Comparison of the Brucella Standard Agglutination Test with the ELISA IgG and IgM in patients with Brucella bacteremia

Brucella Seropositivity at a Tertiary Care Hospital in Chandigarh

There are reports that the neglected zoonotic tropical disease brucellosis is reemerging today. Serological tests are being widely used in the diagnosis of brucellosis. In the present study, we performed a standard agglutination test (SAT) on 1348 suspected cases of brucellosis during the period of four years from April 2018 to March 2022. We noticed an increase in seropositivity from 2.6% in the year 2018-19 to 7.4% in the year 2021-22. We also noticed a spike in seropositivity in the years 2019-20 (12.5%). Our study shows the recent trend in seropositivity of the disease in Chandigarh and, hence, can be a meaningful addition to the existing serological diagnostic data related to brucellosis.

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.

Brucella Spondylitis: Current Knowledge and Recent Advances

The most prevalent zoonotic disease is brucellosis, which poses a significant threat for worldwide public health. Particularly in endemic areas, spinal involvement is a major source of morbidity and mortality and can complicate the course of the disease. The diagnosis of Brucella spondylitis is challenging and should be suspected in the appropriate epidemiological and clinical context, in correlation with microbiological and radiological findings. Treatment depends largely on the affected parts of the body. Available treatment options include antibiotic administration for an adequate period of time and, when appropriate, surgical intervention. In this article, we examined the most recent data on the pathophysiology, clinical manifestation, diagnosis, and management of spinal brucellosis in adults.

DNA Sensor for the Detection of Brucella spp. Based on Magnetic Nanoparticle Markers

Due to the limitations of conventional Brucella detection methods, including safety concerns, long incubation times, and limited specificity, the development of a rapid, selective, and accurate technique for the early detection of Brucella in livestock animals is crucial to prevent the spread of the associated disease. In the present study, we introduce a magnetic nanoparticle marker-based biosensor using frequency mixing magnetic detection for point-of-care testing and quantification of Brucella DNA. Superparamagnetic nanoparticles were used as magnetically measured markers to selectively detect the target DNA hybridized with its complementary capture probes immobilized on a porous polyethylene filter. Experimental conditions like density and length of the probes, hybridization time and temperature, and magnetic binding specificity, sensitivity, and detection limit were investigated and optimized. Our sensor demonstrated a relatively fast detection time of approximately 10 min, with a detection limit of 55 copies (0.09 fM) when tested using DNA amplified from Brucella genetic material. In addition, the detection specificity was examined using gDNA from Brucella and other zoonotic bacteria that may coexist in the same niche, confirming the method's selectivity for Brucella DNA. Our proposed biosensor has the potential to be used for the early detection of Brucella bacteria in the field and can contribute to disease control measures.

Laboratory diagnostics for primary spinal infections in pediatric and adult populations: a narrative review

Primary spinal infection (PSI) is a generic term covering a heterogeneous group of infections that can affect the vertebral body, intervertebral disks, the content of the medullary cavity, and adjacent paraspinal tissues. Patients' characteristics can vary significantly, notably according to their age, and some of these characteristics undoubtedly play a primordial role in the occurrence of a PSI and in the type of offending pathogen. Before approaching the subject of laboratory diagnostics, it is essential to define the characteristics of the patient and their infection, which can then guide the physician toward specific diagnostic approaches. This review critically examined the roles and usefulness of traditional and modern laboratory diagnostics in supporting clinicians' decision-making in cases of pediatric and adult primary spinal infection (PSI). It appears impossible to compare PSIs in children and adults, whether from an epidemiological, clinical, bacteriological, or biological perspective. The recipients are really too different, and the responsible germs are closely correlated to their age. Secondly, the interpretation of traditional laboratory blood tests appears to contribute little guidance for clinicians attempting to diagnose a PSI. Biopsy or needle aspiration for bacterial identification remains a controversial subject, as the success rates of these procedures for identifying causative organisms are relatively uncertain in pediatric populations.Using nucleic acid amplification assays (NAAAs) on biopsy samples has been demonstrated to be more sensitive than conventional cultures for diagnosing PSI. Recent advances in next-generation sequencing (NGS) are particularly interesting for establishing a microbiological diagnosis of a PSI when standard cultures and NAAAs have failed to detect the culprit. We can even imagine that plasma metagenomic NGS using plasma (known as "liquid biopsy") is a diagnostic approach that can detect not only pathogens circulating in the bloodstream but also those causing focal infections, and thus eliminate the need for source sample collection using costly invasive surgical procedures.

High Seropositivity of Brucella melitensis Antibodies among Pregnant Women Attending Health Care Facilities in Mwanza, Tanzania: A Cross-Sectional Study

Background

Brucellosis is one of the most prevalent zoonotic neglected tropical diseases across the globe. Brucella melitensis (B. melitensis), the most pathogenic species is responsible for several pregnancy adverse outcomes in both humans and animals. Here, we present the data on the magnitude of B. melitensis antibodies among pregnant women in Mwanza, Tanzania, the information that might be useful in understanding the epidemiology of the disease and devising appropriate control interventions in this region. Methodology. A hospital-based cross-sectional study involving pregnant women was conducted at two antenatal clinics in Mwanza between May and July 2019. The pretested structured questionnaire was used for data collection. Blood samples were collected aseptically from all consenting women followed by the detection of B. melitensis antibodies using slide agglutination test. Descriptive data analysis was done using STATA version 17.

Results

A total of 635 pregnant women were enrolled with the median age of 25 (interquartile range (IQR): 16-48) years and median gestation age of 21 (IQR: 3-39) weeks. Seropositivity of B. melitensis antibodies was 103 (16.2 (95% CI:13.3-19.1)). On the multivariate logistic regression analysis, as the gestation age increases, the odds of being seropositive decreases (aOR:0.972 (95% CI: 0.945-0.999), P = 0.045). Furthermore, being a housewife (aOR:3.902 (95% CI:1.589-9.577), P = 0.003), being employed (aOR:3.405 (95% CI:1.412-8.208), P = 0.006), and having history of miscarriage (aOR:1.940 (95% CI:1.043-3.606), P = 0.036) independently predicted B. melitensis seropositivity among pregnant women in Mwanza.

Conclusion

High seropositivity of B. melitensis was observed among employed and housewife pregnant women in Mwanza. This calls for the need of more studies in endemic areas that might lead to evidence-based control interventions.

A rapid direct-differential agglutination assay for Brucella detection using antibodies conjugated with functionalized gold nanoparticles

Brucellosis is the most widespread and serious zoonotic disease worldwide which affects livestock, sylvatic wildlife, marine dwellers, and humans. It is acquired through Alphaproteobacteria which belong to the genus Brucella and is categorized as a potential bio-threat agent. In this study, we developed a rapid and direct differential whole cell (WC) agglutination-based assay for its on-field detection. The recombinant outer membrane (rOmp28) protein-derived specific mice IgG polyclonal antibodies (pAbs) of Brucella were purified using affinity chromatography and conjugated with functionalized gold nanoparticles (AuNPs) for rapid agglutination. A positive blot of 32 kDa protein revealed specific immuno-reactivity of rOmp28-pAbs using immunoblot analysis. For the synthesis of AuNPs, the conventional “Turkevich method” was optimized at a concentration < 1 mM of gold precursor for obtaining 50-nm-sized particles. Also, their physico-chemical characteristics were analyzed using UV-visible spectrophotometry, Fourier transform infra-red spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential (ζ, ZP), and fluorescence spectroscopy. Furthermore, these AuNPs were functionalized with N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) to prepare modified carboxylated AuNPs. For bioconjugation with Brucella rOmp28 IgG pAbs, antibody-conjugated functionalized AuNP constructs were prepared and characterized using FT-IR analysis with strong N–H deformations. Subsequently, these bioconjugated AuNPs were used to develop a direct-differential slide agglutination assay with a detection limit of 104 CFU mL−1. The sensitivity of this assay was compared with standard double-antibody sandwich ELISA (S-ELISA) using rOmp28 IgG pAbs with an LOD of 103 CFU mL−1 and a detection range of 102–108 CFU mL−1. No intraspecies cross-reactivity was observed based on evaluation of its specificity with a battery of closely related bacterial species. In conclusion, the increased sensitivity and specificity of the developed agglutination assay obtained using bioconjugated functionalized AuNPs is ≥ 98% for the detection of Brucella. Therefore, it can be used as an alternate rapid method of direct WC detection of bacteria as it is simple, robust, and cost-effective, with minimal time of reaction in the case of early disease diagnosis.

Brucellosis of the spine - A global public health problem - An analysis of 37 patients from a 'high risk' region

Background

Brucellosis is a global public health issue. Brucellosis of the spine presents as a wide spectrum. The aim was to present the outcome analysis of patients treated for Spinal Brucellosis in the endemic region. Secondly to assess the accuracy of IgG and IgM Elisa in the diagnosis.

Results

A retrospective study of all patients who were treated for Brucellosis of the spine from 2010 to 2020 was conducted. Confirmed cases of Brucellosis of spine and who had adequate follow up after completion of treatment were included. The outcome analysis was based on clinical, laboratory and radiological parameters. There were 37 patients enrolled with a mean age of 45 and an average follow up of 24 months. All of them presented with pain and 30% had neurological deficits. Surgical intervention was done in 24%(9/37patients). All the patients were treated with triple drug regimen for an average duration of 6 months. Those patients with relapse had a 14month period of triple drug regimen. The sensitivity and specificity of IgM was 50% and 85.71%. The sensitivity and specificity of IgG was 81.82% and 7.69%.76% of them had good functional outcome and 82% of them had near normal neurological recovery and 97.3%(36 patients) were healed of the disease with relapse in one patient(2.7%).

Conclusions

Majority (76%) of the patients with Brucellosis of the spine were treated conservatively. Average duration of treatment of triple drug regimen was 6 months. The sensitivity of IgM & IgG was 50% and 81.82% The specificity of IgM and IgG was 85.71% and 7.69% respectively.

Evaluating the efficacy of serological testing of clinical specimens collected from patients with suspected brucellosis

BACKGROUND

This study aims to evaluate the efficacy of the standard agglutination test (SAT), the Brucellacapt test and enzyme-linked immunosorbent assay (ELISA) in clinical specimens collected from patients with suspected brucellosis.

METHODS

A prospective study was conducted from December 2020 to December 2021. Brucellosis was diagnosed on the basis of clinical evidence, and confirmed by isolation of Brucella or a four-fold rise in SAT titer. All samples were tested by the SAT, ELISA and the Brucellacapt test. Titers ≥1:100 were considered as SAT positive; ELISA was considered positive when an index greater than 11 was detected, while titers ≥1/160 indicated positivity on the Brucellacapt test. The specificity, sensitivity, and positive (PPVs) and negative predictive values (NPVs) of the three different methods were calculated.

RESULTS

A total of 149 samples were collected from patients with suspected brucellosis. The sensitivities for the SAT, IgG, and IgM detection were 74.42%, 88.37% and 74.42%, respectively. The specificities were 95.24%, 93.65%, and 88.89%, respectively. The simultaneous measurement of IgG and IgM improved the sensitivity (98.84%) but reduced the specificity (84.13%) compared to each antibody test separately. The Brucellacapt test had excellent specificity (100%) and a high PPV (100%); however, the sensitivity and NPV were 88.37% and 86.30%, respectively. The combination of IgG detection by ELISA and the Brucellacapt test had excellent diagnostic performance, with 98.84% sensitivity and 93.65% specificity.

CONCLUSION

This study showed that the simultaneous performance of IgG detection by ELISA and the Brucellacapt test has the potential to overcome the current limitations of detection.

Brucellosis with rare complications and review of diagnostic tests: a case report

BACKGROUND

Brucellosis is one of the most common zoonotic diseases in the world. Osteoarticular complications, especially vertebral system involvement, are most commonly reported. However, reports and coreports of pulmonary complications and thoracal spondylodiscitis and epidural abscess are rare.

CASE PRESENTATION

Spondylodiscitis was detected at the T11-12 vertebral level, followed by epidural and paravertebral abscess, and then empyema was detected in a 17-year-old Asian female patient without any additional disease. The patient had used various antibiotics and the disease could not be proven bacteriologically. Also, the Rose Bengal test was negative. However, serologically high titer Brucella positivity was detected in the blood and pleural fluid sample. Drainage was required for bilateral empyema. Disease duration prolonged due to multiple complications. The patient was cured with combined long-term treatment for brucellosis.

CONCLUSIONS

Although some are rare, brucellosis is a zoonotic disease that can cause many complications. The gold standard for diagnosis is the growth of bacteria in blood culture or tissue culture. However, isolation of the microorganism can be very difficult. Clinical suspicion and serological tests are important guides.

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.

Gold Nanoparticles Prepared with Cyclodextrin Applied to Rapid Vertical Flow Technology for the Detection of Brucellosis

Currently, brucellosis seriously threatens the health of humans and animals and hinders the development of animal husbandry. However, the diagnostic methods for brucellosis have some disadvantages, such as low sensitivity, long detection time, professional operation, and high cost. This study aims to establish a convenient, fast, effective, and inexpensive detection method for brucellosis. Gold nanoparticles with β-cyclodextrin as a reducing agent were prepared and optimized, applied to rapid vertical flow technology (RVFT), and used to establish a kit for the detection of brucellosis. In this study, gold nanoparticles prepared from β-cyclodextrin were applied to RVFT for the first time, and on this basis, silver staining amplification technology was introduced, which further improved the sensitivity and reduced the detection limit of this method. Standard Brucella-Positive Serum (containing Brucella antibody at 4000 IU/mL) could be detected in this system even for a dilution factor of 1 × 10⁻³. The detection limit was 4 IU/mL. RVFT is simple to operate, has a short reaction time, and is 5–6 min visible to the naked eye, without any equipment.

Early diagnosis and treatment of acute brucellosis knee arthritis complicated by acute osteomyelitis: two cases report

Background

Brucellosis is an endemic systemic infectious disease, the most common complication is bone and joint involvement. Sacroiliac joint and spinal joint are the most frequently involved sites in adults, but knee joint infection is rare, and acute infectious knee arthritis complicated by acute osteomyelitis is even extremely uncommon in adults. Here, we report two cases of acute septic knee arthritis complicated by acute osteomyelitis caused by Brucella melitensis (B. melitensis).

Case presentation

Both patients had a history of traveling in animal husbandry areas within three months. On clinical examination, their right knee joint was tender, swollen, had limited movement and an effusion was present. Imaging examination showed effusion and synovial thickening of the right knee joint, as well as subchondral bone edema of the distal femur and proximal tibia. Laboratory examination showed that the serum agglutination test (SAT) in both patients were positive (1: 640 and 1: 320) without leukocytosis, although the proportion of lymphocytes, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) significantly increased. Both patients underwent knee joint aspiration. Real-time polymerase chain reaction (Real-time PCR) analysis of synovial fluid showed that there was B. melitensis, and blood bacterial culture was negative. We determined that two patients had acute brucellosis knee arthritis complicated by acute osteomyelitis. Antibiotic treatment was given during hospitalization consisting of doxycycline (0.1 g po bid) and rifampicin (0.6 g po qd) for six weeks, and the changes of inflammatory indexes were closely monitored. At discharge, the symptoms had completely resolved, imaging abnormalities disappeared, and inflammatory indexes returned to normal. There was no recurrence of the disease at 1-year follow-up.

Conclusion

Acute brucellosis knee arthritis complicated by acute osteomyelitis is a rare but serious complication of brucellosis in adults. There is no obvious specificity of clinical manifestation and imaging examination. Early diagnosis and treatment can prevent the occurrence of knee joint deformity and even pathological fracture. Clinicians should fully consider the possibility of brucellosis where the travel or occupational history is suggestive.

Gold Nanobiosensor Based on the Localized Surface Plasmon Resonance is Able to Diagnose Human Brucellosis, Introducing a Rapid and Affordable Method

Brucellosis is considered as the most common bacterial zoonosis in the world. Although the laboratory findings are the most reliable diagnosis today, the current laboratory methods have many limitations. This research aimed to design and evaluate the performance of a novel technique based on the localized surface plasmon resonance (LSPR) to eliminate or reduce existing shortcomings. For this purpose, smooth lipopolysaccharides were extracted from Brucella melitensis and Brucella abortus and fixed on the surface of the gold nanoparticles through covalent interactions. After some optimizing processes, dynamic light scattering was used to characterize the probe. The detection of captured anti-Brucella antibody was performed by measuring the redshift on LSPR peak followed by the determination of cutoff value, which indicated a significant difference between controls and true positive patients (P value < 0.01). Furthermore, 40 sera from true negative samples and positive patients were used to evaluate the performance of this method by comparing its outcomes with the gold standard (culture), standard tube agglutination test, and anti-brucellosis IgM and IgG levels (ELISA). The sensitivity, specificity, positive predictive value, and negative predictive value showed an appropriate performance of the LSPR-based method (85%, 100%, 100%, and 86%, respectively). The current research results provide a promising fast, convenient, and inexpensive method for detecting the anti-Brucella antibodies in human sera, which can be widely used in medical laboratories to diagnose brucellosis quickly and effectively.

Fluorescence polarization assay improves the rapid detection of human brucellosis in China

Background

Brucellosis is an infectious-allergic zoonotic disease caused by bacteria of the genus Brucella. Early diagnosis is the key to preventing, treating, and controlling brucellosis. Fluorescence polarization immunoassay (FPA) is a new immunoassay for relatively rapid and accurate detection of antibodies or antigens based on antigen–antibody interaction. However, there is no report on FPA-based detection of human brucellosis in China. Therefore, this study is to evaluate the value of FPA for the diagnosis of human brucellosis in China.

Methods

We recruited 320 suspected brucellosis cases who had the clinical symptoms and epidemiological risk factors between January and December, 2019. According to China Guideline for Human Brucellosis Diagnosis, the Rose Bengal test (RBT) was used for the screening test, and the serum agglutination test (SAT) was used as the confirmatory test. Brucellosis was confirmed only if the results of both tests were positive. Additionally, FPA and enzyme linked immune sorbent assay (ELISA) were compared with SAT, and their sensitivity, specificity, coincidence rate and consistency coefficient (Kappa value) as diagnostic tests were analyzed individually and in combination. The optimal cut-off value of FPA was also determined using the receiver operator characteristic (ROC) curve.

Results

The optimum cut-off value of FPA was determined to be 88.5 millipolarization (mP) units, with a sensitivity of 94.5% and specificity of 100.0%. Additionally, the coincidence rate with the SAT test was 96.6%, and the Kappa value (0.9) showed excellent consistency. The sensitivity and specificity of FPA and ELISA combined were higher at 98.0% and 100.0% respectively.

Conclusions

When the cut-off value of FPA test is set at 88.5 mP, it has high value for the diagnosis of brucellosis. Additionally, when FPA and ELISA are combined, the sensitivity of diagnosis is significantly improved. Thus, FPA may have potential in the future as a diagnostic method for human brucellosis in China.

Graphic abstract

Lack of correlation of Brucella antibody titers with clinical outcomes and culture positivity of brucellosis

Background

Brucellosis is a zoonotic disease caused by Brucella spp., namely B. melitensis and B. abortus in humans. Culturing is the gold standard method for diagnosis; however, because Brucella is a slow-growing bacterium, which may delay diagnosis, other faster methods, such as serology, are used. Studies on the correlation between Brucella antibody titers and clinical outcomes are limited. Therefore, this study assessed such correlation and evaluated the correlation between baseline serological results with culture positivity and clinical picture.

Methods

Patients tested positive for Brucella antibodies at baseline and diagnosed with brucellosis between January 2008 and December 2018 were included. Collected data included clinical outcomes, baseline culture positivity (growth in culture), arthralgia, baseline and end of therapy (EOT) temperature, white blood cell count, C-reactive protein level, and erythrocyte sedimentation rate.

Results

Of 695 patients tested for Brucella antibodies, only 94 had positive baseline serology and diagnosed with acute brucellosis, among whom 63 had EOT serology. No significant correlations were found between EOT antibody titers of both Brucella spp. and clinical cure, mortality, length of stay, and duration of therapy. Additionally, no correlations were found between baseline serology and culture positivity, arthralgia, temperature, and other lab values.

Conclusion

Brucella serology does not correlate with clinical outcomes at EOT nor with culture positivity at baseline. Therefore, healthcare providers are advised to consider the whole clinical picture of a brucellosis patient without relying solely on serological results during follow up and not replace culturing with serology testing alone at the time of diagnosis.

Neurobrucellosis associated with feral swine hunting in the southern United States

Although uncommon, Brucella infection can occur outside the areas of high endemicity, such as the USA. In the southern USA, hunters of wild swine are at risk for brucellosis. We present a case of a patient with fever, headache and constitutional symptoms that were ongoing for 11 months. He was diagnosed with neurobrucellosis. The patient was treated successfully with intravenous ceftriaxone, oral doxycycline and oral rifampin therapy. He had persistent neurological sequelae after completing treatment. This case illustrates the high index of suspicion needed to diagnose neurobrucellosis in a non-endemic country because initial symptoms can be subtle. The disease can be treated successfully, but long-lasting neurological sequelae are common.

Sentinel surveillance of selected veterinary and public health pathogens in camel population originating from Southern Punjab province, Pakistan

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Camels are susceptible to a wide range of infectious diseases with varying rate of morbidity and mortality.

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Blutongue, peste des petits ruminants and brucellosis are prevalent among camels in southern part of the Punjab provinvce, Pakistan.

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Genome corresponding to Brucella abortus and multiple serotypes of bluetongue were detected among camels.

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Camels should be included for disease control interventions reltaed to brucellosis, blutongue and PPR from their endemic setting worldwide.

An extended range of host susceptibility including camel has been evidenced for some of the important veterinary and public health pathogens, such as brucellosis, peste des petits ruminants (PPR) and bluetongue (BT). However, in disease endemic settings across many parts of the globe, most of the disease control interventions accounts for small and large ruminants, whereas unusual hosts and/or natural reservoirs, such as camels, remain neglected for disease control measures including routine vaccination. Such a policy drawback not only plays an important role in disease epizootiology particularly in settings where disease is endemic, but also serves an obstacle in disease control and subsequent eradication in future. With this background, using pre-validated ELISA and molecular assays [multiplex PCR, reverse transcriptase (RT)-PCR and real-time (rt)-PCR], we conducted a large-scale pathogen- and antibody-based surveillance for brucellosis, peste des petits ruminants and bluetongue in camel population (n = 992) originating from a wide geographical region in southern part of the Punjab province, Pakistan. Varying in each of the selected districts, the seroprevalence was found to be maximum for bluetongue [n = 697 (70.26%, 95% CI: 67.29–73.07)], followed by PPR [n = 193 (19.46%, 95% CI: 17.07–22.09)] and brucellosis [n = 66 (6.65%, 95% CI: 5.22–8.43)]. Odds of seroprevalence were more significantly associated with pregnancy status (non-pregnant, OR = 2.23, 95% CI: 1.86–5.63, p<0.01), farming system (mixed-animal, OR = 2.59, 95% CI: 1.56–4.29, p<0.01), breed (Desi, OR = 1.97, 95% CI: 1.28–4.03, p<0.01) and farmer education (illiterate, OR = 3.17, 95% CI: 1.45–6.93, p<0.01) for BTV, body condition (normal, OR = 3.54, 95% CI: 1.92–6.54, p<0.01) and breed (Desi, OR = 2.19, 95% CI: 1.09–4.40, p<0.01) for brucellosis, and feeding system for PPR (grazing, OR = 2.75, 95% CI: 1.79–4.22, p<0.01). Among the total herds included (n = 74), genome corresponding to BT virus (BTV) and brucellosis was detected in 14 (18.92%, 95 CI: 11.09–30.04) and 19 herds (25.68%, 95% CI: 16.54–37.38), respectively. None of the herds was detected with genome of PPR virus (PPRV). Among the positive herds, serotype 1, 8 and 11 were detected for BTV while all the herds were exclusively positive to B. abortus. Taken together, the study highlights the role of potential disease reservoirs in the persistence and transmission of selected diseases in their susceptible hosts and, therefore, urges necessary interventions (e.g., inclusion of camels for vaccine etc.) for the control of diseases from their endemic setting worldwide.

Demyelinating steroid-responsive neurobrucellosis

Young man with acute onset nausea, vomiting, joint pain, abdominal pain, fever and weight loss was found to have gait ataxia and positive B rucella titres. He deteriorated despite appropriate antibiotics and developed confusion and disorientation. Lumbar puncture revealed lymphocytosis with high protein and low glucose. MRI showed diffuse demyelination. Pulse steroids resulted in rapid clinical, biochemical and radiological recovery.

Bayesian Evaluation of Three Serological Tests for Detecting Antibodies against Brucella spp. among Humans in the Northwestern Part of Ecuador

Brucellosis is an important but neglected zoonosis that causes serious economic losses both in livestock and human populations. The aim of the present study was to estimate the true prevalence of brucellosis together with diagnostic sensitivity and specificity of three serological tests in humans of the northwestern part of Ecuador using a Bayesian approach adjusted for the dependencies among the multiple tests to avoid any misinterpretation. In addition, the causal agent responsible for human brucellosis was also identified. Using a total of 3,733 samples collected from humans in this area between 2006 and 2008, the prevalence of human brucellosis and the diagnostic test characteristics of the Rose Bengal fast agglutination test (RBT), Wright's slow agglutination test with ethylenediaminetetraacetic acid disodium salt dehydrate (EDTA) (SAT-EDTA), and indirect ELISA (iELISA) were estimated using a Bayesian approach. The estimated true prevalence of human brucellosis was 1% (credibility interval: 0.4-1.6). The sensitivities of iELISA and RBT were higher than and similar (95.1% and 95.0%, respectively) to those of SAT-EDTA (60.8%). Even though all tests indicated a high specificity (> 99.0%), the specificity of SAT-EDTA was highest (99.9%). The circulating strain in this study area was identified to be Brucella abortus biotype 4 based on culture and microbiological characterization. The RBT and the iELISA are recommended for estimating the true prevalence of human brucellosis and/or for surveillance programs following their high sensitivities and specificities. The proposed strategy supports evidence-based medicine for clinicians and policy-makers to ensure appropriate preventive and control program of brucellosis worldwide.

Current therapeutic strategy in osteoarticular brucellosis

Brucellosis is a common zoonotic disease with high morbidity. In the majority of human cases, the causative agent is B. melitensis. Infection is transmitted to humans by direct/indirect contact with the contaminated animal products (e.g., consumption of unpasteurized milk), infectious aerosols and aborted fetus. Brucellosis often affects middle-aged adults and young people. Patients with brucellosis tend to have non-specific symptoms, including fever, chills, night sweats, joint pain and myalgia. Brucellosis affects various organs and tissues. The osteoarticular system is one of the most commonly described affected systems in humans. In several clinical studies, the prevalence of Osteoarticular Brucellosis (OB) is reported as 2-77%. Most important osteoarticular clinical forms osteomyelitis, spondylitis, sacroiliitis, arthritis and bursitis. Spondylitis and spondylodiscitis are the most frequent complications. Spondylodiscitis often affects the lumbar (especially at the L4- L5 levels) and low thoracic vertebrae than the cervical spine. Back pain and sciatica radiculopathy are the most common complaints about patients. Sacroiliitis is associated with severe pain, especially back pain in affected individuals. Spinal destructive brucellar lesions are also reported in adults in previous studies. Brucellosis is diagnosed with clinical inflammatory signs (eg. tenderness, pain) of the affected joints together with positive serological tests and positive blood/synovial fluids cultures. Serological test measures the total amount of IgM/IgG antibodies. Standard agglutination test (SAT) titer ≥1:160 is in favor of brucellosis diagnosis. Enzyme-Linked Immunosorbent Assay (ELISA) and Polymerase chain reaction (PCR) are other types of diagnostic tests. Radiological assessments, such as joint sonography, computed tomography, magnetic resonance imaging, are the most helpful radiological methods to diagnose spinal brucellosis.

The agents commonly used in the treatment of brucella spondylitis are doxycycline, streptomycin, gentamicin, ciprofloxacin, trimethoprim/sulfamethoxazole and rifampicin. The recommended regimens for treatment of brucella involve two or three antibiotics combinations. No standard treatment, physicians prescribe drugs based on conditions of the disease. Patients need a long-term (usually at three months) antibiotic therapy for mainly aiming to prevent relapses. Surgery may be required for patients with spinal abscess. This review focused on physicians’ awareness for osteoarticular involvement, clinical presentation, diagnosis and current treatment of OB.

Diagnostic Testing in Central Nervous System Infection

Patients with central nervous system (CNS) infection experience very high levels of morbidity and mortality, in part because of the many challenges inherent to the diagnosis of CNS infection and identification of a causative pathogen. The clinical presentation of CNS infection is nonspecific, so clinicians must often order and interpret many diagnostic tests in parallel. This can be a daunting task given the large number of potential pathogens and the availability of different testing modalities. Here, we review traditional diagnostic techniques including Gram stain and culture, serology, and polymerase chain reaction (PCR). We highlight which of these are recommended for the pathogens most commonly tested among U.S. patients with suspected CNS infection. Finally, we describe the newer broad-range diagnostic approaches, multiplex PCR and metagenomic sequencing, which are increasingly used in clinical practice.

Clinical and serological approach to patients with brucellosis: A common diagnostic dilemma and a worldwide perspective

According to the WHO factsheet, although approximately half a million brucellosis cases are reported annually, the true incidence is always 10-25 times higher than the reported number of cases. Therefore, we face a common yet uncommonly recognized entity of brucellosis, which highlights the importance of providing precise and understandable guidelines for physician to recognize and manage the disease. Up to now, there is no distinct and clear guideline for brucellosis diagnosis. Hence, this article presents for the first time an algorithm based on our 30 years clinical experiences for brucellosis diagnosis. There are several serological patterns of brucellosis due to the insidious nature and serologic response of this disease. In contrast to most infectious diseases, the IgM response to brucellosis remains after the acute phase, IgG responses often fade after improvement and there is no lifelong positivity for IgG antibody. This diversity of serological pattern leads to seven clinical subtypes of the disease; three of those do not need any medical intervention. In endemic regions, this issue makes a challenging diagnostic puzzle for clinicians, which may consequently lead to national and international over- or underestimation of brucellosis incidence. On one hand, this may change the epidemiological landscape of brucellosis. On the other hand, drugs used in therapy are often accompanied by serious or sometimes irreversible side effects. Accordingly, we attempt to create a unique template to better identify these seven serological patterns and give a comprehensive insight into the diagnostic approach to brucellosis. Moreover, we describe in detail the appropriate use of wright, 2 ME, Coomb's WRIGHT, and ELISA tests.

Predominance of Brucella abortus antibodies among women with spontaneous abortion in the city of Mwanza: unrecognized link or coincidence?

OBJECTIVE

This study investigated the association of Brucella seropositivity and spontaneous abortions in human population in the city of Mwanza, Tanzania.

RESULTS

A comparative cross sectional study which used 148 sera from women with spontaneous abortion and 250 sera from full-term delivered women was conducted in July 2017. Detection of Brucella abortus and Brucella melitensis antibodies was done using slide agglutination test. Data were analyzed using STATA version 13 software. The median age of the study participants was 25 (interquartile range 21-30) years. The overall seropositivity of Brucella antibodies was significantly higher among sera from women with spontaneous abortion than full term delivered women; (86/148, 58.1%: 95% CI 50-66 vs. 65/250, 26%: 95% CI 18-33, P < 0.001). Seropositivity of B. abortus was significantly higher among sera from women with spontaneous abortion than full-term delivered women (31.8% vs. 10.8%, P < 0.001). Women with abortion had 3.59 odds of being brucella seropositive compared to full term women (OR: 3.59, 95% CI; 2.25-5.74, P < 0.001). Seropositivity of Brucella antibodies is significantly higher among women with spontaneous abortion than full-term delivered women necessitating a need to investigate the relationship between Brucellosis and adverse pregnancy outcomes.

Comparisons of brucellosis between human and veterinary medicine

Brucellosis is the world's most widespread zoonosis, but also ranks as one of the seven most neglected diseases, according to the World Health Organization. Additionally, it is recognized as the world's most common laboratory-acquired infection. There are a reported 500,000 incident cases of human brucellosis per year. However, true incidence is estimated to be 5,000,000 to 12,500,000 cases annually. Once diagnosed, focus is directed at treating individual patients with antibiotic regimes, yet overall neglecting the animal reservoir of disease. Countries with the highest incidence of human brucellosis are Syria (1,603.4 cases per 1,000,000 individuals), Mongolia (391.0), and Tajikistan (211.9). Surveillance on animal populations is lacking in many developed and developing countries. According to the World Animal Health Information Database, Mexico had the largest number of reported outbreaks, 5,514 in 2014. Mexico is followed by China (2,138), Greece (1,268), and Brazil (1,142). The majority of these outbreaks is Brucella abortus, the etiologic agent of bovine brucellosis. Brucellosis is an ancient disease that still plagues the world. There are still knowledge gaps and a need for better diagnostics and vaccines to make inroads towards control and eradication.

Seropositivity of Brucella spp. and Leptospira spp. antibodies among abattoir workers and meat vendors in the city of Mwanza, Tanzania: A call for one health approach control strategies

INTRODUCTION

Brucellosis and leptospirosis are among neglected tropical zoonotic diseases particularly in the resource limited countries. Despite being endemic in these countries, there is paucity of information on its magnitude. This study investigated seropositivity of Brucella spp. and Leptospira spp., and associated factors among abattoir workers and meat vendors in the city of Mwanza, Tanzania.

METHODOLOGY

A community based cross-sectional study was conducted in Mwanza city from May to July 2017. Socio-demographic and other relevant information were collected. Detection of Brucella spp. and Leptospira spp. antibodies were done using slide agglutination test and microscopic agglutination test, respectively. Data were analyzed using STATA version 13 Software.

FINDINGS

A total of 250 participants (146 abattoir workers and 104 meat vendors) were enrolled with median age of 31 (IQR: 25-38) years. The overall, seropositivity of Brucella spp. antibodies was 48.4% (95% Cl: 42-54). Seropositivity of B. abortus was significantly higher than that of B. melitensis (46.0%, 95%Cl: 39-52 vs. 23.6%, 95% Cl: 18-28, P<0.001) while seropositivity of both species was 21.2% (95%Cl: 16-26). The seropositivity of Leptospira spp. was 10.0% (95% CI: 6-13) with predominance of Leptospira kirschneri serovar Sokoine which was detected in 7.2% of the participants. Being abattoir worker (OR: 2.19, 95% CI 1.06-4.54, p = 0.035) and long work duration (OR: 1.06, 95%CI: 1.01-1.11, p = 0.014) predicted presence of both B.abortus and B. melitensis antibodies. Only being married (p = 0.041) was significantly associated with seropositivity of Leptospira spp. Primary education was the only factor independently predicted presence of Brucella spp. antibodies among abattoir workers on sub-analysis of occupational exposure. None of factors were found to be associated with presence of Brucella spp. antibodies among meat vendors on sub-analysis.

CONCLUSION

Seropositivity of B.abortus antibodies among abattoir workers and meat vendors is high and seem to be a function of being abattoir worker, having worked for long duration in the abattoir and having primary education. In addition, a significant proportion of abattoir workers and meat vendors in the city was seropositive for Leptospira kirschneri serovar Sokoine. There is a need to consider 'one health approach' in devising appropriate strategies to control these diseases in the developing countries.

A Novel PCR Assay for Detecting Brucella abortus and Brucella melitensis

OBJECTIVES

Brucellosis is a major zoonotic disease that poses a significant public health threat worldwide. The classical bacteriological detection process used to identify Brucella spp. is difficult and time-consuming. This study aimed to develop a novel molecular assay for detecting brucellosis.

METHODS

All complete sequences of chromosome 1 with 2.1-Mbp lengths were compared among all available Brucella sequences. A unique repeat sequence (URS) locus on chromosome 1 could differentiate Brucella abortus from Brucella melitensis. A primer set was designed to flank the unique locus. A total of 136 lymph nodes and blood samples were evaluated and classified by the URS-polymerase chain reaction (PCR) method in 2013-2014.

RESULTS

Biochemical tests and bacteriophage typing as the golden standard indicated that all Brucella spp. isolates were B. melitensis biovar 1 and B. abortus biovar 3. The PCR results were the same as the bacteriological method for detecting Brucella spp. The sensitivity and specificity of the URS-PCR method make it suitable for detecting B. abortus and B. melitensis.

CONCLUSION

Quick detection of B. abortus and B. melitensis can provide the most effective strategies for control of these bacteria. The advantage of this method over other presented methods is that both B. abortus and B. melitensis are detectable in a single test tube. Furthermore, this method covered 100% of all B. melitensis and B. abortus biotypes. The development of this URS-PCR method is the first step toward the development of a novel kit for the molecular identification of B. abortus and B. melitensis.

Predictors of specific anti-Brucella antibodies among humans in agro-pastoral communities in Sengerema district, Mwanza, Tanzania: the need for public awareness

Background

Human brucellosis remains to be a neglected zoonotic disease among agro-pastoral communities where livestock rearing is one of the main economic activities. This study was conducted in different agro-pastoral communities in Sengerema district, Mwanza, Tanzania, to determine seroprevalence and predictors of anti-Brucella antibodies, information that may influence public awareness on the risk factors and strategies to improve the diagnosis of brucellosis in developing countries.

Methods

A cross-sectional community-based study was conducted between July and September 2008 in ten villages of Sengerema district. Sociodemographic and other related information were collected using a standardized data collection tool. Detection of Brucella abortus and Brucella melitensis antibodies were done using rapid Brucella serum agglutination test. Data were analysed by using STATA version 11.0. Adjusted odds ratios (AOR) were calculated using multivariate logistic regression analysis.

Results

A total of 382 adults were enrolled with the median age of 30 (interquartile range 15–40) years. Males formed the majority of the participants 234 (61.5 %). Overall, seroprevalence of anti-Brucella antibodies was found to be 14.1 % (54/382, 95 % CI 10.6–17.5). Seroprevalence of B. melitensis was 11 % (42/382) while that of B. abortus was found to be 7 % (26/282), P = 0.0267. Co-infection of B. melitensis and B. abortus was observed in 3.6 % (14/382, 95 % CI 1.7–5.4) of participants. On a multivariate logistic regression analysis, male sex (AOR 3.2, 95 % CI 1.3–7.5, P = 0.007), touching goat placenta (AOR 2.54, 95 % CI 1.05–6.14, P = 0.012) and agro-pastoralist occupation (AOR 2.07, 95 % CI 1.01–4.24, P = 0.04) were found to predict B. melitensis infection. Males (AOR 3.07, 95 % CI 1.45–6.51, P = 0.003) and agro-pastoralists (AOR 2.98, 95 % CI 1.38–6.43, P = 0.005) were found to be predictors for specific anti-Brucella antibodies.

Conclusions

A significant proportion of the agro-pastoralist male population in agro-pastoral communities in Sengerema district is positive for anti-Brucella antibodies. With the decrease incidence of malaria fever, other causes of fever such as Brucella spp. should be considered of public health concern in Tanzania especially in agro-pastoral communities.

Latent class evaluation of three serological tests for the diagnosis of human brucellosis in Bangladesh

Background

A Bayesian latent class evaluation was used to estimate the true prevalence of brucellosis in livestock farmers and patients with prolonged pyrexia (PP) and to validate three conditionally dependent serological tests: indirect ELISA (iELISA), Rose Bengal Test (RBT), and standard tube agglutination (STAT). A total of 335 sera from livestock farmers and 300 sera from PP patients were investigated.

Results

The true prevalence of brucellosis in livestock farmers and PP patients was estimated to be 1.1 % (95 % credibility interval (CrI) 0.1–2.8) and 1.7 % (95 % CrI 0.2–4.1), respectively. Specificities of all tests investigated were higher than 97.8 % (95 % CrI 96.1–99.9). The sensitivities varied from 68.1 % (95 % CrI 54.5–80.7) to 80.6 % (95 % CrI 63.6–93.8). The negative predictive value of all the three tests in both populations was very high and more than 99.5 % (95 % CrI 98.6–99.9). The positive predictive value (PPV) of all three tests varied from 27.9 % (95 % CrI 3.6–62.0) to 36.3 % (95 % CrI 5.6–70.5) in livestock farmers and 39.8 % (95 % CrI 6.0–75.2) to 42.7 % (95 % CrI 6.4–83.2) in patients with PP. The highest PPV were 36.3 % for iELISA and 42.7 % for RBT in livestock farmers and pyrexic patients, respectively.

Conclusions

In such a low prevalence scenario, serology alone does not help in diagnosis and thereby therapeutic decision-making. Applying a second test with high specificity and/or testing patients having history of exposure with known risk factors and/or testing patients having some clinical signs and symptoms of brucellosis may increase the positive predictive value of the serologic tests.

Electronic supplementary material

The online version of this article (doi:10.1186/s41182-016-0031-8) contains supplementary material, which is available to authorized users.

Comparison of a New and Rapid Method: Brucella Coombs Gel Test With Other Diagnostic Tests

BACKGROUND

The aim of this study was to detect reliability of Brucella Coombs gel test (BCGT) by comparing with with ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination methods in serological diagnosis of brucellosis.

METHODS

Brucella Coombs gel test (BCGT), Brucella ELISA (IgG + IgM), Standard agglutination test, and Brucella immunocapture agglutination tests of 78 patients with presumptive diagnosis of brucellosis which were sent to Microbiology Laboratory of Konya Numune Hospital from various regions of Konya were studied.

RESULTS

RESULTS

Of 78 patients with ELISA IgG and IgM, STA, BICA and BCGT; 26, 21, 10, 12 and 12 were positive. When compared with BICA, the sensitivity and specifity of BCGT were 100% and 100%, respectively.

CONCLUSION

According to results BCGT can be used as a diagnostic test in routine laboratories after more comprehensive studies in control groups and patients.

Mean platelet volume in brucellosis: correlation between brucella standard serum agglutination test results, platelet count, and C-reactive protein

BACKGROUND

Brucellosis, a zoonotic infection, was most widely diagnosed by the Brucella standard serum agglutination test (SAT). No previous publication has demonstrated a correlation between the degree of Brucella SAT agglutination positivity and the severity of brucellosis infection.

OBJECTIVE

To contribute to the clarification of the relationship between patelets and brucellosis. It is also aimed at evaluating the usefulness of the SAT titer as a measure of brucellosis severity.

MATERIAL AND METHODS

We compared the control (n=60) and patients (n=96) groups in terms of mean platelet volume (MPV), C-reactive protein (CRP) and platelet values. Patients were grouped according to their degree of agglutination positivity titers and compared by means of CRP, MPV and platelet values. We also investigated the relationship among logarithmic values of MPV, platelet and CRP parameters for each group.

RESULTS

Although statistically meaningful difference was observed between control and patients group in terms of MPV and platelet value, there were no statistically significant differences observed among patients groups. The physiological negative correlation between MPV and platelet count was not encountered in group 2 and 3. Logarithmic values of CRP were not correlated with logarithmic values of MPV and platelet counts.

CONCLUSION

The MPV could be a new parameter to evaluate hematologic abnormalities in patients with brucellosis. The SAT titer was not a useful measure for evaluation of the severity of brucellosis.

Bayesian estimation of the seroprevalence of brucellosis in humans and livestock in Kyrgyzstan

Kyrgyzstan reported 77.5 new cases of human brucellosis per 100,000 inhabitants in 2007, which is one of the highest incidences in the world. However, because this number is based on official records, it is very likely that the incidence is underreported. The diagnostic tests most commonly used in Kyrgyzstan are the Rose Bengal test in ruminants and the Huddleson test in humans. The sensitivity and specificity of these tests have never been evaluated under field conditions in Kyrgyzstan, where the strains circulating in livestock and humans are unknown. Therefore, a representative national cross-sectional serological study was undertaken in humans, cattle, sheep and goats to assess the true seroprevalence and to compare different serologicaltests. In the year of study (2006), few animals were vaccinated against brucellosis in Kyrgyzstan. A total of 5,229 livestock sera and 1,777 human sera from three administrative regions were collected during spring 2006 and submitted to a range of serological tests. The true seroprevalence of brucellosis, estimated using Bayesian methodology, was 7% (95% credibility interval 4%-9%) in humans, 3% (1%-5%) in cattle, 12% (7%-23%) in sheep and 15% (7%-30%) in goats. The Rose Bengal test was confirmed as a useful screening test in livestock and humans, although its sensitivity was lower than that of other tests. The estimates of specificity of all tests were significantly higher than those for sensitivity. The high seroprevalence of brucellosis in humans, cattle and small ruminants in Kyrgyzstan was confirmed. Bayesian statistical approaches were demonstrated to be useful for simultaneously deriving test characteristics and true prevalence estimates in the absence of a gold standard.

Knowledge and perceptions of brucellosis in the pastoral communities adjacent to Lake Mburo National Park, Uganda

Background

Brucellosis is one of the most common zoonotic infections globally. Lack of knowledge about brucellosis may affect the health-seeking behavior of patients, thus leading to sustained transmission in these communities. Our study assessed knowledge and perceptions of brucellosis among pastoral communities adjacent to Lake Mburo National Park (LMNP), Kiruhura District, Uganda.

Methods

A community cross-sectional questionnaire survey involving 371 randomly selected household heads from three sub-counties neighboring LMNP were interviewed between June and August 2012. Data collected included communities’ knowledge on causes, symptoms, transmission, treatment, prevention and risk factors of brucellosis. Multivariable logistic regression analysis was performed to explore strength of association between overall knowledge of brucellosis and various individual factors using odds ratios and 95% confidence intervals.

Results

Only 70 (19%) knew the symptoms of brucellosis in animals, and three quarters (279, 75.5%) mentioned joint and muscle pain as a common symptom in humans. Almost all participants (370, 99.3%) had ever heard about brucellosis, majority (311, 84.7%) believed it affects all sexes and two thirds (67.7%) of the respondents believed close proximity to wildlife contributes to the presence of the disease. Almost all (352, 95.4%) knew that brucellosis in humans could be treatable using modern drugs. The main routes of infection in humans such as consumption of unpasteurized dairy products were known by 97% (360/371); eating of half-cooked meat by 91.4% and eating contaminated pasture in animals by 97.4%. There was moderate overall knowledge of brucellosis 197 (53.1%). Factors associated with higher overall knowledge were being agro-pastoralists (aOR: 2.08, CI: 1.17-3.71) compared to pure pastoralists while those who reported that the disease was a health problem (aOR: 0.18, CI: 0.06-0.56) compared to those who said it was not were less likely to be knowledgeable.

Conclusions

There was moderate overall knowledge of human and animal brucellosis among the participants. Majority of the participants believed that close proximity to wildlife contributes to the presence of the disease in the area. There is a need for collaboration between the public health, veterinary and wildlife sectors to provide health education on brucellosis for better management of the disease in the communities.

Brucellosis in the Middle East: A Persistent Medical, Socioeconomic and Political Issue

Human brucellosis remains endemic in the majority of Middle Eastern countries, accounting for tens of thousands of new annual cases, despite partly successful efforts at disease control. In the Middle East, more pronouncedly than elsewhere, brucellosis exhibits significant socioeconomic and political correlations, including population literacy and distribution, and development of health networks. Currently, Middle Eastern countries, having a vast pool of human cases, generate important information regarding the disease's clinical manifestations, diagnosis, and treatment. Given the socioeconomic framework of brucellosis endemicity, specific approaches allowing for rapid, cost-effective diagnosis, and efficient cost-effective therapy should be pursued. Overall, attempts at controlling disease without altering the socioeconomic and political correlations may prove futile, unfortunately projecting similar fates for attempts related to more important communicable diseases.

Two-stage PCR assay for detection of human brucellosis in endemic areas

Background

Brucellosis is a common zoonosis that can cause a severe febrile illness in humans. It constitutes a persistent health problem in many developing countries around the world. It is one of the most frequently reported diseases in Saudi Arabia and incidence is particularly high in the Central region, and around the city of Riyadh. The aim of this study was to evaluate a two-stage PCR assay for detection of human brucellosis particularly in endemic areas.

Methods

A total of 101 serum samples were collected from patients with acute febrile illness (AFI) of unknown cause from two different locations in the Western region of Saudi Arabia. The first location (Northern) is characterized by a nomadic rural population while the second (Central) is a modern urban city. All samples were subjected to DNA extraction and Brucella genus-specific PCR amplification using B4/B5 primers of the bcsp31 gene. Positive B4/B5 samples were subjected to multiplex species-specific Brucella PCR amplification.

Results

In the Northern location, 81.9% of the AFI samples were confirmed Brucella positive, while all the samples collected from the Central region proved to be Brucella negative. Samples positive for Brucella were subjected to multiplex species-specific Brucella amplification. B. abortus was detected in 10% and B. melitensis in 8% of the samples, while the majority (82%) of samples showed both B. abortus and B. melitensis. As expected, B. suis was not detected in any of the samples.

Conclusions

This study concluded that a two-stage PCR assay could be useful as a rapid diagnostic tool to allow the consideration of brucellosis as a possible cause of AFI, particularly in non-urban locations. It also recommends the collection of epidemiological data for such patients to obtain further information that may help in rapid diagnosis.

Comparison of total antibody and interferon-γ T-cell responses in patients following infection with brucellosis in Georgia

Brucellosis is an ancient disease that still remains a significant threat to humans and is typically linked to exposure to infected animals and/or consumption of unpasteurized animal products. Despite this history, we have a relatively limited understanding of the host characteristics of this disease; consequently, further research is necessary. In this study, we examined the humoral immune response in 43 Georgian individuals that had been diagnosed with brucellosis 3-12 months before enrollment in the study, many of whom still had symptoms after the completion of antibiotic therapy. In total, 35 of 43 (83%) of the patients had antibodies that bound to Brucella lipopolysaccharide (LPS) by COMPELISA, and 34 of 38 (89%) patients had demonstrable specific antibodies to Brucellergene™ antigens; the results from the two ELISAs were highly correlated (p=0.031, r=0.851). We also studied the cellular immune responses in 15 patients. All of the patients generated interferon (IFN)-γ in response to ex vivo stimulation with Brucella protein antigens, and the majority of the patients maintained measurable humoral responses to both LPS and protein antigens. From this initial study, we conclude that measurement of antibody and of cellular (IFN-γ) responses to brucellergene OCB protein epitopes may be worthy of further investigation as an alternative or adjunct to current diagnostics.

A high percentage of serum samples that test reactive by enzyme immunoassay for anti-Brucella antibodies are not confirmed by the standard tube agglutination test

We describe a retrospective analysis of Brucella enzyme immunoassay (EIA) IgM and IgG results compared to those of the standard tube agglutination test (SAT). Among 1,091 samples tested, 104 (9.5%) and 24 (2.2%) sera were positive by IgM and IgG EIA, respectively. Supplemental testing by SAT showed that 82.7% (86/104) of IgM EIA-reactive samples and 54.2% (13/24) of IgG EIA-reactive samples were negative by SAT. Testing all EIA screen-reactive samples by SAT is required when evaluating patients for potential brucellosis. Due to the limitations of serology, culture remains the gold standard for detecting Brucella infection.

Serological and molecular diagnosis of human brucellosis in Najran, Southwestern Saudi Arabia

This study aimed to investigate the prevalence of human brucellosis in Najran, southwestern Saudi Arabia, and to assess the performances of ELISA and PCR as diagnostic tools for brucellosis with respect to conventional methods. The study included 340 patients with clinical characteristics of brucellosis. Blood samples from cases and controls were subjected to culture, standard tube agglutination test (SAT), ELISA for IgM and IgG, and brucella PCR. The diagnosis of brucellosis was confirmed in 54 (15.9%) of the 340 provisionally diagnosed brucellosis patients. Blood culture identified only 14 (25.9%) cases. The SAT was positive for 50 (92.6%) cases, whereas ELISA IgM, IgG and PCR were found positive in 46, 52 and 38 cases respectively. The sensitivities of ELISA IgM and IgG were 85.2% and 96.3% respectively and the specificity was 100% for each. For PCR, the sensitivity and specificity were 70.4% and 100% respectively. In conclusion, ELISA offers a significant advantage over conventional serological methods in the diagnosis of brucellosis in endemic areas. The PCR test results can be particularly important in patients with clinical signs and symptoms, and negative serological results, allowing the early and rapid confirmation of the brucellosis.

Challenges of establishing the correct diagnosis of outbreaks of acute febrile illnesses in Africa: the case of a likely Brucella outbreak among nomadic pastoralists, northeast Kenya, March-July 2005

An outbreak of acute febrile illness was reported among Somali pastoralists in remote, arid Northeast Kenya, where drinking raw milk is common. Blood specimens from 12 patients, collected mostly in the late convalescent phase, were tested for viral, bacterial, and parasitic pathogens. All were negative for viral and typhoid serology. Nine patients had Brucella antibodies present by at least one of the tests, four of whom had evidence suggestive of acute infection by the reference serologic microscopic agglutination test. Three patients were positive for leptospiral antibody by immunoglobulin M enzyme-linked immunosorbent assay, and two were positive for malaria. Although sensitive and specific point-of-care testing methods will improve diagnosis of acute febrile illness in developing countries, challenges of interpretation still remain when the outbreaks are remote, specimens collected too late, and positive results for multiple diseases are obtained. Better diagnostics and tools that can decipher overlapping signs and symptoms in such settings are needed.

Evaluation of the recombinant 10-kilodalton immunodominant region of the BP26 protein of Brucella abortus for specific diagnosis of bovine brucellosis

Brucellosis is a disease with worldwide distribution affecting animals and human beings. Brucella abortus is the causative agent of bovine brucellosis. The cross-reactions of currently available diagnostic procedures for B. abortus infection result in false-positive reactions, which make the procedures unreliable. These tests are also unable to differentiate Brucella-infected and -vaccinated animals. The present work is focused on the use of a nonlipopolysaccharide (LPS) diagnostic antigen, a recombinant 10-kDa (r10-kDa) protein of B. abortus, for specific diagnosis of brucellosis. The purified recombinant protein was used as a diagnostic antigen in plate enzyme-linked immunosorbent assay (p-ELISA) format to screen 408 bovine serum samples (70 presumptively negative, 308 random, and 30 vaccinated), and the results were compared with those of the Rose Bengal plate agglutination test (RBPT) and the standard tube agglutination test (STAT). Statistical analysis in presumptive negative samples revealed 100 and 98.41% specificity of p-ELISA with RBPT and STAT, and an agreement of 91.43% with the tests using Cohen's kappa statistics. In random samples, the agreement of p-ELISA was 77.92% and 80.52% with RBPT and STAT, respectively. p-ELISA investigation of vaccinated samples reported no false-positive results, whereas RBPT and STAT reported 30% and 96.6% false-positive results, respectively. The data suggest that p-ELISA with r10-kDa protein may be a useful method for diagnosis of bovine brucellosis. Furthermore, p-ELISA may also be used as a tool for differentiating Brucella-vaccinated and naturally infected animals.

A comparison of immuncapture agglutination and ELISA methods in serological diagnosis of brucellosis

BACKGROUND

Different serological tests are used in serologic diagnosis of brucellosis. The most widely used of these are Standard Tube Agglutination and Coombs anti-brucella tests. Whereas ELISA Ig M and Ig G tests have been in use for a long time, immuncapture agglutination test has been recently introduced and used in serological diagnosis. The aim of this study was to compare diagnostic values of ELISA Ig M and Ig G and immuncapture agglutination tests with Coombs anti-brucella test.

METHODS

Sera from 200 patients with presumptive diagnosis of brucellosis were included into the study. Coombs anti-brucella test, ELISA Ig M and Ig G tests and Immuncapture test were investigated in these sera. Then, sensitivity, specificity, negative predictive and positive predictive values were calculated.

RESULTS

Sensitivity, specificity, negative predictive and positive predictive values were found to be 90.6%, 76.3%, 94.2%, and 65.9% respectively for the Immuncapture test, whereas they were found to be 73.7%, 58.9%, 84.2%, and 42.8% for Ig G and 72.2%, 67.8%, 85.2%, and 48.7% for Ig M. The Immuncapture test was found to be compatible with ELISA Ig M and Ig G tests but it was statistically incompatible with Coombs anti-brucella test.

CONCLUSIONS

Immuncapture agglutination test yields similar results to those of Coombs anti-brucella test. This test is a useful test by virtue of the fact that it determines blocking antibodies in the diagnosis and follow-up of brucellosis.

False positive seroreactivity to brucellosis in tuberculosis patients: a prevalence study

Background:

The rising worldwide incidence of tuberculosis (TB) increases the demand for knowledge about its potential seroreactivity with other microbial agents. A few reports and the authors’ experiences indicate that tuberculosis may result in a false-positive brucellosis serology. This may cause a diagnostic challenge because of the close clinical resemblance of these two infections.

Objective:

The aim of the present prevalence study was to elucidate brucellosis seroreactivity in patients with active TB.

Methods:

Ninety-eight patients with newly diagnosed and active TB were studied using an enzyme-linked immunosorbent assay (ELISA) and Wright’s and Coombs–Wright’s tests. Seventy-five healthy individuals were used as controls. The patients showed signs of recovery after starting a standard anti-TB regimen and had no clinical evidence of brucellosis at a subsequent 6-month follow-up. The data were analyzed statistically by Fisher’s exact test using SPSS 11.0.

Results:

We found that 9.2% of TB patients versus 1.3% of healthy controls had positive results on the anti-Brucella IgG ELISA (P = 0.04). Five TB patients were found to have agglutination on Wright’s tests, while none of the controls showed agglutination.

Conclusion:

Active TB patients may have some seroreactivity with Brucella antigens, and Brucella IgG ELISA may give a false positive in these patients. Clinicians should consider false positive brucellosis seroreactivity in patients with active TB.

Evaluating the validity of serum neopterin and chitotriosidase levels in follow-up brucellosis patients

OBJECTIVE

Due to its high morbidity rates brucellosis, a systemic inflammatory disease, is still an important health problem, particularly in Mediterranean regions. One-third of the patients are characterized with musculoskeletal involvement. Principally in chronic cases, there are difficulties in the follow-up of therapy success. Radiological imaging methods are used in musculoskeletal brucellosis in addition to standard serological tests. Two macrophage products, namely neopterin (NPT) and chitotriosidase (ChT), are used as novel markers in order to reflect the status of inflammatory diseases. In this study, we aimed to test the validity of these markers in follow-up of patients with brucellosis.

PATIENTS AND METHODS

A total of 40 brucellosis cases were included in the study and 27 healthy individuals were used as controls. Twenty of the brucellosis patients were presented with sacroiliac joint involvement. A 6-week treatment of doxycycline combined with rifampicin or streptomycin was used to treat brucellosis. Clinical observations and serological outcome were used to determine whether treatment was successful or not.

RESULTS

All of the 20 brucellosis patients without musculoskeletal involvement healed with the first cure of treatment, but all of the brucella-sacroiliitis patients had to be retreated. In addition to routine testing, serum NPT and ChT levels were evaluated after each treatment. The results presented a clear fall in both NPT and ChT levels in parallel with the serological data of the patients.

CONCLUSION

In conclusion, NPT as well as ChT seems to be a useful marker in the follow-up of brucellosis patients and for evaluating the success of therapy.

[Seroprevalence and risk factors of brucellosis among slaughterhouse workers in Korea]

OBJECTIVES

The incidence of zoonoses in Korea has increased recently. However, the study of high risk groups for zoonoses has not been conducted to date in Korea. Thus, we did this study to obtain data on brucellosis among slaughterhouse workers in Korea.

METHODS

We evaluated the structure of slaughterhouses and the process of slaughtering by reviewing the relevant literature and doing field studies. We visited 73 slaughterhouses and 62 residual products handle houses across the country. In addition, we conducted a questionnaire survey of the work activities, and obtained blood samples in order to determine the seroprevalence and risk factors of brucellosis. The titers of brucellosis antibodies were measured using the standard tube agglutination test (SAT). We diagnosed subjects as seropositive for Brucellosis if the titers were more than 1:160. The data collected was evaluated using SPSS ver. 17.0.

RESULTS

We included 1,503 subjects and obtained 1,482 blood samples among them: 849 workers involved in slaughtering, 351 handlers of residual products, 190 inspectors and their assistants, and 92 grading testers and their assistants. The seroprevalence of brucellosis among the slaughterhouse workers was 0.8% (95% CI=0.4-1.5). Broken down, the seroprevalence of brucellosis among the workers involved in slaughtering was 0.7% (95% CI=0.3-1.6), the handlers of residual products was 1.7% (95% CI=0.7-3.9) respectively. Risk factors for contracting brucellosis among slaughterhouse workers were being splashed with cattle blood around the mouth, cattle secretions around the body and not putting on protective apron while at work.

CONCLUSIONS

An educational program is needed for high risk groups on zoonoses about the prevention of infection. Thus, effective working guidelines for workers who participate in the slaughter of animals must be developed in order to protect them from zoonoses.