scholarly journals Prevalence of bovine abortion, calf mortality, and bovine viral diarrhea virus (BVDV) persistently infected calves among pastoral, peri-urban, and mixed-crop livestock farms in central and Northwest Ethiopia

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Erdachew Yitagesu ◽  
Wendi Jackson ◽  
Nigatu Kebede ◽  
Woutrina Smith ◽  
Tsegaw Fentie
Keyword(s):  
Bovine Viral Diarrhea Virus ◽  
Production Systems ◽  
Economic Losses ◽  
Bovine Viral Diarrhea ◽  
Persistently Infected ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Calf Mortality ◽  
Bovine Abortion ◽  
Viral Diarrhea Virus

Abstract Background Bovine Viral Diarrhea virus (BVDV) is one of important diseases of cattle worldwide causing economic losses to the cattle industry primarily due to increased premature culling and decreased reproductive performance. The virus can cross the placenta during early pregnancy and result in the birth of persistently infected (PI) calves that are efficient transmitters of BVDV and serving as the primary reservoirs for BVDV. Relatively few studies have focused on understanding BVDV seroprevalence, virus detection, genotyping and its distribution in Africa. Most BVDV research in Ethiopia has involved serologic surveys in adult cattle, rather than the identification of PI calves, despite their role in viral shedding and recurring infections. A cross-sectional study was undertaken in three different livestock production systems of Ethiopia with the objective to estimate the prevalence of bovine abortion, calf mortality, and BVDV persistently infected calves. Results Ear notch samples (882) collected from calves in 349 households were tested for BVDV antigen using antigen capture enzyme-linked immunosorbent assay (ACE). All samples tested were negative for BVDV antigen. The overall animal level crude abortion and calf mortality prevalence were 4.0% (95% CI: 2.9–5.2) and 9.2% (95% CI: 7.7–11.0) respectively. The lower BVDV PI prevalence may be due to a lower effective contact rate between cattle reared in small-scale extensive production systems in Ethiopia. Conclusions This is the first report of BVDV Ag test in Ethiopia and no PI was detected in calves in the study areas. Since BVDV is a disease of great economic importance, this study finding must be interpreted with care since absence of evidence is not evidence of absence and even a single BVDV infected animal can serve as source of infection and contribute to the persistent spread of the virus. Greater attention needs to be given to screening for PI animals through testing large number of animals and culling positive animals. Hence, future research should focus on regions and production systems with high BVDV seroprevalence followed by antigen ELISA or BVDV real-time PCR to detect persistently infected and acutely viremic animals.

scholarly journals The means of combating persistent infection of viral diarrhea

2019 ◽  
Vol 49 (2) ◽  
pp. 49-56
Author(s):  
T. I. Glotova ◽  
A. A. Nikonova ◽  
S. V. Koteneva ◽  
A. G. Glotov
Keyword(s):  
Cell Culture ◽  
Bovine Viral Diarrhea Virus ◽  
Persistent Infection ◽  
Antiviral Treatment ◽  
Economic Losses ◽  
Bovine Viral Diarrhea ◽  
Persistently Infected ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Viral Diarrhea Virus

The paper presents results of research into the means of inhibiting persistent infection caused by noncytopathic biotype of bovine viral diarrhea virus. It was shown that bovine viral diarrhea virus, widespread in the cattle population in the whole world, can be a primary cause of pathology development of the respiratory and reproductive organs, and can cause a persistent form of infection in animals. The virus can contaminate fetal serum, cell cultures, trypsin, and other biological products, which leads to a decrease in the quality of biotech products from these materials and the spread of bovine viral diarrhea virus in a population of susceptible animals. The study was done on the model of a continuous calf coronary cell culture persistently infected with the noncytopathic biotype of the bovine viral diarrhea virus. The antiviral effect of two commercial preparations Ribavirin-Lipint and Reaferon-EC-Lipint was studied. The effectiveness of antiviral treatment of the infected cell culture was determined by the reverse transcription polymerase chain reaction, carried out in two versions: with electrophoresis and in real-time mode. It was found that these drugs in doses of 0.05 mg / ml and 30000 IU / ml, respectively, when added to growth medium for 24 consecutive passages, led to a decrease in the infectious activity of the bovine viral diarrhea virus in the cell culture, but did not cure it completely from the persistent infection caused by the noncytopathic biotype of the virus. Application of antiviral drugs is one of the ways to decrease economic losses caused by biological product contamination, the use of persistently infected animals for pedigree purposes and restrictions in international cattle trade.

scholarly journals Genetic Diversity of Bovine Viral Diarrhea Virus Infection in Goats in Southwestern China

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Yu Deng ◽  
Silu Wang ◽  
Runxia Liu ◽  
Guiying Hao
Keyword(s):  
Genetic Diversity ◽  
Infection Rate ◽  
Bovine Viral Diarrhea Virus ◽  
Southwestern China ◽  
Economic Losses ◽  
Bovine Viral Diarrhea ◽  
Border Disease Virus ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Viral Diarrhea Virus

Bovine viral diarrhea virus (BVDV) affects cows, pigs, sheep, goats, and other ruminants, as well as some wild animals. BVDV causes considerable economic losses every year and many countries have developed programs aimed at the eradication of this disease. The genetic diversity of BVDV in diseased goats has never been described in southwestern China. Thus, in this study, we applied antigen-capture ELISA and RT-PCR to survey the infection rate of BVDV in diseased goats in this region. Our results demonstrated that the average BVDV infection rate in goats was 17.51%, with all positive samples indicating infection by BVDV-1 and not BVDV-2, BVDV-3, or Border disease virus. The molecular characteristics of the 5′-untranslated region (5′-UTR) of BVDV-1 were recognized as belonging predominantly to the BVDV-1a, 1b, 1c, 1m, and 1p subtypes. BVDV-1b and 1m were the most abundant subtypes identified in this region, similar to the BVDV epidemics in cattle in other regions of China. This is the first study that describes the genetic characterization of BVDV in sick goats from southwestern China and is important for future studies and control programs.

Attenuated lymphocyte activation leads to the development of immunotolerance in bovine fetuses persistently infected with bovine viral diarrhea virus†

2020 ◽  
Vol 103 (3) ◽  
pp. 560-571 ◽  
Author(s):  
Hanah M Georges ◽  
Katie J Knapek ◽  
Helle Bielefeldt-Ohmann ◽  
Hana Van Campen ◽  
Thomas R Hansen
Keyword(s):  
Immune System ◽  
Bovine Viral Diarrhea Virus ◽  
Lymphocyte Activation ◽  
Control Measures ◽  
Bovine Viral Diarrhea ◽  
Type I ◽  
Persistently Infected ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Viral Diarrhea Virus

Abstract Bovine viral diarrhea virus continues to cost the cattle industry millions of dollars each year despite control measures. The primary reservoirs for bovine viral diarrhea virus are persistently infected animals, which are infected in utero and shed the virus throughout their lifetime. The difficulty in controlling the virus stems from a limited understanding of transplacental transmission and fetal development of immunotolerance. In this study, pregnant bovine viral diarrhea virus naïve heifers were inoculated with bovine viral diarrhea virus on day 75 of gestation and fetal spleens were collected on gestational days 82, 97, 190, and 245. Microarray analysis on splenic RNA from days 82 and 97 revealed an increase in signaling for the innate immune system and antigen presentation to T cells in day 97 persistently infected fetuses compared to controls. Reverse transcription quantitative polymerase chain reaction on select targets validated the microarray revealing a downregulation of type I interferons and lymphocyte markers in day 190 persistently infected fetuses compared to controls. Protein was visualized using western blot and tissue sections were analyzed with hematoxylin and eosin staining and immunohistochemistry. Data collected indicate that fetal immunotolerance to bovine viral diarrhea virus developed between days 97 and 190, with mass attenuation of the immune system on day 190 of gestation. Furthermore, lymphocyte transcripts were initially unchanged then downregulated, suggesting that immunotolerance to the virus stems from a blockage in lymphocyte activation and hence an inability to clear the virus. The identification of lymphocyte derived immunotolerance will aid in the development of preventative and viral control measures to implement before or during pregnancy.

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