Quantifying Risk Factors for Human Brucellosis in Rural Northern Tanzania

Background

Brucellosis is a zoonosis of veterinary, public health and economic significance in most developing countries. Human brucellosis is a severely debilitating disease that requires prolonged treatment with a combination of antibiotics. The disease can result in permanent and disabling sequel, and results in considerable medical expenses in addition to loss of income due to loss of working hours. A study was conducted in Northern Tanzania to determine the risk factors for transmission of brucellosis to humans in Tanzania.

Methods

This was a matched case-control study. Any patient with a positive result by a competitive ELISA (c-ELISA) test for brucellosis, and presenting to selected hospitals with at least two clinical features suggestive of brucellosis such as headache, recurrent or continuous fever, sweating, joint pain, joint swelling, general body malaise or backache, was defined as a case. For every case in a district, a corresponding control was traced and matched by sex using multistage cluster sampling. Other criteria for inclusion as a control included a negative c-ELISA test result and that the matched individual would present to hospital if falls sick.

Results

Multivariable analysis showed that brucellosis was associated with assisted parturition during abortion in cattle, sheep or goat. It was shown that individuals living in close proximity to other households had a higher risk of brucellosis. People who were of Christian religion were found to have a higher risk of brucellosis compared to other religions. The study concludes that assisting an aborting animal, proximity to neighborhoods, and Christianity were associated with brucellosis infection. There was no association between human brucellosis and Human Immunodeficiency Virus (HIV) serostatus. Protecting humans against contact with fluids and tissues during assisted parturition of livestock may be an important means of reducing the risk of transferring brucellosis from livestock to humans. These can be achieved through health education to the communities where brucellosis is common.     

T mu and T gamma-lymphocyte counts and their ratio in patients with brucellosis

The levels of circulating T mu- and T gamma-lymphocytes in brucellosis patients have been studied in relation to the clinical form of the disease, the severity of the process and the allergic transformation of the body. A decrease in the content of lymphocytes, affecting mainly T mu-cells and less commonly T gamma-cells, as well as a change in their ratio has been revealed. The level of this decrease depended on the clinical form of brucellosis, the severity of the course of acute and subacute brucellosis, the phase of chronic brucellosis and the allergic transformation of the body. The disproportion of immunoregulating cells in brucellosis, revealed in this study, is supposed to be of pathogenetic importance.     

The T mu- and T gamma-lymphocyte count and their ratio in patients with brucellosis of various focal natures

The content of T mu- and T gamma-lymphocytes and their ratio in patients having subacute and chronic brucellosis with different foci of infection have been studied. The relationship between the decrease in the levels of T mu- and T gamma-cells and the clinical form of the disease and its clinical manifestations, such as polyarthritis, has been established. Manifestations of disturbances in the T mu-cell/T gamma-cell ratio were more pronounced in patients with subacute brucellosis in whom the lesions of the osteoarticular system prevailed. The detected changes in the counts of immunoregulatory cells in brucellosis are assumed to be of pathogenetic importance.     

Clinical Manifestations of Human Brucellosis: A Systematic Review and Meta-Analysis

Background

The objectives of this systematic review, commissioned by WHO, were to assess the frequency and severity of clinical manifestations of human brucellosis, in view of specifying a disability weight for a DALY calculation.

Methods/Principal Findings

Thirty three databases were searched, with 2,385 articles published between January 1990–June 2010 identified as relating to human brucellosis. Fifty-seven studies were of sufficient quality for data extraction. Pooled proportions of cases with specific clinical manifestations were stratified by age category and sex and analysed using generalized linear mixed models. Data relating to duration of illness and risk factors were also extracted. Severe complications of brucellosis infection were not rare, with 1 case of endocarditis and 4 neurological cases per 100 patients. One in 10 men suffered from epididymo-orchitis. Debilitating conditions such as arthralgia, myalgia and back pain affected around half of the patients (65%, 47% and 45%, respectively). Given that 78% patients had fever, brucellosis poses a diagnostic challenge in malaria-endemic areas. Significant delays in appropriate diagnosis and treatment were the result of health service inadequacies and socioeconomic factors. Based on disability weights from the 2004 Global Burden of Disease Study, a disability weight of 0.150 is proposed as the first informed estimate for chronic, localised brucellosis and 0.190 for acute brucellosis.

Conclusions

This systematic review adds to the understanding of the global burden of brucellosis, one of the most common zoonoses worldwide. The severe, debilitating, and chronic impact of brucellosis is highlighted. Well designed epidemiological studies from regions lacking in data would allow a more complete understanding of the clinical manifestations of disease and exposure risks, and provide further evidence for policy-makers. As this is the first informed estimate of a disability weight for brucellosis, there is a need for further debate amongst brucellosis experts and a consensus to be reached.     

Ciprofloxacin in the treatment of patients with brucellosis]

With the aim to estimate the clinical and immunological efficiency of the ciprofloxacin (cifloxinal) 105 patients with acute (51), subacute (19) and chronic (35) brucellosis were studied. Control group (17 patients with acute and 30 patients with chronic brucellosis) have been treated with combination of two antibiotics: doxycycline and rifampicin. Ciprofloxacin in a dose 500 mg bid within 14 days in acute stage and 20 days in chronic stage of disease essentially reduced duration of local inflammatory processes of brucellosis with simultaneous treatment of the chronic infection focus, provides good proximate and distant outcomes of treatment. Ciprofloxacin can be considered as an alternative drug for the treatment of brucellosis, more effective (clinically and immunologically) than a combination of two antibiotics: doxycycline and rifampicin.     

Increasing the effectiveness of antibiotic therapy by correcting immunologic disorders with vitamin A in patients with brucellosis

Experimental studies and clinical trials were performed on possible increase of antibiotic therapy efficacy in brucellosis patients by correction of the immunity disorders with vitamin A. It was experimentally shown that vitamin A increased cellular immunity and accelerated sanation of guinea pigs sensitized with Brucella abortus 19 BA. The clinical trials demonstrated that the use of vitamin A in a dose of 33,000 IU thrice a day for 10 to 12 days during the complex treatment of patients with acute (36 persons) and subacute (57 persons) brucellosis lowered the average period of manifestation of the disease clinical signs and formation of the antibodies, increased the skin allergic sensitivity, the lymphocyte blast cell transformation, the total number and subpopulations of the active T-cells, theophylline-resistant lymphocytes, phagocytic and metabolic activity of neutrophils, showed 1.5- and 2-fold increased in the frequency of the infection transformation into a chronic process in patients with acute or subacute brucellosis, respectively.     

犬布鲁氏菌病

目前,犬布鲁氏菌病在全球多个国家和地区都有发生,而且发病数量逐年上升,由犬布鲁氏菌病感染人的病例报道也日益增多。因此,犬布鲁氏菌病的控制和根除对人类健康和公共卫生安全具有重要的意义。据报道,我国多个省份存在犬布鲁氏菌病,而且感染和发病率有上升的趋势。由于我国养犬数量巨大,犬与人类接触密切,病犬作为人类布鲁氏菌病的传染源不容忽视。犬布鲁氏菌病的研究起步较晚,流行病学资料欠完善,公共卫生学意义有待阐明,诊断、免疫预防等诸多问题还没完全解决,加强犬布鲁氏菌病的研究和防控应引起足够的重视。本文就犬布鲁氏菌病的病原学、流行病学、病理学、临床症状、诊断、治疗、预防及公共卫生安全等分别做一阐述。     

Gaucher disease and brucella: just a mere coincidence?

Gaucher disease type I and brucellosis are chronic diseases with similar symptoms and physical signs though the former is the most common lysosomal storage disease and the latter is an infectious disease. The similarities between these diseases make differential diagnosis difficult. Immunodeficiency is a feature of Gaucher disease type I and increases the susceptibility towards infections. A Gaucher disease type I patient with brucellosis is presented with improvement after treatment of brucellosis.     

88例布鲁氏菌病例流行病学特征及临床特点分析

对沈阳市第六人民医院2009年1月至2011年12月收治的88例布鲁氏菌病(简称布病)患者的流行病学特征和临床表现特点进行了回顾性分析。分析结果表明:在88例布病病例中,男性与女性比例为4.91;21~60岁为布病的高发年龄段;5~9月份是布病的高发季节;牧民是主要的易感者;牛羊是布病的主要转染源。患者最共同的临床表现为发热,常见的临床表现有发汗、乏力、关节痛、腰痛及肝脾肿大等。布病仍然是我国重要的公共卫生问题,充分了解布病患者的流行病学特征和临床表现特点,将会为布病防治措施的制定和疫情的控制提供科学合理的依据。     

Serum cytokine levels in patients with acute brucellosis and their relation to the traditional inflammatory markers

The number of clinical studies on gamma interferon (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4) in human brucellosis is limited. The present study was focused on IFN-gamma, TNF-alpha and IL-4 levels in acute brucellosis cases, in the acute phase and at the end of the treatment. The relation of these cytokines to traditional inflammation markers was also investigated. The study included 27 cases of acute brucellosis and 20 healthy volunteers who had no complaints. It was found that mean IFN-gamma and TNF-alpha levels, CRP (C-reactive protein) levels and ESR (erythrocyte sedimentation rate) values were significantly higher in acute brucellosis cases as compared to post-treatment values and values measured in the control group. In addition, IFN-gamma and TNF-alpha levels measured in the acute phase correlated with the increase in CRP levels and ESR values. Our results confirmed that IFN-gamma and TNF-alpha are involved in the pathophysiology of brucellosis and are closely related to the inflammatory activation of the disease. In view of the present findings, it is suggested that IFN-gamma and TNFalpha may be used for monitoring brucellosis.     

Circulating L-lymphocytes in brucellosis patients

The content of L-lymphocytes in patients with different clinical forms of brucellosis has been studied. The degree of a decrease in the level of these cells has been found to depend on the activity of the infectious process and its clinical manifestations in the form of polyarthritis. The severity of the course of acute and subacute brucellosis has been found to produce no essential influence on the level of L-cells. These cells are supposed to participate in the processes of pathogenesis and the elimination of the pathogen in brucellosis.     

Lay attitudes and misconceptions and their implications for the control of brucellosis in an agro-pastoral community in Kilombero district,Tanzania

Brucellosis is a priority zoonotic disease in Tanzania that causes ill-health in people and affects livestock productivity. Inadequate awareness and behavior risking transmission can impede control efforts. We conducted a cross-sectional survey of 333 livestock owners in three villages in the Kilombero district, Tanzania, to understand their awareness, knowledge and behavior associated with brucellosis. Six Focus Group Discussions (FGDs), two in each village, were conducted, as well as an additional FGD with male herders from one of the villages. Factors associated with knowledge on brucellosis, food consumption and animal husbandry behavior risking transmission of this disease, were identified using generalized linear models. Predictors for knowledge of brucellosis were being male and having a higher educational level, while age was positively associated with a higher level of knowledge. Faith and ethnicity were associated with the performance of practices risking transmission. Following traditional religion and belonging to the Wamaasai ethnicity significantly increased the odds of carrying out these practices. Qualitative analysis gave insight into risk practices and reasoning. Of the 333 respondents, 29% reported that they had experienced abortions in their herds, 14% witnessed retained placentas, and 8% had seen still-births in their cattle within the previous year. However, survey results also showed that only 7.2% of participants had heard about brucellosis as a disease in livestock. Of those who had heard about brucellosis in livestock, 91% associated abortions with it and 71% knew that humans can get infected through raw milk consumption. People overwhelmingly attributed symptoms and transmission of brucellosis in livestock to infection with trypanosomiasis and to supernatural reasons instead. In the community, consumption of raw milk was valued and handling of aborted material was not considered a risk for infection. This agro-pastoralist community holds on to long-held beliefs and practices and lacks understanding of the biomedical concept of brucellosis. Transmission routes and symptoms of brucellosis in humans and livestock are completely unknown. The disparity between risk perception and actual transmission risk related to animal handling and consumption of animal products presents a challenge for disease awareness communication. This study recommends focused community engagement and sensitization to address the limited awareness and misconceptions among agro-pastoralists.     

布鲁菌病的生物安全及防控

布鲁菌病(brucellosis)是布鲁菌入侵机体引起的传染-变态反应性人兽共患传染病,易被忽视。该病严重威胁人类健康,影响畜牧业、旅游业的发展,阻碍正常国际贸易,还会造成食品安全隐患。布鲁菌可通过消化道、呼吸道及皮肤黏膜破损处等途径传播至人。人群对布鲁菌的易感性无年龄和性别差异,可通过直接或间接接触感染。从事布鲁氏菌研究的实验室操作人员有发生实验室获得性感染的风险,但可通过有效的生物安全防护措施避免感染的发生。布鲁菌病是一种可防可控的疾病,必须早期诊断和正确治疗,防止疾病慢性化。本文对布鲁菌病的生物安全及其防控原则进行介绍。     

Diagnostic value of serum concentrations of high‐mobility group‐box protein 1 and soluble hemoglobin scavenger receptor in brucellosis

Both cluster of differentiation (CD)4⁺ and CD8⁺ T lymphocytes play key roles in immunity to Brucella, in part because they secrete interferon (IFN)‐γ and activate bactericidal functions in macrophages. Therefore, use of markers of macrophage activation may have diagnostic and prognostic significance. High‐mobility group‐box 1 protein (HMGB1), a late‐onset pro‐inflammatory cytokine, is secreted by activated macrophages. Soluble hemoglobin scavenger receptor (sCD163) is a specific marker of anti‐inflammatory macrophages. The aim of this study was to investigate the diagnostic value of HMGB1 and sCD163 concentrations in brucellosis and its various clinical forms. Serum HMGB1 and sCD163 concentrations in 49 brucellosis patients were compared with those in 52 healthy control subjects. Both serum HMGB1 and sCD163 concentrations were significantly higher in brucellosis patients than in healthy controls (P < 0.001). There were no statistically significant differences in serum concentrations of HMGB1 and sCD163 between cases of acute, subacute and chronic brucellosis. Additionally, serum HMGB1 concentrations were positively correlated with sCD163 concentrations, whereas neither HMGB1 nor sCD163 concentrations were correlated with C‐reactive protein concentrations, white cell counts or erythrocyte sedimentation rates. Therefore, serum concentrations of HMGB1 and sCD163 may be diagnostic markers for brucellosis, but neither can be used to differentiate the three different forms of this disease (acute, subacute and chronic).     

Free and bound Brucella antigen and the level of circulating immune complexes in brucellosis patients

The aggregate hemagglutination test has been shown to be a highly sensitive and specific method for the detection of infectious antigenemia in different forms of brucellosis, permitting the determination of free Brucella antigen in 34% of patients with the acute form of the disease and in 53% of patients with the chronic course of brucellosis. The results of the determination of the quantitative level of circulating immune complexes (CIC) indicate that in the acute form of the disease their level exceeds the CIC level observed in the chronic course of brucellosis. The preliminary dissociation of CIC in the patients' blood sera has been found to increase the overall release of Brucella antigen to 80%.     

Characteristics of brucellosis epidemiology in children in the Kazakh SSR

The analysis of brucellosis morbidity among children in the Kazakh SSR for the last 10 years revealed the following facts. The highest morbidity rate among children was registered in zones with developed sheep breeding. Privately owned agricultural animals, mainly small cattle, proved to be the main source of infection, transferred in most cases through contacts. contacts. The occurrence of brucellosis among children was found to be directly related to their age. Most of the sick children were boys. The pronounced seasonal character of brucellosis morbidity, falling mainly on spring and summer, was observed. In surveying the population for brucellosis the use of a complex of sero-allergic tests permitted the detection of a great number of infected subjects. Most sick children showed a typical picture of acute brucellosis. Treatment resulted in their clinical convalescence.,     

Paper-based ELISA diagnosis technology for human brucellosis based on a multiepitope fusion protein

BackgroundBrucellosis, as a serious zoonotic infectious disease, has been recognized as a re-emerging disease in the developing countries worldwide. In china, the incidence of brucellosis is increasing each year, seriously threatening the health of humans as well as animal populations. Despite a quite number of diagnostic methods currently being used for brucellosis, innovative technologies are still needed for its rapid and accurate diagnosis, especially in area where traditional diagnostic is unavailable.Methodology/Principal findingsIn this study, a total of 22 B cell linear epitopes were predicted from five Brucella outer membrane proteins (OMPs) using an immunoinformatic approach. These epitopes were then chemically synthesized, and with the method of indirect ELISA (iELISA), each of them displayed a certain degree of capability in identifying human brucellosis positive sera. Subsequently, a fusion protein consisting of the 22 predicted epitopes was prokaryotically expressed and used as diagnostic antigen in a newly established brucellosis testing method, nano-ZnO modified paper-based ELISA (nano-p-ELISA). According to the verifying test using a collection of sera collected from brucellosis and non-brucellosis patients, the sensitivity and specificity of multiepitope based nano-p-ELISA were 92.38% and 98.35% respectively. The positive predictive value was 98.26% and the negative predictive value was 91.67%. The multiepitope based fusion protein also displayed significantly higher specificity than Brucella lipopolysaccharide (LPS) antigen.ConclusionsB cell epitopes are important candidates for serologically testing brucellosis. Multiepitope fusion protein based nano-p-ELISA displayed significantly sensitivity and specificity compared to Brucella LPS antigen. The strategy applied in this study will be helpful to develop rapid and accurate diagnostic method for brucellosis in human as well as animal populations.     

Cell immunologic reactions in estimating chronic brucellosis activity

The study of cellular immunological reactions- lymphocyte blasttransformation reaction (LBTR) and leucocyte migration inhibition test (LMIT) in 201 patients with chronic brucellosis showed that they can be used as additional diagnostic criteria of chronic brucellosis activity estimation, especially in seronegative cases of the disease. On the basis of results obtained a diagnostic table is devised.     

Cattle brucellosis in traditional livestock husbandry practice in Southern and Eastern Ethiopia,and its zoonotic implication

Background  

Cattle brucellosis has significant economic and zoonotic implication for the rural communities in Ethiopia in consequence of their traditional life styles, feeding habits and disease patterns. Hence, knowledge of brucellosis occurrence in traditional livestock husbandry practice has considerable importance in reducing the economic and public health impacts of the disease.