Publications by authors named "John Mcgiven"

Background: Brucellosis remains a significant health and economic challenge for livestock and humans globally. Despite its public health implications, the factors driving the endemic persistence of at the human-livestock interface in Tanzania remain poorly elucidated. This study aimed to identify the seroprevalence of infection in livestock and humans within a ranching system and determine associated risk factors for disease endemicity.

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  • A new zoonotic bacteria is emerging as the primary cause of canine brucellosis in Europe, leading to reproductive issues in dogs and potential chronic illnesses in humans.* -
  • Current understanding of host interactions and effective diagnostic tools for this infection is limited, with no vaccine available and ineffective antimicrobial treatments increasing the risk of antibiotic resistance.* -
  • The lack of systematic surveillance and legal frameworks to address canine brucellosis complicates management efforts, prompting the need for improved strategies to combat this disease among pets and in kennel settings.*
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  • Bacteria from the genus Brucella cause brucellosis, a serious disease affecting both animals and humans, and have been controversially merged with other unrelated bacterial species based on genomic findings.
  • Researchers argue this merger is inappropriate due to lack of thorough phylogenetic analysis and exclusion of expert opinions in brucellosis.
  • They warn that combining these groups could lead to confusion and risks in public health, particularly impacting those dealing with brucellosis in under-resourced regions, and call for keeping the Brucella genus distinct.
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The aim of this study was to develop a multiplex bead assay using a rLPS antigen, a smooth antigen, and a O:9 antigen that not only discriminates -infected from -uninfected pigs and wild boar, but also overcomes the cross reactivity with O:9. Sera from 126 domestic pigs were tested: 29 pigs were infected, 80 were non-infected and 17 were confirmed to be false positive serological reactors (FPSR). Sera from 49 wild boar were tested: 18 were positive and 31 were negative.

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Brucellosis is a global disease and the world's most prevalent zoonosis. All cases in livestock and most cases in humans are caused by members of the genus that possess a surface O-polysaccharide (OPS) comprised of a rare monosaccharide 4-deoxy-4-formamido-D-mannopyranose assembled with α1,2 and α1,3 linkages. The OPS of the bacterium is the basis for serodiagnostic tests for brucellosis.

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Brucellosis is a neglected debilitating zoonosis widely recognized as an occupational health hazard. The seroprevalence of human anti- antibodies in high-risk populations, as well as their risk factors, have not been well-documented in Zambia. This study aimed at estimating the seroprevalence in herdsmen and abattoir workers and assess the associated risk factors.

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The control of brucellosis across sub-Saharan Africa is hampered by the lack of standardized testing and the use of tests with poor performance. This study evaluated the performance and costs of serological assays for human brucellosis in a pastoralist community in northern Tanzania. Serum collected from 218 febrile hospital patients was used to evaluate the performance of seven index tests, selected based on international recommendation or current use.

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  • * A study in rural Ludhiana investigated bovine brucellosis among dairy farms, revealing a 15.1% seropositivity rate in cattle and buffalo, and nearly one-third of farms had at least one infected animal.
  • * The findings indicate high exposure risk to Brucella spp. for individuals in contact with livestock, emphasizing the importance of disease control for improving both animal and public health.
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Brucellosis is an endemic zoonosis in sub-Saharan Africa. Pastoralists are at high risk of infection but data on brucellosis from these communities are scarce. The study objectives were to: estimate the prevalence of human brucellosis, identify the Brucella spp.

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The English surveillance system for bovine brucellosis was evaluated. The confidence in detecting at least one infected herd in the local population (surveillance system sensitivity or SSe), and the confidence in freedom from disease (PFree) adjusted (PFreeAdj) for the probability of disease introduction from abroad by imported animals (PIntro), were estimated for quarterly surveillance periods of 2016; because dairy herds were tested quarterly on bulk tank milk (BTM) with an antibody indirect ELISA. A stochastic model was developed and six surveillance components (representing also the local population strata), were evaluated.

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  • Brucellosis is a neglected zoonosis with available vaccines for cattle that are underutilized in India, where many rural households depend on cattle for protein and income.
  • A study conducted in Punjab involving 1,927 individuals found a Brucella infection prevalence of 2.24%, with risk factors such as assisting in cattle calving/abortions and consuming goat's milk linked to higher infection odds.
  • The findings suggest that vaccinating livestock against Brucella and implementing biosecurity measures could significantly reduce human infection risk.
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Ten herd-level cross-sectional studies were conducted in peri-urban dairy production areas of seven West and Central African countries (Burkina Faso, Burundi, Cameroon, Mali, Niger, Senegal and Togo). The objectives were to estimate herd level Brucella spp. seroprevalence and identify risk factors for seropositivity.

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The health and well-being of cattle is an important issue in maintaining and increasing global agricultural output. In dairy production within low and middle income countries (LMICs), there is a significant biosensing challenge in detecting sexually transmitted infection (STI) pathogens during animal husbandry, due in part to difficulties associated with the limited infrastructure for veterinary medicine. Here we demonstrate low-cost, multiplexed, and sample-to-answer paper-origami tests for the detection of three bovine infectious reproductive diseases in semen samples, collected at a test site in rural India.

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Brucellosis is a serious zoonotic bacterial disease that is ranked by the World Health Organization among the top seven "neglected zoonoses" that threaten human health and cause poverty. It is a costly, highly contagious disease that affects ruminants, cattle, sheep, goats, and other productive animals such as pigs. Symptoms include abortions, infertility, decreased milk production, weight loss, and lameness.

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Brucellosis is diagnosed by detection of antibodies in the blood of animals and humans that are specific for two carbohydrate antigens, termed A and M, which are present concurrently in a single cell wall O-polysaccharide. Animal brucellosis vaccines contain these antigenic determinants, and consequently infected and vaccinated animals cannot be differentiated as both groups produce A and M specific antibodies. We hypothesized that chemical synthesis of a pure A vaccine would offer unique identification of infected animals by a synthetic M diagnostic antigen that would not react with antibodies generated by this vaccine.

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Members of the genus Brucella have cell wall characteristics of Gram-negative bacteria, which in the most significant species includes O-polysaccharide (OPS). Serology is the most cost-effective means of detecting brucellosis, as infection with smooth strains of Brucella leads to the induction of high antibody titers against the OPS, an unbranched homopolymer of 4,6-dideoxy-4-formamido-D-mannopyranosyl residues (D-Rha4NFo) that are variably α(1→2)- and α(1→3)-linked. Six d-Rha4NFo homo-oligosaccharides were synthesized, each containing a single α(1→3) link but with a varied number of α(1→2) links.

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The cell wall O-polysaccharides of pathogenic Brucella species are homopolymers of the rare sugar 4,6-dideoxy-4-formamido-α-D-mannopyranose. Despite the apparent simplicity of the polysaccharide it appears to be a "block copolymer" composed of A and M polysaccharide sequences expressed as a single molecule. The simultaneous presence of both in the cell wall has complicated the understanding of the molecular recognition of these antigens by antibodies present in the serum of infected animals and humans and by monoclonal antibodies.

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Brucella abortus, a smooth strain of the genus Brucella, is the causative agent of bovine brucellosis. To support the ongoing development of diagnostic tests for bovine brucellosis, the use of Protein Saver cards (Whatman) for bovine blood serum and plasma sample collection has been evaluated. These cards offer significant logistical and safety alternatives to transporting and storing liquid samples and may aid in diagnostic programs and validation studies.

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Aim: To evaluate competitive enzyme-linked immunosorbent assay (cELISA) for its suitability as an additional serological test for the diagnosis of animal brucellosis.

Methods: cELISA, which was developed at the Veterinary Laboratories Agency, has been evaluated for its accuracy and suitability as an additional serological test for the diagnosis of animal brucellosis. Samples from naturally and experimentally infected animals and those from Brucella-free flocks and herds were tested.

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Brucellosis is a globally significant zoonosis, the control of which is difficult and resource intensive. Serological tests form a vital part of a multifactorial approach to control and are often performed in large numbers. The aim of the present study was to develop a new assay to improve the efficiency, ease, and effectiveness of serological testing.

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Brucellosis is a bacterial zoonotic disease of major global importance. Natural hosts for Brucella species include animals of economic significance, such as cattle and small ruminants. Controlling brucellosis in natural hosts by high-throughput serological testing followed by the slaughter of seropositive animals helps to prevent disease transmission.

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The control and eradication of brucellosis is highly desirable but heavily resource intensive as high throughput serological testing is required. The aim of this study was to meet the needs of high throughput screening laboratories involved in this process through the development of a new assay. An existing cELISA used for the serodiagnosis of brucellosis in ruminants was converted to an AlphaLISA homogenous proximity based assay.

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