Brucellosis remains a neglected disease in the developing world: a call for interdisciplinary action

Brucellosis and associated risk factors, spatial distribution and cluster analysis: Case study in Khorasan Razavi Province, Iran

BACKGROUND

Brucellosis is a common zoonotic disease in Iran. This study aimed to investigate the epidemiological characteristics of human brucellosis and its affecting factors in Khorasan Razavi province, an endemic region in north-eastern Iran.

METHODS

In this descriptive-analytical study, the data of 15,334 brucellosis cases in Khorasan Razavi province from 2016 to 2022 were analyzed. Descriptive analysis and geographic information system (GIS)-based Inverse Distance Weighting (IDW) were conducted to assess the demographic factors and spatial modeling of the study population. Chi-squared and Fisher's exact tests were used for intergroup comparisons. A latent class cluster analysis (LCCA) in R programming language (poLCA) was employed to identify clusters and better understand the factors affecting the disease.

RESULTS

The results indicated that most of the brucellosis cases had been registered from 2020 to 2022 (26.5 %, 21.4 %, and 14.5 % of the total cases). The average incidence rate of brucellosis during the study period was 33.57 cases per 100,000 population. Over 84 % of the cases in clusters 1 and 3 (60.4 % of the whole study population) were males who often lived in rural areas. Only 29.3 % of the patients had a job related to livestock. These findings are consistent with the data on the consumption of unpasteurized dairy products and the history of animal vaccination.

CONCLUSION

Brucellosis cannot be significantly controlled by merely focusing on people working in the livestock industry, highlighting the impact of herd vaccination, and promoting public awareness, especially among housewives and younger people. Meanwhile, proper handling and disposal of infected animals, regular quarantine and inspection of livestock, and sanitization of animal environments have been recommended.

A Comprehensive Bibliometric Analysis of Brucellosis Research: Insights from CNKI and Web of Science Databases (2014-2023)

Purpose

This study aimed to analyze the current status, research hotspots, and frontiers of brucellosis from 2014 to 2023 using data from China National Knowledge Infrastructure (CNKI) and Web of Science (WoS) via CiteSpace, and to provide new insights for researchers in the field.

Material and Methods

Articles related to brucellosis published from 2014 to 2023 were retrieved from CNKI and WoS databases. CiteSpace V.6.3.R3 was employed to generate network maps and perform bibliometric analysis.

Results

A total of 467 references from CNKI and 3686 references from WoS were analyzed. In CNKI, the annual publication trend showed a decline, with Xu Liqing, Ma Li, and Yang Xuxin being the most prolific authors, and the Chinese Center for Disease Control and Prevention being the leading institution. The keyword cluster analysis identified 13 main clusters, while the keyword emergence map highlighted 15 keywords with the strongest emergence intensity. In contrast, WoS displayed an increasing trend in annual publications, with Heinrich Neubauer, Egyptian Knowledge Bank (EKB), and China as the top contributors in terms of authors, institutions, and countries, respectively. "Infection" was the most frequently occurring keyword. WoS analysis revealed 16 primary clusters and 25 keywords with high emergence intensity.

Conclusion

Between 2014 and 2023, CNKI saw a slight dip in brucellosis studies, while WoS research on it gained growing attention. CNKI literature primarily focuses on epidemiology, clinical manifestations, complications, and diagnostic methods, while WoS literature emphasizes pathogenesis and public health management. Effective prevention and control of brucellosis require interdisciplinary, cross-sectoral, and transnational cooperation.

Improving human brucellosis susceptibility mapping using effective and simultaneously metaheuristic-based feature selection and hyperparameter tuning

Human Brucellosis, a neglected zoonotic disease, affects 1.6 to 2.1 million people globally each year. In Iran, it has become a significant health concern, with an average annual incidence rate of 19.91 cases per 100,000 people. This study aims to create a reliable Human Brucellosis Susceptibility Map (HBSM) for Mazandaran Province using a hybrid machine learning approach that enhances performance through metaheuristic algorithms for feature and hyperparameter optimization. A transformation function is integrated into these algorithms to reduce computational and time complexities while simultaneously executing feature selection and hyperparameter tuning. Additionally, a two-phase mutation operator is employed to improve the performance of feature selection. The results indicate that the hybrid model of Support Vector Regression-Transformation Mutation Grey Wolf Optimizer (SVR-TMGWO) outperformed other models, achieving RMSE=0.7723, MAE=0.614, MdAE=0.473, and R = 0.536. The predicted HBSM for 2018 identified 68 rural districts in Mazandaran Province as being in the High and Very High susceptibility classes. The susceptibility map can help decision-makers more effectively prevent, control, and manage Human Brucellosis in Mazandaran Province.

Preparation and application of specific chicken yolk antibodies in detecting Brucella

Brucellosis, caused by Brucella, is a severe zoonotic disease. Conventional IgG antibody-based ELISA testing faces challenges such as false positives and cross-reactivity. In this study, three specific chicken yolk antibodies (IgY) targeting Brucella were isolated from the eggs of immunized hens, and a method for detecting Brucella utilizing these antibodies was developed and subsequently compared to traditional IgG antibodies. These IgY antibodies were generated against a fusion protein, LPS, and whole-cell antigen, and their potency was evaluated through indirect ELISAs. Testing was conducted to assess cross-reactivity, limit of detection, and detection in simulated samples. The IgY antibodies demonstrated high potency and no cross-reactivity with common foodborne pathogens. Both LPS-IgY and Brucella-IgY showed excellent detection capabilities in identifying Brucella, particularly in food samples. These results underscore the potential of using LPS-IgY and Brucella-IgY antibodies as replacements for conventional IgG antibodies in Brucella detection, especially in the realm of food safety. The implications of this study are significant, as it presents a promising alternative approach for detecting Brucella in food products, thereby reducing the risk of transmission and ensuring public health and safety.

Exploring potential cytokine profiles as diagnostic biomarkers for brucellosis in Mediterranean Buffaloes

Brucellosis is a zoonotic disease, with an important economic impact on the livestock industry and public health worldwide. Both Brucella abortus and Brucella melitensis can infect Mediterranean Buffalo (Bubalus bubalis), leading to infertility and abortion. In ruminants, the standard diagnostic approach involves two serological tests, the Rose Bengal Test and the Complement Fixation Test, applied in parallel, though their specificity requires improvement. Cytokines play a crucial role in coordinating immune responses through complex networks and can serve as biomarkers for various diseases. This study explored the potential use of cytokines as immunological biomarkers for Brucella infection in Mediterranean Buffalo. For this purpose, we included 18 healthy and 20 Brucella-infected buffaloes in our analysis. Heparinized blood samples were stimulated with the Brucella antigen, with PBS as nil control and PWM as lymphocyte viability control. After 16-24 h, plasma levels of IL-1α, IL-1β, IL-4, IL-6, IL-10, IL-17, IL-36Ra, MIP-1α, MIP-1β, MCP-1, CXCL8, IP-10, IFN-γ, TNF, and VEGF-A were measured using multiplex ELISA. Our results showed that infected animals released significantly higher levels of IFN-γ, IP-10, MCP-1 in response to Brucella antigen compared to healthy controls. Conversely, healthy animals released instead higher levels of IL-1α, IL-1β, IL-6 and IL-10 following antigen stimulation compared to infected animals. Finally, sequential canonical discriminant analyses were performed to generate predictive cytokine profiles for each group. The findings indicated that a combination of five cytokines (IFN-γ, IP-10, IL-1α, IL-1β, IL-6) can effectively distinguished infected from healthy buffaloes. Overall, this study suggests that incorporating these key immune cytokines could improve the diagnostic accuracy of brucellosis in Mediterranean Buffalo.

Development and Bayesian analysis of a competitive inhibition ELISA for caprine brucellosis

Caprine brucellosis, caused by Brucella melitensis, is a zoonotic disease responsible for abortions in goats and is endemic in several countries. Control measures include vaccination, serological assays, and culling of infected animals. Sensitive, specific, automatable, and low-cost serological assays are essential for use in endemic regions. This study aimed to develop and validate a competitive inhibition enzyme-linked immunosorbent assay (ciELISA) to detect anti-B. melitensis antibodies in goats. The ciELISA was standardized with pre-dilutions of ISaBmS (1/8 and 1/300) in negative goat serum. Validation was done using 1254 serum samples from non-vaccinated goats: 843 from brucellosis-free flocks and 411 from infected flocks in Argentina. Serum samples were tested with the ciELISA, buffer plate antigen (BPA) test, fluorescence-polarized antigen (FPA) test, and complement fixation test (CFT). The optimal ciELISA cutoff was determined using a receiver operating characteristic (ROC) curve, with CFT as the gold standard. Sensitivity and specificity were evaluated using the Bayesian Latent Class Model (BLCM). The ciELISA showed sensitivity of 98.29 % (95 % CI: 96.4-99.6) and specificity of 98.62 % (95 % CI: 97.6-99.6). The kappa statistic (κ) values between ciELISA and other tests were: BPA (κ = 0.94), FPA (κ = 0.79), and CFT (κ = 0.95). The ciELISA demonstrated excellent performance, being rapid and objective, making it suitable for detecting anti-B. melitensis antibodies in goat serum.

Short communication: Effects of age on the immune response induced by Brucella abortus S19 or RB51 vaccination in calves

Vaccination of bovine calves is one of the main policies for bovine brucellosis control in endemic areas. However, the effect of animal age on vaccine immunogenicity is still unknown and could help to determine an ideal age for vaccination, in order to maximize immune response. Thus, the objective of this study was to compare the in vitro expression of IFN-γ by stimulated PBMC after vaccination with B. abortus S19 and RB51 strains in calves vaccinated at different ages, between 3 and 8 months. Cell-mediated immune response was assessed through culture of peripheral blood mononuclear cells (PBMC) and quantification of IFN-γ in the supernatant by enzyme-linked immunosorbent assay (ELISA). In addition, serological assays were performed using 2-mercaptoethanol (2-ME), Standard Tube Agglutination (STAT) and Fluorescent polarization assay (FPA) tests. Blood samples and sera were collected in the inoculation day, as well as at 28 and 56 days after vaccination. A generalized linear mixed model was used to evaluate effect of age at vaccination on in vitro production of IFN-γ and no differences were observed comparing the different ages, for both RB51 and S19 vaccines (p > 0.05). A higher percentage of animals vaccinated with S19 at 3-4 months-old [77.28 % (7/9)] returned to the serological negative status at day 56, when compared to 5-6-months [50 % (5/10)] and 7-8 months-old animals [27.28 % (3/11)]. In conclusion, our findings indicated similar levels of IFN-γ in vitro production in animals between 3 and 8 months of age, following vaccination with S19 and RB51 strains.

Advances in biosensors: A breakthrough in rapid and precise brucellosis detection

Brucellosis, a significant zoonotic disease, poses a threat to both livestock and human health. Infections in livestock lead to abortion, infertility, and substantial economic losses in the industry. In humans, acute brucellosis can progress to a chronic condition, resulting in multisystemic infections with high morbidity and mortality rates. Additionally, the bioterrorism potential of certain Brucella species through aerosol transmission poses risks to laboratory workers and livestock handlers. Therefore, there is an urgent need for rapid and precise diagnosis of brucellosis in both animals and humans. Even with the availability of routine diagnostic techniques that are effective they frequently have some limitations. Biosensors, as innovative techniques, have demonstrated significant potential in detecting various pathogens with high efficiency. These biosensors can identify specific analytes, biomolecules of pathogenic bacteria, secreted antibodies against bacteria, and even the bacterial body in real time. Their high sensitivity, selectivity, and user-friendly configurations make them valuable tools for diagnostics. In this comprehensive review, beside the reviewing routine diagnostic tests for detecting brucellosis and discussing the positive and negative aspects of these methods, we explore different types of biosensors and their applications in diagnosing brucellosis. We hope to show how these advancements can result in quicker and more precise disease detection by offering a thorough evaluation of these technologies performance and contrasting it with more conventional diagnostic techniques. This improves patient outcomes by lowering the complications linked to delayed diagnosis in addition to advancing scientific knowledge of brucellosis.

Development of a plant-based vaccine against brucellosis: stable expression of Brucella abortus OMP25 in transgenic tobacco

Brucellosis, caused by Brucella species, is a global threat to livestock farming, resulting in economic losses and socio-economic challenges, particularly in rural areas. Despite its impact, no licensed human vaccines are available. Animal vaccination remains the most cost-effective control method, but traditional vaccine production is expensive. Edible vaccines, using plants as bioreactors to produce immunogenic antigens, offer a low-cost alternative by eliminating complex purification processes. This study developed a transgenic plant by expressing the Brucella abortus outer membrane protein OMP25 in tobacco plants. OMP25, a conserved transmembrane protein with high immunogenicity, was cloned into a Gateway pDONR vector via a Boundary Pairing reaction and transferred to a binary destination vector via a Left-Right reaction. The destination vector was introduced into Agrobacterium tumefaciens and subsequently used for Agrobacterium-mediated transformation of tobacco plants. Transgenic plants were selected on media containing kanamycin, and the expression of the transgene was verified through the fluorescence of green fluorescent protein. Microcallus formation and shoot development on selective media confirmed kanamycin resistance and the successful integration of the transgene. After phenotypic selection, genomic DNA was extracted from transgenic plants and analyzed by PCR (Polymerase Chain Reaction) using primers specific to the OMP25 gene. Positive PCR results validated the successful integration of the OMP25 gene into the plant genome. Gene expression was further confirmed at the RNA level through real-time quantitative PCR (qRT-PCR) and at the protein level via Western blot analysis. Future studies will evaluate immune responses in animal models. This approach demonstrates the potential for low-cost, effective vaccines to combat brucellosis, addressing critical economic and public health challenges.

Malaria misdiagnosis substantially contributes to the underestimation of global human brucellosis incidence

BACKGROUND

Brucellosis is a neglected and re-emerging zoonotic disease of nearly worldwide distribution. Recently, a new model utilizing publicly available data, voluntarily provided by countries to the World Organization for Animal Health (WOAH), estimated a global annual incidence of at least 1.62-2.10 million cases. However, global and regional knowledge gaps, partially attributed to lack of diagnostic capability and disease unawareness, result in misdiagnosis.

METHODS

This study incorporated misdiagnosis to assess the potential impact on incidence estimates. Specifically, we examined the potential impact of misdiagnosing brucellosis as malaria. Incidence rates modeled from WOAH data comprised a baseline estimate for brucellosis rates. A range of potential misdiagnosis rates based on World Bank malaria data and scientific literature were utilized to estimate the number of misdiagnosed cases. We assumed a conservative misdiagnosis range of 0.25-4.00% based on clinical studies that reported a 4-11% misdiagnosis rate.

RESULTS

We show that malaria misdiagnosis can significantly impact global annual incidence estimation of brucellosis. Rates of 0.25% increase brucellosis incidence by 0.34-5.4 M cases, while rates of 4% increase these estimates by 2.43-7.45 M cases.

CONCLUSIONS

Human brucellosis misdiagnosed as malaria can significantly impact global annual incidence estimates. Enhanced efforts are needed to identify misdiagnosed cases in countries where both diseases are endemic.

A novel IgG-Fc-Fused multiepitope vaccine against Brucella: robust immunogenicity

Brucellosis is one of the most common zoonotic diseases caused by Brucella spp. However, there is currently no Brucella vaccine available for humans. Although some attenuated live vaccines have been approved for animals, their protective efficacy is suboptimal. In previous studies, we utilized an epitope- and structure-based vaccinology platform to identify the immunodominant epitopes of Brucella antigens OMP19, OMP16, OMP25, and L7/L12, and constructed the multi-epitope vaccine MEV-Fc against Brucella. In this study, OMP19, OMP16, OMP25, and L7/L12, and MEV-Fc was expressed and purified via an Escherichia coli expression system, which validated that MEV-Fc possesses high immunological efficacy and exerts a significant protective effect in BALB/c mice within the Brucella infection model. MEV-Fc enhanced Th1 and Th2 immune responses and strongly induced the production of the pro-inflammatory cytokine IFN-γ. Furthermore, MEV-Fc protected mice against Brucella infection compared to control group (PBS). In conclusion, our results provide new insights and data support for the development of human Brucella vaccines.

[Risk factors associated with the presence of brucellosis in mixed establishments (caprine and bovine) in the province of Formosa, Argentina]

Brucellosis is a zoonotic disease with a worldwide distribution that causes significant productive losses and negative impacts on public health. The aim of this work was to identify the risk factors associated with the presence of brucellosis in mixed farms (cattle/goats) in the central-western region of the province of Formosa. Sixty seven mixed farms with 7,855 animals (2,943 cattle and 4,912 goats) were randomly sampled during 2022/2023. The samples were serologically analyzed (BPA + FPA) to determine which animals were positive. Likewise, in each farm, a confidential survey was carried out to evaluate potential associated variables. The statistical analysis was performed using Generalized Linear Mixed Models (GLMM) with binomial distribution, logarithmic link function, and farm as a random variable. The estimated prevalence of brucellosis in mixed farms was 9%, while the joint prevalence per animal (cattle and goats) was 2.75%. The prevalence of brucellosis in cattle and goats was explained by the presence of animals with reproductive signs (odds ratio, OR=40), the occurrence of abortions in the last term of gestation and the birth of weak offspring (OR=5.3), incorrect treatment of abortions (OR=8), the introduction of animals from other farms (OR=5.9), and not having a negative brucellosis certificate (OR=9.6). The management practices conducted in each farm such as preventive measures, sanitation practices for the pens, and prevention measures for the workers, are important for the control of brucellosis.

Risk perception, seroprevalence, and real-time PCR detection of Brucella among pyretic patients and domestic animals in Kwara State, Nigeria

Brucellosis is a neglected, reportable, and under-reported zoonosis that poses a significant public health challenge in endemic countries like Nigeria. In this study, the risk perception was assessed and 103 pyretic patients from three local government areas of Kwara State, Nigeria were screened by using Rose Bengal plate test (RBPT) and confirmed the analytical sensitivity through real-time PCR (qPCR). We further screened 150 cattle and 52 goats from within a 1-km radius of pyretic patients to determine disease burden in domestic animal reservoirs. Our findings revealed that most of the farmers have heard of brucellosis (89.3%, n = 92/103) while 38.8% (n = 40/103) reported they could identify the symptoms of brucellosis in their herds. The most important risk factors were the consumption of raw milk (92.2%, n = 95/103) and animal abortion within the last year (19.4%, n = 20/103). Also, most study participants (94.2%, n = 97/103) did not believe that they could be infected with the disease. The seroprevalence of brucellosis in humans was 5.8% (n = 6/103) and there was 100% concordance between the results of the RBPT and qPCR in humans. The seroprevalence was 18% and 25% in cattle and goats respectively. The qPCR revealed a lower prevalence rate of 11.3% and 15.4% in cattle and goats respectively. There was high discordance in sensitivity between the RBPT and qPCR in animal samples screened, although both tests had an analytical specificity of 100%. There was no association between awareness and positivity for brucellosis among the study participants and none of the sociodemographic variables significantly influenced the brucellosis positivity rate of humans. Public health physicians and community health workers should consider brucellosis as a differential diagnosis when clerking pyretic patients. In addition, we advocate for mass animal vaccinations and public education with an emphasis on identified risks.

Prevalence of human brucellosis in Ethiopia: systematic review and meta-analysis

Brucellosis is a significant public health challenge in Ethiopia, which is characterized by a high prevalence among humans. The disease is primarily transmitted through the consumption of unpasteurized dairy products, direct contact with infected animals, or inhalation of contaminated aerosols. In addition to its impact on human health, brucellosis imposes substantial economic burdens. However, existing epidemiological studies provide inconsistent prevalence estimates, underscoring the need for a more comprehensive and systematic analysis of the disease's burden and associated risk factors in Ethiopia. This systematic review and meta-analysis aimed to generate representative data on the prevalence of human brucellosis in Ethiopia. We searched databases like PubMed and Science Direct for articles published between 2007 and 2022. The analysis included 26 studies covering 5,718 human serum samples. The Complement Fixation Test served as the confirmatory diagnostic test. The results suggest a relatively high seroprevalence of human brucellosis in Ethiopia, with an overall pooled prevalence of 14.0% (95% CI: 10.23, 18.12). Prevalence varied significantly across regions, with the highest observed in Afar (24.21%) and the lowest in Oromia (7.75%). Substantial heterogeneity was observed (I² = 97.64%), suggesting significant variations in prevalence across regions and over time. Additionally, the analysis suggests a possible increasing trend in prevalence over the years. Human brucellosis is a significant health concern in Ethiopia, and further research is crucial for effective prevention and control. The higher prevalence than previously reported in meta-analyses underscores the urgent need for intervention strategies from policymakers, such as the Ministry of Health. Identifying risk factors associated with human brucellosis is essential for implementing effective control measures. Prioritizing brucellosis prevention and control is vital for ensuring public health and well-being. Prospero registration number: CRD42022350237.

Seroprevalence of Brucellosis in Livestock and Farmers' Choice of Milk Marketing Channels in Rwamagana District, Rwanda

Brucellosis remains an endemic disease in livestock populations in Rwanda, but the prevalence of the disease varies by geographic region. The common use of informal milk marketing channels represents a health hazard to humans when milk from Brucella-infected cows from one or more households is mixed with milk from other households for human consumption. In Rwanda, knowledge about the burden of brucellosis in livestock and factors associated with farmers' choice of milk marketing channels is very limited. The objectives of this study were 1) to estimate the seroprevalence of brucellosis in livestock in Rwamagana District in Rwanda and 2) to estimate the frequency of and identify determinants associated with farmers' choice of milk marketing channels. The seroprevalence of brucellosis in livestock at the household level was 1/160 (0.6%; 95% CI = 0.1-3.4%). Among 100 households that sold milk, 72 used informal milk trade channels. By the use of logistic regression, milk price and distance to closest milk collection center were positively associated with the use of informal milk marketing channels. Although the seroprevalence of brucellosis in livestock in Rwamagana District was low, the risk of disease transmission to humans through consumption of unpasteurized milk or milk products is not negligible. In this report, we present several policy options available to animal health authorities that can mitigate the risk of brucellosis disease transmission in populations.

Point-of-need diagnostics in a post-Covid world: an opportunity for paper-based microfluidics to serve during syndemics

Zoonotic outbreaks present with unpredictable threats to human health, food production, biodiversity, national security and disrupt the global economy. The COVID-19 pandemic-caused by zoonotic coronavirus, SARS-CoV2- is the most recent upsurge of an increasing trend in outbreaks for the past 100 years. This year, emergence of avian influenza (H5N1) is a stark reminder of the need for national and international pandemic preparedness. Tools for threat reduction include consistent practices in reporting pandemics, and widespread availability of accurate detection technologies. Wars and extreme climate events redouble the need for fast, adaptable and affordable diagnostics at the point of need. During the recent pandemic, rapid home tests for SARS-CoV-2 proved to be a viable functional model that leverages simplicity. In this perspective, we introduce the concept of syndemnicity in the context of infectious diseases and point-of-need healthcare diagnostics. We also provide a brief state-of-the-art for paper-based microfluidics. We illustrate our arguments with a case study for detecting brucellosis in cows. Finally, we conclude with lessons learned, challenges and opportunities for paper-based microfluidics to serve point-of-need healthcare diagnostics during syndemics.

Spatio-temporal analysis of human brucellosis distribution in Neyshabur, Iran from 2015 to 2022, a cross-sectional study

BACKGROUND

Human brucellosis is a global endemic disease and a significant public health concern. This cross-sectional study aims to explore the characteristics of human brucellosis, as well as its spatial and temporal clustering.

METHODS

This cross-sectional study analyzed the population infected with human brucellosis in Neyshabur, Iran from 2015 to 2022. Data were obtained from the Neyshabur health center. Spatial analysis was conducted using Anselin Local Moran's I and Global Moran's I with ArcGIS 10.8.2. Descriptive statistical analyses were performed using SPSS 26.

RESULTS

During the study period, a total of 4568 brucellosis patients were reported. The incidence of disease was higher in men with 55.37%. The majority of patients belonged to the 30 to 39-year-old age group. Temporal clustering analysis revealed a peak incidence between March and June. The highest incidence rates were observed in spring and summer, with 34.76% and 33.84% of cases, respectively. Spatial clustering analysis indicated a higher prevalence in the southern and southeast districts of Neyshabur. The results of Global Moran's I analysis indicated that the distribution of brucellosis was not clustered in Neyshabur (P-value > 0.05).

CONCLUSION

The findings of this study highlight the importance of educational programs for mothers and animal vaccination strategies, particularly in the months leading up to the peak brucellosis season in high-incidence areas. Further research is needed to assess the coverage of livestock vaccination and its impact on human brucellosis rates.

Seroprevalence of brucellosis in camels and humans in the Al-Qassim region of Saudi Arabia and its implications for public health

Brucellosis is a significant zoonotic disease caused by intracellular, gram-negative bacteria from the genus Brucella. Although camels are classified as secondary hosts for Brucella species, they are among the most susceptible and vulnerable animals to brucellosis, particularly Brucella abortus (B. abortus) and Brucella melitensis (B. melitensis). The present study aimed to investigate the epidemiology of camel brucellosis as a zoonotic disease by determining the seroprevalence of brucellosis in both camels and humans, assessing potential risk factors (e.g., age, size, and location), and conducting molecular characterization of Brucella spp. associated with abortion in camels. The Rose Bengal Test (RBT), Antigen Rapid Brucella Antibody Test (ARBT), indirect enzyme-linked immunosorbent assay (I-ELISA), and complement fixation test (CFT) were used to detect brucellosis in both camels and humans. Additionally, a molecular method using polymerase chain reaction was used as a confirmatory technique. A total of 625 camel serum samples and 100 human serum samples were collected in sterile vacuum tubes from various camel farms and individuals across different localities in the Al Qassim region. Additionally, samples from 10 confirmed Brucella-infected camels (including the uterus and supramammary lymph nodes) were analyzed. The results indicated that the overall prevalence of brucellosis in camel sera was 9.72%, as determined by RBT, and 8.16%, as determined by ARBT. In contrast, the overall prevalence of brucellosis in human sera from febrile patients was found to be 17% via RBT. Notably, 57.98% of camel sera that tested positive for Brucella antibodies via RBT were also positive according to I-ELISA and CFT. Furthermore, 42.1%, 70.58%, and 47.05% of human sera that were positive for Brucella antibodies as determined by RBT were also positive according to I-ELISA and CFT, respectively. The highest seropositivity for camel brucellosis was observed in female camels, particularly in the Unaizah area of the Qassim region and among the Homr breed. The prevalence of human brucellosis was highest among females and individuals who consumed raw milk. At the molecular level, B. melitensis biovar 3 was detected in the examined tissues. In conclusion, intervention measures are vital for reducing brucellosis in humans and camels. Public awareness campaigns should highlight the importance of protective clothing when handling aborted she-camels and the need to boil or pasteurize milk. Additionally, studies should differentiate between vaccinated and nonvaccinated camels, and standardizing serological tests for diagnosing brucellosis should be prioritized.

Social network analysis of key stakeholders in Brucellosis prevention in Western Iran

BACKGROUND

Brucellosis remains a persistent public health challenge in Iran, particularly in rural regions such as Lorestan province, due to systemic, economic, and cultural barriers. Effective disease control requires multisectoral collaboration among stakeholders. This study aimed to map the stakeholder network involved in brucellosis prevention in Lorestan province, identify gaps in coordination, and provide actionable recommendations for improving control strategies.

METHODS

This cross-sectional study employed social network analysis (SNA) to explore the relationships among key stakeholders in brucellosis prevention. Data were collected through a structured questionnaire administered to 75 experts from various sectors, including health, veterinary, agriculture, and non-governmental organizations. The SNA evaluated network density, clustering coefficient, and centrality metrics to determine the levels of collaboration and influence among stakeholders.

RESULTS

The analysis revealed a moderately dense network (density: 0.2745; clustering coefficient: 0.2839) with central roles played by the Veterinary Organization of Lorestan Province, Lorestan University of Medical Sciences, and the Ministry of Agriculture. These organizations exhibited high levels of influence, support, and interest in brucellosis prevention. However, limited involvement of community-based organizations and environmental agencies was identified, highlighting a critical gap in grassroots engagement. Fragmented coordination was particularly evident in rural areas, where traditional livestock practices, inadequate veterinary services, and the consumption of unpasteurized dairy products perpetuate disease transmission. Economic constraints, such as the high cost of vaccines, along with limited public awareness, further hinder effective control efforts.

CONCLUSIONS

Brucellosis prevention in Lorestan province requires a comprehensive, multisectoral approach. The adoption of a One Health framework can improve collaboration among stakeholders, enhance resource allocation, and address systemic barriers. Community engagement and intersectoral coordination are essential for improving public awareness and compliance with preventive measures. These findings provide a foundation for developing a National Brucellosis Control Program and inform strategies to mitigate zoonotic diseases in similar high-risk regions.

Clinical Characteristics, Treatment, and Prognosis of Osteoarticular Brucellosis: A Retrospective Real-World Study in Shenyang, China, 2014-2019

This study aimed to assess the clinical characteristics, treatment, and prognosis of osteoarticular brucellosis. We conducted a retrospective study enrolling brucellosis patients from the Sixth People's Hospital of Shenyang between September 2014 and June 2019. A total of 1917 participants were admitted during this period. After applying propensity score matching, we retrospectively analyzed 429 patients with osteoarthritis and 429 patients without osteoarthritis. The primary outcome was treatment completion. The secondary outcome was symptom disappearance and seroconversion. Brucellosis patients with osteoarthritis had longer treatment course (160 [134.3-185.7] vs. 120 [102.3-137.7] d, p = 0.008) than those without osteoarthritis. The most common involved site was lumbar vertebrae (290 [67.6%]) in brucellosis patients with osteoarthritis. Longer symptom duration (90 [83.0-97.0] vs. 42 [40.2-43.8], p < 0.001) along with no significant difference in seroconversion (180 [178.8-181.2] vs. 180 [135.1-224.9], p = 0.212) was observed in osteoarthritis patients with treatment course >90 d. Peripheral joint involvement (adjusted hazard ratio [95% confidence interval] 1.485 [1.103-1.999]; p = 0.009) had a shorter symptom duration compared with shaft joint involvement. No significant differences were observed in treatment therapy between doxycycline plus rifampin (DR) or plus cephalosporins (DRC) in treatment course (p = 0.190), symptom persistence (p = 0.294), and seroconversion (p = 0.086). Lumbar vertebra was the most commonly involved site. Even if all symptoms disappeared, Serum agglutination test potentially remained positive in some patients. Compared with peripheral arthritis, shaft arthritis was the high-risk factor for longer symptom duration. The therapeutic effects were similar between DR and DRC. In summary, our study provided important insights into the clinical characteristics, treatment, and outcomes of osteoarticular brucellosis. Clinical Trial Registration number: NCT04020536.

Livestock production losses attributable to brucellosis in northern and central Tanzania: Application of an epidemiological-economic modelling framework

Livestock brucellosis is an endemic disease in many low-resource settings. Despite its widespread distribution, little is known about the scale of economic impacts caused by the disease. This study aimed to develop an integrated epidemiological-economic modelling framework to estimate production losses attributable to livestock brucellosis, using Tanzania as a case study. Data on livestock production and prevalence of exposure to Brucella spp. were obtained from surveys conducted in northern and central Tanzania between 2013 and 2019. A clustering algorithm was applied to classify households into pastoral and non-pastoral production systems. A Bayesian latent-class analysis model was applied to derive livestock brucellosis prevalence estimates. A herd-growth model was used to estimate production losses attributable to brucellosis. A total of 1,541 households (384 classified as pastoral and 1,157 as non-pastoral) contributed data on livestock production or prevalence of exposure to Brucella spp. The median (95% uncertainty interval, UI) individual-level brucellosis prevalence in cattle, sheep, and goats was 5.1% (3.4-6.9), 1.3% (0.1-3.0), and 2.5% (0.3-4.8) in the pastoral system, and 0.7% (0.1-1.6), 1.6% (0.2-3.8), and 2.5% (0.3-4.9) in the non-pastoral system, respectively. The median (95% UI) annual losses attributable to brucellosis in cattle, sheep, and goats, per infected animal, were 74.4 (26.2-211.7), 9.7 (3.4-23.1) and 10.6 (3.7-25.0) international dollars (int. $) in the pastoral system, and 62.3 (16.8-228.6), 6.3 (1.8-17.1) and 7.0 (2.2-17.9) int. $ in the non-pastoral system, respectively. Household-level losses were equivalent to 4.4% (2.1-8.8) and 0.6% (0.2-1.6) of the median (95% UI) livestock-derived income in the pastoral and non-pastoral systems, respectively. This study did not capture the system-wide impacts of brucellosis, including on human health. The estimated losses are only a part of the full societal economic impact of the disease. These results can be used to inform cost-benefit analyses of potential interventions and guide policy development for brucellosis control.

The Prevalence of Brucella spp. in Dairy Products in Iran: A Systematic Review and Meta-Analysis

Brucellosis, a significant zoonotic disease, threatens food safety substantially, particularly in developing nations such as the Middle East. This study aimed to comprehensively assess the prevalence of Brucella spp. in Iranian milk and dairy products through a systematic review and meta-analysis. A thorough search of international and domestic databases from January 2008 to October 2023 identified 38 relevant studies encompassing 11,130 samples for meta-analysis. The overall prevalence of Brucella spp. in Iranian dairy products was 22% (95% CI: 16-28%). The highest and lowest overall prevalence of Brucella spp. in milk were found in raw goat milk 27% (95% CI: 11-42%) and raw camel milk 15% (95% CI: -0.42 to 72%), respectively. The overall prevalence of traditional cheese, ice cream, and cream is estimated to be 9% (95% CI: -16 to 35%), 2% (95% CI: -2.78 to 2.82%), and 9% (95% CI: -0.94 to 1.12%). Geographical disparities were evident, with Zanjan province reporting the highest contamination rate, 53%, while Razavi Khorasan province had the lowest, 1%. However, the prevalence of Brucella spp. in Iranian dairy products has fluctuated over time, with a significant association between the study year and sample size. Comprehensive planning, robust policy implementation, and rigorous monitoring are imperative to mitigate and ultimately eliminate Brucella contamination in dairy products effectively. Further research is essential to refine prevalence estimates and develop targeted prevention strategies to safeguard public health.

A One Health Approach to Reducing Livestock Disease Prevalence in Developing Countries: Advances, Challenges, and Prospects

Challenges in livestock production in developing countries are often linked to a high disease prevalence and may be related to poor husbandry, feeding, and nutrition practices, as well as to inadequate access to preventive veterinary care. Structural barriers including chronic poverty, gender roles, inadequate supply chains, and limitations in surveillance infrastructure further complicate progress. Despite many challenges, the livestock sector substantially contributes to agricultural GDP, and reducing livestock disease prevalence is a goal for many countries. One Health initiatives that work across disciplines and sectors to reduce livestock diseases are underway around the world and use integrated approaches that consider the connections between humans, animals, and their shared environments. The growing recognition of the role livestock play in sustainability and livelihoods, as well as their involvement in zoonotic disease transmission and global health security, has highlighted the need for disease reduction strategies as described in this review.

Change point detection in brucellosis time series from 2010 to 2023 in Xinjiang China using the BEAST algorithm

Brucellosis is a significant global challenge, but there has been a lack of epidemiological studies on brucellosis in Xinjiang from a change point perspective. This study aims to bridge this gap by employing sequence decomposition and identifying significant change points, with datasets sourced from the Xinjiang Disease Prevention and Control Information System. This study employed the BEAST algorithm to decompose the brucellosis time series in Xinjiang from 2010 to 2023, while simultaneously identifying change points in the decomposed seasonal and trend components. The probability of four change points occurring within the seasonal component is 0.8950. And the locations where these four change points occur and the probabilities associated with each change point are August 2013 ([Formula: see text]), August 2017 ([Formula: see text]), February 2022 ([Formula: see text]), and May 2023 ([Formula: see text]), respectively. The probability of the existence of five change points in the trend factors of brucellosis in Xinjiang is highest ([Formula: see text]). The times at which these five change points occur, along with the probabilities of change at those moments, are as follows: March 2013 ([Formula: see text]), August 2015 ([Formula: see text]), July 2017 ([Formula: see text]), February 2020 ([Formula: see text]), and May 2023 ([Formula: see text]). Change point analysis holds significant utility within the field of epidemiology. These discoveries furnish pivotal insights for epidemiological investigations and the development of early warning systems tailored to brucellosis.

A Genomic Characterization of Clinical Brucella melitensis Isolates from Tunisia: Integration into the Global Population Structure

Brucellosis represents a significant global health concern that is endemic in many regions of the world, especially in Maghreb (Tunisia, Morocco and Algeria). In Tunisia the diagnosis of human brucellosis is primarily based on serological tests and cultivation of the causative pathogen, without the knowledge of the underlying Brucella species or biovar. In addition, the scarcity of laboratories with adequate biosecurity measures to handle suspected specimens constitutes a significant challenge. Furthermore, the absence of full genome data limits our understanding of the genetic diversity of Brucella in Tunisia in comparison to the strains circulating in the North African region and the world. In the present study, a total of 36 bacterial isolates derived from human patients diagnosed with brucellosis in Tunisia were subjected to examination. Real-time PCR confirmed all isolates as B. melitensis. In the subsequent core genome-based MLST analysis (cgMLST) based on 2706 target genes, the isolates formed two separate but closely related clusters with a distance of 140 alleles. The intra-cluster diversity was one to six alleles. In the larger geographical context and in comparison to almost 1000 other Brucella genomes, the isolates showed the highest genetic relationship to B. melitensis isolates from Italy and Egypt with distances of 130 and 150 alleles, respectively. All the isolates were most similar to the biovar 3 genotype. Markedly, strains from a reported brucellosis outbreak in Austria were grouped closely (26 and 27 alleles, respectively) together with strains from Tunisia, suggesting that this country may represent their geographical origin. This research represents a significant advancement in our understanding of B. melitensis strains circulating in the Maghreb region, as it is the first study to elucidate the molecular characterization of strains isolated from humans in Tunisia. The cgMLST analysis of the strains provided information on the regional distribution of the strains and the association with neighboring countries and significant outbreaks in the region. The data will form the basis of a future reference framework for strains circulating in the Mediterranean region.

Camel milk is a neglected source of brucellosis among rural Arab communities

The World Health Organization describes brucellosis as one of the world's leading zoonotic diseases, with the Middle East a global hotspot. Brucella melitensis is endemic among livestock populations in the region, with zoonotic transmission occurring via consumption of raw milk, amongst other routes. Control is largely via vaccination of small ruminant and cattle populations. Due to sociocultural and religious influences camel milk (camelus dromedarius) is widely consumed raw, while milk from other livestock species is largely boiled. To investigate the potential public health impact of Brucella in camels we conduct a cross-sectional study in southern Jordan including 227 herds and 202 livestock-owning households. Here we show daily consumption of raw camel milk is associated with Brucella seropositive status among the study population, ORadj 2.19 (95%CI 1.23-3.94) on multivariable analysis, highlighting the need for socioculturally appropriate control measures; targeted interventions among the camel reservoir being crucial for effective control.

Prediction analysis of human brucellosis cases in Ili Kazakh Autonomous Prefecture Xinjiang China based on time series

Human brucellosis remains a significant public health issue in the Ili Kazak Autonomous Prefecture, Xinjiang, China. To assist local Centers for Disease Control and Prevention (CDC) in promptly formulate effective prevention and control measures, this study leveraged time-series data on brucellosis cases from February 2010 to September 2023 in Ili Kazak Autonomous Prefecture. Three distinct predictive modeling techniques-Seasonal Autoregressive Integrated Moving Average (SARIMA), eXtreme Gradient Boosting (XGBoost), and Long Short-Term Memory (LSTM) networks-were employed for long-term forecasting. Further, the optimal model will be used to explore the impact of COVID-19 on the transmission of Human brucellosis in the region. We constructed a SARIMA(4,1,1)(3,1,2)12 model, an XGBoost model with a time lag of 22, and an LSTM model featuring 3 LSTM layers and 100 neurons in the fully connected layer to predict monthly reported cases from January 2021 to September 2023. The results indicated that the occurrence of brucellosis exhibits pronounced seasonal patterns, with higher incidence during summer and autumn, peaking in June annually. Performance evaluations revealed low Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Symmetric Mean Absolute Percentage Error (SMAPE) for all three models. Specifically, the coefficient of determination (R2) was 0.6177 for the SARIMA model, 0.8033 for the XGBoost model, and 0.6523 for the LSTM model. The study found that the XGBoost model outperformed the other two in long-term forecasting of brucellosis, demonstrating higher predictive accuracy. This discovery can aid public health departments in advancing the deployment of prevention and control resources, particularly during peak seasons of brucellosis. It was also found that the impact of the COVID-19 pandemic on the transmission of human brucellosis in the region was minimal. This research not only provides a reliable predictive tool but also offers a scientific basis for formulating early prevention and control strategies, potentially reducing the spread of this disease.

Human and animal brucellosis and risk factors for human infection in Ethiopia: a systematic review and meta-analysis (2015-2024)

BACKGROUND AND OBJECTIVE

Brucellosis is a neglected zoonotic disease caused by Brucella species. Unlike most developed nations, the problem of brucellosis in Ethiopia remains a public and animal health concern. This study was conducted to determine the magnitude of brucellosis in animals (mainly cattle, sheep, goats, dogs and camels) and humans, and to identify the risk factors for human brucellosis.

METHODOLOGY

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed to conduct this systematic review and meta-analysis, which was performed from May 2024 to July 2024. Academic databases such as PubMed, ScienceDirect, Scopus, PubMed Central, Web of Science, and Google Scholar were searched to identify articles focusing on brucellosis in humans and animals in Ethiopia. Data extraction was performed according to predefined inclusion and exclusion criteria. The included articles were appraised using the appraisal tool for cross-sectional studies to assess study quality. Publication bias and small study effects were examined using funnel plot observation and Egger's test, respectively. Statistical analysis was conducted using R software version 4.4.1.

RESULTS

Thirty-nine articles published between 2015 and 2024 were included in the final analysis from a total of 1,427 identified articles. The overall pooled seroprevalence of brucellosis was 5.0% (95% CI: 3.0, 6.0). The seroprevalence of brucellosis was higher in humans at 6.9% (95% CI: 4.9, 8.8) and lower in cattle at 3.5% (95% CI: 2.2, 4.7). There was high heterogeneity in the reports of brucellosis seroprevalence between studies (τ² = 0.0038, H² = 255.9, I² = 99.61%, Q-test = 1954.99, df = 56, p ≤ 0.001). Laboratory tests and study location were identified as factors contributing to potential sources of variation in the pooled seroprevalence. Drinking raw milk from aborted animals, touching aborted materials or fetuses, and occupation were among the risk factors for human brucellosis. No publication bias or small study effects were detected.

CONCLUSION

The findings indicate that brucellosis continues to pose a significant zoonotic threat, particularly to humans, where the seroprevalence is notably higher than in animals. These results highlight the need for targeted public health interventions and greater awareness to reduce the incidence of brucellosis, especially among high-risk populations.

Intraperitoneal Treatment of Cambinol, a Synthetic SIRT1 and SIRT2 Inhibitory Compound, Exacerbates Brucella abortus 544 Burden in the Spleens of Institute of Cancer Research Mice

Our preliminary data using bone marrow-derived macrophages (BMDMs) collected from ICR mice treated with anti-sirtuin (anti-SIRT) 1 antibody showed that Brucella uptake was significantly attenuated. We then further investigated the effect of an inhibitor of SIRT1/2, cambinol, in the progression of Brucella. The in vitro results using RAW264.7 cells revealed that cambinol treatment had no effect on adhesion, uptake, intracellular survival and nitric oxide (NO) production during B. abortus infection, nor did it directly affect bacterial growth for up to 72 h. Finally, intraperitoneal treatment of 8-week-old female ICR mice infected with Brucella showed no differences in the total average weights of spleens and livers; however, the treated mice displayed higher Brucella colony-forming units (CFUs) from the spleens. Furthermore, the interleukin (IL)-10 serum level was observed to be lower in treated mice at 7 d post-infection, and none of the cytokines tested showed a change at 14 d post-infection. The overall findings showed that cambinol treatment had no effect on the proliferation of Brucella in RAW264.7 macrophages but exacerbated the splenic proliferation of the bacteria in mice and displayed reduced anti-inflammatory cytokine IL-10 at the first week of infection, suggesting that cambinol as an inhibitory of SIRT1/2 could be beneficial in the context of Brucella dissemination in animal hosts and that exploration of activating SIRTs could be an alternative treatment against Brucella infection.

Seroprevalance of Brucellosis and Q-fever in water buffaloes (Bubalus bubalis) in Haryana state, India

Brucellosis and Q-fever are two highly contagious bacterial diseases with significant zoonotic potential and economic threats, yet they often remain underreported and neglected in low- and middle-income countries. The present study aimed to determine the seroprevalence of Brucellosis and Q-fever in water buffaloes in the Haryana state of India to implement effective preventive measures for disease control. The study covered all 22 districts of Haryana and involved 400 serum samples collected from female buffaloes belonging to two age groups and three distinct agro-climatic zones. The collected sera were tested using the Rose Bengal Plate agglutination test (RBPT) and commercial indirect enzyme linked immunosorbent assay (i-ELISA) for the presence of antibodies against smooth strains of Brucella spp. Additionally, the same serum samples were examined by i-ELISA for antibodies against Coxiella burnetii. The overall seroprevalence of brucellosis was observed as 8.25% (CI: 5.75-11.39) using the RBPT and 7.5% (CI: 5.12-10.53) by i-ELISA. The overall observed seroprevalence of Q-fever was 2.00% (CI: 0.87-3.90). No significant variation was seen in seropositivity of both diseases based on age and agroclimatic zones of the state. The findings of this study provide critical insights to farmers, agricultural organizations, veterinary services, and healthcare providers, facilitating more effective implementation of disease control measures.

Trends and age-period-cohort effect on incidence of brucellosis from 2006 to 2020 in China

Brucellosis remains a major public health challenge in China and globally. This study analyzed long-term trends in brucellosis incidence in China from 2006 to 2020, assessed the effects of age, period, and birth cohort, and projected future incidence up to 2030. Data on brucellosis were obtained from the Data-center of China Public Health Science, and temporal trends in incidence rates were analyzed using joinpoint regression, while an age-period-cohort model evaluated the effects of age, period, and cohort. A Bayesian age-period-cohort model was applied for future projections. From 2006 to 2020, 586,371 brucellosis cases were reported, with an upward trend in age-standardized incidence rates for both males and females, showing average annual percent changes of 3.37 % and 4.61 %, respectively. The age-period-cohort model revealed that age, period, and cohort all influenced incidence, with males facing higher rates. High-risk groups were identified among those aged 50-84, particularly in the 65-69 age range, where incidence was highest and showed the most significant annual increase. Period risk initially rose then declined, while later-born cohorts had higher risks. Projections indicate a continued rise in brucellosis incidence. Targeted prevention and control measures are recommended, especially for older adults and males.

Molecular prevalence, phylogenetic analysis, and PCR-based detection of Brucella melitensis in humans and cattle in Southern Khyber Pakhtunkhwa, Pakistan

Brucellosis is a bacterial disease due to Brucella melitensis, considered a zoonotic agent affecting humans and animals, especially in areas with high disease occurrence, south Khyber Pakhtunkhwa, Pakistan. This work was designed to evaluate the molecular rate of B. melitensis in humans and cattle species and also to perform a phylogenetic analysis between both species. A cross-sectional survey involving 800 participants, including 600 cattle and 200 human participants, underwent blood sample collection with conventional PCR and IS711 locus PCR amplification and Sanger sequencing. The findings detected Brucella melitensis in 37 of the 800 samples, with a molecular prevalence of 3.1 % in cattle and 9 % in humans. The molecular trees play a role in zoonotic transmission and point to the necessity of a further unified approach toward the management of brucellosis in both humans and animals. This is further backed by the use of 95 % C.I for the prevalence rates making the results statistically robust. This research shows that using the IS711 insertion sequence is an efficient and selective method for identifying Brucella species.

A meta-analysis of livestock brucellosis prevalence in Indonesia

Indonesia has a long history of livestock brucellosis, but the overall pooled prevalence remains unclear. This study aims to determine the pooled estimated prevalence of livestock brucellosis in Indonesia using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Five databases were searched and screened using predefined inclusion and exclusion criteria. Data from included studies were extracted and analyzed using a random effects model in R 4.3.0 for pooled estimated prevalence, subgroup meta-analysis, and meta-regression. Publication bias and sensitivity tests were conducted using Egger's test, funnel plot, trim and fill plot, and leave-one-out. The screening process identified 46 included studies, representing 47,057 samples for brucellosis testing. The pooled estimated prevalence for livestock brucellosis was 3.25% (95% CI, 1.81%-5.78%) with high heterogeneity (Q = 2130.91, p = 0, I2=98%). Subgroup meta-analysis indicated no significant difference in the prevalence of livestock brucellosis across the main islands in Indonesia (p = 0.44) and across provinces in Sulawesi Island (p = 0.83), but significant differences were found among provinces in Java (p < 0.01). The subgroup meta-analysis based on animal type showed no significant difference between cattle, small ruminants, and pig brucellosis estimated prevalence (p = 0.26). Between serological tests, no significant difference was found (p = 0.77). Meta-regression showed no significant difference in brucellosis prevalence from 1988-2023. Egger's test and funnel plot showed publication bias. Trim and fill test indicated 21 studies should be added. As most studies were conducted in Java and Sulawesi Islands, caution should be exercised in interpreting the results, emphasizing the necessity of increasing the study of brucellosis in other regions.

Molecular epidemiology of brucellosis in Asia: insights from genotyping analyses

Brucellosis infects humans and animals worldwide but is particularly prevalent in Asia. In many Asian countries, molecular diagnostic tools for accurate molecular diagnostics and molecular epidemiology are lacking. Nonetheless, some countries have conducted in-depth molecular epidemiological studies. The objective of this study was to reveal the genetic relationships, geographic origins, and distributions of Brucella strains across Asia for two primary species, B. abortus and B. melitensis. For this, we systematically searched genotyping data from published studies on the molecular epidemiology of Brucella species for both humans and livestock in Asia. We used data from multilocus sequence typing (MLST), multiple-locus variable-number tandem repeat analysis (MLVA), and whole genome sequencing analysis of Brucella strains. We also analyzed the MLVA genotypes of 129 B. abortus isolates and 242 B. melitensis isolates with known origins in Asia from an online MLVA database using MLVA-11 data in minimum spanning trees and MLVA-16 data in neighbor-joining trees. We found that the B. melitensis East Mediterranean lineage is predominant across the continent, with only a small number of samples from the Africa and Americas lineages, and none from the West Mediterranean lineage. The "abortus C" genotype was the most common group of B. abortus in Asia, with limited genetic variation for this species. Several studies also reported that Near Eastern countries frequently encounter human brucellosis cases of B. abortus from genotypes 42 and 43. Our study highlights the inconsistent collection of genetic data for Brucella species across Asia and a need for more extensive sampling in most countries. Finally, a consistent nomenclature is necessary to define various groupings of strains within a lineage (i.e., clade) so uniform terminology should denote particular genetic groups that are understood by all researchers.

Effective intervention of brucellosis prevention in developing countries: A dynamic modelling study

Objective

Brucellosis has a considerable impact on human health and the economy in developing countries. In China, the biggest developing country, brucellosis shifted spread of the epidemic from northern to southern regions. Understanding the transmission characteristic of brucellosis on Hunan province, located in central China, is of great significance for successful control.

Methods

We developed a multi-population and multi-route dynamic model (MPMRDM), which is an animal-human-environment coupled model. The model is an extension of the SEIR model, taking into account direct transmission and indirect transmission. We used the model to explore the spread of brucellosis and evaluate the effectiveness of various intervention strategies.

Results

The animal-to-animal transmission rate was the highest at 5.14 × 10-8, while the environment-to-person transmission rate was the lowest at 9.49 × 10-12. The mean R0 was 1.51. The most effective intervention was taking personal protection, followed by shortening the infection period. Shortening the infection period combined with personal protection is the most effective two-combined intervention strategy. After any comprehensive intervention strategy was implemented, TAR dropped by 90% or more.

Conclusion

The results demonstrate that animal transmission route is essential for controlling human brucellosis. Strengthening personal protection, early detection, and early treatment can effectively control the trend of brucellosis. These results can provide an important reference for optimizing brucellosis intervention plans.

The arginine/ornithine binding protein ArgT plays an essential role in Brucella neotomae/Brucella melitensis to prevent intracellular killing and contribute to chronic persistence in the host

Brucella species are facultative intracellular bacterial pathogens that cause the contagious zoonotic disease, brucellosis. Brucella spp. infect a wide range of animals, including livestock, wild animals, and marine mammals. Compared with other invasive bacterial pathogens, partial information is available on the virulence factors of Brucella that enable them to survive in the host. Here, we performed transposon-based random mutagenesis of B. neotomae and identified the arginine/ornithine binding protein, ArgT, as one of the crucial virulence determinants of Brucella. Deleting ArgT from B. neotomae or B. melitensis resulted in its attenuation in macrophages, which was restored upon complementation with an ArgT expression plasmid. We observed that macrophages infected with ΔArgT-B. neotomae produced elevated levels of NO due to the inability of these mutants to deplete the host intracellular arginine through their importer. Furthermore, defective survival of ΔArgT B. neotomae and B. melitensis was observed in the infected mice, which correlated with enhanced NO production in the mice. Our studies revealed that ArgT plays a vital role in preventing intracellular killing and contributes to the chronic persistence of B. neotomae/B. melitensis in the host. This study highlights the essential role of arginine in clearing intracellular infections and the subversion of this host defense mechanism by intracellular pathogens for their chronic persistence.

Seroprevalence and risk factors of brucellosis in pastoralists and their livestock in Central Equatoria State, South Sudan

BACKGROUND

Brucellosis poses serious public health implications and substantial economic losses in pastoral rural settings in South Sudan. In humans, brucellosis is almost always originating from animals. Current literature provides scant data regarding the seroprevalence of brucellosis in South Sudan. This cross-sectional study investigates the seroprevalence of brucellosis among the pastoral community and livestock and identifies risk factors for the disease from two Counties, Terekeka and Juba in Central Equatoria State (CES), South Sudan.

METHODOLOGY

A total of 986 sera; from humans (n = 143), cattle (n = 478), sheep (n = 86), and goats (n = 279) were randomly collected from 17 cattle camps in CES. Sera for the humans, cattle and goats were screened for Brucella-specific antibodies using Rose Bengal plate test (RBPT) and further confirmed by competitive enzyme-linked immunosorbent assay (c-ELISA) in series due to the cost of testing. All the sera from sheep were tested in parallel using RBPT and c-ELISA as the sheep samples were few and were all tested negative on the RBPT. A camp was considered positive when at least one animal of either species tested positive on the c-ELISA. A structured questionnaire was used to collect information on potential individual and herd level risk factors. Univariate analysis using binary logistic regression with a confidence interval of 95% at a p-value of ≤ 0.05 was used to identify the association between the potential individual risk factors and Brucella seropositivity. The investigated risk factors for livestock included age, sex, species, prior abortion history, retained placenta, parity, and reproductive status. Variables found to have associations in univariate analysis (p = 0.25) with Brucella seropositivity were further included in multivariable logistic regression. The risk factors investigated for humans included, gender, age, educational level, occupation, marital status, drinking of raw milk, aiding female animals during delivery, eating undercooked meat and blowing of air into the cow's uterus through the vagina, a practice in South Sudan.

RESULTS

The study revealed seroprevalence of 21.7%, 11.8%, and 4.8% in cattle, goats, and humans, respectively. Our results indicated that all sheep serum samples were negative on both RBPT and c-ELISA. The seropositive in the 13 camps from Terekeka County was 100.0% (13/13) compared to 50.0% (2/4) seropositive from 4 camps in Juba County. All the variables investigated in the univariate analysis of risk factors in cattle were significantly associated with Brucella seropositivity: sex (OR:4.5, 95% CI: 2.2-8.9, p<0.001), age (OR:6.6, 95% CI: 2.3-19.1, p:<0.001), abortion history (OR:3.1, 95% CI: 1.8-5.2, p:<0.001), retained placenta (OR:2.5, 95% CI: 1.4-4.4, p = 0.001), parity (OR:2.3, 95% CI: 1.1-4.7, p = 0.020), However, in small ruminants, none of the potential risk factors were associated with Brucella seropositivity. In humans, blowing air through a cow's vagina (OR: 1.4, 95%CI: 0.782-2.434, p = 0.035) was the only variable found to be significantly associated with Brucella seropositivity in the univariate analysis. The forceful blowing of air into a cow's vagina to induce milk letdown is a common practice among the pastoral communities in South Sudan. The multivariable logistic regression model identified sex, age, and abortion history as statistically significant factors for Brucella seropositivity in cattle. The odds of seropositivity were nearly threefold (OR: 2.8; 95% CI: 1.3-5.8, p = 0.006) higher in cows compared to bulls (male cattle). Cattle over two years old had higher odds of Brucella seropositivity than young animals (OR: 3.5, 95% CI: 1.2-10.3-, p: 0.025). Cows with a history of abortion had higher odds of Brucella seropositivity (OR: 2.8, 95% CI: 1.6-4.7, p = 0.001).

CONCLUSION

This study reports the occurrence of brucellosis in goats and its absence in sheep in (CES), South Sudan. The present study also shows the occurrence of brucellosis in cattle, goats and people in the pastoral community and recommends for the implementation of the One Health approach and awareness campaigns for effective mitigation of this disease.

Bovine brucellosis in dual-purpose cattle herds and its potential economic impact in the Colombian Caribbean region

Bovine brucellosis (BB) is a cosmopolitan zoonotic disease caused by certain bacteria of the genus Brucella. It has negative health implications for the cattle, economic implications for the owners and is present in numerous cattle and wildlife populations worldwide. To determine the seroprevalence of BB in dual-purpose herds and assess its impact in the southern part of the Department of Atlántico, northern Colombia. 1,000 female cattle were tested for brucellosis, using the Rose Bengal Plate Test (RBPT) and indirect ELISA (iELISA) as screening and confirmatory tests, respectively. Of these, 100 animals tested positive by RBPT and 204 were inconclusive, while 38 positive animals were identified by iELISA. Consequently, the apparent seroprevalence was 3.8%, and the estimated true prevalence was 4.4%. Based on estimates of the economic losses caused by BB, the cost was calculated at $2,496,364 COP ($822 USD) per animal. The costs identified in this study include medication costs, loss of lactation, and others. It highlights the significant impact of BB on food security, particularly concerning the availability of and access to bovine food products, as well as on the economy of livestock farmers in the region.

Bone features reinforce differential diagnosis between tuberculous spondylitis and brucellosis spondylitis

BACKGROUND

Tuberculous spondylitis (TS) and brucellar spondylitis (BS) both cause major long-term morbidity and disability. Though Spondylodiscitis is sensitive to magnetic resonance images, some are difficult to differentiate. This study aims to identify specific bone changes on computed tomography (CT) images, further to differentiate TS from BS.

METHODS

We retrospectively analyzed and enrolled 70 patients with TS and 65 with BS at our hospital from December 2012 to January 2024. Information of bone destruction and formation, vertebral wall integrity, osteosclerosis, and sequestrum on CT images was collected and compared using the chi-square test or t-test. P < 0.01 was considered statistically significant.

RESULTS

Bone destruction was greater in the TS group compared to the BS group (519.55 mm2 vs. 316.00 mm2, t = 6.01, P < 0.001), preferentially involving each third of the vertebral body horizontally (41.22% vs. 16.67%, χ2 = 77.76, P < 0.001; positive predictive value [PPV] = 80.6%) and the area under the endplate and equatorial portion of the vertebra longitudinally (80.53% vs. 28.20%, χ2 = 134.19, P < 0.001, PPV = 82.75%). Patients with BS more frequently exhibited fan-shaped osteosclerosis (12.82% vs. 1.15%, χ2 = 71.30, P < 0.001; PPV = 86.96%), longer bone formation surrounding the vertebra (18.06 mm vs. 1.97 mm, t = 14.28, P < 0.001), and longer anterior bone formation (3.86 mm vs. 0.92 mm, t = 6.51, P < 0.001). Anterior and closed bone formation was more common in the BS group than in the TS group (44.87% vs. 7.63%, χ2 = 152.53, P < 0.001; PPV = 77.78%). Fragmented and blocked sequestrum was more common in the TS group than in the BS group and tended to spread in and out of the erosions (22.14% vs. 0.64%, PPV = 98.31% and 22.14% vs. 0.00%, PPV = 100%, χ2 = 102.43, P < 0.001).

CONCLUSIONS

TS and BS exhibit specific features of bone formation, bone destruction, and sequestrum on CT imaging. Our findings indicate that bone features on CT can help clinicians distinguish between two spinal infections.

Seroprevalence and risk factors for brucellosis amongst livestock and humans in a multi-herd ranch system in Kagera, Tanzania

Background

Brucellosis remains a significant health and economic challenge for livestock and humans globally. Despite its public health implications, the factors driving the endemic persistence of Brucella at the human-livestock interface in Tanzania remain poorly elucidated. This study aimed to identify the seroprevalence of Brucella infection in livestock and humans within a ranching system and determine associated risk factors for disease endemicity.

Methods

A cross-sectional sero-epidemiological study was conducted in 2023 in Tanzania's Karagwe District, involving 725 livestock (cattle, goats, sheep) from 10 herds and 112 humans from associated camps. Seroprevalence was assessed using competitive ELISA while epidemiological data were collected via questionnaires. Generalized Linear Models and Contrast Analysis were used to identify risk factors for infection.

Results

Overall seroprevalence was 34% in livestock and 41% in humans. Goats exhibited the highest prevalence (69.2%), while cattle had the lowest (22.6%). Mixed-species herds (Odds Ratio, OR = 2.96, CI [1.90-4.60]) and small ruminants-only herds (OR = 6.54, CI [3.65-11.72]) showed a significantly higher risk of seropositivity compared to cattle-only herds. Older cattle (OR = 5.23, CI [2.70-10.10]) and lactating females (OR = 2.87, CI [1.78-4.63]) represented significant risks for brucellosis in livestock. In humans, close contact with animals (OR = 7.20, CI [1.97-36.31]) and handling animals during parturition or aborted fetuses (OR = 2.37, CI [1.01-5.58]) were significant risk factors. Notably, no spatial association was found in seroprevalence between herds and nearby human communities.

Conclusion

The lack of spatial correlation between livestock and human seroprevalence suggests complex transmission dynamics, potentially involving endemic circulation in livestock and human infections from multiple sources of exposure to livestock. This study highlights the need for comprehensive zoonotic risk education and targeted intervention strategies. Further research is crucial to elucidate transmission pathways and improve Brucella infection control. This includes developing robust methods for identifying infective species and implementing effective strategies to mitigate Brucella infection in endemic regions.

Whole-genome sequencing-based analysis of Brucella species isolated from ruminants in various regions of Türki̇ye

BACKGROUND

Brucellosis, a zoonotic disease in Türkiye, which has significant direct and indirect impacts on the healthcare system and livestock. This study, which aimed to investigate the differences among Brucella spp. isolates originating from different regions of Türkiye, for implications for public health and veterinary medicine.

METHOD

Twenty-one isolates from ruminants and two isolates from humans obtained from various regions of Türkiye were utilized in the study. The isolates were identified and biotyped using traditional microbiological procedures, and whole-genome sequencing (WGS) was performed. This was followed by single nucleotide polymorphism (SNP)--based phylogenetic analysis and WGS-based analysis of virulence and resistance genes. Additionally, phenotypic antimicrobial resistance and phage susceptibilities were determined. The obtained data were then compared for concordance, ensuring the validity and reliability of the results.

RESULTS

Our study, employing culture methods, polymerase chain reaction (PCR), and WGS analyses, identified 11 Brucella melitensis (bv 3 (n = 9), one each bv 1 and bv 2) and 12 B. abortus (bv 3 (n = 11), bv 9 (n = 1)) isolates All B. abortus isolates were of bovine origin, while the B. melitensis isolates were from sheep (n = 7), goat (n = 1), ram (n = 1), and humans (n = 2). In the whole-genome SNP-based phylogenetic tree, all B. melitensis strains were found to be of the IIb subtype of genotype II associated with the Eastern Mediterranean lineage. Ten different genotypes were identified in the SNP analysis of the isolates, with a maximum SNP difference of 278 and a minimum SNP difference of 4 among these genotypes. According to the WGS-SNP-based phylogenetic tree of B. abortus isolates, they were grouped in clade C1. In the SNP analysis, where ten different genotypes were identified, the SNP difference among these genotypes was a maximum of 316 and a minimum of 6. In the in silico MLST analysis performed with WGS data, B. melitensis isolates were identified as ST8 and ST102 genotypes, while B. abortus isolates were identified as ST2 and ST3 genotypes. The dominant genotypes were ST8 for B. melitensis and ST2 for B. abortus, respectively. Virulence gene analysis conducted based on WGS data of the 23 B. abortus and B. melitensis isolates revealed 43 virulence gene-associated regions in all strains, irrespective of species, host, or isolation year. Although classical resistance-related genes were not detected by WGS-based antimicrobial resistance gene analysis, phenotypic resistance analysis revealed resistance to azithromycin, rifampin, and trimethoprim/sulfamethoxazole in B. abortus and B. melitensis isolates.

CONCLUSION

Both B. melitensis and B. abortus were circulating species in animals and human. The dominant genotypes were ST8 for B. melitensis and ST2 for B. abortus, respectively. All B. melitensis strains were found to be of the IIb subtype of genotype II associated with the Eastern Mediterranean lineage, while B. abortus isolates, they were grouped in clade C1. Further, a comprehensive study with a sufficient number of isolates covering all regions of Türkiye would provide more accurate information about the current epidemiological situation in the country.

Novel dual-pathogen multi-epitope mRNA vaccine development for Brucella melitensis and Mycobacterium tuberculosis in silico approach

Brucellosis and Tuberculosis, both of which are contagious diseases, have presented significant challenges to global public health security in recent years. Delayed treatment can exacerbate the conditions, jeopardizing patient lives. Currently, no vaccine has been approved to prevent these two diseases simultaneously. In contrast to traditional vaccines, mRNA vaccines offer advantages such as high efficacy, rapid development, and low cost, and their applications are gradually expanding. This study aims to develop multi-epitope mRNA vaccines argeting Brucella melitensis and Mycobacterium tuberculosis H37Rv (L4 strain) utilizing immunoinformatics approaches. The proteins Omp25, Omp31, MPT70, and MPT83 from the specified bacteria were selected to identify the predominant T- and B-cell epitopes for immunological analysis. Following a comprehensive evaluation, a vaccine was developed using helper T lymphocyte epitopes, cytotoxic T lymphocyte epitopes, linear B-cell epitopes, and conformational B-cell epitopes. It has been demonstrated that multi-epitope mRNA vaccines exhibit increased antigenicity, non-allergenicity, solubility, and high stability. The findings from molecular docking and molecular dynamics simulation revealed a robust and enduring binding affinity between multi-epitope peptides mRNA vaccines and TLR4. Ultimately, Subsequently, following the optimization of the nucleotide sequence, the codon adaptation index was calculated to be 1.0, along with an average GC content of 54.01%. This indicates that the multi-epitope mRNA vaccines exhibit potential for efficient expression within the Escherichia coli(E. coli) host. Analysis through immune modeling indicates that following administration of the vaccine, there may be variation in immunecell populations associated with both innate and adaptive immune reactions. These types encompass helper T lymphocytes (HTL), cytotoxic T lymphocytes (CTL), regulatory T lymphocytes, natural killer cells, dendritic cells and various immune cell subsets. In summary, the results suggest that the newly created multi-epitope mRNA vaccine exhibits favorable attributes, offering novel insights and a conceptual foundation for potential progress in vaccine development.

Serological and Molecular Prevalence and Associated Risk Factors in Caprine Brucellosis, Northeastern Thailand

Brucellosis is a significant zoonotic disease with global implications for animal and human public health. This study investigated the prevalence of caprine brucellosis in 39 meat goat herds in northeastern Thailand using serological and molecular methods. Seroprevalence, determined by the modified Rose Bengal test (mRBT), was negative, indicating no detectable antibodies against Brucella. However, real-time PCR identified Brucella spp. DNA in 11 samples from 8 herds. Intraherd prevalence varied from 0.0% to 9.09%, averaging 6.73% (95% CI, 4.74-8.72). Univariate analysis revealed significant risk factors associated with brucellosis at the herd level. Larger herd size correlated with increased brucellosis odds ratio (OR: 6.30; 95% CI: 1.07-36.93; p=0.041). Herds with multiple reproductive failures, including abortion, repeat breeding, and sterile, together with weak offspring, showed higher prevalence (OR: 9.37; 95% CI: 1.17-74.84; p=0.034). Multivariable analysis identified herd sizes over thirteen as a significant risk factor (OR: 10.20; 95% CI: 1.06-97.40; p=0.044). Notably, herds where owners were aware of direct transmission risks exhibited lower infection rates (OR: 0.05; 95% CI: 0.006-0.54; p=0.012). This study underscores the complementary role of molecular techniques alongside serological tests in detecting Brucella infection accurately. The findings highlight the importance of effective herd management, reproductive health monitoring, and owner education in mitigating brucellosis transmission. Implementing robust control measures, including stringent biosecurity protocols and enhanced stakeholder awareness, is crucial for controlling brucellosis in meat goat populations.

Draft genome sequences of Brucella melitensis from human and animal sources in India

We present the draft genome sequences of 23 Brucella melitensis isolates derived from human and animal sources across India with genome size predominantly at 3.207 M and uniform GC content (57.24%) across isolates. The accession numbers and detailed sequencing data enhance the utility of this resource for further genomic studies.

Epidemiology of brucellosis in Mazandaran, North of Iran in a nine-year period (2009-2017)

Background

Brucellosis is a common disease between humans and animals that still exists in most parts of Iran. This study investigated the epidemiology of brucellosis in Mazandaran province, Iran, during a nine-year period from the beginning of 2009 until the end of 2017.

Methods

This descriptive-analytical study was conducted based on the guidelines of Iran's Ministry of Health and Medical Education on the data of 3732 brucellosis patients. The data were retrieved from the private and public laboratories gathered in a Ministry's database. We used the generalized estimating equation (GEE) for the Poisson regression model (Poisson GEE) to examine the disease incidence based on the studied variables.

Results

The age-standardized incidence rate has been 13.2 per 100,000 people (15.6 in men and 21.3 in rural areas). The highest rate (17.2) was in 2012 and the lowest (10.6) was in 2014. The cities of Galugah (35.0) and Qaemshahr and Fereydunkenar (3.0) had the highest and lowest incidence rates. The patients' professions had been 30% housewives, 14.9% ranchers, and 14.4% livestock-related professions. The highest standard incidence was in people older than 55 years old. The results of the Poisson GEE regression model showed that the disease incidence has been higher in men compared to women and in rural compared to urban areas (risk ratio = 1.5, 3.4, P = 0.001).

Conclusion

Mazandaran faces the risk of increased brucellosis incidence rate. Taking preventive measures, including educating people, are recommended for the near future.

Structures of Brucella ovis leucine-, isoleucine-, valine-, threonine- and alanine-binding protein reveal a conformationally flexible peptide-binding cavity

Brucella ovis is an etiologic agent of ovine epididymitis and brucellosis that causes global devastation in sheep, rams, goats, small ruminants and deer. There are no cost-effective methods for the worldwide eradication of ovine brucellosis. B. ovis and other protein targets from various Brucella species are currently in the pipeline for high-throughput structural analysis at the Seattle Structural Genomics Center for Infectious Disease (SSGCID), with the aim of identifying new therapeutic targets. Furthermore, the wealth of structures generated are effective tools for teaching scientific communication, structural science and biochemistry. One of these structures, B. ovis leucine-, isoleucine-, valine-, threonine- and alanine-binding protein (BoLBP), is a putative periplasmic amino acid-binding protein. BoLBP shares less than 29% sequence identity with any other structure in the Protein Data Bank. The production, crystallization and high-resolution structures of BoLBP are reported. BoLBP is a prototypical bacterial periplasmic amino acid-binding protein with the characteristic Venus flytrap topology of two globular domains encapsulating a large central cavity containing the peptide-binding region. The central cavity contains small molecules usurped from the crystallization milieu. The reported structures reveal the conformational flexibility of the central cavity in the absence of bound peptides. The structural similarity to other LBPs can be exploited to accelerate drug repurposing.

Establishment of an A/T-Rich Specifically MGB Probe digital droplet PCR Assays Based on SNP for Brucella wild strains and vaccine strains

In recent years, immunization with the S2 live-attenuated vaccine has been recognized as the most economical and effective strategy for preventing brucellosis in Inner Mongolia, China. However, there are still challenges related to vaccine toxicity and the inability to distinguish between vaccine immunization and natural infection. Therefore, in this study, we developed a digital droplet polymerase chain reaction (ddPCR) assay based on single-nucleotide polymorphism (SNP) loci to identify wild Brucella strains and S2 vaccine strains. The assay demonstrated excellent linearity (R2> 0.99) with a lower detection limit of 10 copies/µL for both wild and vaccine strains. Additionally, the ddPCR assay outperformed the real-time fluorescent quantitative PCR (qPCR) assay in screening 50 clinical samples. We have established an effective and highly sensitive ddPCR assay for Brucella, providing an efficient method for detecting and differentiating wild strains of Brucella from the S2 vaccine strain.

Seroprevalence of Brucellosis, Knowledge, and Risky Practices in Dairy Cattle Owners and Workers in Maekel and Debub Regions, Eritrea

Brucellosis is a zoonotic disease with worldwide distribution. In Eritrea, the status of the disease in occupationally exposed dairy farmers is unknown. The objective of this study was to determine the seroprevalence of brucellosis, level of knowledge, and risky practices of dairy cattle owners/workers in Maekel and Debub regions, Eritrea. A cross-sectional study was conducted between August 2021 and February 2022. A total of 416 dairy cattle owners and workers underwent blood collection and interview using a standardized questionnaire. Blood samples were tested using Rose Bengal Plate Test, and positive samples were confirmed using competitive ELISA. Variation in knowledge scores by sociodemographic factors and practices were explored statistically. The apparent and true seroprevalence was 1.2% (95% CI: 0.05-2.8%) and 1.4% (95% CI: 0.6-3.4%), respectively. Apparent seroprevalence was similar in Maekel (1.1%) and Debub (1.2%) regions. Nearly half of the participants (49.5%) had never heard of brucellosis before. Overall, brucellosis knowledge score was low (mean score: 6.53/20). Knowledge score was higher in participants from Maekel region (P <0.001), older participants (P = 0.035), those with higher educational attainment (P = 0.001), and those with more years of experience working in dairy farming (P = 0.001). Knowledge score was lower in farm workers compared with family members (P = 0.016). No significant differences in knowledge score existed between participants who engaged in or did not engage in potential risky practices. In summary, the prevalence of brucellosis in dairy cattle owners/workers in Maekel and Debub regions, Eritrea, was low. Participants demonstrated limited knowledge of brucellosis and engaged in risky practices.