Prevalence of bovine viral diarrhea virus antibodies and risk factors in dairy cattle in Gondar city, Northwest Ethiopia

Serosurvey and associated risk factors for bovine viral diarrhea virus infection in cattle in Egypt

Bovine viral diarrhea virus (BVDV), is widely spread, poses a considerable risk of infection in the majority of dairy farms, causing respiratory, gastrointestinal, and reproductive problems. The aim of this study was to determine the seroprevalence and the risk variables associated with the seroprevalence of BVDV infection in cattle in four Egyptian governorates. A total of 680 blood samples were collected from cattle and examined for the presence of antibodies against BVDV using indirect ELISA (iELISA). Reproductive and management factors were considered, and epidemiological surveys were conducted. The total seroprevalence of BVDV in cattle was 18.24% (124/680) and it was significantly higher in females 19.66% (116/590), cattle older than 8 years 22.14% (62/280), dairy animals 22.65% (94/514), introduction of new animals to herd 21.39% (89/416), breeding with artificial insemination 28.46% (74/260), animals with history of abortion 28.76% (49/357), or during lactation stage 23% (89/387). The present findings suggest that BVD is prevalent in Egyptian dairy cattle and has an impact on farm productivity and production. Therefore, older, lactating, and aborted animals should also be identified for the disease, pose a risk of infection, and be handled appropriately.

Comparative Analysis of the Prevalence of Bovine Viral Diarrhea Virus in Cattle Populations Based on Detection Methods: A Systematic Review and Meta-Analysis

Infectious diseases of cattle, including bovine viral diarrhea (BVD), pose a significant health threat to the global livestock industry. This study aimed to investigate the prevalence and risk factors associated with bovine viral diarrhea virus (BVDV) infections in cattle populations through a systematic review and meta-analysis. PubMed, Web of Science, and Scopus were systematically searched for relevant articles reporting the prevalence of and associated risk factors in studies published between 1 January 2000 and 3 February 2023. From a total of 5111 studies screened, 318 studies were included in the final analysis. BVDV prevalence in cattle populations was estimated using various detection methods. The analysis detected heterogeneity in prevalence, attributed to detection techniques and associated risk factors. Antibody detection methods exhibited a higher prevalence of 0.43, reflecting the cumulative effect of detecting both active and past infections. Antigen detection methods showed a prevalence of 0.05, which was lower than antibody methods. A prevalence of 0.08 was observed using nucleic acid detection methods. The health status of the examined cattle significantly influenced the prevalence of BVDV. Cattle with bovine respiratory disease complex (BRDC) exhibited higher antibody (prevalence of 0.67) and antigen (prevalence 0.23) levels compared to cattle with reproductive problems (prevalence 0.13) or diarrhea (prevalence 0.01). Nucleic acid detection methods demonstrated consistent rates across different health conditions. Age of cattle influenced prevalence, with higher rates in adults compared to calves. Risk factors related to breeding and reproduction, such as natural or extensive breeding and a history of abortion, were associated with increased prevalence. Coinfections with pathogens like bovine herpesvirus-1 or Neospora caninum were linked to higher BVDV prevalence. Management practices, such as commingling, introducing new cattle, and direct contact with neighboring farms, also influenced prevalence. Herd attributes, including larger herd size, and the presence of persistently infected cattle, were associated with higher prevalence. These findings indicated the importance of detection methods and risk factors in BVDV epidemiological studies.

Prevalence of bovine viral diarrhea virus in cattle between 2010 and 2021: A global systematic review and meta-analysis

Background

Bovine viral diarrhea is one of the diseases that cause huge economic losses in animal husbandry. Many countries or regions have successively introduced eradication plans, but BVDV still has a high prevalence in the world. This meta-analysis aims to investigate the prevalence and risk factors of BVDV in the world in recent 10 years, and is expected to provide some reference and theoretical basis for BVDV control plans in different regions.

Method

Relevant articles published from 2010 to 2021 were mainly retrieved from NCBI, ScienceDirect, Chongqing VIP, Chinese web of knowledge (CNKI), web of science and Wanfang databases.

Results

128 data were used to analyze the prevalence of BVDV from 2010 to 2021. BVDV antigen prevalence rate is 15.74% (95% CI: 11.35-20.68), antibody prevalence rate is 42.77% (95% CI: 37.01-48.63). In the two databases of antigen and antibody, regions, sampling time, samples, detection methods, species, health status, age, sex, breeding mode, and seasonal subgroups were discussed and analyzed, respectively. In the antigen database, the prevalence of dairy cows in the breed subgroup, ELISA in the detection method subgroup, ear tissue in the sample subgroup, and extensive breeding in the breeding mode were the lowest, with significant differences. In the antibody database, the prevalence rate of dairy cows in the breed subgroup and intensive farming was the highest, with a significant difference. The subgroups in the remaining two databases were not significantly different.

Conclusion

This meta-analysis determined the prevalence of BVDV in global cattle herds from 2010 to 2021. The prevalence of BVDV varies from region to region, and the situation is still not optimistic. In daily feeding, we should pay attention to the rigorous and comprehensive management to minimize the spread of virus. The government should enforce BVDV prevention and control, implement control or eradication policies according to local conditions, and adjust the policies in time.

The Epidemiology of Bovine Viral Diarrhea Virus in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Introduction

Bovine viral diarrhea virus (BVDV) causes reproductive inefficiencies and negatively impacts the economy of low- and middle-income countries (LMICs). It is characterized by a combination of syndromes that result in poor production performance and calf morbidity and mortality. BVDV control is possible by introduction of biosecurity measures, test-and-cull, and vaccination programs as accomplished in high-income countries. Knowledge of BVDV epidemiology is limited in many LMICs, which hinders implementation of effective control programs. We carried out a systematic review and meta-analysis to estimate the burden of BVDV, identify risk factors related to its occurrence, and health and economic impacts on production systems.

Materials and Methods

Relevant BVD articles were collated from library databases; 690 abstracts and full texts were found in an initial search followed by filtering of 59 manuscripts. We accounted for quality and risk of bias in the meta-analysis. Prevalence, exposure, and current infection at regional, production, and farming system levels were estimated using logistic random-effects meta-regression models. Finally, we calculated the proportion of studies that addressed risk factors and health and economic impacts across different production systems to inform future preventative strategies in LMICs.

Results

Seroprevalence was high and varied between regions. Mean weighted prevalence was 39.5% (95% CI 25-56.1), 45.2% (95% CI 35.9-54.8), 49.9% (95% CI 25.5-74.3), and 21.6% (95% CI 0.5-56) for sub-Saharan Africa, South America, Middle East, and Asia, respectively. Seroprevalence varied across farming systems, with smallholder farming showing the highest values. Herdsize was the most frequently reported risk factor, and the percentage of articles that reported herdsize as a risk factor were 20.6%, 33.3%, and 38.4% for dairy, beef and mixed systems respectively. Abortion (13.7% of articles) was the main reported health impact in dairy systems. Some articles reported milk drop (4.6% of articles), but no article investigated the economic cost of BVDV in farming systems.

Conclusion

Animal-level seroprevalence varied across all regions. Most of the studies focused on BVDV seroprevalence. There were some articles that investigated risk factors and health impacts, and there were even less that investigated economic impacts. Future studies should focus on identifying risk factors and quantifying health and economic impacts across systems. Understanding these aspects is crucial to develop management strategies to apply across diverse production systems in LMICs.

Seroprevalence of bovine viral diarrhea virus antibodies and risk factors in dairy cattle from the central desert of Iran

Bovine viral diarrhea virus (BVDV) infects cattle worldwide and causes one of the most important economic diseases of the dairy industry. BVDV infection reduces reproductive efficiency, suppresses the immune system, and causes gastrointestinal and respiratory diseases. A first cross-sectional study was conducted in the central desert of Iran (Yazd and South Khorasan provinces) to estimate the seroprevalence and identify BVDV-related risk factors in dairy cattle. A total of 800 cows were randomly selected of 76 herds, and their serum samples were tested by the indirect enzyme-linked immunosorbent assay (ELISA) method for BVDV antibody detection. Data were analyzed using the logistic regression model. The serum prevalence of BVDV at animal and herd levels was 66.83% and 91.6%, respectively. Traditional housing system (OR = 3.22; 95% CI = 1.20-9.09) and cattle introduction to the herd (OR = 2.12; 95% CI = 1.21-3.70) were the important risk factors for BVDV seropositivity (p < 0.05). Increasing of age per year caused adding in 0.33 log (odds) of BVDV seropositivity (p < 0.05). It is necessary to implement control and eradication programs because of the high seroprevalence at the individual level and at the herd in the central desert of Iran.

First detection of emerging HoBi-like Pestivirus (BVD-3) among some persistently infected dairy cattle herds in Egypt

Bovine viral diarrhoea virus (BVDV) is a serious veterinary health concern worldwide. We conducted this study to determine the prevalence of persistent infections (PI) and identify the current strain among some dairy cattle herds in Egypt. A total of 240 serum samples were collected from six Egyptian provinces. Between 2019 and 2020, samples were tested by Enzyme linked immunosorbent assay (ELISA) for detection of PI animals, and then molecular characterization was performed. Six calves were found PI with a prevalence of 2.5% (6/240). Using molecular characterization, HoBi-like Pestivirus (BVD-3) was successfully identified in Egypt for the first time. Based on the BVD-3 reference strains on Genbank, the detected strains had an identity ranging from 98.8 to 99.6%. Partial nucleotide sequence of the 5'UTR gene for six tested samples was submitted to Genbank with accessions: OM324396, OM324397, OM324398, OM324399, OM3243100, and OM3243101.

BVDV, BHV-1 and BLV antibodies in dromedary camels of Turkey kept without and with ruminants

Camels are the only animals bred to sustain the tradition of wrestling in Turkey and are reared within a limited set of geographic areas. Farmers of such animals may also be engaged in ruminant breeding. The current research was aimed at documenting bovine viral diarrhoea virus (BVDV), bovine herpesvirus-1 (BHV-1), and bovine leukaemia virus (BLV) infections in sera collected from dromedary camels in four different geographical regions of Turkey during the years 2019-2021. All samples were tested for BVDV, BHV-1 and BLV antibodies as well as BVDV antigen by ELISA. Antibodies against BVDV were found in 16.8% of the camel sera tested. However, none of the camels sampled were positive in terms of BHV-1 and BLV antibodies as well as BVDV antigen. The prevalence was observed higher in the herds in which ruminants were raised in addition to camels (OR = 4.583, 95% CI, 1.298-16.182), (p = 0.018), while the prevalence was observed lower in the herds in which only camels were raised. This study showed that BVDV infection was more prevalent than BHV-1 and BLV infections in Turkish dromedary camels. Herewith, the camels, being a susceptible species to numerous viral ruminant diseases, may also serve as an important source of BVDV infection for other ruminant animals in the same flock.

Seroprevalence and association of bovine viral diarrhea virus (BVDV) serostatus with reproductive problems in dairy cattle in central and southern Ethiopia

Bovine viral diarrhea (BVD) is an economically important cattle disease with worldwide distribution and characterized mainly by suboptimal fertility in the affected herds. The objectives of this study were to estimate the seroprevalence of BVDV within dairy cattle, to identify potential risk factors, and to assess the association with occurrence of reproductive problems. Sera (n = 954) collected from dairy cattle from 98 herds in southern and central Ethiopia were tested for BVDV antibodies using a commercial ELISA. Among screened sera samples, 20.9% (95% CI, 18.4, 23.6) tested positive to BVDV antibodies. The herd prevalence was 50% (95% CI, 40.1, 59.9) and the intra-herd prevalence ranged between 2.6 and 100% (mean = 31.4%) in positive herds. Geographic region, herd size, and animal arrangement in the farm had significant association with serostatus (p < 0.05). Cattle from southern Ethiopia and herds of large size had 2.8 (95% CI, 1.9, 4.2) and 2.6 (95% CI, 1.5, 4.6) times higher odds of being seropositive compared to their counterparts, respectively. Serostatus to BVDV was associated with history of anestrus, repeat breeding (RB), mastitis, and extended calving interval (CI) (p < 0.05). Animals with history of extended CI and mastitis were 1.7 (95% CI, 1.0, 2.7) and 2.2 (95% CI, 1.5, 3.2) times more likely to be seropositive compared with those with normal CI and no history of mastitis, respectively. On the other hand, animals with history of anestrus and RB were less likely to be seropositive to BVDV compared to cattle with no such history. Sera from 26 selected cattle were also examined using reverse transcription (RT)-PCR for detection of BVDV RNA; however, all samples tested were negative for the presence of BVDV nucleic acid. Our study highlights the variation in BVDV status within Ethiopian dairy herds, and association with some important reproductive performance traits and potential risk factors.

Seroprevalence of bovine viral diarrhea virus (BVDV) in cattle from Sotaquirá, Colombia

Worldwide distributed Bovine Viral Diarrhea Virus (BVDV) represents a high risk of infection in most bovine farms, in which it is associated with gastrointestinal, respiratory, and reproductive diseases. The purpose of this research was to establish the seroprevalence and the main risk factors associated with the presentation of BVDV in the municipality of Sotaquirá, Colombia. Samples were taken from 1000 cattle of Holstein, Ayrshire, Jersey, Normande Gyr and Holstein x Gyr. Epidemiological surveys were implemented, reproductive and management variables were taken into consideration. Indirect ELISA was performed to detect specific antibodies against BVDV using the commercial kit SERELISA® BVD p80 Ab Mono Blocking. The overall seroprevalence of antibodies against BVDV was 42.5% (425/1000), where the Gyr breed (59.1% apparent prevalence (AP); 60.3% real prevalence (PR)) and the age group > 4 years (53.0% PA; 54.4% PR) presented the highest seroprevalences. A significant statistical association was found for the breed, age, management practices evaluated and the presentation of PI3 (p ≤ 0.05). Age group > 4 years, Normande breed, presentation of PI3 and grazing lease were established as risk factors associated with BVDV in the herds. These infections are mainly associated with dairy cattle and herds with many animals, so it is important to consider vaccination plans as a preventive system and follow up on the most common diseases.