animal Health, Embryology Group, Compton, Berkshire, Newbury, UK.
| | | | | |
Collapse
|
28
|
Guérin B, Le Guienne B, Thibier M. A secure health status associated with the production and trade of in vitro derived cattle embryos. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s0301-6226(99)00162-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
29
|
Givens MD, Galik PK, Riddell KP, Brock KV, Stringfellow DA. Quantity and infectivity of embryo-associated bovine viral diarrhea virus and antiviral influence of a blastocyst impede in vitro infection of uterine tubal cells. Theriogenology 1999; 52:887-900. [PMID: 10735128 DOI: 10.1016/s0093-691x(99)00180-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In previous studies, bovine viral diarrhea virus (BVDV) remained associated with IVF embryos after viral exposure and washing. However, uterine tubal cells (UTC) were not infected when exposed embryos were washed and individually co-cultured with them. The objective of this study was to evaluate quantity and infectivity of embryo-associated virus and antiviral influence of a blastocyst as possible explanations for failure to infect the UTC in vitro. Morulae and blastocysts were produced in vitro and washed. A portion of the embryos were incubated for 2 h in medium containing 10(6) to 10(8) cell culture infective doses (50%, CCID50) of a genotype I, noncytopathic BVDV per milliliter and then washed again. Virus isolation was attempted on sonicated negative (virus unexposed) and positive (virus exposed) control embryo groups after washing. The influence of quantity and infectivity of embryo-associated virus was evaluated by transferring exposed, washed embryo groups (2, 5, and 10 embryos/group) or sonicate fluid of exposed, washed, sonicated embryo groups (2, 5, and 10 embryos/group) to cultures containing bovine UTC in IVC medium that was free of BVDV neutralizing activity. The antiviral influence of an embryo was evaluated by adding 1 to 10(5) CCID50 of BVDV to UTC in the presence or absence of a single unexposed blastocyst in IVC medium. After 2 d in co-culture, the UTC, IVC medium and washed embryos (when present) were tested separately for the presence of BVDV using virus isolation. Virus was isolated from sonicate fluids of all positive but no negative controls. Virus was not isolated from any UTC following 2 d of culture with virally exposed groups of intact embryos. However, virus was isolated from UTC cultured with sonicate fluids from some groups of 5 (60%) and 10 (40%) embryos. Infective virus also remained associated with some groups of 2 (20%), 5 (40%) and 10 (60%) intact embryos after 48 h of post-exposure culture. Finally, primary cultures of UTC were more susceptible to infection with BVDV in the absence of a blastocyst (P = 0.01). Results indicate that insufficient quantity and reduced infectivity of embryo-associated virus as well as an antiviral influence of intact IVF blastocysts may all contribute to failure of embryo-associated virus to infect UTC in vitro.
Collapse
Affiliation(s)
- M D Givens
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849-5519, USA
| | | | | | | | | |
Collapse
|
30
|
Givens MD, Galik PK, Riddell KP, Stringfellow DA. Uterine tubal cells remain uninfected after culture with in vitro-produced embryos exposed to bovine viral diarrhea virus. Vet Microbiol 1999; 70:7-20. [PMID: 10591493 DOI: 10.1016/s0378-1135(99)00131-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Bovine viral diarrhea virus (BVDV) has been isolated from washed and sonicated, in vitro-produced embryos, but the infectivity of BVDV associated with intact, developing, embryos has not been demonstrated. The objective of this study was to determine if a dose of BVDV infective for co-culture cells was associated with individual, developing embryos, following artificial exposure to the virus and washing. In 5 replicates, zona pellucida-intact, in vitro-produced embryos were assigned to a negative control embryo group, or were incubated in 10(5)-10(6) cell culture infective doses (50%, CCID50) per milliliter of a type I, noncytopathic (strain SD-1) BVDV for 2 h. Unexposed negative control embryos and exposed positive control embryos were washed, sonicated and assayed for BVDV using virus isolation with immunoperoxidase monolayer assay. Immediately or following cryopreservation, remaining virally-exposed, washed embryos were co-cultured individually with BVDV-negative cultures of bovine uterine tubal cells in a medium free of BVDV-neutralizing activity. After two days in culture, uterine tubal cells and embryos (including the zona pellucida) were separated and washed. The culture medium, uterine tubal cells and embryos were then assayed for BVDV. Bovine viral diarrhea virus was not isolated from any negative control embryo group, but was isolated from all positive control embryo groups. Although all uterine tubal cell populations were confirmed to be susceptible to BVDV, virus was never isolated from uterine tubal cells or embryos from post-exposure culture. In conclusion, although BVDV remains associated with washed in vitro-produced embryos, the virus associated with unsonicated embryos was not infective for uterine tubal cells in vitro.
Collapse
Affiliation(s)
- M D Givens
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849-5512, USA.
| | | | | | | |
Collapse
|
31
|
Ferrari G, Scicluna MT, Bonvicini D, Gobbi C, Della Verità F, Valentini A, Autorino GL. Bovine virus diarrhoea (BVD) control programme in an area in the Rome province (Italy). Vet Microbiol 1999; 64:237-45. [PMID: 10028176 DOI: 10.1016/s0378-1135(98)00273-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A BVD control programme based on the identification and removal of persistently infected (PI) animals is being undertaken in an area in the Rome province, where BVD outbreaks had been previously detected. It involves 174 mainly dairy herds, from which blood samples of all bovines older than 1 year are obtained through the national brucellosis and leukosis eradication programme. Samples sufficient to detect the presence of seropositive animals at a prevalence of 5% or more are initially screened for antibodies against BVD virus (BVDV) using an immunoenzymatic assay. Upon identification of seroreagents additional blood samples are tested from the 6-12-month age category not included in the initial samples. Animals are considered immunotolerant if BVDV is demonstrated twice at a minimum 30-day interval. When no seropositive animals are detected during the first serological screening the herd is declared BVD-free if a second testing, preferably carried on the same animals previously tested, confirms the seronegative status of the herd. At present 147 farms have been tested, of which 63 (42.9%) are negative with respect to antibodies against BVDV. Of the 84 remaining herds in which one or more seropositives are detected, 13 are classified as recently infected. In eight of these recently infected herds, 22 PI animals have been identified.
Collapse
Affiliation(s)
- G Ferrari
- Istituto Zooprofilattico Sperimentale delle Regioni Lazio e Toscana, Rome, Italy
| | | | | | | | | | | | | |
Collapse
|
32
|
Houe H. Epidemiological features and economical importance of bovine virus diarrhoea virus (BVDV) infections. Vet Microbiol 1999; 64:89-107. [PMID: 10028165 DOI: 10.1016/s0378-1135(98)00262-4] [Citation(s) in RCA: 405] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Infections with bovine virus diarrhoea virus (BVDV) are widespread throughout the world. Although the prevalence of infection varies among surveys, the infection tends to be endemic in many populations, reaching a maximum level of 1-2% of the cattle being persistently infected (PI) and 60-85% of the cattle being antibody positive. Persistently infected cattle are the main source for transmission of the virus. However, acutely infected cattle as well as other ruminants, either acutely or persistently infected, may transmit the virus. Transmission is most efficient by direct contact. However, as infections have been observed in closed, non-pasturing herds, other transmission routes seem likely to have some practical importance. Differences in BVDV prevalence among regions or introduction of virus in herds previously free of BVDV are often associated with particular epidemiological determinants such as cattle population density, animal trade and pasturing practices. However, on a few occasions there have been no obvious explanations for infection of individual herds. Estimates of economic losses due to BVDV infection vary depending on the immune status of the population and the pathogenicity of the infecting virus strains. Introduction of the infection into a totally susceptible population invariably causes extensive losses until a state of equilibrium is reached. Infection with highly virulent BVDV strains causing severe clinical signs and death after acute infection gives rise to substantial economical losses. At an estimated annual incidence of acute infections of 34%, the total annual losses were estimated as US$ 20 million per million calvings when modeling the losses due to a low-virulent BVDV strain. At the same incidence of infection, the losses due to a high-virulent BVDV strain were estimated as US$ 57 million per million calvings. Low-virulent BVDV infections caused maximum losses at an incidence of 45%, whereas high-virulent BVDV infections caused maximum losses at an incidence of 65%. Thus, cost-benefit analyses of control programs are highly dependent on the risks of new infections under different circumstances and on the strains of the virus involved.
Collapse
Affiliation(s)
- H Houe
- Royal Veterinary and Agricultural University, Frederiksberg, Denmark
| |
Collapse
|
33
|
Brock KV, Grooms DL, Ridpath J, Bolin SR. Changes in levels of viremia in cattle persistently infected with bovine viral diarrhea virus. J Vet Diagn Invest 1998; 10:22-6. [PMID: 9526856 DOI: 10.1177/104063879801000105] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Virus isolation and serum neutralizing antibody titers were determined over a period of time from samples collected from animals persistently infected with bovine viral diarrhea virus (BVDV). To evaluate over time the ability to detect BVDV by virus isolation from serum or white blood cell preparations, 4 persistently infected calves were monitored from birth until 70 days of age. In 3 of 4 persistently infected calves, virus isolation from serum and white blood cells was negative until approximately 42 days of age, when colostral antibody had declined. The level of viremia in 7 adult (> 12 months) persistently infected animals decreased by 1 10-fold dilution over at least a 2-year period. The level of viremia became undetectable by virus isolation from serum in 1 of the 7 animals examined. This decline was associated with the development of virus neutralizing antibody. Although the level of viremia is fairly stable within persistently infected animals, the presence of specific neutralizing antibody may affect the ability to isolate BVDV. These findings are important when considering diagnostic testing to identify persistently infected animals by virus isolation.
Collapse
Affiliation(s)
- K V Brock
- Ohio Agricultural Research and Development Center, Food Animal Health Research Program, Ohio State University, Wooster 44691, USA
| | | | | | | |
Collapse
|
34
|
Stringfellow DA, Riddell KP, Brock KV, Riddell MG, Galik PK, Wright JC, Hasler JF. In vitro fertilization and in vitro culture of bovine embryos in the presence of noncytopathic bovine viral diarrhea virus. Theriogenology 1997; 48:171-83. [PMID: 16728117 DOI: 10.1016/s0093-691x(97)84065-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/1996] [Accepted: 11/21/1996] [Indexed: 11/30/2022]
Abstract
In vitro embryo production has been used extensively in research and is now offered as a commercial service, yet the hazards of introducing specific infectious agents into in vitro embryo production systems have not been completely defined. The introduction of noncytopathic bovine viral diarrhea virus (BVDV) is a special concern. One objective of this study was to determine if noncytopathic BVDV-infected uterine tubal cells in IVF and IVC systems affected the rate of cleavage and development. An additional objective was to determine if either degenerated ova or embryos produced in the presence of the infected cells had virus associated with them after washing. Follicular oocytes (n = 645) collected from slaughterhouse ovaries were matured and fertilized in vitro, and presumptive zygotes were cultured for 7 d. Primary cultures of uterine tubal cells for use during IVF and IVC were divided into 2 groups. One-half of the cultures was infected with noncytopathic BVDV while the other half was not exposed to the virus. Approximately equal groups of mature oocytes were inseminated, and the presumptive zygotes were cultured with infected or noninfected uterine tubal cells. After 7 d in IVC, zona pellucida-intact (ZP-I) morulae and blastocysts and degenerated ova were washed and assayed for the presence of infectious virus. Infections of uterine tubal cells were not apparent and did not reduce rates of cleavage and development (P > 0.05; Chi-square test for heterogeneity). After washing, BVDV was isolated at a significantly higher rate from groups of virus-exposed degenerated ova (79%) than from individual virus-exposed morulae and blastocysts (37%; P = 0.0002; Mantel-Haenszel summary, Chi-square).
Collapse
Affiliation(s)
- D A Stringfellow
- College of Veterinary Medicine Auburn University, AL 36849-5519, USA
| | | | | | | | | | | | | |
Collapse
|
35
|
Brock KV, Lapin DR, Skrade DR. Embryo transfer from donor cattle persistently infected with bovine viral diarrhea virus. Theriogenology 1997; 47:837-44. [PMID: 16728033 DOI: 10.1016/s0093-691x(97)00039-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/1996] [Accepted: 07/31/1996] [Indexed: 11/30/2022]
Abstract
This study was done to examine the reproductive efficiency of embryo transfer donors that were persistently infected with bovine viral diarrhea virus (BVDV) and to determine the potential for vertical or horizontal transmission of BVDV during embryo transfer from persistently infected donors. The reproductive inefficiency of 7 different persistently infected donors was evident by consistent failure at superovulation and/or fertilization. Washing of embryos according to the reccommendations of the International Embryo Transfer Society (IETS) prevented the adherence of BVDV to embryos and to unfertile and degenerated ova, as determined by virus isolation and polymerase chain reaction (PCR) assay. In addition, a normal, BVDV antibody seronegative and BVDV-negative calf was born following transfer from a PI donor to a seronegative recipient.
Collapse
Affiliation(s)
- K V Brock
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Wooster, OH, USA
| | | | | |
Collapse
|
36
|
|
37
|
Abstract
Prevalence studies around the world show that BVDV is widespread in most cattle raising countries. There are significant differences, however, in prevalence between areas, probably the result of differences in cattle population structure and management practice. Direct contact with PI animals is probably the most important method of transmission of infection; however, field studies have shown that some limited spread of infection also occurs in the absence of PI animals. This may be due to contact with acutely infected animals or contact with other species infected with BVDV. Different ways of indirect transmission such as contaminated needles and equipment have been proven experimentally, and indirect transmission is considered to have some importance. If a PI animal is introduced directly into a dairy herd, most animals will be infected within a few months. On many occasions, however, a herd gets infected by other means than direct introduction of PI animals. In these cases, the infection is often spread to only a few animals after which the infections stops. The infection is then reinforced when PI animals are born. Slow and hence prolonged spread of infection in herds without PI animals also has been described, but the mechanism is not fully understood. Family lines of PI animals delivering PI calves are fairly common and can cause the infection to continue for several years. The clinical manifestations, acute BVDV, reproductive disorders, birth of malformed, weak and undersized calves, unthrifty PI animals, and mucosal disease often appear within certain periods. Large variation, however, can occur between herd outbreaks due to variation in virulence of the BVDV strain, housing of the cattle, and variation in transmission patterns. The extensive transmission of infection from PI animals makes different surveillance methods possible. Thus testing of a screening sample of a few young stock of antibodies and determination of antibody titer in bulk milk will often give good indication of presence of PI animals in herds not using BVDV vaccines. In herds using killed vaccine, determination of antibody titers among few young stock can show the presence of PI animals. The high incidence of infection combined with all the different damages that are seen after BVDV infection cause huge economical losses, which on a national level in the UK and Denmark (i.e., areas with widespread occurrence of infection) has been calculated as between 7 and 27 million pounds (between $11 and $42 million) per million calvings. Epidemiologic studies are important as a basis for selection of control strategy. Because of the variation in epidemiology between geographic areas, evaluation of a control strategy in an area preferentially should be based on epidemiologic studies in the same area.
Collapse
Affiliation(s)
- H Houe
- Department of Clinical Studies, Royal Veterinary and Agricultural University, Frederiksberg, Denmark
| |
Collapse
|
38
|
Abstract
Because of complex pathogenesis and insidious nature of BVDV infections, the laboratory diagnosis is an essential component of developing measures for the control and prevention of BVDV infections. The positive isolation of BVDV from animal submissions or from aborted fetuses should provide a strong indication for further epidemiologic investigations within the identified infected herds. In these situations, the ultimate goal should be the establishment of sound control and prevention methods by prevention of any potential exposure to BVDV (i.e., removal of PI animals and preventing the introduction of infected animals) and by protecting animals by using effective vaccination programs.
Collapse
Affiliation(s)
- K V Brock
- Ohio Agricultural Research and Development Center, Ohio State University, Wooster, USA
| |
Collapse
|
39
|
Evermann JF, Berry ES, Baszler TV, Lewis TL, Byington TC, Dilbeck PM. Diagnostic approaches for the detection of bovine viral diarrhea (BVD) virus and related pestiviruses. J Vet Diagn Invest 1993; 5:265-9. [PMID: 8389602 DOI: 10.1177/104063879300500222] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Affiliation(s)
- J F Evermann
- Washington Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Washington State University, Pullman 99164
| | | | | | | | | | | |
Collapse
|