In September 2023, the official national reference laboratory confirmed the presence of BTV serotype 3 in The Netherlands. In the following weeks, it appeared that the infection caused very severe clinical signs in sheep, but it was challenging for the involved veterinary clinicians to select appropriate labeled drugs to treat them. The objective of this study was therefore to document the clinical presentation and survival outcomes of sheep affected by bluetongue and to evaluate the effects of a treatment protocol with and without antihistamines. From a group of 83 sheep with acute and clear clinical signs of bluetongue, one group of 41 sheep received a single injection of meloxicam (1 mg/kg) followed by oral paracetamol tablets (10-20 mg/kg, 3dd for 3d). Another group with 42 sheep received the same treatment with the addition of an antihistamine injection (chlorphenamine maleate, 1 mg/kg, 1dd for 3d). Clinical signs and survival rates were monitored for all sheep. Logistic regression and survival analyses were performed to evaluate the data. An overall case fatality rate of 57% was observed, which illustrates the challenge in treating infected naïve animals with BTV-3. The most commonly encountered clinical signs were excessive salivation, dyspnea, depression, and lameness. Severe salivation was associated with significantly reduced survival time. The mean survival time for the group treated with antihistamines was 0.8 days, whereas it was 2.5 days for the group without antihistamines. The results of this study may not be representative of bluetongue infections caused by other serotypes or under different conditions. Based on our findings, however, we cannot recommend the use of antihistamines for treating bluetongue-affected sheep, as they did not improve survival. We would like to emphasize the importance of timely decision-making regarding the continuation or cessation of treatment, given the typically low survival rates in clinically affected sheep.

Most viral diseases display a variable clinical outcome due to differences in virus strain virulence and/or individual host susceptibility to infection. Understanding the biological mechanisms differentiating a viral infection displaying severe clinical manifestations from its milder forms can provide the intellectual framework toward therapies and early prognostic markers. This is especially true in arbovirus infections, where most clinical cases are present as mild febrile illness. Here, we used a naturally occurring vector-borne viral disease of ruminants, bluetongue, as an experimental system to uncover the fundamental mechanisms of virus-host interactions resulting in distinct clinical outcomes. As with most viral diseases, clinical symptoms in bluetongue can vary dramatically. We reproduced experimentally distinct clinical forms of bluetongue infection in sheep using three bluetongue virus (BTV) strains (BTV-1IT2006, BTV-1IT2013 and BTV-8FRA2017). Infected animals displayed clinical signs varying from clinically unapparent, to mild and severe disease. We collected and integrated clinical, haematological, virological, and histopathological data resulting in the analyses of 332 individual parameters from each infected and uninfected control animal. We subsequently used machine learning to select the key viral and host processes associated with disease pathogenesis. We identified and experimentally validated five different fundamental processes affecting the severity of bluetongue: (i) virus load and replication in target organs, (ii) modulation of the host type-I IFN response, (iii) pro-inflammatory responses, (iv) vascular damage, and (v) immunosuppression. Overall, we showed that an agnostic machine learning approach can be used to prioritise the different pathogenetic mechanisms affecting the disease outcome of an arbovirus infection.

Prediction and transmission analysis of bluetongue disease in China

In 2021, a pregnant Rottweiler dog living on a sheep farm was diagnosed with clinical bluetongue (BT) infection. This study reports on the investigation of this farm where bluetongue virus (BTV) infection was diagnosed in this atypical host species. Samples were collected during farm visits 14, 28, 60, and 89 days after the onset of clinical signs in the pregnant Rottweiler. Blood was collected from all farm dogs (n = 6) and tested for BTV genome using a reverse-transcriptase quantitative PCR (RT-qPCR) assay and BTV antibodies with the competitive ELISA (cELISA) and dogs positive by RT-qPCR were further tested using virus neutralization (VN) serological testing. Blood was also collected from 16 sick sheep and tested using RT-qPCR. Midges were trapped on the study farm using an Onderstepoort UV light trap placed above a sheep pen for 36 hr at the first farm (14 days) visit. Parous/gravid midges were tested by BTV RT-qPCR in batches of up to 200 midges per species. Blood-fed midges (n = 308) were tested using a PCR species probe (KAPA Multiplex Master Mix) to identify the host species on which the midge had fed. Three dogs (n = 3/6) had detectable BTV RNA with RT-qPCR and high VN antibody titers to BTV. All RT-qPCR-positive dogs and one additional dog tested cELISA seropositive (n = 4/6). Bluetongue virus RNA was detected in 5/16 sheep tested. The most abundant midge species was Culicoides imicola (99.3%) and BTV was only detected in this species (n = 3/4 batches of 200 parous midges). Dog blood was not detected in any blood-fed midges tested. The occurrence of natural BT viraemia in exposed dogs creates a potential risk of BTV entry into BT-free countries through dog importation. It remains unclear whether BT viremia in dogs is capable of onward transmission.

In southern California, USA, annual reoccurrence of bluetongue infection in cattle (Bos taurus Linnaeus (Artiodactyla: Bovidae)) suggests that bluetongue virus (BTV) persists year-round but escapes detection during cooler months, reappearing when the weather gets warmer. The persistence of the virus in the adult biting midge vector, Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae), has been suggested. However, it is unknown whether adult C. sonorensis are sufficiently active during the winter months to transmit BTV throughout this period. This study captured host-seeking C. sonorensis in the Chino dairy region of southern California throughout the BTV interseasonal period (winter through early spring) over 3 years to assess adult host-seeking activity and adult survival during this period. BTV prevalence in host-seeking midges was also determined. Host-seeking nulliparous and parous C. sonorensis were consistently captured throughout the winter months, which combined with wintertime adult midge survival of ≤27 d, suggests the BTV overwintering is likely due to ongoing low-level transmission to available cattle hosts. However, BTV was not detected in midges captured during January through April in this study, suggesting that BTV transmission during the winter months may be occurring at too low a level to detect even with the substantial trapping effort applied in this study.

Bluetongue virus (BTV) is an arbovirus that is transmitted between domestic and wild ruminants by Culicoides spp. Its worldwide distribution depends on competent vectors and suitable environmental ecosystems that are becoming affected by climate change. Therefore, we evaluated whether climate change would influence the potential distribution and ecological niche of BTV and Culicoides insignis in Peru. Here, we analyzed BTV (n = 145) and C. insignis (n = 22) occurrence records under two shared socioeconomic pathway scenarios (SSP126 and SSP585) with five primary general circulation models (GCMs) using the kuenm R package v.1.1.9. Then, we obtained binary presence-absence maps and represented the risk of transmission of BTV and niche overlapping. The niche model approach showed that north and east Peru presented suitability in the current climate scenario and they would have a decreased risk of BTV, whilst its vector would be stable and expand with high agreement for the five GCMs. In addition, its niche overlap showed that the two niches almost overlap at present and would completely overlap with one another in future climate scenarios. These findings might be used to determine the areas of highest priority for entomological and virological investigations and surveillance in order to control and prevent bluetongue infections in Peru.

Bluetongue (BT) is an insect-borne, non-contagious viral disease which affects domestic ruminants including camels and is transmitted by Culicoides spp. Clinical symptoms of BT are typically seen in sheep, although subclinical BT infections are mostly seen in cattle, goats, and camelids. The goal of the present study was to evaluate the sero-prevalence of Bluetongue virus (BTV) in camels from some governorates in Egypt’s southern and northern regions, as well as the infection’s potential risk factors. During 2020–2021, a cross sectional study was conducted to screen presence of anti-BTV antibodies in 400 serum samples, which were collected randomly from camels, examined using competitive enzyme-linked immunosorbent assay (cELISA). The sera of 102 out of 400 camels tested positive for BTV, representing a frequency of 25.5%. Moreover, the odds of sero-positivity were higher among camels living in Aswan (OR = 5.33, 95%CI: 2.35–12.11), especially in females (OR = 2.63, 95%CI = 1.44–4.09) during summer season (OR = 2.40, 95%CI = 1.20–4.81). Furthermore, the probability of getting BTV infection increased when camels were exposed to the insect vectors (OR = 1.63, 95%CI = 0.87–3.09). The high prevalence of BTV in camels in several Egyptian regions highlights the need for more epidemiological investigations of BTV infection in other ruminant species in order to better control BT disease in these regions.

Bluetongue (BT) causes an economic loss of $3 billion every year in the world. After two serious occurrences of BT (bluetongue virus [BTV] occurrence in 2006 and 2015), France has been controlling for decades, but it has not been eradicated. As the largest live cattle export market in the world, France is also one of the major exporters of breeding animals and genetic materials in the world. The biosafety of its exported cattle and products has always been a concern. The scenario tree quantitative model was used to analyze the risk of BTV release from French exported live cattle and bovine semen. The results showed that with the increase in vaccination coverage rates, the risk decreased. If the vaccine coverage is 0%, the areas with the highest average risk probability of BTV-4 and BTV-8 release from exported live cattle were Haute-Savoie and Puy-de-Dôme, and the risk was 2.96 × 10-4 and 4.25 × 10-4 , respectively. When the vaccine coverage was 90%, the risk probability of BTV-4 and BTV-8 release from exported live cattle was 2.96 × 10-5 and 4.24 × 10-5 , respectively. The average probability of BTV-8 release from bovine semen was 1.09 × 10-10 . Sensitivity analysis showed that the probability of false negative polymerase chain reaction (PCR) test and the probability of BT infection in the bull breeding station had an impact on the model. The identification of high-risk areas and the discovery of key control measures provide a reference for decision makers to assess the risk of French exports of live cattle and bovine semen.

Bluetongue (BT) is an infectious, noncontagious, vector-borne viral disease that affects wild and domestic ruminants transmitted by Culicoides spp. A cross-sectional study was carried out during the period 2016-2017 in Gadarif state. A total of 276 sera samples were collected from camels in six localities of Gadarif state, eastern Sudan, to investigate bluetongue virus (BTV) seroprevalence and associated risk factors of BTV infection including age, sex, breed, locality, and ecology of the region. Enzyme-linked immunosorbent assay (ELISA) was used for estimation of BTV seroprevalence rate. The overall BTV seroprevalence rate was 96.7% in the study area ranging from 93.5% to 100% in six screened localities with no significant differences. The findings revealed similar BTV seroprevalence rates in both males and females, but high rates were found in age group of less than one year and two to three years with estimated 100%. However, the lowest seroprevalence was found in the age group of five to four years with estimated BTV to be 92.3%. BTV seropositivity was not found to be statistically associated with examined different camel breeds which revealed 93%, 94.4%, 97.6%, and 97.8% seroprevalence in Bushari, Rashide, Arabi, and Anafi, breeds, respectively. Epidemiology of BTV assessment according to the ecology of the area showed high BTV seroprevalence in desert and savanna with estimated 100% and lower BTV seroprevalence in arid and rich savanna with estimated 94.8% and 95.7%, respectively. There was no significant association between BTV ELISA positivity and sex, breed, and ecology of the area.

Astudy was undertaken to find out the concurrent mixed bluetongue and theileriosis in Pattanam sheep in the Cauvery delta region of Tamil Nadu. During September to October 2018, a total of 42 sheep (aged 3 months to 5 yrs.) from five flocks exhibiting symptoms of anorexia, oral lesions, lameness and lymph node enlargement was studied. On reverse transcriptase polymerase chain reaction (RT-PCR), the presence of bluetongue virus was confirmed in 2 (4.76%) sheep. Giemsa stained peripheral blood smears showed the presence of Theileria spp. in 8 (19.05%) animals. Besides these, 15 (35.71%) sheep had the concurrent infections of both bluetongue and theileria. Blue tongue virus antibodies could not be detected in all the serum samples by ELISA. The morbidity and mortality rates in flocks ranged from 10.0 to 85.7% and 3.1 to 16.0%, respectively. The mixed infections were predominantly seen in males aged between 7 months to 2 yrs. The positive animals were treated with oxytetracycline (10 mg/kg IV), buparvaquone (2.5 mg/kg IM) and meloxicam (0.5 mg/kg IM) along with supportive treatment. After treatment, 95% of animals recovered while 5% succumbed due to advanced stage of disease. Early diagnosis and screening of animals for concurrent/multiple pathogens and implementation of vector control measures are needed to reduce the losses associatedwith these diseases.

Bluetongue is an infectious viral disease that is endemic in the domestic livestock populations of all tropical and subtropical countries. BT was first reported in Iran in 1972, however until now there is the absence of comprehensive information on the BT status in Iran. We aimed to present the seroprevalence on BT in farm animals of Iran based-on a meta-analysis study. The meta-analysis study was conducted in national and international databases to find articles which evaluated bluetongue seroprevalence by antibody-captured ELISA test in livestock in Iran by searching terms including bluetongue, sheep, ovine, goat, caprine, cow, cattle, bovine, buffalo, camel, Iran and prevalence alone or in combination in both English and Farsi language. After reviewing 82 published articles, a total of 48 studies from 29 articles were eligible to be included in this meta-analysis study. The total seroprevalence of bluetongue in apparently healthy sheep, goat, cow and camel at animal level based on ELISA test was 50.4% (95% CI= 43.5-57.2), 79.2% (95% CI= 70.7-85.8), 3.3% (95% CI= 0.6-15.0) and 44.8% (95% CI= 20.8-71.5), respectively. The estimated pooled odds ratios between abortion history and bluetongue infection estimated among sheep (OR=1.75, 95 % CI= 0.84 to 3.68) and goat (OR=2.93, 95 % CI= 1.26 to 6.80). A well-defined control strategy for preventing and controlling BTV spread in Iran should be based on further studies on BT epidemiology and BTV serotypes, vector control, animal movement restrictions and vaccination program to reduce.

In this rapid communication, a novel atypical bluetongue virus (BTV) strain detected in goats in the Piedmont region (north-western Italy) is described. This strain, BTV-Z ITA2017, is most related in Seg-2/VP-2 (83.8% nt/82.7% aa) to strain TOV of BTV-25. Reactive antisera of goats positive by cELISA for BTV antibodies failed to neutralize a chimeric virus expressing the outermost protein of TOV. Infected animals displayed low levels of RNAemia and absence of clinical signs consistent with bluetongue infection, a scenario described in animals infected with atypical BTV strains.

Aim:The study was undertaken to find out the spatial dynamic occurrence and patterns of the global spread of bluetongue (BT) disease for the period from 1996 to 2016, as well as the assessment of the risk of occurrence and its spread in 2017-2018.Materials and Methods:Outbreaks (serum samples were collected from clinically healthy as well as suspected animals in infected points) were confirmed and reported officially by veterinary departments which represent different geographical regions in the world to World Organization for Animal Health. These reports explained that ELISA and polymerase chain reaction were used to identify the BT disease, taking in the account number of infected, dead animals, and focus of BT infection in all susceptible animals from 1996 to 2016. Once conventional statistical population was defined (an observational study), we had classified data as well as possible to answer to our aim, using descriptive statistics methods, including the test of the relationship between different epizootiological indicators.Results:The spatial dynamic study of BT’s occurrence and its spread in the world over the two past decades was presented by different epizootic indicators. The given analysis includes assessment and measurement of risk factors. It was built too, regression models, and allowed to put different forecasts on the different epizootic indicators in the years 2017-2018 by the extrapolation method. We had also determined that, in 2017, BT continues to spread with the total expectancy of 3.4 focus of infection (number of diseased animals in a single unfavorable point) and mortality of about 26 %; these rates tend to decrease in 2018. At abused points by BT, up to 78.4% of animals are mixed (more than one type) and in 21.6% - uniform. By this way, the relative risk of the incidence of appearance-abused points in mixed households has 3.64, which might be considered higher for the BT dissemination. Moreover, between the enzootic index and other epizootiological indicators had revealed an inverse correlation, i.e., to an increase in the level of enzootic index among the cattle population would be formed population less sensitive to BT. Cluster analysis was done, which had demonstrated the zoning of risk levels in the world and the occurrence of the disease intensity in the period 1996-2016 years. Then, assess connection degree of the dynamic of BT tension with geographical and socioeconomic conditions background 0.66 and 0.68, respectively.Conclusion:It is important to define a variety of BT risk factors and assess their influence on BT occurrence. However, the most important is to define the overlapping coinfluence between them that cause serious losses. To have an out of BT territory needs to make an emphasis of co-influence of risk factors on this zone. Was predicted a continue hits of disease in the next year with weight moderation through one year. Far from statists, to assess the given forecast may have a serious variety, taken in account problems of actual climate change in the world.

Orbiviruses, some of which are virulent in ruminant species, are transmitted by blood- sucking insects. They can cause the smallest blood vessels to leak, leading to oedema, which is presented as Bluetongue (BT) and/or Epizootic haemorrhagic diseases (EHD). Other clinical manifestations include big-muscle necrosis, excessive scialorrea, and coronitis. Pathology and laboratory testing can con rm the involvement of orbivirus. Bluetongue infection in naïve sheep can elicit the 'classical signs' of the disease and, therefore, can warn of Bluetongue virus' (BTV) attacks and of increased vector activity. In 2006, infection of cattle by serotype 7 of the Epizootic haemorrhagic disease virus (EHDV) was detected in Israel, with lesions clinically identical to those of BT disease in sheep. In 2006, serotype 15 of the BTV (BTV-15) was isolated in Israel from sheep with acute BT. In 2008 clinical BT in cattle was reported and con rmed in Israel. To date, additional serotypes (BTV-2, BTV-4, BTV-5, BTV-8, BTV-12, BTV-16, and BTV-24) have been reported, of these BTV-5, BTV-8, BTV-12, and BTV-24 were isolated for the rst time in the region. Some of these serotypes have been detected in animals with simultaneous double/triple infections with di erent BTV serotypes, so that reassortment may also occur during these simultaneous infections. The use of local strains for the development of inactivated or subunit vaccines would however help to ensure antigenic matching. Various changes in orbiviral diseases occurred between 2006 and 2013 in Israel, and similarities and di erences between Israel and Europe have been reported in this study.

Bluetongue is an infectious, a non-contagious, arthropod borne viral disease ofruminants and has been reported from most of the tropical and subtropical regionsof the world. Seroprevalence study was carried from July, 2013 to January,2015 to understand bluetongue virus infection in selected areas of sheep andgoats found in and around small ruminant breed improvement center. A total of1420 sera samples from sheep and goats were collected and screened for the presence of group specific bluetongue virus antibody using competitive Enzyme-Linked Immuno-Sorbent Assay(c-ELISA) with sensitivity of 100% and specificity of 99%. The overall seroprevalence of bluetongue virus antibody was 69.01% and 60.53% in sheep and goats, respectively. Seroprevalence of bluetongue ranges from 14.5% (Adami Tulu Research Center) to 91.43 % (Benestemay). Antibody to bluetongue virus was detected from both sheep and goats in all study areas. Result of this study showed that small ruminant dwelling in and around the small ruminantbreed improvement centers are exposed to bluetongue virus. In the present studyareas there were no observation of clinical cases in any species of animals. Thisindicates that local breed of animals are resistant to clinical disease of bluetongueinfection and or there may be circulation of mild virus strain in the population andso further studies are required to determine the bluetongue serotypes that arecirculating in sheep and goats.Keywords: Bluetongue Virus, ELISA, Seroprevalence, Sheep and Goats, Ethiopia

A total of 552 serum samples of sheep, goats and cattle from different localities at Assiut governorate, Egypt were screened for qualitative analysis of the BTV antibodies using a commercial competitive ELISA (cELISA) kit. The results showed an overall percentage of BTV positive sheep, goats and cattle serum samples were 41.86%, 24% and 85.42% respectively. A highest percentage of seropositivity was found inArab El- Awamer farm (100%), followed by Abnoub( 63. 64%), Sedfa(11. 43%), veterinary teaching hospital (11.11%), Aboteeg (3.57%) and Bani zeed el akrad (0% ) respectively. From examined sera all over the four years from 2012 to 2015 indicates prevalence of BTV antibodies by ( 62. 69%) during the non hot months and (10%) during the hot months, Female ruminants were more susceptible to the infection (61.29%) than male( 21.67%). The association between sex and prevalence of BT disease among ruminants observed in table (4). The results showed that the prevalence of BT was higher in female (61.29%) than male (21.67%). In conclusion, this study confirms the presence of blue tongue infection in Assiut Governorate, and cELISA were found to be sensitive and effective for screening of BTV group specific antibodies. The disease should be notifying its presence in Egypt since it was free from this disease and more studies should be attempets to estimate the serotype of blue tongue virus

The bluetongue (BT) is an infectious, non-contagious disease of ruminants with a substantial impact on income and welfare of animals. To date, scarce information about this disease in domestic yaks is available in Tibetan area of China. Seroprevalence of circulating antibodies to Bluetongue virus (BTV) in yaks from three regions of Tibet and Hongyuan area of Sichuan Province in China was investigated by a commercial competitive enzyme-linked immunosorbent assay kits. A total of 736 blood samples were collected during the year 2012 and 2013, and nearly 2% serum samples were found positive for BTV antibodies in Hongyuan area during the year 2012, and 4.89 and 3.88% of samples showed positive results for BTV in Tibetan and Hongyuan area, respectively, in 2013. The results indicated the occurrence of BT infection in Chinese yaks for the first time in Tibet and Hongyuan area of Sichuan Province with the presence of BTV antibodies in these ruminants.

Peste des Petits Ruminants (PPR) is a highly contagious transboundary animal disease of wild and domestic small ruminants and notifiable byworld organization for animal health (OIE). It constitutes a serious threat to livestock production in many developing countries, in western Africa and southern Asia. The disease is caused by peste des petits ruminants virus (PPRV), a negative sense, single stranded RNAvirus belonging to the genus Morbillivirus of the family Paramyxoviridae (Gibbs et al. 1979). PPRV causes huge disease burden on agriculture across developing world, affecting small ruminant production and in turn increases poverty in some of the poorest parts of the world (Banyard et al. 2010). In PPR endemic regions of the world, conventional live attenuated vaccines are being used to vaccinate small ruminants (Diallo et al. 1989). Currently, the original Nigerian strain of PPRV (Nig 75/1) is used in the African countries (Diallo 2003). In India, three Indian strains of PPRV have been attenuated and shown to provide protective immunity (Saravanan et al. 2010). Although the live attenuated vaccines are efficacious, they suffer from the same draw back as that of live attenuated Rinderpest vaccine in terms of heat stability. This puts severe constraints on the coverage of small ruminant’s population during vaccination campaigns. Although there is one report of a method for making a heat stable live attenuated vaccine (Worrwall et al. 2000), such a thermo stable vaccine has not been put to use or field tested. Another major disadvantage of using live attenuated vaccine is that the antibody responses they induce in animals cannot be distinguished from those following a natural infection. This makes sero-epidemio surveillance of the disease impossible in endemic areas where a vaccination programme has been or is being implemented. The immune response to a given antigen can be regulated by a number of idiotypic determinants (Ids), and its counterpart, an anti-idiotypic antibody (anti-Id) or Ab2 (Jerne 1974). An idiotype is located on the variable regions of antibody molecules. An internal image anti-Id, Ab2 β recognizes an idiotypic determinant within the antigen combining site and bears a structural resemblance to the original antigen (Bona and Kohler 1984). The internal image Ab2 β antibodies have been shown to induce specific immune responses to hepatitis B surface antigen in chimpanzees (Kennedy et al. 1986) and as a vaccine candidate for the control of bluetongue infection by functionally mimicking VP7 antigen of bluetongue virus (Zhou and Lin 1997). We had earlier demonstrated that an internal image Ab2 against Rinderpest virus/Peste des petits Ruminants virus H/HN protein elicits virus neutralizing antibodies as well as T cell responses in the mouse model (Vani et al. 2007a). Further, using the mouse model, DNA encoding VH region of Ab2 elicited both neutralizing antibody and T cell responses, in the complete absence of viral antigen and these responses were long lasting (Vani et al. 2007b). * M. S. Shaila shaila@mcbl.iisc.ernet.in

The objective of the present study is to assess the sero-prevalence and associated risk factors for small ruminants’ bluetongue infection in selected agro-ecology of woliyta zone, southern Ethiopia. Serum samples were collected randomly from the accessed small ruminates and screened for detection of BTV-specific immunoglobulin G (IgG) antibodies using a competitive enzyme-linked immunosorbent assay (c-ELISA). A total of 476 serum samples were tested and 196 (41.17%) were positive for bluetongue virus antibodies. A prevalence rate ranging from 26.53% for the midland altitude to 73.47% for the lowland was recorded. To disease associated risk factor age, and location was recorded using multivariate analysis of logistic regression model. Within species goat 114 (58.2%) and sheep 82 (41.8%) sero positive reactors was recorded. This is the first report indicating the presence of bluetongue virus infection in the area.

BackgroundBluetongue virus causes febrile disease in sheep and a fatal hemorrhagic infection in North American White-tailed deer. However, in cattle the disease is typically asymptomatic and no clinical overt disease is associated with bluetongue infection. Bluetongue virus activity has been detected in Khartoum, Sennar and South Darfur states of the Sudan. Currently, no information is available in regard to previous exposure of livestock to Bluetongue virus in North Kordufan State, the largest livestock producing region in the country. The present study was conducted to determine the prevalence of bluetongue antibodies and to identify the potential risk factors associated with the presence of bluetongue antibodies among cattle in North Kordufan State, Sudan. A total of 299 bovine blood samples were collected randomly from six localities in North Kordufan State and were tested by enzyme-linked immunosorbent assay (ELISA) for detection of BTV-specific immunoglobulin G (IgG) antibodies.ResultsThe serological evidence of Bluetongue virus infection was observed in 58 out of 299 cows, accounting for a 19.4% prevalence rate among cattle in North Kordufan State. Older cattle (>2 years of age) had four times the odds to be infected with BTV compared to young cattle (OR = 4.309, CI = 1.941-9.567, p-value = 0.01). Application of preventive measures, such as spraying or dipping with insecticide protects cattle against Bluetongue infection. Application of vector control measures decreased the odds for bluetongue seropositivity by 7 times (OR = 7.408, CI = 3.111-17.637, p-value = 0.01).ConclusionsThe results of this study indicated that age and application of routine insecticides are influential risk factors for seroprevalence of Bluetongue in cattle. Surveillance of Bluetongue virus should be extended to include other susceptible animals and to study the distribution of the insect vectors in the region to better predict and respond to BTV outbreak in the State of North Kordufan, Sudan.