REVIEW OF CLINICAL AND LABORATORY FEATURES OF HUMAN BRUCELLOSIS

Determining Diagnostic Sensitivity: A Comparison of Rose Bengal Test, Coombs Gel Test, ELISA and Bacterial Culture in Brucellosis Diagnosis-Analyzing Clinical Effectiveness in Light of Inflammatory Markers

BACKGROUND

Brucellosis is a zoonotic infectious disease. It is estimated that the number of cases reported today is much less than the actual number. We still have difficulty in diagnosing the disease and its organ involvement. In this sense, new approaches that can be useful in clinical practice are required, and we aimed to evaluate this situation in our study.

METHODS

171 of 213 patients followed in our center between January 2021 and April 2024 were included in the study. A total of 150 patients were included in the study as a control group. Rose Bengal test (RBT), Coombs gel test (CGT), enzyme-linked immunosorbent assay (ELISA), and automated blood culture were used for diagnosing brucellosis. Complete blood count, sedimentation, C-reactive protein, and biochemical parameters were obtained. Inflammation markers such as neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, systemic immune-inflammation index, and systemic inflammation response index were calculated.

RESULTS

The most successful results in the diagnosis were ELISA (89.4%), RBT (88.3%), CGT (83%), and blood culture (34.8%). For diagnosing sacroiliitis and spondylodiscitis, instead of resorting to expensive methods like magnetic resonance, a combination of ELISA positivity with elevated acute phase reactants and inflammatory markers could be significantly instructive.

CONCLUSIONS

Optimizing diagnostic algorithms and exploring novel diagnostic approaches, such as inflammatory markers, hold promise for improving diagnosis and management.

Ocular Involvement in Patients with Brucellosis: A Single-Center Prospective Study

PURPOSE

The aim of this study was to evaluate the prevalence, type and treatment outcomes of ocular involvement in patients with brucellosis.

METHODS

This prospective, single-center study enrolled patients admitted to the infectious disease outpatient clinic with diagnosed brucellosis between July 15, 2022 and July 15, 2023. Diagnosis was based on clinical symptoms and a standard Brucella tube agglutination test (≥1/160) or a positive blood culture. Ophthalmologic examinations were performed at baseline and in the first month of treatment. Third and sixth month follow-up examinations were also performed for patients with ocular findings.

RESULTS

Ocular involvement occurred in 60 (24.8%) of 242 patients. Conjunctivitis was the most common ocular involvement and was observed in 39 patients (16.1%). Uveitis was the second most common ocular involvement in 14 patients (5.8%). Scleritis was the least common ocular involvement and was observed in only one patient. Patients with ocular involvement were older (p = 0.027) and had higher rates of weight loss and spondylodiscitis (p = 0.044 and 0.001, respectively). Among laboratory parameters, erythrocyte sedimentation rate and lactate dehydrogenase levels were significantly higher in patients with ocular involvement (p = 0.001 and 0.036, respectively). There were no significant differences in other demographic, clinical, and laboratory characteristics between patients with and without ocular involvement. In 56 (93.3%) patients, the ocular findings improved during the follow-up examination.

CONCLUSION

Brucellosis, a systemic infection, can manifest with ocular involvement. Early detection and treatment through ophthalmological examination are crucial in managing brucellosis.

Rapid Colorimetric Quantita2tive Portable Platform for Detection of Brucella melitensis Based on a Fluorescence Resonance Energy Transfer Assay and Nanomagnetic Particles

Brucellosis is a bacterial zoonotic disease that requires major attention for both health and financial facilities in many parts of the world including the Mediterranean and the Middle East. The existing gold standard diagnosis relies on the culturing technique, which is costly and time-consuming with a duration of up to 45 days. The Brucella protease biosensor represents a new detection approach that will lead to low-cost point-of-care devices for sensitive Brucella detection. In addition, the described diagnostic device is portable and simple to operate by a nurse or non-skilled clinician making it appropriate for the low-resource setting. In this study, we rely on the total extracellular protease proteolytic activity on specific peptide sequences identified using the FRET assay by high-throughput screening from the library of peptide (96 short peptides such as dipeptides and tripeptides) substrates for Brucella melitensis (B. melitensis). The B. melitensis-specific protease substrate was utilized in the development of the paper-based colorimetric assay. Two specific and highly active dipeptide substrates were identified (FITC-Ahx-K-r-K-Ahx-DABCYL and FITC-Ahx-R-r-K-Ahx-DABCYL). The peptide-magnetic bead nanoprobe sensors developed based on these substrates were able to detect the Brucella with LOD as low as 1.5 × 102 and 1.5 × 103 CFU/mL using K-r dipeptide and R-r dipeptide substrates, respectively, as the recognition element. The samples were tested using this sensor in few minutes. Cross-reactivity studies confirmed that the other proteases extracted from closely related pathogens have no significant effect on the sensor. To the best of our knowledge, this assay is the first assay that can be used with low-cost, rapid, direct, and visual detection of B. melitensis.

Motor polyradiculoneuropathy as an unusual presentation of neurobrucellosis: a case report and literature review

Brucellosis, a zoonotic disease caused by Brucella species, poses a significant global health concern. Among its diverse clinical manifestations, neurobrucellosis remains an infrequent yet debilitating complication. Here, we present a rare case of neurobrucellosis with unusual presentations in a 45-year-old woman. The patient's clinical course included progressive lower extremity weakness, muscle wasting, and double vision, prompting a comprehensive diagnostic evaluation. Notable findings included polyneuropathy, elevated brucella agglutination titers in both cerebrospinal fluid and blood, abnormal EMG-NCV tests, and resolving symptoms with antibiotic therapy. The clinical presentation, diagnostic challenges, and differentiation from other neurological conditions are discussed. This case underscores the importance of considering neurobrucellosis in regions where brucellosis is prevalent and highlights this rare neurological complication's distinctive clinical and radiological features. Early recognition and appropriate treatment are crucial to mitigate the significant morbidity associated with neurobrucellosis.

The spatiotemporal epidemiological study on human brucellosis in shenyang, China from 2013 to 2022

Background

Epidemiological characteristics of human brucellosis (HB) have changed over the last decade. In this study, we depicted the spatiotemporal features of HB in Shenyang, China, from 2013 to 2022 and the objective was to visualise spatiotemporal patterns and identify high-risk regions with the purpose to provide evidence for HB prevention and control.

Methods

We performed an observational epidemiological study using HB data obtained from the National Notifiable Disease Reporting System (NNDRS). Joinpoint regression analysis was employed to determine the changing trends in the annual incidence. A vector boundary map of Shenyang was used to visualise spatial distribution. Spatial autocorrelation was identified using both global and local Moran's autocorrelation coefficients, while hotspot areas were determined using the Getis-Ord statistic.

Results

A combined sum of 4103 HB cases were analysed, and the average level of annual incidence of HB was 5.52 per 100,000. The incidence of HB showed obvious seasonality, with a notable peak observed from April to July (summer peak). The annual incidence in Shenyang has been on the rise since 2013, with an annual percentage change (APC) of 6.39% (95%CI 1.29%, 12.39%). Xinmin County exhibited the most elevated average annual incidence rate, with Faku County ranking second. The average annual incidence in rural areas exhibited a significantly greater disparity compared to suburban areas (P < 0.001), whereas the incidence rate in suburban areas demonstrated a significantly higher contrast when compared to urban areas (P < 0.001). A clustered distribution of the annual incidence of HB was observed for all years from 2013 to 2022. Abnormally high values were found in suburban areas, and no abnormally high values were found after 2017. The low-low clustering areas were found in urban as well as suburban areas from 2013 to 2022. Hotspots (P < 0.05) were located in rural areas, while cold spots (P < 0.05) were found in both urban and suburban areas. Since 2020, there have been no hotspots in Shenyang.

Conclusions

Rural areas are high-risk areas for HB and may be key to controlling HB epidemics. Although the annual incidence of HB in rural areas has increased, owing to the stability of spatial relationships and the disappearance of hotspots, there is little possibility of outbreaks; however, stricter monitoring should be applied in rural areas to prevent the emergence of new transmission routes.

A case report of acute renal failure caused by anti-brucellosis treatment

RATIONALE

Rifampicin, as a main chemotherapy drug treating brucellosis, is widely used in clinical practice. Rifampicin-associated ARF is not rare, especially in those rifampicin re-exposure patients. However, this was rare complication of severe renal involvement due to multiple factors including rifampicin, nephrotoxic gentamicin, and contrast medium, and few studies have reported it.

PATIENT CONCERNS

A 59-year-old male presented to our hospital with acute renal failure (ARF) caused by anti-brucellosis treatment with rifampicin (675 mg/day), gentamicin (320 mg/day), and doxycycline (200 mg/day). He had a contrast-enhanced CT of the upper abdomen before the onset of. After stopping rifampicin and undergoing integrated therapy, the patient's renal function gradually recovered.

DIAGNOSES

Considering that the patient had a history of using rifampicin for pulmonary tuberculosis in the past, based on the examination results, the patient was diagnosed with rifampicin-associated ARF.

INTERVENTIONS

Symptomatic treatment such as hemodialysis, and anti-brucella treatment with doxycycline and moxifloxacin were given.

OUTCOMES

The patient had significant anuric and polyuric periods and acute tubular necrosis is considered. After treatment, his renal function and urine volume returned to normal, and Brucella melitensis was not isolated from blood cultures.

LESSONS

The case reveals that severe renal involvement due to multiple factors including rifampicin, nephrotoxic gentamicin, and contrast medium. Misdiagnosis and mistreatment can deteriorate the patient's condition. Renal function should be closely monitored in the susceptible patients. Early recognition can provide appropriate therapy to patients. If unexplained renal failure during the use of rifampicin, especially in those rifampicin re-exposure patients, rifampicin-associated ARF should be considered.

A novel Bayesian Latent Class Model (BLCM) evaluates multiple continuous and binary tests: A case study for Brucella abortus in dairy cattle

Bovine brucellosis, primarily caused by Brucella abortus, severely affects both animal health and human well-being. Accurate diagnosis is crucial for designing informed control and prevention measures. Lacking a gold standard test makes it challenging to determine optimal cut-off values and evaluate the diagnostic performance of tests. In this study, we developed a novel Bayesian Latent Class Model that integrates both binary and continuous testing outcomes, incorporating additional fixed (parity) and random (farm) effects, to calibrate optimal cut-off values by maximizing Youden Index. We tested 651 serum samples collected from six dairy farms in two regions of Henan Province, China with four serological tests: Rose Bengal Test, Serum Agglutination Test, Fluorescence Polarization Assay, and Competitive Enzyme-Linked Immunosorbent Assay. Our analysis revealed that the optimal cut-off values for FPA and C-ELISA were 94.2 mP and 0.403 PI, respectively. Sensitivity estimates for the four tests ranged from 69.7% to 89.9%, while specificity estimates varied between 97.1% and 99.6%. The true prevalences in the two study regions in Henan province were 4.7% and 30.3%. Parity-specific odds ratios for positive serological status ranged from 1.2 to 2.2 for different parity groups compared to primiparous cows. This approach provides a robust framework for validating diagnostic tests for both continuous and discrete tests in the absence of a gold standard test. Our findings can enhance our ability to design targeted disease detection strategies and implement effective control measures for brucellosis in Chinese dairy farms.

Efficacy and safety of therapeutic strategies for human brucellosis: A systematic review and network meta-analysis

BACKGROUND

Human brucellosis is a neglected, re-emerging, and endemic zoonosis in many countries. The debilitating and disabling potential of the disease is a warning about its morbidity, generating socioeconomic impact. This review aims to update the current evidence on the efficacy and safety of therapeutic options for human brucellosis using the network meta-analysis (NMA).

METHODOLOGY

A systematic search was conducted in four different databases by independent reviewers to assess overall therapy failure, adverse events, and time to defervescence associated with different therapies. Randomized clinical trials (RCTs) evaluating any therapeutic drug intervention were selected, excluding non-original studies or studies related to localized forms of the disease or with less than 10 participants. Data were analyzed by frequentist statistics through NMA by random effects model. The risk of bias and certainty of evidence was assessed, this review was registered at PROSPERO.

RESULTS

Thirty-one (31) RCTs involving 4167 patients were included. Three networks of evidence were identified to evaluate the outcomes of interest. Triple therapy with doxycycline + streptomycin + hydroxychloroquine for 42 days (RR: 0.08; CI 95% 0.01-0.76) had a lower failure risk than the doxycycline + streptomycin regimen. Doxycycline + rifampicin had a higher risk of failure than doxycycline + streptomycin (RR: 1.96; CI 95% 1.27-3.01). No significant difference was observed between the regimens when analyzing the incidence of adverse events and time to defervescence. In general, most studies had a high risk of bias, and the results had a very low certainty of evidence.

CONCLUSIONS

This review confirmed the superiority of drugs already indicated for treating human brucellosis, such as the combination of doxycycline and aminoglycosides. The association of hydroxychloroquine to the dual regimen was identified as a potential strategy to prevent overall therapy failure, which is subject to confirmation in future studies.

Diagnosis of human brucellosis: Systematic review and meta-analysis

BACKGROUND

Brucellosis, a widely spread zoonotic disease, poses significant diagnostic challenges due to its non-specific symptoms and underreporting. Timely and accurate diagnosis is crucial for effective patient management and public health control. However, a comprehensive comparative review of available diagnostic tests is lacking.

METHODOLOGY/PRINCIPAL FINDINGS

This systematic review addressed the following question: 'What is the accuracy of the available tests to confirm human brucellosis?' Two independent reviewers examined articles published up to January 2023. The review included original studies reporting symptomatic patients with brucellosis suspicion, through any index test, with sensitivity and/or specificity as outcomes. As exclusion criteria were considered: sample size smaller than 10 patients, studies focusing on complicated brucellosis, and those lacking essential information about index or comparator tests. Sensitivity and specificity were assessed, with consideration for the index test, and 'culture' and 'culture and standard tube agglutination test (SAT)' were used as reference standards. Bias assessment and certainty of evidence were carried out using the QUADAS-2 and GRADE tools, respectively. A total of 38 studies reporting diagnostic test performance for human brucellosis were included. However, the evidence available is limited, and significant variability was observed among studies. Regarding the reference test, culture and/or SAT are deemed more appropriate than culture alone. Rose Bengal, IgG/IgM ELISA, and PCR exhibited equally high performances, indicating superior overall diagnostic accuracy, with very low certainty of the evidence.

CONCLUSIONS/SIGNIFICANCE

This systematic review underscores the potential of the Rose Bengal test, IgG/IgM ELISA, and PCR as promising diagnostic tools for brucellosis. However, the successful implementation and recommendations for their use should consider the local context and available resources. The findings highlight the pressing need for standardization, improved reporting, and ongoing advancements in test development to enhance the accuracy and accessibility of brucellosis diagnosis.

Seroprevalence of brucellosis among animal handlers in West Bengal, India: an occupational health study

Brucellosis is a highly contagious zoonotic disease and a major human health problem worldwide. Due to its ways of transmission, direct or indirect contact with infected animals or their contaminated biological products, the disease exhibits strong occupational association with animal handlers comprising a significant population at risk. This study was undertaken to estimate the seroprevalence of brucellosis in animal handlers and to understand the epidemiological and serological aspects of the same. The animal handlers from the state of West Bengal, India were included in this study. It was a prospective and observational cohort study from November 2021 to March 2022. A total of 669 sera samples were collected from animal handlers and tested using various serological tests for Brucella antibodies. All serum samples were tested using the Rose Bengal plate test (RBPT), standard tube agglutination test (STAT), and enzyme-linked immunosorbent assay (ELISA). 106 (15.8%) patients were diagnosed with brucellosis among the total number of patients tested. Most of the patients affected with brucellosis belonged to the age group 51-60 years (23.5%). The seropositivity rate in male animal handlers was higher than female animal handlers in this study. More studies are needed to understand the occupational association of this disease. Awareness programs, safe livestock practices, and prevention of the disease by timely diagnosis must be implemented in order to control human brucellosis.

Brucella infection-induced hemophagocytic syndrome with subsequent development of the probable vanishing bile duct syndrome: A case report and literature review

Vanishing bile duct syndrome is a rare clinical manifestation, and many clinicians tend to classify vanishing bile duct syndrome as a surgical disease and perform emergency surgery, leading to poor prognosis for patients. In this report, we present a case of a patient initially diagnosed with probable vanishing bile duct syndrome. However, through a meticulous step-by-step investigation, we ultimately determined that the patient was suffering from Brucella infection-induced hemophagocytic syndrome, which contributed to the development of the probable vanishing bile duct syndrome. Once a definitive diagnosis was established, the patient underwent treatment following anti-Brucella and Hemophagocytic lymphohistiocytosis-2004 protocols, leading to an improvement in the patient's condition. We conducted a literature review on brucellosis, and it demonstrated the lack of specificity in diagnosing Brucella infections and the diverse range of clinical manifestations. Failure to arrive at a definitive diagnosis may result in clinical misdiagnosis and delayed treatment, thereby leading to grave consequences.

Immuno-profiling of Brucella proteins for developing improved vaccines and DIVA capable serodiagnostic assays for brucellosis

Brucellosis remains a worldwide zoonotic disease with a serious impact on public health and livestock productivity. Controlling brucellosis in livestock is crucial for limiting human infections in the absence of effective human vaccines. Brucellosis control measures are majorly dependent on rigorous monitoring of disease outbreaks and mass vaccination of livestock. Live attenuated vaccines are available for livestock vaccination that play a vital role in brucellosis control programs in many countries. Even though the existing animal vaccines confer protection against brucellosis, they carry some drawbacks, including their infectivity to humans and interference with sero-monitoring. The available serodiagnostic assays for brucellosis depend on detecting anti-LPS antibodies in the serum. Since diagnosis plays a vital role in controlling brucellosis, developing improved serodiagnostic assays with enhanced specificity, sensitivity and DIVA capability is required. Therefore, it is essential to identify novel antigens for developing improved vaccines and serodiagnostic assays for brucellosis. In the present study, we performed a high throughput immunoprofiling of B. melitensis protein microarray using brucellosis-positive human and animal serum samples. The screening identified several serodominant proteins of Brucella that exhibited common or differential reactivity with sera from animals and humans. Subsequently, we cloned, expressed, and purified ten serodominant proteins, followed by analyzing their potential to develop next-generation vaccines and improved serodiagnostic assays for brucellosis. Further, we demonstrated the protective efficacy of one of the serodominant proteins against the B. melitensis challenge in mice. We found that the seroreactive protein, Dps (BMEI1980), strongly reacted with brucellosis-positive serum samples, but it did not react with sera from B. abortus S19-vaccinated cattle, indicating DIVA capability. A prototype lateral flow assay and indirect ELISA based on Dps protein exhibited high sensitivity, specificity, and DIVA capability. Thus, the present study identified promising candidates for developing improved vaccines and affordable, DIVA-capable serodiagnostic assays for animal and human brucellosis.

Genomic analysis of Brucella melitensis reveals new insights into phylogeny and evolutionary divergence

PURPOSE

Brucellosis is a bacterial zoonotic disease caused by genus Brucella. The disease is often transmitted to humans by direct or indirect contact with infected livestock or from laboratory exposure. In this study two clinical isolates of Brucella melitensis were subjected to whole genome sequencing (WGS) using Ion Torrent PGM and Oxford Nanopore MinIon platform.

METHODS

The two hybrid complete genomes were subjected to core gene SNP analysis to identify the relative evolutionary position. To distinguish between the various lineages of B. melitensis, Pangenome analysis was carried out.

RESULTS

Phylogenetic analysis revealed that both the study isolates (ST8) clustered along the other Asian isolates that formed genotype II. Genome wide analyses of 326 B melitensis isolates suggests 2171 gene clusters were shared across all the genomes while 3552 gene clusters were considered as accessory genes.

CONCLUSION

Here we attempted to provide the gain and loss of six unique genes that defined the phylogenetic lineages and complex evolutionary process. As the severity and prevalence of human brucellosis is increasing a better understanding of Brucella genomics and transmission dynamics is needed.

Next-generation sequencing in the diagnosis of neurobrucellosis: a case series of eight consecutive patients

BACKGROUND

Neurobrucellosis (NB) presents a challenge for rapid and specific diagnosis. Next-generation sequencing (NGS) of cerebrospinal fluid (CSF) has showed power in detection of causative pathogens, even some infrequent and unexpected pathogens. In this study, we presented 8 cases of NB diagnosed by the NGS of CSF.

METHODS

Between August 1, 2018 and September 30, 2020, NGS was used to detect causative pathogens in clinically suspected central nervous system (CNS) infections. Data on demographics, clinical features, and laboratory tests, imaging results and NGS results were collected and reviewed.

RESULTS

Among the presented 8 patients, Brucella was rapidly detected using NGS of CSF within 1-4 days, despite those eight patients had variable medical history, disease course, clinical manifestations, laboratory tests and imaging findings. NGS showed the sequence reads corresponded to Brucella species were 8 to 448, with genomic coverage of 0.02 to 0.87%. The relative abundance was 0.13% to 82.40% and sequencing depth was 1.06 to 1.24. Consequently, patients were administered with 3 to 6 months of doxycycline, ceftriaxone and rifampicin, double or triple combination, supplemented with symptomatic therapy and were fully recovered except for case 1.

CONCLUSION

NGS of CSF provides a powerful tool in detection of Brucella in a prompt and specific manner, and can be considered for first-line diagnostic use in practice.

Early predictors of Brucella epididymo-orchitis

Introduction

Epididymo-orchitis (EO) is a common urological condition. In endemic areas, EO may be the presenting picture of brucellosis. Early suspicion and proper diagnosis is necessary for patient recovery.

Objective

The aim of our study is to identify early predictors of Brucella EO.

Patients and Methods

We retrospectively collected the data of all patients who were treated at the Urology Unit, Farwaniya Hospital, with acute EO above the age of 12 years between April 2017 and February 2019. Data from electronic and hardcopy files were gathered and analyzed. The diagnosis of acute EO was based on clinical, laboratory, and radiological findings. A total of 120 patients under the diagnosis of EO, epididymitis, and orchitis were reviewed. Thirty-one patients were tested for Brucella based on the history of animal contact, ingestion of unpasteurized dairy products, or persistent fever for more than 48 h. of those patients, 11 tested positive for Brucella orchitis.

Results

A comparison between Brucella-positive and Brucella-negative patients regarding age, presence of fever, complete blood count (CBC) parameters, pyuria, and abscess formation was made. In the Brucella group, 72% of the patients had a history of animal contact compared to 33% in non-Brucella group (P = 0.006). When comparing CBC parameters in the two groups, Brucella group had statistically significant lower total leukocytic count and neutrophil count (mean ± standard deviation [SD]) 13.07 ± 4.22, 6.4 ± 9.98 versus Brucella negative group 17.35 ± 5.28, 7.8 ± 10.53, and P values were 0.037 and 0.004, respectively. Brucella group showed lymphocytosis (mean ± SD) 25.95 ± 9.78 versus non-Brucella group 13.22 ± 8.05 and P < 0.01.

Conclusion

Brucella orchitis constituted 9% of the orchitis patients treated in our hospital. Patients with a history of animal contact, EO with lymphocytosis, and relative neutropenia should raise the suspicion for Brucella orchitis in endemic areas.

The association between skeletal lesions and tuberculosis in a pre-antibiotic South African sample

OBJECTIVE

This study assessed the sensitivity and specificity of skeletal lesions to accurately diagnose TB in a pre-antibiotic South African skeletal sample.

MATERIALS

A total of 435 skeletons of individuals who died before 1950 from the Raymond A. Dart Collection of Human Skeletons. 176 died of TB, 109 died of other pulmonary diseases, and 150 died of other causes.

METHODS

The presence / absence of 23 skeletal lesions were assessed for differences in frequency between groups. Sensitivities and specificities were calculated and compared to Dangvard Pedersen et al. (2019).

RESULTS

Lesions on the ventral surface of thoracic and lumbar vertebral bodies were observed significantly more often in TB and pulmonary cases than in other cause of death group and yielded a 55% probability of a true TB diagnosis, if observed. An association between skeletal lesions and TB was found for rib and vertebral lesions.

CONCLUSIONS

The results suggest that even when not documented to have died of TB, TB-related changes are observed in many individuals in a South African skeletal sample, indicating that they may have been infected with the disease.

SIGNIFICANCE

The study provides information that can assist palaeopathologists in making inferences about the prevalence of TB in past populations.

LIMITATIONS

Sample sizes were small, and the inclusion of a pulmonary disease group may have confounded the results.

SUGGESTIONS FOR FURTHER RESEARCH

The selection of a control group without any possible contact with TB may improve the results and should be investigated.

Proteome-Wide Screening of Potential Vaccine Targets against Brucella melitensis

The ongoing antibiotic-resistance crisis is becoming a global problem affecting public health. Urgent efforts are required to design novel therapeutics against pathogenic bacterial species. Brucella melitensis is an etiological agent of brucellosis, which mostly affects sheep and goats but several cases have also been reported in cattle, water buffalo, yaks and dogs. Infected animals also represent the major source of infection for humans. Development of safer and effective vaccines for brucellosis remains a priority to support disease control and eradication in animals and to prevent infection to humans. In this research study, we designed an in-silico multi-epitopes vaccine for B. melitensis using computational approaches. The pathogen core proteome was screened for good vaccine candidates using subtractive proteomics, reverse vaccinology and immunoinformatic tools. In total, 10 proteins: catalase; siderophore ABC transporter substrate-binding protein; pyridoxamine 5'-phosphate oxidase; superoxide dismutase; peptidylprolyl isomerase; superoxide dismutase family protein; septation protein A; hypothetical protein; binding-protein-dependent transport systems inner membrane component; and 4-hydroxy-2-oxoheptanedioate aldolase were selected for epitopes prediction. To induce cellular and antibody base immune responses, the vaccine must comprise both B and T-cells epitopes. The epitopes were next screened for antigenicity, allergic nature and water solubility and the probable antigenic, non-allergic, water-soluble and non-toxic nine epitopes were shortlisted for multi-epitopes vaccine construction. The designed vaccine construct comprises 274 amino acid long sequences having a molecular weight of 28.14 kDa and instability index of 27.62. The vaccine construct was further assessed for binding efficacy with immune cell receptors. Docking results revealed that the designed vaccine had good binding potency with selected immune cell receptors. Furthermore, vaccine-MHC-I, vaccine-MHC-II and vaccine-TLR-4 complexes were opted based on a least-binding energy score of -5.48 kcal/mol, 0.64 kcal/mol and -2.69 kcal/mol. Those selected were then energy refined and subjected to simulation studies to understand dynamic movements of the docked complexes. The docking results were further validated through MMPBSA and MMGBSA analyses. The MMPBSA calculated -235.18 kcal/mol, -206.79 kcal/mol, and -215.73 kcal/mol net binding free energy, while MMGBSA estimated -259.48 kcal/mol, -206.79 kcal/mol and -215.73 kcal/mol for TLR-4, MHC-I and MHC-II complexes, respectively. These findings were validated by water-swap and entropy calculations. Overall, the designed vaccine construct can evoke proper immune responses and the construct could be helpful for experimental researchers in formulation of a protective vaccine against the targeted pathogen for both animal and human use.

Influence and prediction of meteorological factors on brucellosis in a northwest region of China

This paper aims to study the cumulative lag effect of meteorological factors on brucellosis incidence and the prediction performance based on Random Forest model. The monthly number of brucellosis cases and meteorological data from 2015 to 2019 in Yongchang of Gansu Province, northwest China, were used to build distributed lag nonlinear model (DLNM). The number of brucellosis cases of lag 1 month and meteorological data from 2015 to 2018 were used to build RF model to predict the brucellosis incidence in 2019. Meanwhile, SARIMA model was established to compare the prediction performance with RF model according to R² and RMSE. The results indicated that the population had a high incidence risk at temperature between 5 and 13 °C and lag between 0 and 18 days, sunshine duration between 225 and 260 h and lag between 0 and 1 month, and atmosphere pressure between 789 and 793.5 hPa and lag between 0 and 18 days. The R² and RMSE of train set and test set in RF model were 0.903, 1.609, 0.824, and 2.657, respectively, and the R² and RMSE in SARIMA model were 0.530 and 7.008. This study found significant nonlinear and lag associations between meteorological factors and brucellosis incidence. The prediction performance of RF model was more accurate and practical compared with SARIMA model.

Prevalence, diagnosis, and manifestations of brucellosis: A systematic review and meta-analysis

Objectives

Brucellosis is one of the most prevalent zoonotic diseases common between humans and animals. Despite eradication efforts, the burden of the disease is well-known in endemic countries and in countries where brucellosis has not been an important health issue until recently. The aim of this study was to evaluate the prevalence, diagnosis, and manifestations of brucellosis.

Methods

In this study, PubMed, Web of Science, Scopus, Embase, and Google scholar databases were systematically searched to find studies published from 2011 to 2021. The search was conducted using text words and Medical Subject Headings (MeSH) Terms on the prevalence of brucellosis. Stata software 14.0 was used for all analyses.

Results

Based on the results, the pooled prevalence of brucellosis was 15.27% (95% CI: 9.68-21.86; heterogeneity I 2 index: 97.43; p < 0.001) for man and 15.33% (95% CI: 7.19-25.75; heterogeneity I 2 index: 98.19; p < 0.001) for woman. Age (coefficient: 0.240; p = 0.480), gender (coefficient: -0.017; p = 0.800), and publication year (coefficient: 0.114; p = 0.861) showed no significant effect on heterogeneity among studies. Egger's test indicated a significant publication bias for the prevalence of brucellosis (coefficient 3.894; p < 0.001). Moreover, the trim-and-fill method exhibited that the adjusted prevalence of brucellosis (18.30%, 95% CI: 14.10-22.52) was not significantly different from the original prevalence of brucellosis.

Conclusion

The pooled estimate for brucellosis prevalence was estimated as 15.53%. To better understand the epidemiology of brucellosis globally, more extensive studies are needed to be conducted throughout the world, especially in developing and low-income countries.

Sibling Screening in Pediatric Brucellosis

Objective Routine screening of household members of index cases is a priority in regions where brucellosis is endemic. This study aimed to identify seropositive and seronegative pediatric patients by screening the siblings of our pediatric patients diagnosed with brucellosis (index cases) and to investigate the relationships among these groups by comparatively evaluating their demographic, epidemiological, clinical, and laboratory characteristics.

Materials and Methods Eighty-five pediatric household members of 59 pediatric patients diagnosed with acute brucellosis were evaluated. A total of 144 children were included in the study.

Results Among 85 pediatric household members, 34 (40%) children were seropositive and 51 (60%) were seronegative. The predominant clinical symptom was arthralgia (81.4%), and the main finding was abnormal liver function tests (LFTs). The most frequent osteoarticular involvement was monoarticular arthritis (88%). Index cases and seropositive patients showed significantly greater elevations in LFTs compared with seronegative patients (p < 0.001 and p < 0.001). C-reactive protein values of index cases and seropositive patients were significantly higher compared with seronegative patients (p < 0.001 and p = 0.001). Neutrophil and platelet counts of index cases were significantly lower than those of seronegative patients (p = 0.017 and p = 0.002). Index cases and seropositive patients were given treatment, and after follow-up of at least 1 year, none of the seropositive patients relapsed, but relapse occurred in nine (15.3%) children from the index group. Two (3.9%) seronegative patients were diagnosed with acute brucellosis.

Conclusion Additional cases of brucellosis can be detected by screening household members of index cases in endemic areas. Elevations in LFTs when detected early in the asymptomatic period may provide a clue for brucellosis.

Brucellosis: A Rare Cause of Febrile Neutropenia in a Child

We report a case of brucellosis-induced severe neutropenia in a 2-year-old girl who presented with a 2-week history of fever. On clinical examination, the patient was febrile with mild aphthous stomatitis. However, her general condition was stable, and systemic examination did not show involvement of any other organ. Laboratory test results revealed severe neutropenia, mild anemia, and an elevated serum C-reactive protein level. Flow cytometry of peripheral blood leukocytes revealed no malignancy, and blood film morphology was unremarkable except for mild microcytosis and hypochromia. Antineutrophil antibody and Coombs test results were negative. We administered intravenous cefuroxime; however, therapy was switched to meropenem plus clarithromycin because fever persisted for 5 days, despite treatment. On the 10th day after admission, Brucella serology tests showed positive results, and trimethoprim-sulfamethoxazole plus rifampicin therapy was prescribed for 8 weeks. The fever defervesced, and the child was discharged in a good state of health. Neutropenia persisted for several months but gradually resolved. Neutropenia, defined as an absolute neutrophil count (ANC) < 1.5 cells × 10 9 /L beyond the first year of life, is a benign transient condition associated with an intercurrent infection (usually viral illnesses or infections) in immunocompetent children. However, severe neutropenia (ANC < 0.5 × 10 9 /L) associated with fever necessitates hospitalization and administration of broad-spectrum antibiotics to avoid the high risk of sepsis, particularly in children. Brucellosis is rarely associated with hematologic abnormalities such as neutropenia. Early diagnosis of hematologic complications of brucellosis is essential for prompt initiation of specific and aggressive treatment.

The role of shoulder arthroplasty after chronic brucellosis of glenohumeral joint septic arthritis. A case report and literature reviews

INTRODUCTION

The main socioeconomic area in Thailand has been the agricultural endemic area, where brucellosis infection, one of the bacterial infectious diseases has been an overlooked diagnose.

PRESENTATION OF CASE

A 50-year-old Thai woman was admitted to the hospital with pain and limited motion in her left shoulder. These symptoms have been prolonging with progressive clinical for two years. The physical examination revealed stiffness in all directions. The glenohumeral joint appeared to be narrowing on radiographic evaluation. The multiple loculate mass and septic glenohumeral joint arthritis were seen by magnetic resonance imaging (MRI). Furthermore, the Brucellosis investigation specificity was Brucella IgM/IgG positive. This patient was treated with a combination of surgery and oral antimicrobial medication. We decided to perform a total shoulder arthroplasty because the patient was still in pain and stiff from secondary arthritis.

DISCUSSION

As a result of the late treatment for osteoarticular involvement, secondary osteoarthritis develops until leading to significant cartilage loss. Therefore, even medical treatment and surgical debridement, the patient still suffers from secondary osteoarthritis, which causes pain and limited activity. The arthroplasty treatment method plays a role in the treatment of function following secondary osteoarthritis infection.

CONCLUSION

The role of arthroplasty was selected in the treatment of brucellosis osteoarticular involvement, which is an uncommon and difficult to identify condition that can lead to maltreatment. So that this case report offers the treatment option if the patient was not responsible for the medical and surgical debridement therapy with secondary osteoarthritis at the glenohumeral joint, even though the brucellosis infection condition had completely resolved.

Clinical profile and biochemical abnormalities in brucellosis: A cross-sectional study

Introduction

Brucellosis is the commonest zoonotic disease worldwide and a common public health problem in Nepal. Because of the highly variable clinical presentation and non-specific manifestations, it remains a big challenge for clinicians from developing countries. Brucellosis has a tropism for the reticuloendothelial system, the liver is frequently involved. There is a paucity of data about the laboratory and clinical findings of human Brucellosis from Nepal. To address this knowledge gap, we conducted this study to find out the clinical profile and biochemical abnormalities of patients with brucellosis at a tertiary-care teaching hospital in western Nepal.

Methods

A cross-sectional study was carried out at Gandaki Medical College Teaching Hospital, Pokhara, Nepal. All patients admitted to the in-patient department of our hospital with probable or definitive diagnoses of brucellosis were included. We excluded those who did not consent to their participation in our study, those who were under 18 years of age, and those who had deranged liver function due to other pre-existing illnesses. Descriptive statistics were used to analyze the data in terms of demography, clinical manifestations, and laboratory parameters.

Results

There was a total of 40 confirmed cases of Brucellosis (age: 18–66 years) during the study period. More than half (55%, n = 22) of the study participants were males and most of them lived in a rural setting (77.5%, n = 31). Most of them (70%, n = 28) gave history of ingestion of high-risk food. The commonest clinical findings were fever with/out chills (90%, n = 36) followed by nausea/vomiting (72.5%, n = 29), headache (40%, n = 16) and malaise (37.5, n = 15). Liver function was deranged in a majority of the patients, the common parameters being Alkaline phosphatase in 96% (n = 38) cases, followed by SGOT (62.5%, n = 25), leukocytosis (57.5%, n = 23), total bilirubin (52.5%, n = 21) and SGPT (37.5%, n = 15). Characteristic increment (more than two folds of the upper limit of normal) was observed for alkaline phosphatase.

Conclusion

The reticuloendothelial system is frequently involved in brucellosis. Notable changes were observed in liver function and hematological parameters in a majority of the participants in our study. These findings highlight the need for the implementation of effective control programs to address this problem in the Nepalese context.

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There is a lack of evidence about human Brucellosis from Nepal.

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Liver function was deranged in majority of the cases.

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Characteristics increment was seen for alkaline phosphatase.

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There is a need of effective brucellosis control program.

Evaluation of the Fluorescence Polarization Assay for the Diagnosis of Brucellosis in Goat Milk

The milk ring test is a detection assay for antibodies against Brucella in bovine milk. It has good sensitivity but tends to give false positive results. In this study, we standardized the application of the fluorescence polarization assay (FPA) for the detection of antibodies against B.melitensis in goat milk. We obtained negative serum and milk samples from healthy goat flocks in the northern zone of Nuevo León. Positive milk and negative, weak, and strong controls were obtained by mixing volumes of positive control serum with negative control milk. Milk samples were treated with citric acid, after which an FPA was performed. Results were then compared with the Rose Bengal test and the FPA in serum. Milk treatment allowed the quantification of antibodies in samples. Significant differences were found between the 2%, 4%, and 6% groups, compared with the control group (F3, 67 = 17.45, p < 0.0001) but not between the 2% and 4% groups (p = 0.0718). The cut-off value was 74.1 mP, with a sensitivity (Se) of 95% and a specificity (Sp) of 100%. Se and Sp values in field milk samples were 84% and 74.55%, respectively. Despite the FPA test on milk samples showed lower Se and Sp than the FPA test on serum samples, its cutoff may be adjusted. It may be recommended as a screening test in goat milk and become useful for the control and eradication of the disease.

Brucellosis control methods with an emphasis on vaccination: a systematic review

INTRODUCTION

Brucellosis is considered as one of the main zoonotic infections and a major public health concern worldwide. The aim of the present study was to evaluate various strategies for controlling brucellosis with an especial emphasis on efficacy of vaccination.

AREAS COVERED

International databanks (Web of Science, PubMed, Embase) were searched for potentially relevant studies published from January 1, 2011 to March 25, 2021 using the following keywords: "Brucella", "Brucella abortus", "Brucella melitensis", "Brucella canis", "Brucella suis", "brucellosis", "Bang disease", "undulant fever", "Malta fever", "vaccination", "vaccine", and "immunization". The literature search was restricted to original articles published in English.

EXPERT OPINION

Various methods are employed to prevent and control brucellosis, such as removing sick animals by slaughtering, separating sick animals from the herd, and vaccination. Preventing, controlling, and eradicating brucellosis requires a lot of financial support, perseverance, and time. In order to conduct a detailed study, it is recommended that more studies be conducted in developing countries and different parts of the world.

Brucellosis in pregnancy and its response to the changing immunoglobulin A: A prospective controlled study

Objective:

This study aimed to define the rare Brucella infection in pregnancy and its effects on immunoglobulins (Ig).

Materials and Methods:

This prospective study has conducted Brucella screening using the Rose Bengal test on pregnant and non-pregnant outpatients who did not show any specific Brucella symptoms. The immunoglobulin levels were measured using the enzyme-linked immunosorbent assay. The study group consisted of pregnant women who were at 20 weeks or below gestation and applied to our hospital outpatient clinic for routine check-ups. The control group consisted of healthy patients who applied for routine controls.

Results:

This study included a total of 584 participants, 293 of whom were controls and 291 were the study (pregnant) participants. The study revealed a 1.5% incidence of Brucella during pregnancy. In acute and chronic Brucella infection, lower levels of IgA response were observed in pregnant cases compared to the control group.

Conclusion:

Brucella infection is a disease that can cause fetal problems, especially in endemic areas. The role of the altered IgA response in pathologies that are associated with Brucella infection stands out as a new target for disease pathophysiology.

Long-Read Sequencing and Hybrid Assembly for Genomic Analysis of Clinical Brucella melitensis Isolates

Brucella melitensis is a key etiological agent of brucellosis and has been increasingly subject to characterization using sequencing methodologies. This study aimed to investigate and compare short-read, long-read, and hybrid assemblies of B. melitensis. Eighteen B. melitensis isolates from Southern Israel were sequenced using Illumina and the Oxford Nanopore (ONP) MinION, and hybrid assemblies were generated with ONP long reads scaffolded on Illumina short reads. Short reads were assembled with INNUca with SPADes, long reads and hybrid with dragonflye. Abricate with the virulence factor database (VFDB) and in silico PCR (for the genes BetB, BPE275, BSPB, manA, mviN, omp19, perA, PrpA, VceC, and ureI) were used for identifying virulence genes, and a total of 61 virulence genes were identified in short-read, long-read, and hybrid assemblies of all 18 isolates. The phylogenetic analysis using long-read assemblies revealed several inconsistencies in cluster assignment as compared to using hybrid and short-read assemblies. Overall, hybrid assembly provided the most comprehensive data, and stand-alone short-read sequencing provided comparable data to stand-alone long-read sequencing regarding virulence genes. For genomic epidemiology studies, stand-alone ONP sequencing may require further refinement in order to be useful in endemic settings.

Seroprevalence, hematological and biochemical alterations in Brucella-seropositive Muturu cattle in Nigeria

This study evaluated the prevalence, hematological and some biochemical alterations in Brucella seropositive Muturu breed of cattle which may change the narratives of multi-disease tolerance of the breed. Sera from 33 Muturu cattle herds chosen by snow ball sampling were screened for Brucella antibodies with modified Rose Bengal test (RBT) supported with the cELISA. Eighteen (18) seropositive samples matched to18 sero-negatives, with regard to age and sex of the animals and chosen by simple random sampling, were analyzed for hematological and biochemical changes, following standard procedures. Individual seroprevalence of 38% and 10% were recorded with the RBT and cELISA respectively, while herd seroprevalence of 52% was recorded with the RBT and none with the cELISA. Seropositivity to brucellosis was significantly associated with farm origin (OR = 16.67; 95%CI = 1.56-153.85; p = 0.019). There was significantly lower packed cell volume (PCV) (p = 0.048) and absolute eosinophil count (p = 0.006), and significantly higher absolute lymphocyte count (p = 0.014) in the seropositive than the negative Muturu cattle. In addition, plasma fibrinogen (p < 0.001), serum albumin (p = 0.037), urea (p = 0.001) and cholesterol (p = 0.032) were significantly lower while serum globulin (p = 0.004), alanine aminotransferase (ALT) activity (p = 0.012) and bilirubin (p = 0.012) were significantly higher in the seropositive than sero-negative Muturu cattle. No significant variations were observed in the rest of the parameters assayed. These findings suggest that Muturu cattle are apparently susceptible to brucellosis and experience active organism-host interactions with resultant clinicopathological effects and therefore could be passive harbingers of Brucella for other animals as well as humans.

Bovine Brucellosis: Epidemiology, Public Health Implications, and Status of Brucellosis in Ethiopia

Brucellosis is a globally distributed zoonotic disease that causes serious problems in developing countries such as Ethiopia. Brucella abortus is the primary cause of brucellosis in cattle, and Brucella melitensis and Brucella suis also occasionally cause Brucella infection in cattle. Abortion and the retained fetal membrane are typical signs in females, whereas orchitis and bursitis are the known signs in male cattle. Brucellosis is typically transmitted to healthy cattle by direct or indirect contact with diseased cattle or their discharges. Humans can acquire brucellosis through the consumption of unpasteurized milk or milk products, and through contact with diseased cattle or their discharges. The occurrence of bovine brucellosis is affected by different factors related to the management system, host, and environmental factors. In Ethiopia, the occurrence of brucellosis is high in pastoral and mixed cattle management systems, wherever humans live closely with cattle and so have a higher probability of picking up the Brucella organism. The most suitable technique in the management of Brucella infection is the vaccination of young female cattle. Brucella abortus can also be eradicated by the isolation of diseased cattle, administration of immunizing agents, and test-and-slaughter methods. Therefore, it is important to implement applicable management techniques and to increase public awareness about the transmission of brucellosis, and further research should be conducted on brucellosis in high-risk groups.

Analysis of Electrocardiogram Among 108 Patients with Brucella

Objective

To improve our knowledge of cardiac manifestations caused by brucellosis through analyzing abnormal electrocardiograms of patients infected with brucella.

Methods

A total of 108 cases were enrolled, and their electrocardiograms were analyzed and summarized retrospectively.

Results

Among 108 cases, 77 (71.3%) had a normal electrocardiogram, and 31 (28.7%) had an abnormal electrocardiogram. There were 13 cases with nodal tachycardia (12%), 9 cases with sinus bradycardia (8%), 7 cases with sinus arrhythmia (6%), 8 cases with left ventricular high voltage (7%), 13 cases with abnormal ST segment and T wave (12%), 2 cases with abnormal Q wave (1.85%), 3 cases with complete right bundle branch block (2.78%), 3 cases with ventricular premature beat (2.78%), 1 case with left anterior fascicular block (0.9%), 1 case with first degree a-v block (0.9%), 1 case with QT internal prolongation (0.9%), 1 case with poor R wave progression (0.9%), and 1 case with short PR interval (0.9%).

Conclusion

The cardiac manifestations of brucellosis were rare, but the mortality was high. Patients with abnormal electrocardiogram should have improved echocardiography in time. Early detection of the abnormal electrocardiogram could give a hint of cardiac damage to avoid the serious consequences.

Clinical and laboratory characteristics of childhood brucellosis in high-risk area of Western China

Childhood brucellosis present various non-specific clinical symptoms, and limited laboratory data exist for clinical diagnosis. A better understanding of these clinical and laboratory characteristics can avoid clinical misdiagnosis and mistreatment. In this case-series study, a total of 78 children with confirmed diagnosis of brucellosis were evaluated retrospectively. We observed that the incidence rate was higher in the first two quarters every year. The most common symptom was fever. Osteoarticular involvement was found in 44.87% of the patients. Laboratory tests showed that the values of erythrocyte sedimentation rate(ESR), C-reactive protein(CRP), Hemoglobin(Hb), Neutrophils(NEU), Alanine aminotransfease(ALT) and Ferritin in childhood brucellosis with osteoarticular involvement had significant differences than those without osteoarticular involvement or control group (P<0.05). Childhood brucellosis without osteoarticular involvement often accompanied by decrease of NEU , increase of CRP and ALT compared with that control group (P<0.05). The Receiver Operating Curves (ROC) analysis revealed that NEU, CRP and ALT can be used as adjunct parameters in the differential diagnosis of childhood brucellosis. These data suggest that clinical and laboratory characteristics are very important for every clinician, which may have a complementary role in diagnosis of childhood brucellosis.

Relapsed Brucellosis Manifested as Endocarditis with Vegetation on the Implantable Cardioverter Defibrillator Lead

Implantable cardioverter defibrillator lead endocarditis due to Brucella melitensis is a rare and life-threatening complication of brucellosis. Successful management requires a combination of medical treatment and device extraction. We present a case of relapsing brucellosis manifested as infective endocarditis colonizing the lead of the implantable cardioverter defibrillator with formation of vegetation on the lead. A 63-year-old male presented to the rehabilitation unit with hypotension. No other signs of infection were noted. The patient had a history of drinking unpasteurized milk since childhood and a previous episode of Brucella infective endocarditis. A transthoracic echocardiography showed an oscillating vegetation on the lead of the tip of the right atrial ICD, and the blood cultures were positive for Brucella melitensis. Surgical removal of the device was infeasible, and medical management was the only feasible option in this case.

Bovine brucellosis - a comprehensive review

Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of B. abortus infection has been shown. The most widely used vaccine strains to protect against Brucella infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.

Brucellosis: Prevalence with reference to East African community countries - A rapid review

Brucellosis is a zoonotic disease which is endemic to certain regions of the world including Sub-Saharan Africa. The aim of this article is to provide a recent and rapid review on brucellosis prevalence in East African Community (EAC) countries. Literature was obtained using Google Scholar search engine and screened for relevancy and fulfilment of criteria to 1, 17, 4, 4, 30 and 29 articles retained for brucellosis prevalence in Burundi, Kenya, Rwanda, South Sudan, Tanzania and Uganda. Recent literature (published in the last decade 2010 to 2019) was considered for prevalence results in this review. In EAC, livestock had an animal-level prevalence of 0.2% to 43.8%, 0.0% to 20.0% and 0.0% to 13.8% for cattle, goats and sheep respectively. In humans, the prevalence varied mostly between 0.0% and 35.8%. In conclusion, brucellosis is quite prevalent in the region. The reported prevalence calls for plans or more efforts from individual member countries and from EAC, as a region, to control brucellosis.

The current therapeutical strategies in human brucellosis

Prompt and adequate treatment of human brucellosis continues to be the most important strategy in its management, as eradication of animal brucellosis is not possible so far, and there is no adequate vaccine for humans. The goal of antibrucellar treatment is to alleviate and shorten the symptomatic period and reduce complications, relapses, and chronicity. Contemporary trends in the treatment of human brucellosis are postulated on the ability of Brucellae to persist in host macrophages through the inhibition of phagolysosome fusion and to survive for prolonged periods intracellularly without restricting basic cellular functions. As a result of this and despite satisfactory antibiotic treatment, relapses and therapeutical failures are inevitable to a certain degree. The current principles for the treatment of brucellosis advocate for a long enough treatment duration combined with antimicrobial regimens that possess activity in the intracellular acidic environment. In the future, other antimicrobial agents, immunomodulation, decrease in the intracellular acidic environment, or development of agents that would act on well-defined molecular bacterial targets, might be incorporated to improve the therapeutical effects.

Brucella, a bacterium with multiple ways of causing infection

Brucellosis is a zoonotic infection caused by the intracellular gram-negative bacterium Brucella. It is the most common zoonosis worldwide, and its transmission is classically associated with consumption of unpasteurized animal products. However, other mechanisms of transmission include contact of the skin or mucous membranes with infected animal tissue. We present a case of a patient who had more than one possible route of infection.

Knee and the farm animals: An unusual presentation of Brucella melitensis masquerading as tuberculosis

In many developed countries, brucellosis has been successfully eradicated. However, brucellosis, with its myriad presentations, continues to be a clinical and diagnostic challenge in primarily agrarian countries such as India. We present a case of a rare manifestation of brucellosis i.e., septic arthritis of the knee joint associated with a lytic lesion of the proximal tibia. The patient belonged to a Brucella endemic country, and clinical features were of chronic reactive knee arthritis with synovial hypertrophy and effusion. Advanced diagnostic methods played a pivotal role in excluding the diagnosis of tuberculosis, and thus unnecessary administration of antitubercular therapy and initiating focused narrowed anti-Brucella management, achieving the goal of antimicrobial stewardship also.

Seroprevalence of brucellosis in Western Rajasthan: A study from a tertiary care centre

Brucellosis is a significant bacterial zoonotic disease with a high seroprevalence in low-to-middle-income countries where there is a significant contact of humans with animals. This prospective study was conducted to observe the seroprevalence of brucellosis in 75 symptomatic patients with pyrexia of unknown origin (PUO) and 75 high-risk individuals (10 veterinarians, 15 milkmen and 50 healthy contacts of symptomatic patients) with possible exposure to brucellosis. Serum samples collected from these patients and individuals were subjected to rose Bengal test (RBT) and ELISA for the detection of IgM and IgG antibodies. RBT was positive in 50 samples (40 PUO and 10 high risk), of which 25 (33.3%) PUO cases had detectable IgM antibodies, whereas IgG antibodies were detected in 20 patients. None of samples from high-risk individuals was reactive for IgM/IgG antibodies by ELISA. The overall seroprevalence in this study was 16.7% (33.3% in PUO patients). Being a predominantly livestock rearing area, brucellosis is a significant health-care problem in this part of India with this entity being linked to 33% of PUO cases.

Trend of human brucellosis over a decade at tertiary care centre in North Karnataka

BACKGROUND

Brucellosis is an important zoonotic disease. India having a major agrarian population is expected to have a higher prevalence. However, due to lack of laboratory facility or awareness among clinicians, the disease is largely underreported. The aim of this study was to know the prevalence and trend of human brucellosis over a decade, in patients attending a teaching hospital in North Karnataka, and to understand their geographical distribution.

MATERIALS AND METHODS

The study was conducted from January 2006 to December 2015 at a tertiary care teaching hospital in North Karnataka. A total of 3610 serum samples were evaluated from suspected cases of brucellosis. All serum samples were initially screened by Rose Bengal plate test, and positive samples were further analysed by Serum agglutination test (SAT) using standard Brucella abortus antigen from Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India. A titre above or equal to 1:80 IU/ml was considered as positive. Demographic data such as age, sex and native place of these patients were also analysed.

RESULTS

We observed that human brucellosis is present in North Karnataka. The overall seropositivity of brucellosis in suspected cases was 5.1%. The positive titres ranged from 1:80 to 163,840 IU/ml. The majority of the patients were from Gadag, Koppal and Haveri districts of North Karnataka.

CONCLUSION

Our study confirms the presence of human brucellosis in the northern part of Karnataka. Further studies to understand the prevalence of animal brucellosis in these areas will help in implementing prevention measures.

Systems biology approach predicts antibody signature associated with Brucella melitensis infection in humans

A complete understanding of the factors that determine selection of antigens recognized by the humoral immune response following infectious agent challenge is lacking. Here we illustrate a systems biology approach to identify the antibody signature associated with Brucella melitensis (Bm) infection in humans and predict proteomic features of serodiagnostic antigens. By taking advantage of a full proteome microarray expressing previously cloned 1406 and newly cloned 1640 Bm genes, we were able to identify 122 immunodominant antigens and 33 serodiagnostic antigens. The reactive antigens were then classified according to annotated functional features (COGs), computationally predicted features (e.g., subcellular localization, physical properties), and protein expression estimated by mass spectrometry (MS). Enrichment analyses indicated that membrane association and secretion were significant enriching features of the reactive antigens, as were proteins predicted to have a signal peptide, a single transmembrane domain, and outer membrane or periplasmic location. These features accounted for 67% of the serodiagnostic antigens. An overlay of the seroreactive antigen set with proteomic data sets generated by MS identified an additional 24%, suggesting that protein expression in bacteria is an additional determinant in the induction of Brucella-specific antibodies. This analysis indicates that one-third of the proteome contains enriching features that account for 91% of the antigens recognized, and after B. melitensis infection the immune system develops significant antibody titers against 10% of the proteins with these enriching features. This systems biology approach provides an empirical basis for understanding the breadth and specificity of the immune response to B. melitensis and a new framework for comparing the humoral responses against other microorganisms.

Establishment of systemic Brucella melitensis infection through the digestive tract requires urease, the type IV secretion system, and lipopolysaccharide O antigen

Human brucellosis is caused mainly by Brucella melitensis, which is often acquired by ingesting contaminated goat or sheep milk and cheese. Bacterial factors required for food-borne infection of humans by B. melitensis are poorly understood. In this study, a mouse model of oral infection was characterized to assess the roles of urease, the VirB type IV secretion system, and lipopolysaccharide for establishing infection through the digestive tract. B. melitensis strain 16M was consistently recovered from the mesenteric lymph node (MLN), spleen, and liver beginning at 3 or 7 day postinfection (dpi). In the gut, persistence of the inoculum was observed up to 21 dpi. No inflammatory lesions were observed in the ileum or colon during infection. Mutant strains lacking the ureABC genes of the ure1 operon, virB2, or pmm encoding phosphomannomutase were constructed and compared to the wild-type strain for infectivity through the digestive tract. Mutants lacking the virB2 and pmm genes were attenuated in the spleen (P < 0.05) and MLN (P < 0.001), respectively. The wild-type and mutant strains had similar levels of resistance to low pH and 5 or 10% bile, suggesting that the reduced colonization of mutants was not the result of reduced resistance to acid pH or bile salts. In an in vitro lymphoepithelial cell (M-cell) model, B. melitensis transited rapidly through polarized enterocyte monolayers containing M-like cells; however, transit through monolayers containing only enterocytes was reduced or absent. These results indicate that B. melitensis is able to spread systemically from the digestive tract after infection, most likely through M cells of the mucosa-associated lymphoid tissue.