A cross-sectional serosurvey in a sheep population in central Italy following a bluetongue epidemic

Global hotspots and academic trends of vector-borne diseases in the order Diptera (Arthropoda: Insecta): a bibliometric visualisation

Blood-sucking arthropods belonging to the order Diptera, encompassing mosquitoes, sandflies, midges, blackflies, horseflies and tsetseflies serve as vectors for a myriad of pathogens, inflicting substantial harm on both human and animal health globally. The analysis and visualisation of global hotspots and trends pertaining to vector-borne diseases, stemming from these six categories of arthropods, constituted a reliable reference for further delving into the research on Diptera insect vectors. To achieve this, we mined literature information from the Web of Science Core Collection (WoSCC), encompassing all publications related to these six arthropod groups, and leveraged VOSviewer software for bibliometric analysis and visualisation. This resulted in the construction of comprehensive relationship networks encompassing keywords, countries, institutions and authors. A comprehensive analysis encompassed 41,393 research publications, segmented into 34,363 studies on mosquitoes, 1,668 on sandflies, 3,665 on midges, 241 on blackflies, 336 on horseflies and 1,120 on tsetseflies. The bibliometric analysis, coupled with visual characterisation, offered a multifaceted synthesis of the gathered data from diverse angles. The scientometric analysis quantitatively assessed and identified the contributions of keywords, countries, institutions and authors pertaining to the research of each vector. The resulting visualisation knowledge maps elucidate collaborative network relationships within the respective vector research domains. This research endeavour stems from numerous driving forces, and a comprehensive grasp of its future trajectories and research hotspots can empower scientists with historical perspectives and forward-looking insights, fostering the formulation of innovative and impactful research ideas for the years ahead.

National Seroprevalence and Risk Factors of Bluetongue Virus in Domestic Ruminants of Peru

Bluetongue (BT) is a viral infection caused by the bluetongue virus (BTV) that affects domestic and wild ruminants worldwide. It is primarily transmitted by Culicoides spp. midges, and its infection is highly prevalent across temperate and tropical regions. However, significant changes in the global distribution of BTV have been observed in recent years. We aimed to evaluate the national BTV seroprevalence and risk factors among domestic ruminants (cattle, sheep, and goat species) in Peru. Serum samples were collected from 3452 cattle of 453 districts, 2786 sheep of 408 districts, and 1568 goats of 271 districts using a cross-sectional study in two stages (at the district and animal level) from 2017 to 2019 and analyzed by competitive enzyme-linked immunosorbent assay (cELISA). The national BTV true seroprevalences at animal level for cattle, sheep, and goats were 20.34% (95% CI: 17.76-20.82), 7.63% (95% CI: 7.17-9.56), and 8.58% (95% CI: 7.52-10.85), while the true districts-level seroprevalences were 31.53% (95% CI: 24.06-33.77), 24.41% (95% CI: 18.06-27.53), and 13.35% (95% CI: 8.59-17.98), respectively. In addition, we found that altitude and maximum temperature were identified as important factors influencing the seroprevalence of BTV in cattle, sheep, and goats. Higher altitudes above 3000 m above sea level (masl) played a protective role, reducing the BTV seroprevalence. In conclusion, antibodies against BTV were detected in Peruvian domestic ruminants without clinical signs. The seroprevalence was low in the South (<10.0%), varied in the Center and North, and high (>30%) in the East (Amazon rainforest). This study lays the groundwork for identifying BTV serotypes and Culicoides spp. in different regions, including altitudes above 3000 masl, to enhance BTV surveillance in Peru.

Outlook on RNAi-Based Strategies for Controlling Culicoides Biting Midges

Culicoides are small biting midges with the capacity to transmit important livestock pathogens around much of the world, and their impacts on animal welfare are likely to expand. Hemorrhagic diseases resulting from Culicoides-vectored viruses, for example, can lead to millions of dollars in economic damages for producers. Chemical insecticides can reduce Culicoides abundance but may not suppress population numbers enough to prevent pathogen transmission. These insecticides can also cause negative effects on non-target organisms and ecosystems. RNA interference (RNAi) is a cellular regulatory mechanism that degrades mRNA and suppresses gene expression. Studies have examined the utility of this mechanism for insect pest control, and with it, have described the hurdles towards producing, optimizing, and applying these RNAi-based products. These methods hold promise for being highly specific and environmentally benign when compared to chemical insecticides and are more transient than engineering transgenic insects. Given the lack of available control options for Culicoides, RNAi-based products could be an option to treat large areas with minimal environmental impact. In this study, we describe the state of current Culicoides control methods, successes and hurdles towards using RNAi for pest control, and the necessary research required to bring an RNAi-based control method to fruition for Culicoides midges.

Prevalence and risk factors of bluetongue in small and large ruminants maintained on Government farms in North-western Pakistan

This study reports prevalence of antibodies against bluetongue virus (BTV) in animals kept on Government farms/research stations in North-western Pakistan and its association with different risk factors. In total, 1257 blood samples were collected, at random, from animals on 12 separate Government farms/research stations. The prevalence of antibodies against BTV was evaluated using a competitive ELISA. Mixed effects univariate and multivariate logistic regressions were applied to ascertain different risk factors associated with the prevalence of the infection using farm as random effect variable. The overall weighted seroprevalence was recorded as 52%. In univariate analysis, a significant association between sero-conversion to BTV infection and species (P < 0.0001), sex (P < 0.0001), herd size (P = 0.0295) and age of animal (P < 0.0001) was recorded. In multivariate mixed effects logistic regression analysis, prevalence of the infection was found to be 7 (95% CI =2-28) times higher in goats and buffalo than in sheep. Prevalence of the infection was found to be 2.5 (95% CI =1.7-3.3) times higher in female than male animals. However, no significant association was found between sero-conversion of BTV and herd size in multivariate mixed effects logistic regression. Age was found to be a risk factor for the sero-conversion; odds of sero-conversion to BTV increased by 1.29, 1.4, 1.32 and 1.6 times per year increase in age of sheep, goats, buffalo and cattle, respectively. Prevalence of bluetongue was found higher in animals maintained on Government owned farms than that in individual holdings, as previously reported in Pakistan.

Serological and molecular prevalence study of bluetongue virus in small domestic ruminants in Morocco

Bluetongue is an arthropod-borne viral disease transmitted by Culicoides biting midges, affecting domestic and wild ruminants. The current study aims to assess the seroprevalence of the bluetongue virus (BTV) and confirm its active circulation among sheep and goats populations in Morocco, as well as study the risk factors associated with BTV infection. To this end, a total of 1651 samples were randomly collected from 1376 sheep and 275 goats in eight (out of 12) regions of the country between March 2018 and July 2021.These samples were primarily tested using competitive ELISA (c-ELISA). Subsequently, 65% of c-ELISA positives (n = 452) were analyzed by real-time reverse transcription-polymerase chain reaction (RT-qPCR). The results revealed an overall BTV seroprevalence in small ruminants in Morocco of 41.7%, including 42.6% in sheep and 37.5% in goats. The RT-qPCR results showed that the overall BTV viropositivity rate was 46.7%, including 48.1% in sheep and 41.8% in goats. These viro-serological rates varied significantly by age, sex, and breed of the tested animals, husbandry method, season, and geographic origin. This indicates that these parameters constitute risk factors for BTV transmission routes in Morocco. The findings also indicate that goats play a role as reservoirs in maintaining the BTV in Morocco. It appears from this study that bluetongue is endemic in Morocco. The environmental and climate conditions as well as the husbandry methods adopted in the country are particularly favorable for the virus transmission throughout the country.

Selection for Favorable Health Traits: A Potential Approach to Cope with Diseases in Farm Animals

Disease is a global problem for animal farming industries causing tremendous economic losses (>USD 220 billion over the last decade) and serious animal welfare issues. The limitations and deficiencies of current non-selection disease control methods (e.g., vaccination, treatment, eradication strategy, genome editing, and probiotics) make it difficult to effectively, economically, and permanently eliminate the adverse influences of disease in the farm animals. These limitations and deficiencies drive animal breeders to be more concerned and committed to dealing with health problems in farm animals by selecting animals with favorable health traits. Both genetic selection and genomic selection contribute to improving the health of farm animals by selecting certain health traits (e.g., disease tolerance, disease resistance, and immune response), although both of them face some challenges. The objective of this review was to comprehensively review the potential of selecting health traits in coping with issues caused by diseases in farm animals. Within this review, we highlighted that selecting health traits can be applied as a method of disease control to help animal agriculture industries to cope with the adverse influences caused by diseases in farm animals. Certainly, the genetic/genomic selection solution cannot solve all the disease problems in farm animals. Therefore, management, vaccination, culling, medical treatment, and other measures must accompany selection solution to reduce the adverse impact of farm animal diseases on profitability and animal welfare.

Prevalence and risk factors of some arthropod-transmitted diseases in cattle and sheep in Jordan

Aims:

The objectives of this study were to determine the prevalence and associated risk factors of bluetongue virus (BTV) in sheep and bovine ephemeral fever virus (BEFV) in dairy cattle in Jordan.

Materials and Methods:

A simple randomized study was designed to collect 600 serum samples from sheep and 300 serum samples from dairy cattle located in the Northwestern parts of Jordan. In addition, data regarding farm management were collected using a pre-tested questionnaire through personal interview to determine potential risk factors. The seroprevalences of BEF and BTVs were determined using serum neutralization test and BTV group-specific competitive enzyme-linked immunosorbent assay, respectively.

Results:

The overall seroprevalence of neutralizing antibodies against BEFV in dairy cattle was 45.37%. The overall seroprevalence of BTV group-specific antibodies in sheep was 47.8% (54% true seroprevalence). Logistic regression analysis identified geographic location (Irbid) (odds ratio [OR]=1.0; confidence interval [CI]=0.5-2.1), no use of disinfectants on the farm (OR=1.0; CI=0.05-0.1), and lack of veterinary services (OR=10; CI=3.5-13.2) as risk factors associated with high seropositivity against BTV in sheep. Geographic location (Jarash) (OR=3; CI=1.0-5.5), age of the animal (1-2 years of age (OR=1; CI=0.3-1.9), and lack of veterinary services (OR=9; CI=4-11) were identified as risk factors associated with high seroprevalence against BEFV in dairy cattle.

Conclusion:

Results of this study indicate that BEFV in dairy cattle and BTV in sheep are endemic in Northwestern regions of Jordan. Implementation of appropriate control measures is, therefore, required to reduce the adverse effects of these diseases on animal health and productivity.