Brucellosis Surveillance Research Articles

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 programs 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.

Epidemiology characterization and risk factors of brucellosis among older rural populations in northwest China

Brucellosis causes significant economic damage and public health problems in northwest China. The older rural population is considered a high-risk group. However, the epidemiological characteristics and risk factors for brucellosis in this population remain unclear. This study investigated these factors within this high-risk group by performing a cross-sectional study in five townships of Wuwei City, Gansu Province. Cases were screened via rose Bengal and serum plate agglutination tests. Risk factors were evaluated using a standard questionnaire form. This study included 1073 participants aged >50 years. Among them, 15 (1.4%) tested positive for Brucella. The most common symptoms were arthralgia/myalgia (n=5, 33.3%), and 10 (66.7%) cases were asymptomatic. Raising lambs artificially (odds ratio, 4.7; 95% CI, 1.3–17.0; P=0.02) increased the risk of brucellosis. The results indicated a high proportion of asymptomatic brucellosis in this group. Raising lambs artificially is a risk factor for brucellosis. The surveillance and health education of brucellosis for older rural populations in endemic areas of northwest China should been attention.

Epidemiological changes and molecular characteristics of Brucella strains in Ningxia, China.

Human brucellosis causes serious public health concerns in Ningxia, China. This study employed epidemiological, bacteriological, and multiple-locus variable-number tandem repeat analysis (MLVA) methods to conduct an epidemiological investigation, which is necessary for devising tailored control strategies. Between 1958 and 2022, 29,892 cases were reported, with an average annual number of cases and incidence of 467 and 7.1/100,000, respectively. The epidemic situation gradually worsened, with cases escalating from 26 cases in 2005 to 6,292 in 2022, with the incidence rate rising from 0.441 in 2005 to 86.83 in 2022. Geographically, the disease spread from a single affected county in 2004 to encompass all 22 counties in 2022. Yanchi County had the highest incidence, followed by the Hongsibao and Tongxin counties. These data suggest that Brucella infection has become a rampant regional concern in human brucellosis. Between 1958 and 2019, a total of 230 Brucella strains were identified across four studied hosts. These strains comprised four species with 12 biovars, including B. melitensis bv. 1, bv. 2, bv. 3, B. abortus bv. 1, bv. 3, bv. 4, bv. 5, bv. 6, bv. 7, B. suis bv. 1 and bv. 3, and B. canis. These data highlight the high species/biovars and host diversity of the Brucella population, posing a substantial challenge to brucellosis surveillance. There was an apparent transition from multiple species/biovars historically to the current dominance of a single species, B. melitensis, emphasizing the requirement for strengthening surveillance of B. melitensis. Genotypes 42 and 116, constituting 96.2% of the total number of genotypes, predominated in panel 1 and MLVA-11, indicating that all strains belong to the East Mediterranean lineage. MLVA cluster analysis revealed persistent transmission of dominant circulating genotypes, presenting an epidemic pattern characterized primarily by epidemiologically related cases with a few sporadic cases. Strains in this study exhibited high genetic homogeneity with strains from the Northwest, and those from Kazakhstan and Mongolia. The epidemic situation of human brucellosis has gradually worsened; the rampant epidemic of the disease has become a regional concern. The present study highlights that implementing the of targeted surveillance and intervention strategies is urge.

Pestiviruses in sheep and goats in Austria: Options for integration into the bovine viral diarrhea (BVDV) monitoring program

After the successful eradication of the bovine viral diarrhea virus (BVDV) in cattle in Austria, the risk of infections with the border disease virus (BDV) remains. Both viruses belong to the pestivirus genus. BDV infections lead to false-positive results in BVDV surveillance. This can be attributed to the contact to small ruminant populations. In particular, keeping cattle together with sheep or goats on a farm or alpine pasture are significant risk factors. Between 2015 and 2022, BDV type 3 was detected in 15 cattles in Austria. These animals were almost exclusively persistently infected calves. However, a positive antibody result for pestiviruses can lead to an extremely time-consuming and costly, and not always successful search for the source of the infection if no active virus excretor is found. This study documents how small ruminants can be integrated into pestivirus monitoring with a manageable amount of work and costs. 23 406 sheep and goat samples from two brucellosis surveillance programs in small ruminants were analyzed retrospectively. Blood samples were examined using pestivirus real-time pool RT-PCR (qPCR). Direct virus detection of BDV-3 was achieved in 40 sheep from five different federal states. Over the entire investigation period a further 37 detections of BDV-3 were found in cattle, sheep and goats outside of this study throughout Austria. This study accounts for 52 % of all border disease detections from 2015 to 2022. By including small ruminants in pestivirus monitoring, the disruptive factor BDV and the risk of its introduction into cattle herds can be significantly minimized in the future.

Evaluation of an In-house Indirect ELISA for Differential Detection of IgM and IgG anti-Brucella Antibodies in Human Brucellosis

Brucellosis caused by various species of the genus Brucella is one of the most important zoonotic diseases of global importance with veterinary, public health, and economic concerns. The study aimed to standardize IgM and IgG-based iELISA to detect anti-Brucella antibodies for serodiagnosis of acute and chronic human brucellosis. The test was standardized using 1:320 dilution of smooth lipopolysaccharide (sLPS) antigen from B. abortus S99 strain, 1:80 serum dilution, 1:4000 anti-human IgM and IgG conjugates, respectively for both IgM and IgG iELISA. The cut-off using 50 each brucellosis positive and negative human sera panel samples was set at ≥ 42 for both IgM and IgG iELISA. A total of 700 human sera samples were evaluated (137 veterinary doctors, 157 artificial inseminators, and 406 veterinary assistants). Overall, the study detected 8.3%, 8.1%, 8%, and 6.1% positivity by in-house IgG iELISA, RBPT, IgM iELISA, and SAT tests, respectively. Considering commercial iELISA kit as a gold standard, the sensitivities of IgM and IgG iELISA were 90% and 97.9%, respectively, whereas, specificities were >99%. The study established >98% specificity and >90% sensitivity for differential detection of immunoglobulin classes in the standardized iELISA. The developed assay outperformed the other evaluated tests with a shorter assay time and can be implemented in both endemic and non-endemic regions for surveillance and diagnosis of human brucellosis.

Evaluation of a Lateral Flow Immunochromatography Assay (LFIA) for Diagnosis and Surveillance of Brucellosis in French Alpine Ibex (Capra ibex).

France has been officially free of bovine brucellosis since 2005. Nevertheless, in 2012, as the source of two human cases, a bovine outbreak due to B. melitensis biovar 3 was confirmed in the French Alpine Bargy massif, due to a spillover from wild, protected Alpine ibex (Capra ibex). In order to reduce high Brucella prevalence in the local ibex population, successive management strategies have been implemented. Lateral flow immunochromatography assay (LFIA) was thus identified as a promising on-site screening test, allowing for a rapid diagnosis far from the laboratory. This study compared a commercial LFIA for brucellosis diagnosis with the WOAH-recommended tests for small ruminants (i.e., Rose Bengal test (RBT), Complement fixation test, (CFT) and Indirect ELISA, (iELISA)). LFIA showed the same analytical sensitivity as iELISA on successive dilutions of the International Standard anti-Brucella melitensis Serum (ISaBmS) and the EU Goat Brucella Standard Serum (EUGBSS). Selectivity was estimated at 100% when vaccinated ibex sera were analyzed. When used on samples from naturally infected ibex, LFIA showed high concordance, as well as relative sensitivity and specificity (>97.25%) in comparison with RBT and CFT. This work shows high reliability and ensures a better standardization of LFIA testing for wild ruminants.

Modulation of the One Health Approach to Tackle Brucellosis in Buffaloes and Cattle in Two Italian Territories with Different Characteristics

The new European Union animal health law and its rule concerning brucellosis in cattle and buffaloes
 The authors examine the latest European Union (EU) rules concerning eradication and surveillance of brucellosis and animal infectious diseases of EU concern.
 The Italian rules concerning brucellosis in cattle and buffaloes 
 Italy is included in the EU co-financed compulsory eradication and surveillance programmes for brucellosis in cattle and in buffaloes in the frame of the EU and the related Italian laws, which allowed reaching the Brucellosis Free status without vaccination (former "Officially Brucellosis Free - OBF" status) in the majority of the northern and middle Italian Regions and in some middle and southern Provinces included in Regions where the infection persists.
 Epidemiology of brucellosis in the EU and in Italy
 In the Italian Province of Caserta, the highest prevalence of brucellosis in buffaloes is reported; in 2017-2021, a total of 314 outbreaks occurred, in which 39,163 heads tested positive. Here, brucellosis is threatening not only human health and the widespread buffaloes breeding but also the important satellite activities concerning the Protected Designation of Origin (P.O.D.) cheese “Mozzarella di Bufala Campana". The authors also discuss the reemerged brucellosis in cattle in the Molise Region, which despite bordering the Province of Caserta, shows different hydrographic, orographic, and breeding characteristics. In Molise, the reemerged brucellosis had a very different epidemiological course, which allowed it to limit the adoption of One Health measures.
 The One Health approach to tackle brucellosis in buffaloes
 In order to tackle brucellosis in Campania Region and in its Province of Caserta, the One Health approach has been predisposed through strict control of animal health, human health, and the environment. The adopted model could be exportable to territories having similar characteristics.

The Role of Dairy Farmers in Surveillance and Control Program of Brucellosis in Bogor Regency

Brucellosis is an infectious and zoonotic disease that causes a negative impact on the health and economy of people in almost all countries. The prevalence of brucellosis in several regions in Indonesia is still quite high. The purpose of this study was to analyze the role of farmers in the brucellosis control and surveillance program in Bogor Regency. The study was conducted through a survey of 151 farmers in Bogor Regency from May to July 2022. A total of 68.9% of respondents are aged 25-50 years with an education level of 69.8% are low educated (Elementary School, Junior High School) and not in school . The experience of raising more than five years (58.2%) with the number of dairy cattle ownership is less than five heads, namely 41.7%. The brucellosis prevention practices that need to be improved are related to the use of disinfectants when cleaning the cage, livestock group management practices (separating pregnant cows from other cows, separating cows with suspected brucellosis from other healthy cows, separating newly purchased cows for two weeks before being merged with cows). long in the cage). The practice of brucellosis control that needs to be improved is proper handling of the placenta and cows infected with brucellosis properly. Surveillance practices that need to be improved are the practice of recording and reporting cases of miscarriage in the final trimester. After identifying farmer practices, it is very important to plan interventions in the form of training with a curriculum that refers to the level of farmer practice that is still lacking. It is hoped that by conducting training interventions for farmers, the level of knowledge of farmers will increase and the level of practice of farmers will also increase.

Risk Factors Associated with Brucellosis Seropositivity in Goat Farms of Sing Buri Province, Thailand

During 2012 - 2016, goat farms in Sing Buri province were growing rapidly with support from the Thai government. In the following three years (2017-2019), the analysis of brucellosis surveillance data indicated that the seropositivity of brucellosis in goats increased. Therefore, this study attempted to identify possible risk factors associated with brucellosis seropositivity in meat goats raised in Sing Buri province of Thailand. A case-control study was conducted in a random sampling of 72 goat farms in Sing Buri province, Thailand. Questionnaires were used to collect information regarding farm production types, husbandry, goat health management, grazing management, breeding, carcass management, and goat purchasing. Bivariate and logistic regression analyses were used to determine the risk factors of Brucella seropositivity. Results revealed that the most frequent health complaint by the farmers was a stillbirth. Brucella seropositivity at the farm level was 26.4%. The two most probable risk factors for seropositivity included raising goats in a communal pasture and keeping goats with a history of clinical signs associated with brucellosis. In conclusion, approximately 25% of goat farms in Sing Buri province were infected by the bacteria genus Brucella. The farmers were recommended to attentively seek and cull for a brucellosis-suspected goat in their farms using clinical signs or symptoms together with active serosurveillance. Furthermore, communal pasture avoidance would also help prevent the goat from Brucella infection.

Toward Public Health Resilience in the Eastern Mediterranean Region: Findings From the Seventh Eastern Mediterranean Public Health Network Regional Conference.

The resilience of public health in the Eastern Mediterranean Region (EMR) varies from country to country, mostly based on the governmental and financial situation of the countries. With the theme of Towards Public Health Resilience in the EMR: Breaking Barriers, the seventh Eastern Mediterranean Public Health Network regional conference, held from November 14 to 18, 2021, was dedicated to exploring ways for achieving public health resilience. A total of 101 oral presentations and 13 poster presentations were presented on various public health topics. The conference included 6 keynote sessions, 10 roundtable sessions, and 5 preconference workshops. The preconference workshops were conducted on border health; the mobilization of Field Epidemiology Training Program (FETP) residents and graduates and rapid responders in EMR countries; continuous professional development for the public health workforce; brucellosis surveillance using the "One Health" approach; and strategies to integrate and use noncommunicable diseases data sources. The roundtable sessions included discussions on the following topics: the role of FETPs in responding to COVID-19, institutionalization of rapid response to public health emergencies, health systems resilience, integration of early warning and response with event-based and indicator-based surveillance, sustaining international health regulations, strengthening the "One Health" approach, the anticipated future of public health in the post COVID-19 era, supporting public health research capacity in a diverse region, and COVID-19 vaccines and routine immunization synergies and drawbacks. The keynote speaker sessions covered topics on essential public health functions and the universal health coverage challenge in the EMR, lessons from the US COVID-19 public health response, learning from COVID-19, reshaping public health after the pandemic era, COVID-19 resilient primary health care, and the cohesion of society during and after a pandemic. The conference sessions provided highly promising opportunities to explore ways to achieve such goals in the EMR and shed light on the latest scientific findings, important lessons learned, and discussions on the ways in which current barriers can be broken down through coordination and collaboration.

Seroprevalence of Brucella Infection in Wild Boars (Sus scrofa) of Bavaria, Germany, 2019 to 2021 and Associated Genome Analysis of Five B. suis Biovar 2 Isolates

Brucella species are highly pathogenic zoonotic agents and are found in vertebrates all over the world. To date, Germany is officially declared free from brucellosis and continuous surveillance is currently limited to farm ruminants. However, porcine brucellosis, mostly caused by B. suis biovar 2, is still found in wild boars and hares. In the present study, a three-year monitoring program was conducted focusing on the wild boar population in the state of Bavaria. Serologic screening of 11,956 animals and a direct pathogen detection approach, including a subset of 681 tissue samples, was carried out. The serologic incidence was 17.9%, which is in approximate accordance with previously published results from various European countries. Applying comparative whole genome analysis, five isolated B. suis biovar 2 strains from Bavaria could be assigned to three known European genetic lineages. One isolate was closely related to another strain recovered in Germany in 2006. Concluding, porcine brucellosis is endemic in Bavaria and the wild boar population represents a reservoir for genetically distinct B. suis biovar 2 strains. However, the transmission risk of swine brucellosis to humans and farm animals is still regarded as minor due to low zoonotic potential, awareness, and biosafety measures.

Sero-prevalence of brucellosis in ruminants and awareness of stakeholders on the disease in wet markets in Maswa district, Tanzania

Brucellosis is a zoonotic disease with economic drawbacks worldwide. Livestock wet-markets are known premises for human-animal interaction, livestock products consumption and live animal trades in village setups. However, the contribution of wet-market procedures and the knowledge of stakeholders towards zoonotic diseases are not well documented. The present study assessed the sero-prevalence of brucellosis in on-sale ruminants, knowledge of stakeholders on the disease and practices favoring disease transmission so as to generate evidence-based disease transmission risk at wet-markets. A cross sectional study involved collection of 496 blood samples from cattle, goats and sheep in wet-markets in Maswa district, Tanzania. Sera were harvested and tested for brucellosis using fluorescent polarization assay. Structured questionnaire about the epidemiology and control of brucellosis was administered to 400 wet-market stakeholders. Data were analyzed by computing descriptive statistics. The sero-prevalences of 11.2% (95% CI: 7.6 – 15.8) in cattle, 3.92% (95% CI: 1.1 – 9.7) in sheep and 1.39% (95% CI: 0.2 – 4.9) in goats were recorded. Un-screened ruminants from different herds were mixed during auction. Sold animals moved to different destinations while un-sold ones returned home. Interview results revealed that 91% of respondents had low knowledge about brucellosis. The mean knowledge score on index-summated scale was 18.2%. The results imply that wet markets are a risk epicenter for transmission of brucellosis and stakeholders are not informed about it. It is recommended that wet-markets be brucellosis surveillance points and strategies for brucellosis control should consider an awareness and training package to the community

Dairy farmers' knowledge, attitudes, and practices regarding the brucellosis surveillance and control program in Bogor, Indonesia.

Brucellosis is an infectious and zoonotic disease that affects people's health and the economy in most countries. Brucellosis is still prevalent in several Indonesian regions. This study aimed to analyze the correlation between the characteristics, knowledge, attitudes, and practices (KAP) of dairy farmers in Bogor District in supporting brucellosis control and surveillance programs. The study was cross-sectional. Data were collected through interviews with 151 dairy farmers in Bogor Regency, West Java, Indonesia. The outcome is brucellosis surveillance and control practice among dairy farmers, and the variables include individual characteristics, knowledge, and attitudes toward brucellosis surveillance and control. Descriptive analysis and path analysis were used in statistical analysis. The majority of farmers' knowledge, attitudes and practices were moderate, with the percentages 67.55%, 60.92%, and 41.72% respectively. Formal education, training, and dairy rising length are variables that have a direct and significant impact on knowledge level. Knowledge is the variable that influences the overall level of attitude. Age, knowledge, and attitude are factors that influence the practice of brucellosis surveillance and control. Although the practice level of brucellosis surveillance and control for dairy farmers in Bogor Regency is moderate, efforts to improve it are still required. The basic effort is critical for increasing farmers' knowledge.

Diagnostic challenges of brucellosis in humans and livestock in Tanzania: A thematic review

Abstract Brucellosis is an endemic bacterial zoonosis in Tanzania, and is among the most prioritized zoonotic diseases in the country. Brucellosis affects public health and livestock production in developing countries. Most human and livestock cases are not detected by the existing surveillance systems resulting in significant underestimation of the disease burden, and poor management of human cases by using nonspecific antibiotics may potentially contribute to antimicrobial resistance. To quantify the factors related to underreporting and those associated with the challenges in the diagnosis of brucellosis in Tanzania, search terms including “Brucella” “diagnosis” and “challenges” were used to query in Google search engine and publisher databases such as MEDLINE, PUBMED, NCBI, Springer, Hindawi, and Elsevier. The search parameters were limited to publications between 1995 and 2020. The searches returned 319 publications and grey articles which were screened and 57 were eligible for inclusion in this study. Four main areas were identified that cause underreporting of brucellosis and hinder brucellosis diagnosis: (1) inadequate knowledge of brucellosis among stakeholders in the livestock value chain, (2) limited diagnostic capacity for brucellosis due to unawareness of diagnostic tests and lack of epidemiological background of brucellosis among human and livestock health service workers (3) challenges associated with diagnostic tests, which include unreliable availability of diagnostic tests and unskilled workers, and (4) the uneven distribution of brucellosis surveillance studies in the country. This study suggests that there is a need for (1) training on public health education and brucellosis awareness among stakeholders in the livestock value chain; (2) providing scheduled continuing professional education with regard to brucellosis and other zoonotic diseases to health and livestock workers; (3) future brucellosis surveillance studies must focus on unrepresented regions; and (4) lastly, we recommend that the rose Bengal plate test (RBPT) and competitive enzyme-linked immunosorbent assay (cELISA) should be considered in brucellosis diagnostic schemes as a complementary tool to hasten the implementation of an ongoing national strategy for the prevention and control of brucellosis in humans and livestock in Tanzania. We suggest that these recommendations be considered for inclusion in the national strategy for brucellosis control in Tanzania. One Health Impact Statement Brucellosis is a disease caused by bacteria of genus Brucella and is transmitted from animals to humans. Humans get infected through ingestion of infected animal products but also through contact with bacteria via broken skin or inhalation of aerosolized bacteria particles during culture in the laboratory. Humans working with animals or animal products and laboratory personnel are at higher risk of infection. Tanzania has recently established a One-Health desk in the Prime Minister’s Office to address all matters related to One Health. However, the desk is in the infancy stage, more studies must be done to fill knowledge gaps so that working instruments became realistic. This review provides a synthesis of information that could be used by the One Health desk and other One Health stakeholders in the country on how to improve the existing brucellosis surveillance structures for improvement of One-Health service delivery in the country.

An integrated platform for Brucella with knowledge graph technology: From genomic analysis to epidemiological projection.

Motivation: Brucella, the causative agent of brucellosis, is a global zoonotic pathogen that threatens both veterinary and human health. The main sources of brucellosis are farm animals. Importantly, the bacteria can be used for biological warfare purposes, requiring source tracking and routine surveillance in an integrated manner. Additionally, brucellosis is classified among group B infectious diseases in China and has been reported in 31 Chinese provinces to varying degrees in urban areas. From a national biosecurity perspective, research on brucellosis surveillance has garnered considerable attention and requires an integrated platform to provide researchers with easy access to genomic analysis and provide policymakers with an improved understanding of both reported patients and detected cases for the purpose of precision public health interventions. Results: For the first time in China, we have developed a comprehensive information platform for Brucella based on dynamic visualization of the incidence (reported patients) and prevalence (detected cases) of brucellosis in mainland China. Especially, our study establishes a knowledge graph for the literature sources of Brucella data so that it can be expanded, queried, and analyzed. When similar “epidemiological comprehensive platforms” are established in the distant future, we can use knowledge graph to share its information. Additionally, we propose a software package for genomic sequence analysis. This platform provides a specialized, dynamic, and visual point-and-click interface for studying brucellosis in mainland China and improving the exploration of Brucella in the fields of bioinformatics and disease prevention for both human and veterinary medicine.

Development of a Multiplex Bead Assay to Detect Serological Responses to Brucella Species in Domestic Pigs and Wild Boar with the Potential to Overcome Cross-Reactivity with Yersinia enterocolitica O:9.

The aim of this study was to develop a multiplex bead assay using a Brucella rLPS antigen, a Brucella suis smooth antigen, and a Yersinia enterocolitica O:9 antigen that not only discriminates Brucella-infected from Brucella-uninfected pigs and wild boar, but also overcomes the cross reactivity with Y. enterocolitica O:9. Sera from 126 domestic pigs were tested: 29 pigs were Brucella infected, 80 were non-infected and 17 were confirmed to be false positive serological reactors (FPSR). Sera from 49 wild boar were tested: 18 were positive and 31 were negative. Using the rLPS antigen, 26/29 Brucella-infected domestic pigs and 15/18 seropositive wild boar were positive, while 75/80 non-Brucella infected domestic pigs, all FPSR, and all seronegative wild boar were negative. Using the smooth B. suis 1330 antigen, all Brucella-infected domestic pigs, 9/17 FPSR and all seropositive wild boar were positive, while all non-infected pigs and 30/31 seronegative wild boar were negative. The ratio of the readouts from the smooth B. suis antigen and Y. enterocolitica O:9 antigen enabled discriminating all Brucella infected individuals from the FPSR domestic pigs. These results demonstrate the potential of this assay for use in the surveillance of brucellosis, overcoming the cross-reactivity with Y. enterocolitica.

Brucellosis: A Retrospective Sero-epidemiological Study

Introduction: Brucellosis is one of the most important worldwide zoonotic diseases caused by the bacterial genus Brucella. It is frequently misdiagnosed and can therefore lead to inappropriate treatment and prolonged disease. This study aimed to investigate the seroprevalence of human brucellosis cases and compare it with the national average and the number of goat brucellosis cases in Algeria.
 Materials and methods: A total of 3223 patients suspected of brucellosis were collected during 2008-2015 in Djelfa, central Algeria. Rose Bengal test and Wright's serum agglutination were used for the diagnosis.
 Results: The number of positive cases was 1281 (39.74%), including 743 (58.04%) men and 537 (41.96%) women, resulting in a ratio of 1.38. Men were infected more than women. The number of positive cases was observed frequently between April and September. However, there was no significant difference among the investigated years in terms of infection. The highest prevalence was observed in individuals aged between 11 and 30 years (21.62-22.32%). The seroprevalence of human brucellosis in the current study in Djelfa was significantly higher, compared to the national level. The number of animals (goats) and human cases reported at the national level and Djelfa followed a similar trend.
 Conclusion: Brucellosis still remains a serious public health threat in the study area. Epidemiological surveillance of brucellosis should be considered a priority in order to reduce the prevalence of human and animal brucellosis.

Environment and Offspring Surveillance in Porcine Brucellosis.

Porcine brucellosis, caused by Brucella suis (B. suis), is a notifiable disease causing significant economic losses in production systems. Most infected pigs may act as carriers and shed B. suis even if asymptomatic. This can contribute to environmental persistence, thus hindering control efforts. Here, the environment and the offspring were investigated during and after a B. suis outbreak at a sow breeding farm. The diagnosis of B. suis in sows (n = 1,140) was performed by culture and polymerase chain reaction (PCR) from vaginal swabs, indirect enzyme-linked immunosorbent assay (I-ELISA) from sera, and brucellin skin test (BST). B. suis diagnosis in post-weaning pigs (n = 899) was performed by I-ELISA in sera and BST. The environmental surveillance programme was implemented by placing gauze sponges (n = 175) pre-hydrated in a surfactant and inactivating liquid for Brucella DNA detection by PCR in different farm areas. Our results showed that the offspring of infected sows reacted to in vivo techniques for B. suis. Furthermore, the offspring born during the outbreak displayed higher seropositivity (I-ELISA) and reactivity (BST) than those pigs born after. Brucella DNA was detected in pregnant sow areas, boxes, boots, and post-weaning pig areas. In addition, Brucella DNA environmental detection was higher during the B. suis outbreak than the post B. suis outbreak. The environmental approach has proven to be a simple, practical, valuable, and safe method to detect and monitor B. suis. These results suggest a role of the environment and the offspring that should be considered in porcine brucellosis surveillance and control programmes.

Human brucellosis in the southern West Bank, 2015–17: a seroprevalence and molecular characterisation study

BackgroundBrucellosis is a global zoonotic disease ranked by WHO as being among the top seven neglected zoonoses. After implementing a livestock vaccination strategy in 1998, the incidence rate of human brucellosis in Palestine dropped significantly. However, in 2015 the disease re-emerged with alarming incidence rates similar to those in the period before 1998. The aim of this study was to characterise the strains associated with this episode using genetic and genomic tools. MethodsAll patients were referred to the department of preventive medicine from several public or private clinics in the southern West Bank due to undulant fever. After a careful analysis of a patients’ history to evaluate exposure to Brucella, blood samples from patients suspected of brucellosis were collected. Samples positive for the Rose Bengal test with an antibody titre of 1:80 IU/mL or more by Brucella standard agglutination test, and not under antibiotic treatment, were further cultured using the BACTEC 9240 blood culture system. DNA was extracted from the positive culture samples and analysed using three biomarkers to validate the presence of the Brucella genus, establish the species, and identify the Brucella melitensis Rev 1 vaccine strain. Nine randomly chosen isolates were sequenced using targeted next generation sequencing technology to screen for the rpoB gene mutations. Multiple-locus variable number of tandem repeats analysis (MLVA) with 16 variable number of tandem repeats markers was used to genotype the isolates and BioNumerics version 7.6 software was used to analyse the data using the categorical coefficient and unweighted pair group method using the arithmetic averages algorithm. FindingsBlood samples were obtained from a total of 1324 patients during 2015–17. 704 (53·2%) of 1324 serum samples showed agglutination in the Rose Bengal test and 559 (79·4%) of the 704 were considered seropositive based on a standard agglutination test titre of 1:80 IU/mL or more. Only 130 (23·3%) of the 559 seropositive samples were from patients not under antibiotic treatment. Upon culturing, only 72 (12·9%) of the seropositive samples showed growth signals and were positive by PCR for the Brucella genus marker, and all isolates were B melitensis. None of the samples were associated with the B melitensis Rev 1 vaccine strain. The results of sequencing the rpoB gene by next generation sequencing showed four different single nucleotide variations that were not located within the rifampicin resistance-determining region. Using MLVA-16 analysis and the MLVA bank benchmark, the studied isolates were divided into 22 unique genotypes. A hierarchical clustering analysis for the 72 isolates and 18 B melitensis global isolates representing four major regions in the Middle East, Europe, Africa, and America, clustered the 73 isolates in the Middle East clade, providing a similarity cutoff value of more than 97% for genotype and more than 75% for clade. InterpretationThis study shows that the brucellosis episode of 2015–17 was due to B melitensis local isolates and was not associated with the Rev 1 vaccine stain. The results show that MLVA-16 is a useful tool for the public health surveillance of human brucellosis. The present study analysed samples from the Hebron governorate only. It is recommended to include more human and animal samples from different areas in Palestine to understand the molecular epidemiology of brucellosis in Palestine and to make more effective decisions regarding control and treatment programmes. FundingPalestine Polytechnic University.

Analysis of cases of brucellosis in humans and molecular-biological characteristics of <i>Brucella melitensis</i> strains in regions of South European Russia with a high brucellosis incidence

Introduction. To improve the epidemiological surveillance of brucellosis in Russia, a detailed analysis of incidence and characteristics of Brucella melitensis strains circulating in the territories of the country where there is a persistent epizootic and epidemiological problem with brucellosis is required.Purpose of the study. To study current trends in the brucellosis epidemic process and perform molecular analysis of Brucella isolates from the territories of Southern and North Caucasian Federal Districts with long lasting unfavorable situation with brucellosis — the Republics of Dagestan (RD), Kalmykia (RK) and Stavropol Krai (SK).Materials and methods. The analysis of the brucellosis incidence in the North Caucasus Federal District and the Southern Federal District was carried out on the basis of data from the Rospotrebnadzor Departments for the period 2011–2020. Total 56 cultures of Brucella melitensis, isolated in 1999–2019 from patients with brucellosis that permanently resided in RD, RK and SK were studied.Results. The key factor contributing to the epidemic manifestations of brucellosis in the south of the European part of Russia is the persistence of epizootic foci in cattle and small ruminants. The leading concomitant factors are as follows: the presence in the region of "hidden" epizootic foci, uncontrolled production of food products of animal husbandry and its illegal sale to customers, unauthorized movement of animals and livestock products, untimely delivery (concealment) of sick cattle for stamping out. Results of molecular analysis of B. melitensis strains indicate the circulation of a mixed population of brucella, which is generally characteristic of the entire region, without a pronounced confinement of isolates to separate administrative territories. At the same time, the entire studied sample of strains can be divided into two groups (72% and 28% of strains) based on MLVA-16 genotypes by the variability in the Bruce 19 locus, which makes it possible to associate a part of the studied strains with the territory of their isolation.Discussion. The data obtained make it possible to scientifically substantiate the possibility of considering the affected territories of the Southern Federal District and the North Caucasian Federal District as a single common persistent active anthropurgic epizootic focus with circulation of a mixed, but typical for the region population of Brucella strains.