Global Estimate of Human Brucellosis Incidence

Mapping risks: A value chain approach to brucellosis introduction in Zhijiang's Cattle Population, China

Brucellosis, a zoonotic disease primarily transmitted through livestock, poses significant health and economic challenges globally. Its increasing incidence in China highlights critical gaps in current control measures, particularly in regions with high livestock movement, where domestic ruminants trade networks elevate the risk of disease transmission. Traditional value chain analyses often provide descriptive mappings of these networks but lack quantitative methods to assess specific risk levels. This study integrates value chain with quantitative risk assessment using Monte Carlo simulations to evaluate the risk of brucellosis introduction via cattle imports in Zhijiang. We comprehensively mapped the local cattle value chain, identifying key stakeholders, risk nodes, and critical pathways of infection. Utilizing a stochastic scenario tree model based on local data, we estimated the likelihood of infected cattle entering the region, revealing that unregulated brokers and inadequate quarantine measures significantly contribute to the risk. Our sensitivity analysis confirmed vulnerabilities in existing biosecurity protocols, emphasizing the need for enhanced quarantine measures and reliable testing at high-risk points in cattle trade. By combining value chain insights with quantitative analysis, this study effectively identifies critical vulnerabilities within livestock networks. Our findings lay the groundwork for developing targeted brucellosis prevention strategies in Zhijiang, underscoring the urgent need for strengthened biosecurity and risk management practices.

The Influential factors on clinical outcomes of focal brucellosis: A retrospective cohort study

PURPOSE

Brucellosis, a neglected zoonotic disease, presents significant global health challenges. This study evaluates the impact of focal complications on outcomes in human brucellosis and identifies risk factors affecting prognosis.

METHODS

We conducted a retrospective cohort study of brucellosis patients admitted to Beijing Youan Hospital (January 2010-December 2023). Inclusion criteria required a confirmed diagnosis of brucellosis. Patients with uncertain diagnosis or incomplete records were excluded. Outcomes, including therapeutic failure, relapse, and overall failure, were compared between patients with and without focal brucellosis (defined as infections in specific anatomical sites). Risk factors were assessed using univariable and multivariate logistic regression models.

RESULTS

Among 240 patients, 96 (40 %) had focal brucellosis. Doxycycline-rifampicin was commonly used for non-focal cases (32.6 %), while doxycycline-rifampicin-aminoglycoside therapy was preferred for focal cases (36.5 %). Focal brucellosis (OR 3.52, 95 % CI 1.28 - 9.71, p = 0.015) and low albumin levels (OR 0.90, 95 % CI 0.82 - 0.99, p = 0.04) were independent risk factors for therapeutic failure. Chronic brucellosis and triple antimicrobial therapy were independently associated with relapse and overall therapeutic failure. In focal brucellosis, chronic brucellosis (OR 11.20, 95 % CI 2.58-48.66, p = 0.001) and low albumin (OR 0.86, 95 % CI 0.76-0.97, p = 0.014) were key risk factors.

CONCLUSIONS

The presence of focal complications, low albumin levels, and chronic brucellosis are critical prognostic factors for treatment failure. To improve clinical outcomes, treatment strategies should include early identification and management of focal involvement, proactive nutritional support to correct low albumin levels, and triple-antibiotic therapy.

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.

Follow-up of antibody changes in brucellosis patients in Gansu, China

Brucellosis, caused by the intracellular bacterium Brucella, often leads to chronic infection with recurrent symptoms, posing significant therapeutic challenges. Effective monitoring of antibody dynamics is crucial for understanding disease progression and enhancing clinical outcomes. To investigate the longitudinal dynamics of antibody titers and antigen-specific responses in animal husbandry practitioners exposed to brucellosis in Gansu, China. We conducted a serological study involving 400 animal husbandry workers, identifying 21 seropositive individuals (5.25%). Antibody titers and antigen-specific responses to lipopolysaccharide (LPS) and BP26 protein were assessed using the Rose-Bengal test (RBT), serum agglutination test (SAT), and western blotting. Acute brucellosis patients displayed a distinct three-phase antibody titer pattern: a rapid rise (12-38 days), a rapid decline (19-41 days), and a slow decline (42-148 days). BP26-specific antibodies persisted significantly longer than LPS antibodies, remaining detectable up to 395 days post-infection. Early treatment reduced acute-phase antibody titers, correlating with disease control. This study combined dynamic antibody titer monitoring with specific antigen monitoring, enhancing the accuracy and specificity of brucellosis diagnosis and offering a basis for chronic infection detection. The findings are highly significant for clinical practice and public health strategies, particularly in high-incidence areas, prevention and control, as well as high-risk population surveillance.

IMPORTANCE

Brucella, a zoonotic intracellular bacterium, poses significant threats to both human health and economic security. Clinically, brucellosis can be challenging to differentiate from other long-term febrile illnesses, necessitating prompt and standardized treatment to prevent chronic persistent infections and multi-organ damage, which are notoriously difficult to treat. Thus, gaining a comprehensive understanding of the disease's progression is essential for early diagnosis and effective treatment strategies. This paper delves into the dynamics of serum antibody titers in patients with acute brucellosis, shedding light on the temporal patterns of antibody titers. Such insights are pivotal for monitoring disease progression and assessing the efficacy of treatment interventions. Furthermore, through western blotting analysis, the study reveals that antibodies against the BP26 protein in brucellosis patients persist over an extended period, which is helpful to identify the durable immune response of brucellosis and provides a theoretical basis for vaccine development and treatment strategy formulation.

Genomic insights into Brucella melitensis in India: stability of ST8 and the role of virulence genes in regional adaptations

Brucella melitensis is a highly infectious zoonotic pathogen responsible for brucellosis, which significantly affects both human and livestock health worldwide. This study employed whole-genome sequencing (WGS) to analyze the genetic diversity of 24 B. melitensis isolates from India. Pangenome analysis revealed a highly conserved nature with the involved strains having very limited accessory genes. Multilocus Sequence Typing (MLST) identified sequence type ST8 as predominant among Indian strains. Analysis of virulence genes revealed a total of 43 virulence-related genes in all strains, emphasizing their critical role in the pathogenicity of B. melitensis. Unique gene profiles and distinct phylogenetic clusters suggest regional adaptations and evolutionary pressures. The comprehensive genomic insights from this study help to elucidate the geographic distribution and interspecies transmission of Indian strains, highlighting the importance of targeted brucellosis control measures in India. Additionally, the identification of conserved virulence genes involved in immune evasion and intracellular survival highlights their importance in the bacterium's pathogenicity. This research contributes to the global understanding of B. melitensis genomic diversity, providing valuable insights for broader epidemiological studies and brucellosis management strategies worldwide.IMPORTANCEB. melitensis is a significant cause of illness in both humans and animals, particularly in India, where the disease remains a major concern. This study highlights that only a few genetic types of the bacteria are circulating in the region, which means control efforts can be better focused on these specific types. By understanding the unique characteristics of Indian strains, and how these strains spread and adapt, this research offers valuable guidance for improving brucellosis prevention strategies. These insights can help in developing more effective diagnostic tools, enhancing vaccination efforts, and strengthening disease control programs to reduce the impact of brucellosis on public health and livestock industries.

Development of a competitive ELISA based on Brucella neotomae lipopolysaccharide for detecting brucellosis in livestock

Brucellosis, a global zoonotic threat, requires efficient diagnostic tools for effective surveillance. Commercial competitive enzyme-linked immunosorbent assay (cELISA) predominantly utilizes smooth lipopolysaccharides (S-LPS) extracted from B. abortus and B. melitensis as key antigens for brucellosis serodiagnosis. However, culturing pathogens requires facilities with high biosafety, which is operationally complex and economically demanding. In this study, we developed a cELISA using LPS extracted from B. neotomae, which can be handled more facilely in biosafety level 2 conditions, and analyzed clinical adaptability of the cELISA. The optimized cELISA demonstrated lower detection limits, which was 2-4 times more analytically sensitive than commercial kit by detecting sera against B. melitensis and B. abortus. No cross-reactivity was observed with sera infected with other bacteria, including E. coli, Salmonella, Y. enterocolitica, and M. tuberculosis. The diagnostic sensitivity and specificity of the cELISA were 100 % (40/40) and 100 % (40/40), respectively. The coefficients of variation were less than 10 %. Moreover, compared to the commercial kit, the developed ELISA achieved agreement of 92.51 % across 427 sera from vaccinated livestock, and agreement of 96.98 % across 696 sera from non-vaccinated livestock. In conclusion, the cELISA exhibits excellent sensitivity, specificity and repeatability, indicating its potential for brucellosis diagnosis in livestock.

Antimicrobial resistant Brucella spp. prevail in raw milk and animal feces of different livestock farms

BACKGROUND

Brucella spp. is a zoonotic pathogen that affects both livestock and humans, causing reproductive issues in animals and severe health complications in humans, including undulant fever, hepatomegaly, and arthritis. Contaminated raw milk and feces serve as potential transmission sources, despite its public health significance, limited studies have assessed the prevalence of Brucella spp. in raw milk and feces, particularly in endemic regions like Pakistan.

OBJECTIVE

This study aimed to determine the prevalence of Brucella spp. in raw milk and feces of livestock in Punjab and Islamabad Capital Territory, Pakistan, and evaluate the antibiotic resistance profiles of the isolated strains.

METHODS

The raw milk and fecal samples were collected randomly from the different livestock farms of Punjab, Pakistan. The areas were selected based on the different sociodemographic attributes like climate, land usage, number of animals, husbandry practices and operational convenience, which may influence the spatial and temporal distribution of livestock diseases. Brucella spp. was isolated using Brucella agar, a highly specific medium, and confirmed at the molecular level through IS711 gene analysis. Antibiotic susceptibility testing was performed to determine the multiple antibiotic resistance (MAR) index and identify multidrug-resistant (MDR) strains.

RESULTS

A total of 100 samples, including 60 raw milk samples (cows = 25, buffalo = 25, goats = 10) and 40 fecal samples (cows = 16, buffalo = 15, goats = 9), were collected from various livestock farms. The incidence of Brucella spp. was found higher (7.5%) in raw milk than in the animal´s feca (15%). All the strains showed multiple antibiotic resistance (MAR) index (0.3-0.5) which was higher than the critical value (> 0.2). Additionally, 75% of the strains were classified as multidrug-resistant (MDR), highlighting their resistance to multiple antibiotics.

CONCLUSION

These findings indicate the antimicrobial resistance and prevalence of Brucella spp. in the dairy industry which could be a serious threat to public health.

CLINICAL TRIAL NUMBER

Not applicable.

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.

Differentiating early and advanced Brucella spondylitis using an MRI-based radiomics nomogram model

BackgroundAccurate differentiation between early and advanced Brucella spondylitis is crucial for effective treatment.PurposeTo develop a magnetic resonance imaging (MRI)-based radiomics nomogram model for distinguishing between early and advanced stages of Brucella spondylitis.Material and MethodsWe conducted a retrospective analysis of clinical and imaging data from 100 patients with early Brucella spondylitis and 100 patients with advanced Brucella spondylitis. Regions of interest were marked on sagittal T2-weighted fat-suppressed lumbar MRI scans. Radiomic features were extracted and used to build a radiomics model. The significance of these features was evaluated using the Shapley Additive Explanations (SHAP) method. Intravoxel incoherent motion (IVIM) quantitative parameters were also included as clinical features, with key parameters selected to create a clinical model. A nomogram model was developed by combining clinical and radiomic features. The performance of the three models was compared and validated using receiver operating characteristic curves, calibration curves, and decision curves.ResultsEight radiomic features were selected. The clinical feature's D-value showed significant differences between the training and test sets. The nomogram model integrating both clinical and radiomic features achieved an AUC of 0.998 in the training set and 0.992 in the test set, surpassing the performance of both the clinical and radiomic models alone. Calibration and decision curves confirmed the model's strong predictive performance.ConclusionThis study shows that the MRI-based radiomics nomogram model effectively differentiates between early and advanced Brucella spondylitis, offering clinicians a valuable tool for personalized treatment across different disease stages.

Molecular evidence of Brucella abortus circulating in cattle, goats, and humans in Central Equatoria State, South Sudan

Brucellosis is a neglected zoonotic disease in most developing countries, including South Sudan. Precise identification of Brucella species is crucial for addressing public health and epidemiological concerns associated with brucellosis. The study aimed to identify Brucella species using real-time polymerase chain reaction (qPCR) from seropositive samples that were acquired from an earlier investigation. A total of 143 genomic DNA samples were extracted from brucellosis Rose Bengal plate test (RBPT) seropositive samples from humans (n = 7), cattle (n = 103) and goats (n = 33). The samples were collected from Terekeka and Juba counties, Central Equatoria State (CES), South Sudan. The qPCR targeting the Brucella-specific IS711 insertion gene at the genus level was performed. Samples with a cycle threshold (Ct) of ≤ 35 were considered positive and subjected to further Brucella speciation assays. Out of 143 DNA samples tested for genus-specific Brucella, 15 (10.5%) were positive including 4 (2.8%) from humans, 10 (6.9%) from cattle, and 1 (0.7%) from goats. Brucella abortus was identified in 5 (33.3%) of the positive samples at the genus level. The overall individual species infection rates with B. abortus were 6.6% (1/15) in humans, 20% (3/15) in cattle, and 6.6% (1/15) in goats. There was no B. melitensis detected in this study. This study identified B. abortus in cattle, goats and humans in CES, South Sudan. The findings suggest that cattle are probably the primary reservoirs for transmission of B. abortus, with infections occurring in goats and humans primarily resulting from cattle spillover.

Genome phylogenetic analysis of Brucella melitensis in Northwest China

Brucellosis poses a severe threat to public health in Northwest China; however, the genome phylogeny and transmission pattern of Brucella melitensis from sheep and yaks in this region remain unclear. In this study, bacteriology, conventional biototyping, and whole-genome single-nucleotide polymorphism (WGS-SNP) were applied to depict the phylogenetic profiles of strains from Northwest China. A total of 46 Brucella strains were identified as B. melitensis bv. 3, which was isolated from at least three animal (livestock and wildlife) hosts, implying that B. melitensis infection is prevalent in the Northwest and suggesting that host diversity provides an optimal niche for the spread and maintenance of B. melitensis in this region. WGS-SNP analysis divided the 46 B. melitensis strains into four clades (C-I-IV) that harbored eight SNP genotypes (STs), implying that at least four lineages are prevalent in the Northwest. Global WGS-SNP phylogenetic analysis of strains revealed that all Northwest strains belong to genotype II. Strains from different clades presented high genetic similarity with strains previously collected from the Northwest. This study provides robust evidence supporting the notion that multiple similar B. melitensis lineages are persistently prevalent in human populations and animals in the Northwest. The economic development of animal husbandry has accelerated the cross-regional flow of livestock and livestock products, driving the spread and reach of the disease. Therefore, tailoring a targeted control strategy is necessary to counter the current serious epidemic trend.

Brucella Pneumonia Mimicking Pulmonary Tuberculosis: A Case Report

Brucellosis is a zoonotic infection prevalent in certain regions. It typically presents with nonspecific symptoms but can also cause focal organ involvement, including the musculoskeletal, neurological, or pulmonary systems. Herein, we present a case of a 31-year-old male patient who presented with a 5-day history of fever and cough. Chest X-ray revealed bilateral patchy consolidations, initially suggesting an infectious etiology such as tuberculosis. Given the patient's background, further investigation confirmed brucellosis-related pneumonia, an uncommon pulmonary manifestation of brucellosis. Additional workup excluded tuberculosis as a possible cause for the lung findings. He was treated with doxycycline and rifampin, leading to symptom resolution and improvement on follow-up imaging. This case underscores the importance of considering brucellosis in the differential diagnosis of atypical pneumonia in patients from endemic regions.

When the farm turns fatal: a rare infection causing heart block

Brucellosis, a zoonotic infection typically presenting with nonspecific symptoms, rarely leads to cardiac complications, particularly conduction abnormalities. We report a unique case of an 84-year-old female who presented with dizziness, bradycardia, and hypotension, ultimately diagnosed with complete heart block. On admission, blood cultures and further diagnostic workup identified Brucella bacteremia as the underlying cause, with further history revealing that she had recently traveled from a farm in Colombia, a brucellosis-endemic area. The patient underwent dual-chamber pacemaker implantation to stabilize her heart rhythm and was initiated on a three-month antibiotic regimen of doxycycline and rifampin. This case highlights the importance of considering brucellosis as a differential diagnosis for heart block in patients with recent travel from endemic regions. Early recognition and intervention, including antibiotic therapy and pacemaker placement when necessary, are essential for achieving favorable outcomes in brucellosis-related cardiac complications.

A family cluster of Brucella abortus infections possibly due to contact with a sika deer in Northeast China

Brucellosis is one of the most common zoonotic diseases worldwide. Although deer are reportedly infected by Brucella spp., deer-associated brucellosis cases have been rare. In this study, two patients in Heilongjiang Province, Northeast China, were diagnosed with brucellosis. They have contacted a sick sika deer before onset which was bought from another province, but have no contact with other infection sources. Molecular genotyping indicated that both were infected with Brucella abortus. This might be the first human cases caused by deer-associated B. abortus strains despite the frequent reports of B. abortus in deer. The role of deer in the transmission of B. abortus should be taken into consideration.

The continuous expansion and spread of human brucellosis in the Xinjiang Uygur Autonomous Region: evidence from epidemiological and strains' genotyping-based analysis

Human brucellosis is a severe public health threat in Xinjiang; however, the epidemiological evolution and molecular correlation of strains are still unclear. In this study, join point regression analysis, spatiotemporal scan analysis, conventional biotyping approaches, and multiple locus variable-number tandem repeat analysis (MLVA) were applied to characterize the epidemiological landscape. A total of 78,689 cases were reported from 1957 to 2023. The average annual reported cases and incidence rates were 1174.46 and 5.28/100,000, respectively. Join point analysis revealed that disease incidence trends increased from 2004 (329, 1.77/100,000) to 2023 (9,334, 36.08/100,000) (AAPC = 17.26, P = 0.00), and affected counties expanded from 21 in 2004 to 100 in 2023, implying that human brucellosis continues to worsen. In 2023, the incidence rates in most counties in southern Xinjiang were higher than 2.0/100,000, and human brucellosis has become endemic in southern Xinjiang. These data demonstrate that human brucellosis is continuously spreading and expanding in Xinjiang. High incidence rate of clusters was detected in North Xinjiang from 2013 to 2023, involving 54 counties. The substantial increase in ruminant farming has increased the risk of infection in humans. A total of 28 Brucella strains were isolated in patients, all B. melitensis bv. 3. MLVA revealed that the dominant genotypes consisted of strains from different areas, hosts, and years; strains from a common original continuously spread, small ruminant trade and transfer contributed to the spread of strains in adjacent regions. Therefore, strengthening surveillance and control of animal brucellosis is vital for preventing its further spread.

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.

Quorum sensing LuxR proteins VjbR and BabR jointly regulate Brucella abortus survival during infection

Brucella abortus maintains an N-acetyl homoserine lactone quorum sensing system that consists of two LuxR proteins, VjbR and BabR, as well as two signals, dodecanoyl (C12 AHL) and 3-oxododecanoyl (3-OXO-C12 AHL) homoserine lactone. This system regulates major virulence factors that influence the bacteria's survival during infection. We generated the first strain that lacks both LuxR proteins and found a synergistic interaction for survival in the chronic infection C57BL/6 mouse model. Transcriptomic analyses of the ∆vjbR∆babR double-deletion strain, as well as the cognate single-deletion strains, in a rich medium with vehicle control or supplemented with an AHL signal revealed large-scale genetic dysregulation in all conditions. Moreover, the double mutant maintained a limited response to AHL, even in the absence of the LuxR proteins. We additionally found that quorum sensing regulates the denitrification pathway but found no in vitro differences in the ability of quorum sensing deletion strains to clear nitric oxide stress or grow under anoxic denitrifying conditions. Finally, we confirmed that BabR autoregulates its own expression, and that VjbR mildly represses BabR expression. Altogether, these experiments help further characterize the Brucella quorum sensing systems and indicate that further attention should be given to the joint interactions between VjbR and BabR in controlling virulence.IMPORTANCEBrucella abortus is a zoonotic bacterial pathogen that uses its quorum sensing to survive within hosts. This study further characterizes that system and indicates important future lines of inquiry. We found that both quorum sensing proteins, VjbR and BabR, coordinate to maintain survival, as well as document that both quorum sensing systems appear physiologically active.

Multifocal Brucellosis in a Young Patient: When a Non-inflammatory Knee Effusion Hides Systematic Complications

Brucellosis, a prevalent zoonosis transmitted through unpasteurized dairy products or contact with infected animals, typically presents with fever, malaise, fatigue, hepatic involvement, and various osteoarticular manifestations. However, it rarely presents with hepatic microabscesses and osteomyelitis. We report a case of a 26-year-old female with no known comorbidities who presented with complaints of fever and right knee swelling for three days. On clinical assessment, her pulse was 120 beats per minute, respiratory rate was 18 breaths per minute, blood pressure was 80/54 mmHg, and temperature was 38°C. Musculoskeletal examination revealed knee effusion only. The systemic examination was unremarkable except for an innocent murmur in the heart. Laboratory results showed hemoglobin 6.7 g/dL, mean corpuscular volume 60, white blood cell count 3.29, platelets 232, erythrocyte sedimentation rate 40, C-reactive protein 53 mg/dL, and mild derangement in liver function tests. Autoimmune workup was negative. Synovial fluid analysis showed a non-inflammatory effusion. A computed tomography (CT) scan of the abdomen revealed multiple small microabscesses. The patient was started on empirical antibiotics based on the suspicion of a liver abscess and symptomatic treatment for joint pain, but her symptoms did not improve. Magnetic resonance imaging (MRI) of the knee suggested joint effusion and osteomyelitis. Brucellosis was diagnosed based on antibodies and blood culture. She was started on standard treatment, her symptoms improved, and she was discharged with a six-week course of treatment. Our case highlights the diagnostic challenges of brucellosis, a zoonotic infection with diverse manifestations, in a young female presenting with fever, non-inflammatory knee effusion, osteomyelitis, and hepatic microabscesses. It underscores the importance of a thorough workup and cross-specialty collaboration, including rheumatology, infectious diseases, and radiology, to avoid misdiagnosis and ensure timely intervention.

Validation of an in house iELISA for serodiagnosis of caprine brucellosis and evaluation of the performance of a B. neotomae lysate for the detection of anti-smooth Brucella specific antibodies in ruminants

Enzyme-linked immunosorbent assay (ELISA) is a widely used and effective tool for detection of anti-Brucella antibodies in serum, easy to perform with high sensitivity and specificity. In this study, we validated an in-house indirect ELISA using B. melitensis whole cell lysate as antigen (Bm-WCL iELISA) for the serodiagnosis of caprine brucellosis and evaluated the use of BSL-2 B. neotomae in replacement of BSL-3 Brucella species as an antigen for the detection of Brucella-specific antibodies in ruminant sera. Using 724 serum samples from female crossbred goats classified as brucellosis-positive or -negative by both the buffered plate antigen (BPA) and the complement fixation (CF) tests, the Bm-WCL iELISA was successfully validated with a sensitivity (Se) of 91.83 % (88.51-94.25 %) and a specificity (Sp) of 97.41 % (95.41-98.70 %). In addition, the Bm-WCL iELISA showed a great concordance with a commercial iELISA kit (k = 0.94) in a subset of 217 serum samples. To avoid working with a BSL-3 Brucella for antigen preparation, we replaced it with a less virulent Brucella species such as B. neotomae. A total of 214 goat and 220 cow serum samples were evaluated for the diagnosis of brucellosis using the B. neotomae whole cell homogenate (Bn-WCL) iELISA. The analysis of the ROC curves suggested cut-off values of 63.83 PP for goats and 24.04 PP for cattle, with associated Se and Sp of 98.18 % (93.61-99.68 %) and 90.38 % (83.20-94.69 %) respectively in goat sera, and 95.45 % (89.80-98.04 %) and 96.36 % (91.02-98.58 %) of Se and Sp, respectively in cattle. These results confirm the utility of the in house Bm-WCL iELISA and encourage validation of the Bn-WCL iELISA for the serodiagnosis of ruminant brucellosis in resource-limited areas where the disease is endemic.

The role of climatic changes in the emergence and re-emergence of infectious diseases: bibliometric analysis and literature-supported studies on zoonoses

Climate change (CC) is increasingly recognised as a critical driver in the emergence and re-emergence of infectious diseases. The relationship between CC and infectious diseases is complex and multifaceted, encompassing changes in temperature, precipitation patterns, and extreme weather events. This study describes the role of CC in the emergence and re-emergence of infectious diseases, emphasising zoonoses. It used a mixed methodology, including an initial literature contextualisation and a bibliometric analysis, to identify key thematic research areas related to CC and zoonotic diseases and show their connections. The research relied on the Scopus database for the identification of relevant source literature and focused the search query on publications in English. VOSviewer was used to discover clear thematic clusters that illustrate what research areas have been addressed in the literature and how they are interlinked. In addition, the research selected and analysed twelve literature-supported studies to investigate the relevance of the zoonoses involved in infectious disease emergence and re-emergence linked to CC impacts. Many pathogens and their vectors, such as mosquitoes, ticks, and rodents, are sensitive to temperature and moisture. CC can expand or shift the geographical distribution of these vectors, bringing diseases to new areas. Warmer temperatures may allow mosquitoes that transmit diseases like malaria and dengue fever to survive and reproduce in regions that were previously too cold. Also, extreme events such as floods, droughts, and hurricanes can lead to immediate increases in waterborne and vector-borne diseases (VBD) by facilitating the spread of pathogens. There is a need to better understand the connections between CC and zoonoses. To address the challenges posed by zoonoses linked to CC, international organizations like the WHO should coordinate a global response to provide clear guidance. Governments must integrate CC and zoonoses into national health policies, ensuring that health frameworks address these interconnected risks. Funding should be allocated for research on the root causes of CC and for strengthening defenses, particularly in developing countries with fragile health systems. Additionally, enhanced communication, education, and training for healthcare professionals about the links between CC and zoonoses are essential for raising awareness and promoting proactive measures.

T-Racing: a modern tool for supporting epidemiological investigation in animal disease outbreaks in Italy

The One Health approach unites efforts across human-animal-environment interfaces against shared threats like zoonotic diseases. T-Racing is a Shiny web application, that supports epidemiological investigations and helps contain livestock-related disease spread, aligning with multidisciplinary principles to safeguard public health. The application uses Temporal Network Analysis techniques to address the dynamic nature of animal trade, facilitating backward and forward tracing strategies. T-Racing leverages web services to retrieve data from multiple sources simultaneously and in near real-time through the plumber package and is distributed using Shinyproxy. T-Racing manages and analyze extensive and diverse datasets within the same environment, including animal movement data, disease outbreak data, and genomic data, all obtained from Italian National databases. In this work, we show T-Racing's capabilities by simulating epidemiological investigations of brucellosis and tuberculosis outbreaks that occurred in non-endemic areas of Italy. To further highlight its capabilities, an interactive demo of T-Racing is available, showcasing its potential and features. This tool supports epidemiological investigations by adopting a data-driven approach, guiding users through the analysis via an iterative process while leveraging their expertise. Therefore, it enables faster data analysis, improves understanding of disease transmission patterns, and facilitates prompt and targeted interventions.

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.

Brucella osteoarthritis: recent progress and future directions

Brucellosis is a common zoonosis, and Brucella osteoarthritis is the most common chronic complication of brucellosis. Development of brucellosis osteoarthritis involves multiple organs, tissues, and cells. Brucella grows and multiplies in intrinsic cells of the skeleton, including osteoblasts, osteocyte and osteoclasts, which results in sustained release of bacteria that leads to exacerbation of the immune response. Concurrently, activation of the immune system caused by invasion with Brucella may affect the dynamic balance of the skeleton. A variety of in vitro and in vivo models have been employed to study Brucella osteoarthritis, such as using bone marrow-derived macrophages to establish cell models and mice to develop animal models of Brucella osteoarthritis. However, limited studies on the molecular pathological mechanisms of Brucella osteoarthritis have been performed and inadequate animal models have been developed due to the challenging parameters of Brucella research. This paper reviews recent advances in the clinical features, molecular pathological mechanisms, and animal models of Brucella osteoarticular infections. This review underscores the complexity of the pathogenesis of Brucella osteoarticular infections and highlights inflammation as a contributing factor to bone loss caused by Brucella. Additionally, the significant proliferation of Brucella in skeletal resident cells also is an important factor leading to bone loss. A deeper understanding of the molecular pathological mechanism of Brucella osteoarthrosis and their animal models could provide robust support for the prevention and treatment of Brucella osteoarticular disease.

The burden of brucellosis in donkeys and its implications for public health and animal welfare: A systematic review and meta-analysis

Background and Aim

Brucellosis is a globally significant zoonotic disease affecting a wide range of wild and domestic animals, with implications for human and animal health. Despite donkeys' crucial roles in agriculture, transportation, and livelihoods, there is limited research on the burden of brucellosis in this species. This study systematically reviews the prevalence and role of donkeys as reservoirs for Brucella spp., providing insights into their public health implications.

Materials and Methods

Using the PRISMA guidelines, a systematic search of PubMed, Scopus, and Google Scholar was conducted for studies published from 1990 to May 2024. Out of 1159 retrieved articles, 20 met the inclusion criteria. Data on study design, location, diagnostic methods, and brucellosis prevalence were extracted and analyzed using R statistical software. Pooled prevalence and heterogeneity were calculated, and the Newcastle-Ottawa Scale was employed to assess study quality.

Results

The pooled prevalence of brucellosis in 6785 donkeys across 20 studies was 10.23% (range: 0%-63.7%), with the highest prevalence reported in Asia (26.80%). While 15% of studies suggested that donkeys act as reservoirs for Brucella spp., direct evidence linking donkeys to disease transmission remains scarce. The disease's impact on donkey reproduction, including abortion and infertility, is underexplored, highlighting a significant research gap.

Conclusion

Brucellosis in donkeys represents a notable zoonotic and occupational risk. The limited data from East Africa, despite its high donkey population, emphasize the need for comprehensive epidemiological studies. Findings underscore the importance of targeted interventions, including biosecurity, public education, and enhanced diagnostic approaches, to mitigate brucellosis' impact on donkey health and its broader public health implications.

True prevalence and spatial distribution of antibodies to Brucella spp. in goat populations in Hubei Province, People's Republic of China: Progress toward disease elimination

Caprine brucellosis, mainly caused by Brucella melitensis, remains a significant zoonotic threat worldwide, affecting animal productivity, welfare, and public health. This study aimed to estimate the true prevalence (TP) and spatial distribution of antibodies to Brucella spp. among goat populations in Hubei Province, China. In 2021, approximately 1.4 million serum samples were collected from 23,126 goat flocks across 82 counties of 16 municipal regions of Hubei Province. A combination of the Rose Bengal Test and Serum Agglutination Test in series was used to detect antibodies against Brucella spp. A hierarchical Bayesian Latent Class Model was used to account for imperfect diagnostic sensitivity and specificity of the tests, conditional dependence between the two tests, and hierarchical data structure to estimate the TP and the probability of achieving a 95 % probability of having a TP below 0.1 % for each county and municipal region. Apparent prevalence was 0.051 % and 0.536 % at the animal and flock level, respectively. The median animal level TP in the 82 counties was 0.0088 % (Range: 0.0008 %, 9.3730 %), with 76.8 % of counties showing a median TP estimate below 0.1 %. Counties containing positive goats were mainly clustered in Huanggang and Huangshi, and counties bordering positive counties had a higher risk of seropositivity. Notably, 52.4 % of counties achieved a 95 % probability with a TP below 0.1 %. Sensitivity analyses confirmed the robustness of these findings across prior distributions. It was concluded that Hubei Province has achieved remarkable progress in caprine brucellosis elimination programs, and priority interventions should be given to positive counties and their bordering counties.

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.

Animal Brucellosis in Egypt: Review on Evolution, Epidemiological Situation, Prevalent Brucella Strains, Genetic Diversity, and Assessment of Implemented National Control Measures

Brucellosis is a neglected zoonotic disease that has a significant economic and public health impact, especially in endemic countries. This review delves deeply into brucellosis's current epidemiological situation and potential sources of livestock infection in Egypt during the last two decades. MLVA-16 and Whole Genome Sequencing based on core-genome SNP analyses confirm the presence of different B. abortus and B. melitensis outbreak strains, both older widely disseminated Brucella strains and newly introduced ones. Despite implementing the test-and-slaughter control strategy over forty years, the disease is still endemic, and different Brucella species circulate among several animal species. The raising of mixed animal species in the same households or farms, exposure to aborted animals, and lack of public awareness about brucellosis transmission are among the main risk factors for increasing livestock brucellosis prevalence in Egypt. Young animals' voluntary vaccination, lack of a nationwide animal identification system, and uncontrolled animal movement stand beyond the ineffectively applied control strategy and may be subdued by applying mass vaccination to decrease disease prevalence dramatically and target imported camels, domestic pigs, and dogs (housed and stray) in the national control surveillance. Increasing awareness through educational campaigns is compulsory to reduce brucellosis transmission risk to livestock/humans.

Quantifying research hotspots and trends in brucella spondylitis: a bibliometric analysis

Background

Human brucellosis is the most common bacterial zoonosis worldwide, with brucella spondylitis (BS) being one of its most severe forms, potentially leading to spinal deformity or paralysis. This study aims to provide a comprehensive overview of the current status and research trends in the BS field using bibliometric methods.

Methods

Publications on BS from January 1, 1980, to March 24, 2024, were retrieved from the Web of Science database. We used Biblioshiny, VOSviewer, Scimago Graphica, CiteSpace, and Microsoft Office Excel Professional Plus 2016 to analyze publication frequency, geographic distribution, institutional affiliations, international collaborations, authorship, journal sources, keyword usage, trends, and cited references.

Results

Between January 1, 1980, and March 24, 2024, 197 publications on BS were analyzed. Turkey emerged as the leading contributor, with 62 publications, accounting for 31.47%. Weibin Sheng was the most prolific author, contributing 7 papers (3.55%). Xinjiang Medical University was the leading institution with 13 documents (6.60%). Medicine and Rheumatology International each published 6 papers (3.05%). CiteSpace analysis highlighted "spinal brucellosis," "spondylitis," "complications," "diagnosis," and "involvement" as the core research areas in BS. Keyword clustering analysis identified 11 primary clusters representing the main research directions. Analysis of abstracts and keyword trends revealed that post-2020, emerging research frontiers include "instrumentation," "management," and "debridement."

Conclusion

There has been significant progress in BS research, with a steady increase in publications. Current research focuses on diagnosis and complications, while future studies may explore management and instrumentation. Increased collaboration among countries and researchers is recommended.

Development and evaluation of the recombinant BP26 protein-based C-ELISA for human brucellosis diagnosis

Introduction

Timely and accurate diagnosis is crucial for the effective treatment and prevention of brucellosis. Current serological diagnostics, primarily based on lipopolysaccharide (LPS), suffer from cross-reactivity with other Gram-negative bacteria, which limits their specificity. Periplasmic protein 26 (BP26), a highly immunogenic antigen found in Brucella, has emerged as a promising alternative for enhancing diagnostic specificity. This study aimed to develop and evaluate a competitive enzyme-linked immunosorbent assay (C-ELISA) utilizing monoclonal antibodies against BP26 for the diagnosis of human brucellosis, thereby providing a more accurate and specific diagnostic approach.

Methods

The study produced monoclonal antibody (mAb) against the BP26 protein through traditional mouse hybridoma technology and developed the C-ELISA method, and compared with a C-ELISA method based on LPS mAb. The detection performance was validated through the analysis of 190 human serum samples, which included 95 brucellosis serum samples and 95 negative serum samples collected by the Xuzhou Center for Disease Control and Prevention, and a comparative analysis was conducted on the diagnostic efficacy of indirect ELISA for brucellosis using both BP26 and LPS-based methods.

Results

The BP26 mAb based C-ELISA achieved 100% sensitivity and specificity in detecting human brucellosis, significantly outperforming the C-ELISA based LPS mAb. Furthermore, the accuracy of the indirect enzyme-linked immunosorbent assay (I-ELISA) using BP26 protein was 98.95%, compared to an accuracy of LPS diagnosis was 99.47%. These results indicated that the BP26 mAb can effectively and accurately detected human brucellosis infections.

Conclusion

This study successfully developed and evaluated a BP26 protein-based C-ELISA method for diagnosing human brucellosis, establishing a foundation for identifying alternative diagnostic antigens for brucellosis.

Comprehensive study on human brucellosis seroprevalence and Brucella species distribution in Iran (1970-2023)

Brucellosis is a zoonotic bacterial disease that causes enormous economic losses in livestock populations and severe debilitation in humans globally. This study analyzes the seroprevalence of human brucellosis in Iran from 1970 to 2023, revealing key epidemiological trends based on data from 20,046 individuals. Through serological, culture, and molecular tests, it identifies the Brucella species affecting humans over five decades. The findings emphasize the need for ongoing monitoring and improved disease control efforts. Subsequently, we cultured specimens from seropositive individuals who exhibited suspected symptoms of brucellosis. The specimens included blood (n = 9017), placentas (n = 203), bone marrow (n = 221), aborted fetuses (n = 70), cerebrospinal fluid (CSF) (n = 62), synovial fluid (n = 5), urine (n = 4), sperm (n = 3), lumbar discs (n = 3), abscesses (n = 2), milk (n = 2), and vertebral bodies (n = 1). The overall seroprevalence of brucellosis in Iran was 44.9 % based on RBPT, 20.7 % by SAT, and 8.7 % by 2-ME tests. The highest SAT prevalence occurred in the 2000s (25.8 %), followed by the 1990s (23.8 %), 1980s (22.2 %), 1970s (14.8 %), and 2010s (10.4 %). Two main Brucella species were identified in infected humans as Brucella melitensis and Brucella abortus. Positive culture rates varied by sample type, with 9.9 % for blood, 10.4 % for bone marrow, and up to 100 % for fluids like urine and milk. The most common strain was B. melitensis biovar 1 (89.2 %), while B. abortus biovar 1 had a much lower incidence (0.3 %). This investigation showed that the highest rates of culture positivity were in samples of urine, synovial fluid, abscess, and milk. These findings suggest that B. melitensis continues to be an important public health concern and that recent years of decline may be due to better control measures of the disease. The combined use of serology and culture is recommended for diagnosing brucellosis. Increased awareness among farmers and consumers of raw dairy products, coupled with nationwide control measures, is crucial for combating zoonotic brucellosis.

Febrile neutropenia in an immunocompetent patient with brucellosis: a case report and literature review

Introduction and importance

Brucellosis is a zoonotic disease that can affect various organs, with symptoms like fever, lymphadenopathy, and arthritis. Hematologic complications, including febrile neutropenia, are rare. This report highlights the diagnostic and therapeutic challenges of brucellosis with febrile neutropenia.

Case presentation

A 36-year-old man presented with a 3-week history of fever, polyarthralgia, and night sweats. Examination showed febrile symptoms, joint swelling, and cervical lymphadenopathy. Laboratory tests revealed neutropenia and elevated inflammatory markers. Imaging was unremarkable, and blood cultures were negative, but brucellosis was confirmed by serology. Treatment with doxycycline and rifampicin led to clinical improvement.

Clinical discussion

Brucellosis diagnosis can be challenging due to nonspecific symptoms and requires high suspicion, especially in non-endemic areas. In this case, early identification and targeted therapy led to symptom resolution. This case underlines the importance of considering zoonotic diseases in febrile neutropenia with inconclusive initial findings.

Conclusion

Brucellosis with febrile neutropenia is rare but manageable with timely diagnosis and treatment, leading to favorable outcomes.

Brucellosis Coinfecting with Liver Hydatid Cyst: Case Report and Literature Review of Zoonoses Coinfection of Human Brucellosis

Background: Brucellosis is a major global public health problem. Brucellosis usually coinfects with zoonoses because of their similar reservoir and infection routes. Materials and Methods: Here, we present a patient who was diagnosed with coinfecting with liver cyst and brucellosis. Results: A 57-year-old female farmer was hospitalized with right hip joint pain approximately 4 weeks earlier. The patient reported a history of hydatid cysts and a family history of brucellosis. Abdominal computerized tomography and ultrasonography revealed a liver hydatid cyst. The standard agglutination test titer of Wright's test was 1:100. Computerized tomography and magnetic resonance imaging revealed brucellosis hip arthritis. The patient was treated with a combination of doxycycline, rifampicin, and cefotaxime. The symptoms immediately improved. The patient was well and asymptomatic during the 6-month follow-up. We reviewed the literature on other zoonoses superinfection with brucellosis. Conclusion: Brucellosis coinfects with multiple zoonosis organisms and poses a serious health threat to humans. Awareness of possible brucellosis coinfection with other zoonoses, especially professionally exposed persons in endemic regions, is warranted.

Brucella Seropositivity and Associated Risk Factors in Pastoral Livestock System in Northeastern Ethiopia

Brucellosis is a common zoonotic disease affecting livestock and humans globally. The disease is endemic in Ethiopian livestock. This study was conducted to estimate Brucella seropositivity and identify its risk factors in livestock, and practices that may expose pastoralists to the disease. Data were collected from 2133 animals across 149 households (HHs) in Dubti and Amibara districts, Afar region, Ethiopia. Blood samples from livestock and household data were collected, and interviews were conducted on husbandry and dairy consumption practices. Sera were serially tested using the Rose Bengal test and indirect enzyme-linked immunosorbent assay. The overall seropositivity to anti-Brucella antibodies was 8% (95% CI, 6.6-9.2). The antibodies were found in 12.4%, 6.5%, 6%, and 3% of the goats, cattle, camels, and sheep, respectively. Among the HHs, 59.7% had at least one seropositive animal. A mixed-effects logistic regression analysis revealed species and the acquisition of new animals (in cattle and camels), and age and district (in sheep, goats, and cattle) as significant risk factors. Goats, cattle, and camels had significantly higher odds of Brucella seropositivity than sheep (p < 0.05). Seropositivity was significantly higher (p < 0.05) in adults than in young animals, in acquired than in homebred (cattle and camels), and in those with reproductive disorders than those without. Pastoralists lacked knowledge of brucellosis and its modes of transmission, while practices exposing humans and livestock to brucellosis were common. The findings underscore the need for public awareness campaigns and implementation of brucellosis control measures in pastoral systems.

Detection and Molecular Diversity of Brucella melitensis in Pastoral Livestock in North-Eastern Ethiopia

Brucellosis is a neglected zoonotic disease affecting livestock and humans that remains endemic in Ethiopia. Despite its prevalence, only a few studies have identified Brucella species circulating in livestock in the country. This study aimed to determine the Brucella species responsible for infections in livestock in the Afar region of Ethiopia and characterize the isolates using whole-genome single nucleotide polymorphism (wgSNP) analysis and in silico multi-locus sequence typing (MLST). Comparisons were made between Ethiopian Brucella and regional and global isolates to determine their phylogenetic relationships. Surveys conducted in May and October-November 2022 in six villages of the Amibara district involved the collection of vaginal swabs (n = 231) and milk samples (n = 17) from 32 sheep and 199 goats kept by 143 pastoral households reporting recent abortions in the animals. Brucella melitensis was detected in three sheep and 32 goats, i.e., 15% (35/231) of animals across 20% (29/143) of households using bacterial culture and PCR-based methods (bcsp31, AMOS, and Bruce-ladder multiplex PCR). Of the 35 positive animals, B. melitensis was isolated from 24 swabs, while the remaining 11 were culture-negative and detected only by PCR. The genomic DNA of the 24 isolates was sequenced using Illumina Novaseq 6000 and assembled using the SPAdes pipeline. Nine- and 21-locus MLST identified 23 isolates as genotype ST12, while one isolate could not be typed. The wgSNP-based phylogenetic analysis revealed that the Ethiopian isolates clustered within the African clade and were closely related to isolates from Somalia. Several virulence factors responsible for adhesion, intracellular survival, and regulatory functions were detected in all isolates. No antimicrobial resistance genes associated with resistance to drugs commonly used for treating brucellosis were detected. Since B. melitensis is prevalent in sheep and goats, vaccination with the B. melitensis Rev-1 vaccine is the recommended strategy in these pastoral systems to protect animal and human health.

Sero-prevalence of human brucellosis and associated factors among febrile patients attending Moyale Primary Hospital, Southern Ethiopia, 2023: Evidences from pastoralist community

BACKGROUND

Brucellosis is a neglected zoonotic disease often contracted through contact with animals and consumption of unpasteurized dairy products. Despite being the most common cause of non-malarial acute febrile illness brucellosis is often misdiagnosed in healthcare setups. The global incidence of Brucella infection is reported to be over 2 million cases annually. In Ethiopia, there are varying reports on the prevalence of brucellosis, and just a few researches have been undertaken on the prevalence among febrile patients. Therefore, this study aimed to determine sero-prevalence of human brucellosis and associated factors among febrile patients attending Moyale Primary Hospital in southern Ethiopia.

METHODS

Cross-sectional study was conducted on 293 febrile patients attending Moyale Primary Hospital. We used convenience sampling technique. Blood specimen was collected and screened for Brucella antibody using Rose-Bengal plate test and ELISA was used for confirmation of Brucella infection. We used a questionnaire to collect socio-demographic data and to assess associated factors (S1 Table). Bivariate and subsequent multivariable logistic regression was performed to explore associated factors with the prevalence of human brucellosis.

RESULTS

The sero-prevalence of human brucellosis in this study was 13% (95% CI: 9.5, 16.5). Majority of the study participants (58.7%) were rural dwellers; 54.6% were male and the age range was from 5 to 80 years (mean = 24.17, SD = ±15.9). Higher number of sero-prevalence was seen among rural residents (19.8%) and male participants (14.40%). Drinking unpasteurized camel milk (AOR = 11.62, 95% CI: 3.85, 17.13; P = 0.000) and rural residence (AOR = 7.21, 95% CI: 2.48, 15.90; P = 0.000) were significantly associated with brucellosis. Consumption of pasteurized milk was shown to have protective effect (AOR = 6.12, 95% CI: 1.26, 29.76; P = 0.025) against brucellosis.

CONCLUSION

The current study showed 13% point prevalence of human brucellosis among febrile patients attending Moyale Primary Hospital. Consuming unpasteurized milk, particularly unpasteurized camel milk, and rural residence was significantly associated with Brucella infection. Awareness creation about the zoonotic nature of brucellosis and the role of unpasteurized milk in the transmission of the disease is important to control human brucellosis.

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.

Brucellosis seroprevalence in cattle in China during 2014-2024: a systematic review and meta-analysis

Brucellosis, caused by several species of Brucella, continues to be a significant illness that poses a global threat to public health. China remains a persistent hotspot for brucellosis, despite the implementation of extensive control measures. This study aims to conduct a systematic review and meta-analysis of the seroprevalence of bovine brucellosis in different breeds and regions of China from 2014-2024, and to provide predictions on the future prevalence patterns of brucellosis in cattle and humans. The analysis comprised a total of 80 research studies, which consisted of 187 datasets and a combined sample size of 3,130,706. We estimated the overall pooled seroprevalence of bovine brucellosis in China to be 1.5% (95% CI: 0.6-2.6%). Subgroup analysis revealed that the seroprevalence in dairy cattle was 3.1%, surpassing the seroprevalence in beef cattle (1.3%) and yak (1.5%). Regions that had authorized vaccination programmes exhibited higher seroprevalence (1.8%) compared to regions that did not have vaccination (0.5%). Notably, the study observed a simultaneous rise in both the prevalence of brucellosis in cattle and the number of human brucellosis cases. This suggests that high-quality routine surveillance of brucellosis in cattle will be essential for predicting and responding to cases in humans. Additionally, given the existing prevention and control measures, brucellosis will likely continue to be prevalent in both cattle and people. This systematic review will assist policymakers in adjusting animal surveillance and interregional livestock movement policies, ultimately contributing to the public safety goal of preventing brucellosis in humans by controlling it in animals.

The European Union One Health 2023 Zoonoses report

This report by the European Food Safety Authority and the European Centre for Disease Prevention and Control presents the results of zoonoses monitoring and surveillance activities carried out in 2023 in 27 Member States (MSs), the United Kingdom (Northern Ireland) and 10 non-MSs. Key statistics on zoonoses and zoonotic agents in humans, food, animals and feed are provided and interpreted historically. In 2023, the first and second most reported zoonoses in humans were campylobacteriosis and salmonellosis, respectively. For both agents, an increase in the absolute number of cases was observed in comparison with 2022. Fifteen MSs and the United Kingdom (Northern Ireland) reached all the established targets in poultry populations with regard to the reduction in Salmonella prevalence for the relevant serovars. Salmonella samples from carcases of various animal species, and samples for Campylobacter quantification from broiler carcases, were more frequently positive when performed by the competent authorities than when own-checks were conducted. Shiga toxin-producing Escherichia coli (STEC) was the third most reported zoonotic agent in humans, followed by Yersinia enterocolitica and Listeria monocytogenes. L. monocytogenes and West Nile virus infections were the most severe zoonotic diseases, with the highest percentage of hospitalisations among cases and the highest case fatality rates. Twenty-seven MSs and the United Kingdom (Northern Ireland) reported a slight decrease in food-borne outbreaks in 2023 overall in comparison with 2022, although the overall number of reported human cases and hospitalisations increased. Salmonella Enteritidis remained the most frequently reported causative agent for reported cases and food-borne outbreaks. Salmonella in 'eggs and egg products' was the agent/food pair of most concern. In 2023 this combination caused the largest number of outbreaks and cases among all agent/food combination and ranked second in number of hospitalisations. Salmonella was also the causative agent associated with the majority of multi-country outbreaks reported in the EU in 2023. This report also provides updates on brucellosis, echinococcosis, Q fever, rabies, toxoplasmosis, trichinellosis, tuberculosis due to Mycobacterium bovis or M. caprae, and tularaemia.

Progress and persistence of diseases of high consequence to livestock in the United States

The USDA/ARS-National Disease Center (NADC) will celebrate its 65th anniversary of existence in November 2026. NADC continues as one of the world's premier animal health research centers conducting basic and applied research on endemic diseases with economic impact on U.S. livestock and wildlife. This research center also supports a program studying important food safety pathogens such as Salmonella, E. coli and Campylobacter. NADC has contributed significantly to the elimination of a few diseases, notably hog cholera and milk fever, and made progress in reducing the impact of many other animal diseases through vaccines, therapies and managerial recommendations. Despite nearly 65 years of targeted research on these diseases and much progress, some of these continue to persist. The reasons for such persistence varies for each disease condition and they are often multifactorial involving host susceptibility, virulence and even environmental conditions. Individually and in aggregate, these disease conditions have a massive economic impact and can be devasting to animal producers, owners and individuals that become infected through zoonotic disease agents such as tuberculosis, leptospirosis and avian influenza. They also diminish the health, well-being and welfare of affected animals, which directly affects the food supply. The NADC is using all available technologies including genomic, biochemical, reverse genetics, and vaccine trials in the target host to combat these significant diseases. We review the progress and reasons for persistence of selected diseases and food safety pathogens as well as the progress and potential outcomes should research and programmatic plans to eliminate these disease conditions cease.

Assessment of brucellosis-causing pathogens with an emphasis on the prevalence of Brucella melitensis in the Republic of Korea: insights from a decade of pathogen surveillance (2014-2023), a retrospective study

BACKGROUND

The main Brucella species causing human infections in the Republic of Korea is Brucella abortus, which uses cattle as its host. However, since 2014, Brucella melitensis, which uses sheep and goats as hosts, has also been identified. This study investigated whether a shift has occurred in the predominant species of Brucella pathogens.

METHODS

Brucellosis is a class 3 infectious disease requiring mandatory reporting and registration in the Korea Disease Control and Prevention Agency's infectious disease surveillance system (http://is.kdca.go.kr). Cases from 2014 to 2023 were studied, and whole-genome sequencing analysis was conducted using BruMLSA21.

RESULTS

Out of 51 patients, males (45 patients, 88.2%) were predominantly affected. Twenty-five patients (49%) came from the livestock industry, and within the livestock sector group, the route of infection occurred exclusively through contact (25/25, 100%), whereas in other occupations, it was split between contact (9/26 patients, 34.6%) and ingestion (8/26 patients, 30.8%). Among the 31 patients who underwent Brucella culture tests, B. melitensis was found to be more prevalent than B. abortus (14 patients, 45.2% vs. 11 patients, 35.5%). In all cases where B. melitensis was isolated, the infections were of foreign origin, consistent with the results of BruMLSA21.

CONCLUSION

Regular monitoring of the causative agent of brucellosis is necessary due to its varying host preferences and antibiotic resistance. Furthermore, given the increasing prevalence of B. melitensis worldwide, changes in dietary habits (e.g., increased lamb consumption), and the increase in foreign workers and Chinese immigrants, a multi-ministerial One Health response will be required.

Serological prevalence of Brucella spp. at the livestock-human interface in Jordan

Despite its endemic status in the Middle East, key knowledge gaps persist regarding the prevalence, transmission rate, and geographical distribution of both human and livestock brucellosis in Jordan. This study aimed to investigate the seroprevalence of human and livestock brucellosis as well as the incidence of brucellosis in humans in Jordan. A total of 500 human participants (202 exposed and 296 unexposed to livestock) were enrolled in the study. Sampling was conducted at baseline and 1.5 years later. Additionally, a total of 700 livestock were sampled, comprising 20 animals per taxa (camels, cattle, sheep, goats) per site, at both baseline (N = 350) and the 1.5-year follow-up (N = 350). Human participants were longitudinally followed, whereas livestock sampling was conducted opportunistically. Blood samples obtained from both humans and livestock at baseline and follow-up were tested for Brucella spp. serum antibodies using the Rose Bengal test (RBT) and complement fixation test (CFT). The overall seroprevalence of brucellosis in humans at baseline was 3.4 % (95 % CI: 2.0-5.4). Positive test results in humans were detected from all five sites with no significant regional variation observed. Seroprevalence was higher in individuals regularly exposed to livestock (6.1 %; 95 % CI: 3.5-9.9) compared to those not regularly exposed (0.80 %; 95 % CI: 0.10-2.9). Incidence of human brucellosis was 924 seropositives per 100,000 person-years, with all incident seropositives occurring in the livestock-exposed cohort. In livestock, the overall seroprevalence of brucellosis was 5.4 % (95 % CI: 3.5-8.3) at baseline compared to 2.6 % (95 % CI: 1.4-4.8) at follow-up. Seropositive livestock were detected at all sites apart from Al-Zarqa, and in all species apart from camels. In conclusion: Brucellosis burden was higher among humans regularly exposed to livestock, re-emphasizing the need for disease control in livestock populations to prevent primary infection in humans.

Detection and quantification of Brucella abortus DNA in water buffaloes (bubalus bubalis) using droplet digital polymerase chain reaction

Brucellosis represents a major public health concern worldwide. Human transmission is mainly due to the consumption of unpasteurized milk and dairy products of infected animals. The gold standard for the diagnosis of Brucella spp in ruminants is the bacterial isolation, but it is time-consuming. Polymerase Chain Reaction (PCR) is a quicker and more sensitive technique than bacterial culture. Droplet digital PCR (ddPCR) is a novel molecular assay showing high sensitivity in samples with low amount of DNA and lower susceptibility to amplification inhibitors. Present study aimed to develop a ddPCR protocol for the detection of Brucella abortus in buffalo tissue samples. The protocol was validated using proficiency test samples for Brucella spp by real time qPCR. Furthermore, 599 tissue samples were examined. Among reference materials, qPCR and ddPCR demonstrated same performance and were able to detect up to 225 CFU/mL. Among field samples, ddPCR showed higher sensitivity (100%), specificity and accuracy of 93.4% and 94.15%, respectively. ddPCR could be considered a promising technique to detect B. abortus in veterinary specimens, frequently characterized by low amount of bacteria, high diversity in matrices and species and poor storage conditions.

Bovine brucellosis, associated risk factors and preventive measures in industrial cattle farms

Effective management of brucellosis in human populations is closely tied to controlling the disease in domestic livestock. This study focused on identifying determinants of brucellosis prevalence in mixed industrial dairy and beef cattle farms within Isfahan Province, Iran. Employing a case control design, we compared 32 ranches with documented brucellosis within the previous year (12 months) to 38 farms with no brucellosis during the same timeframe. The comparison examined the farms' adherence to health protocols for raising cattle. Utilizing multivariable logistic regression, the study identified several significant risk factors linked to brucellosis prevalence. These included cleaning milking accessories with a water and chlorine solution (OR 0.25, 95%CI 0.06 to 0.99), cleaning water troughs daily (OR 0.20, 95%CI 0.04 to 0.89), the cows' density per square meter (OR 0.14, 95%CI 0.03 to 0.75), being within 2000 m of another cattle ranch with brucellosis (OR 4.02, 95%CI 1.09 to 14.84) and ovine farms situated within a 500-m radius (OR 8.43, 95%CI 1.66 to 42.70). No meaningful difference was observed in vaccination frequency between infected and non-infected farms (P = 0.645). While vaccination is essential for preventing bovine brucellosis, robust biosecurity measures are crucial for effective disease management.

Whole-Genome Sequencing of Brucella melitensis Isolates from Kuwait for the Identification of Biovars, Variants, and Relationship within a Biovar

OBJECTIVE

The identification of Brucella genotypes is essential for epidemiological studies. The whole-genome sequencing is emerging as a novel tool for genetic characterization of infectious microbes. The aim of this study was to genotype Brucella melitensis isolates from Kuwait using whole-genome sequencing and variant analysis of the sequence data.

METHODS

DNA was purified from 15 heat-inactivated B. melitensis isolates and used to prepare sequencing libraries employing Nextera XT DNA Sample Preparation Kit (Illumina San Diego, CA, USA) and sequenced on a MiSeq (Illumina). The sequence files were aligned to three biovars of B. melitensis, i.e., biovar 1 str. 16M, biovar 2 str. 63/9, and biovar 3 str. Ether. The alignment and variant calling were performed using "bwa-mem" and SAMtools/VCFtools, respectively.

RESULTS

The genome size of all the isolates was around 3.3 mega base pairs and resembled B. melitensis biovar 2. Single-nucleotide polymorphisms (SNPs), insertions, and deletions (indels) were spread all over the genome; but 138 SNPs were common among the 14 isolates, supporting the same ancestral origin. A neighbor-joining tree analysis identified isolate 2 as an outlier. In addition, SNPs (2-478) specific to each isolate were also identified, which divided the B. melitensis biovar 2 into two major groups/genotypes. A further analysis showed that the Kuwaiti isolates of the present study shared phylogeny mainly with strains from the Middle Eastern countries.

CONCLUSIONS

Among the 15 studied isolates from Kuwait, biovar 2 is the most prevalent biovar of B. melitensis. Furthermore, isolate-specific genetic variations were identified, which may be useful in epidemiological investigations.

OBJECTIVE

The identification of Brucella genotypes is essential for epidemiological studies. The whole-genome sequencing is emerging as a novel tool for genetic characterization of infectious microbes. The aim of this study was to genotype Brucella melitensis isolates from Kuwait using whole-genome sequencing and variant analysis of the sequence data.

METHODS

DNA was purified from 15 heat-inactivated B. melitensis isolates and used to prepare sequencing libraries employing Nextera XT DNA Sample Preparation Kit (Illumina San Diego, CA, USA) and sequenced on a MiSeq (Illumina). The sequence files were aligned to three biovars of B. melitensis, i.e., biovar 1 str. 16M, biovar 2 str. 63/9, and biovar 3 str. Ether. The alignment and variant calling were performed using "bwa-mem" and SAMtools/VCFtools, respectively.

RESULTS

The genome size of all the isolates was around 3.3 mega base pairs and resembled B. melitensis biovar 2. Single-nucleotide polymorphisms (SNPs), insertions, and deletions (indels) were spread all over the genome; but 138 SNPs were common among the 14 isolates, supporting the same ancestral origin. A neighbor-joining tree analysis identified isolate 2 as an outlier. In addition, SNPs (2-478) specific to each isolate were also identified, which divided the B. melitensis biovar 2 into two major groups/genotypes. A further analysis showed that the Kuwaiti isolates of the present study shared phylogeny mainly with strains from the Middle Eastern countries.

CONCLUSIONS

Among the 15 studied isolates from Kuwait, biovar 2 is the most prevalent biovar of B. melitensis. Furthermore, isolate-specific genetic variations were identified, which may be useful in epidemiological investigations.

Hypertonic Saline Induces Host Protective Immune Responses against Brucella abortus Infection in Mice

Hypertonic saline (HTS) resuscitation can enhance immune responses against various pathogens, however, the effect of HTS on brucellosis is yet to be defined. In this study, we found that HTS inhibited Brucella infection in mice by augmenting Th1 immunity. HTS treatment enhanced the serum cytokines production and the expression of nitric oxide synthase (NOS2) and nuclear factor kappa B (NF-ĸB) p50 and p65, crucial anti-Brucella effectors in splenocytes. In addition, HTS treatment also inhibited the phosphorylation of MAPK signaling, accompanied by the down-regulation of the autophagy marker LC3B-II. Due to directing an appropriate immune response, HTS treatment substantially decreased bacterial burden in spleen and liver tissues. In summary, corroborating previous studies showing the antimicrobial effects of HTS, our findings indicate that HTS treatment triggers a protective immune response against Brucella infection. Additionally, these results provide promising evidence of the immunomodulatory role of HTS in controlling bacterial infections.

Aspects of brucellosis vaccination in Maranhão state

Bovine brucellosis is a zoonosis of great economic and public health relevance. Understanding the epidemiological aspects of this disease is a determining factor to help developing effective strategies and supporting decision-making processes. The aim of the present study is to carry out a situational vaccination diagnosis against brucellosis in Maranhão State's cattle in order to identify challenges set for vaccination operations and to help the Official Veterinary Service to plan health interventions. In 2022, questionnaires focused on the socioeconomic profile and knowledge on vaccination were applied to the following groups to help achieving the aforementioned aims: (i) cattle breeders (n = 201), (ii) veterinarians registered with the National Program for Control and Eradication of Brucellosis and Animal Tuberculosis (n = 84), (iii) Official Veterinary Service servants involved in conducting the National Program for Control and Eradication of Brucellosis and Animal Tuberculosis (n = 75), and (iv) individuals in charge of vaccine retail outlets (n = 58). Farmers and those in charge of vaccine retail outlets presented average knowledge on this subject (51-70% accuracy). Yet, there were similar knowledge gaps in these two groups. Although the knowledge level recorded for registered veterinarians and Official Veterinary Service servants was high (71-100% accuracy), low adherence to personal protection equipment was also observed, and it is worrisome, given brucellosis' zoonotic nature. In addition, veterinarians presented knowledge gaps when it comes to updates on the National Program for Control and Eradication of Brucellosis and Animal Tuberculosis Technical Regulations, and it can be an indicative that questionnaires were superficially or carelessly answered. Other obstacles to vaccination were poor quality of roads to access properties and breeders with limited number of bred calves in the age group 3 to 8 months. These barriers impair the expansion of vaccination cover against brucellosis in Maranhão State. The Official Veterinary Service must implement a strategic plan to fill out the knowledge gaps shown by those in this production chain and make it easier to get to the basis for effective health interventions aimed at brucellosis control in Maranhão State.

Identification and mapping of objects targeted for surveillance and their role as risk factors for brucellosis in livestock farms in Kazakhstan

Objects for Targeted Surveillance (OTS) are infrastructure entities that can be considered as focal points and conduits for transmitting infectious animal diseases, necessitating ongoing epidemiological surveillance. These entities encompass slaughterhouses, meat processing plants, animal markets, burial sites, veterinary laboratories, etc. Currently, in Kazakhstan, a funded research project is underway to establish a Geographic Information System (GIS) database of OTSs and investigate their role in the emergence and dissemination of infectious livestock diseases. This initial investigation examined the correlation between brucellosis outbreaks in cattle and small ruminant farms in the southeastern region of Kazakhstan and the presence of OTSs categorized as "slaughterhouses," "cattle markets," and "meat processing plants. The study area (namely Qyzylorda, Turkestan, Zhambyl, Almaty, Zhetysu, Abay and East Kazakhstan oblasts), characterized by the highest livestock density in the country, covers 335 slaughterhouses (with varying levels of biosecurity), 45 livestock markets and 15 meat processing plants. Between 2020 and 2023, 338 cases of brucellosis were reported from livestock farms in this region. The findings of the regression model reveal a statistically significant (p<0.05) positive association between the incidence of brucellosis cases and the number of OTSs in the region. Conversely, meat processing plants and livestock markets did not exhibit a significant influence on the prevalence of brucellosis cases. These results corroborate the hypothesis of an elevated risk of brucellosis transmission in regions with slaughterhouses, likely attributable to increased animal movements within and across regions, interactions with vehicles and contact with slaughterhouse staff. These outcomes mark a pivotal advancement in the national agricultural development agenda. The research will be extended to encompass the entire country, compiling a comprehensive OTS database.

Seroprevalence of human brucellosis in Turkey: A comprehensive meta-analysis

AIMS

Brucellosis remains a common zoonotic disease, in developing countries, as well as in Turkey where it is endemic, underdiagnosed, and underreported. The aim of this meta-analysis was to provide a comprehensive estimate of seroprevalence with a large sample size, covering all regions of Turkey, including both grey literature and published studies.

METHODS AND RESULTS

A systematic search was performed in MEDLINE (via PubMed), TürkMedline (National Health Sciences-Periodicals Database), and YÖKSİS database (Higher Education Council Information System) until May 5th, 2023. The quality of the studies was evaluated independently using Joanna Briggs Institute (JBI) critical assessment tool for prevalence studies. A random-effects model (DerSimion and Laird) was utilized to estimate the overall pooled prevalence. A sensitivity analysis was performed, excluding studies with a high risk of bias. The subgroup analyses and meta-regression were conducted to explore sources of heterogeneity. Egger test and funnel plot were used to assess publication bias. The meta-analysis included 30 studies in total published between 1999 and 2021 with 51,560 individuals. In Turkey, the pooled seroprevalence of human brucellosis was estimated to be 4.5% (95% confidence interval [CI]: 3.8%-5.3%). According to the subgroup analysis, a higher seroprevalence was found in rural areas (8.0%, 95% CI: 5.4%-10.7%), high-risk occupational groups (9.9%, 95% CI: 5.3%-14.6%), and the Central East Anatolia Region (13%, 95% CI: 3.2%-22.8%). The meta-regression analysis identified living in rural areas and certain geographic regions as significant risk factors associated with higher seroprevalence.

CONCLUSIONS

This meta-analysis revealed a significant burden of human brucellosis in Turkey. The findings highlight the need for public health measures and targeted interventions to reduce the burden of this zoonotic disease, especially in rural areas, high-risk occupational groups, and the East Anatolia Region.