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Field isolates of foot-and-mouth disease viruses (FMDVs) utilize integrin-mediated cell entry but many, including Southern African Territories (SAT) viruses, are difficult to adapt to BHK-21 cells, thus hampering large-scale propagation of vaccine antigen. However, FMDVs acquire the ability to bind to cell surface heparan sulphate proteoglycans, following serial cytolytic infections in cell culture, likely by the selection of rapidly replicating FMDV variants. In this study, fourteen SAT1 and SAT2 viruses, serially passaged in BHK-21 cells, were virulent in CHO-K1 cells and displayed enhanced affinity for heparan, as opposed to their low-passage counterparts. Comparative sequence analysis revealed the fixation of positively charged residues clustered close to the icosahedral 5-fold axes of the virus, at amino acid positions 83-85 in the ßD-ßE loop and 110-112 in the ßF-ßG loop of VP1 upon adaptation to cultured cells. Molecular docking simulations confirmed enhanced binding of heparan sulphate to a model of the adapted SAT1 virus, with the region around VP1 arginine 112 contributing the most to binding. Using this information, eight chimeric field strain mutant viruses were constructed with additional positive charges in repeated clusters on the virion surface. Five of these bound heparan sulphate with expanded cell tropism, which should facilitate large-scale propagation. However, only positively charged residues at position 110-112 of VP1 enhanced infectivity of BHK-21 cells. The symmetrical arrangement of even a single amino acid residue in the FMD virion is a powerful strategy enabling the virus to generate novel receptor binding and alternative host-cell interactions.
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Vírus da Febre Aftosa/genética , Febre Aftosa/virologia , Modelos Moleculares , Vírion/metabolismo , Animais , Proteínas do Capsídeo/metabolismo , Cricetinae , Heparitina Sulfato/metabolismo , Simulação de Acoplamento Molecular/métodos , Receptores Virais/metabolismoRESUMO
BACKGROUND: Makerere University implemented a One Health Institute (OHI) in 2016 involving undergraduate students selected from different disciplines. The students were first taken through theoretical principles of One Health followed by a field attachment in communities. The field attachment aimed to expose students to experiential educational opportunities in the communities in a One Health approach. In this paper, we present students' experiences and their contributions to the communities of attachment. METHODS: This was a cross-sectional study, utilizing qualitative data collection methods. The study involved students who participated in the OHI field attachment and community members in a One Health demonstration site-Western Uganda. Four focus group discussions (FGDs) and four in-depths interviews (IDIs) were conducted among the students, while four FGDs and twelve IDIs were conducted among community members. All interviews were audio-recorded, transcribed and analysed manually. RESULTS: The four themes that emerged are: students' understanding and appreciation of One Health concept, their experiences and gains from the multi-disciplinary field attachment, students' contributions to the community, and challenges faced by the students. Students had good knowledge of One Health. They appreciated that health cannot be achieved by one discipline or sector and thus the need to collaborate across sectors. Regarding experiences and gains during the multi-disciplinary field attachment, the students appreciated that each discipline had a role to play in achieving health in the community. They appreciated the training citing skills gained in communication, team work and collaboration. They also reported a feeling of gratitude and accomplishment because they felt they made a positive change to the community by putting in place interventions to address some of the community challenges. Similarly, the communities appreciated the students' contribution in solving their health challenges, ranging from conducting health education to improving sanitation and hygiene. CONCLUSIONS: Through the OHI, students gained One Health competencies including communication, teamwork, and collaboration. Adopting an interdisciplinary model in university teaching system especially during field placement would strengthen skills of collaboration, team work and communication which are critical for a multi-disciplinary approach which is needed among the future workforce in order to solve the current health challenges.
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Educação em Saúde , Estudantes , Estudos Transversais , Humanos , Aprendizagem Baseada em Problemas , UgandaRESUMO
OBJECTIVES: In this study, we investigated the causes of measles-like illnesses (MLI) in the Uganda national surveillance program in order to inform diagnostic assay selection and vaccination strategies. METHODS: We used metagenomic next-generation sequencing (M-NGS) on the Illumina platform to identify viruses associated with MLI (defined as fever and rash in the presence of either cough, coryza or conjunctivitis) in patient samples that had tested IgM negative for measles between 2010 and 2019. RESULTS: Viral genomes were identified in 87/271 (32%) of samples, of which 44/271 (16%) contained 12 known viral pathogens. Expected viruses included rubella, human parvovirus B19, Epstein Barr virus, human herpesvirus 6B, human cytomegalovirus, varicella zoster virus and measles virus (detected within the seronegative window-period of infection) and the blood-borne hepatitis B virus. We also detected Saffold virus, human parvovirus type 4, the human adenovirus C2 and vaccine-associated poliovirus type 1. CONCLUSIONS: The study highlights the presence of undiagnosed viruses causing MLI in Uganda, including vaccine-preventable illnesses. NGS can be used to monitor common viral infections at a population level, especially in regions where such infections are prevalent, including low and middle income countries to guide vaccination policy and optimize diagnostic assays.
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Sequenciamento de Nucleotídeos em Larga Escala , Sarampo , Humanos , Uganda/epidemiologia , Pré-Escolar , Sarampo/epidemiologia , Sarampo/virologia , Lactente , Criança , Masculino , Feminino , Adolescente , Vírus/isolamento & purificação , Vírus/genética , Vírus/classificação , Genoma Viral , Adulto , Adulto Jovem , Viroses/epidemiologia , Viroses/virologia , Metagenômica , Vírus do Sarampo/genética , Vírus do Sarampo/isolamento & purificação , Vírus do Sarampo/classificaçãoRESUMO
Peste des Petits Ruminants (PPR) is a transboundary, highly contagious, and fatal disease of small ruminants. PPR causes global annual economic losses of between USD 1.5 and 2.0 billion across more than 70 affected countries. Despite the commercial availability of effective PPR vaccines, lack of financial and technical commitment to PPR control coupled with a dearth of refined PPR risk profiling data in different endemic countries has perpetuated PPR virus transmission. In Uganda, over the past 5 years, PPR has extended from northeastern Uganda (Karamoja) with sporadic incursions in other districts /regions. To identify disease cluster hotspot trends that would facilitate the design and implementation of PPR risk-based control methods (including vaccination), we employed the space-time cube approach to identify trends in the clustering of outbreaks in neighbouring space-time cells using confirmed PPR outbreak report data (2007-2020). We also used negative binomial and logistic regression models and identified high small ruminant density, extended road length, low annual precipitation and high soil water index as the most important drivers of PPR in Uganda. The study identified (with 90-99% confidence) five PPR disease hotspot trend categories across subregions of Uganda. Diminishing hotspots were identified in the Karamoja region whereas consecutive, sporadic, new and emerging hotspots were identified in central and southwestern districts of Uganda. Inter-district and cross-border small ruminant movement facilitated by longer road stretches and animal comingling precipitate PPR outbreaks as well as PPR virus spread from its initial Karamoja focus to the central and southwestern Uganda. There is therefore urgent need to prioritize considerable vaccination coverage to obtain the required herd immunity among small ruminants in the new hotspot areas to block transmission to further emerging hotspots. Findings of this study provide a basis for more robust timing and prioritization of control measures including vaccination.
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Doenças das Cabras , Peste dos Pequenos Ruminantes , Vírus da Peste dos Pequenos Ruminantes , Animais , Análise por Conglomerados , Doenças das Cabras/epidemiologia , Doenças das Cabras/prevenção & controle , Cabras , Peste dos Pequenos Ruminantes/epidemiologia , Peste dos Pequenos Ruminantes/prevenção & controle , Ruminantes , Solo , Uganda/epidemiologia , ÁguaRESUMO
A team of interdisciplinary researchers undertook a mixed methods, participatory epidemiology (PE) based study as part of a pilot project for localized control of Peste des petits ruminants (PPR), a small ruminant disease of high socio-economic impact. Mixed methods research combines qualitative and quantitative methods, allowing iterative comparison of results to arrive at a more comprehensive and informed outcome. In this study, the use of PE and a household survey (HHS) resulted in contradictory results. However, the mixed methods approach also facilitated the detection and the explanation of bias in the HHS, which may have gone undetected and unexplored had only one method been used. Results show that logistical constraints leading to a failure to apply key aspects of the sampling strategy led to problematic gender/ethnic composition of the HHS sample population. Additionally, while PE findings on local disease and terminology were integrated during HHS development and training, there is apparent measurement error related to enumerator bias in HHS results, possibly due to insufficient respondent understanding or a lack of analytic clarity. The extensive nature of the PE, surveillance methodologies used in the initial site assessment, and formative research for the HHS allowed for a critical analysis and interpretation of HHS results as well as reflection on the research process. The findings of this paper underscore the (1) flexibility and utility of participatory methods, (2) the importance of mixed methods research in designing health interventions, and (3) the necessity of tight integration of study design with team planning for implementation of research in environments such as Karamoja, Uganda. If all three are to be achieved not only researchers but funders must provide these space and structure beginning in the study design phase. These findings are relevant in many places, but have particular importance for international, interdisciplinary teams working from various on-and-off-site locations with traditional or indigenous knowledge systems.
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Doenças das Cabras , Peste dos Pequenos Ruminantes , Animais , Doenças das Cabras/epidemiologia , Doenças das Cabras/virologia , Cabras , Peste dos Pequenos Ruminantes/epidemiologia , Vírus da Peste dos Pequenos Ruminantes , Projetos Piloto , Viés de Seleção , Uganda/epidemiologiaRESUMO
BACKGROUND: Anthrax is globally recognized as an important public health and economic challenge in many agricultural communities. A cross-sectional study was conducted in three subcounties in Arua district to assess the community's awareness, cultural norm, and practices regarding anthrax. This followed a report of active cases of human cutaneous anthrax in the district. METHODS: The study was conducted in subcounties of Pawor, Rigbo, and Rhino Camp, Arua district, using focus group discussion. RESULTS: The affected communities had limited knowledge about anthrax, especially its clinical manifestation and modes of transmission both in humans and animals. The community also had no knowledge of the anthrax vaccine or treatment and where they can be accessed from. Poor practices associated with anthrax outbreaks included poor disposal of carcasses and ruminal wastes, occupational hazards (butchers, slaughter men, and herdsmen), consumption of meat from infected animals, communal herding, and cultural norms encouraging consumption of dead animals. CONCLUSION: This study shows that there is a knowledge gap about anthrax among the people in the affected communities. Key drivers for the anthrax outbreak such as poor cultural beliefs and practices and wildlife-livestock-human interactions were observed in all the three subcounties studied. All these findings could imply a high risk of outbreak of anthrax in Arua and Ugandan agricultural communities where the public health programs are less standardized and less effective.
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Uganda is considered as a 'hot spot' for emerging and re-emerging infectious disease epidemics. The country has experienced several epidemics including; Ebola, Marburg, plague, Rift Valley fever, yellow fever and Crimean Congo haemorrhagic fever. Epidemics overwhelm health systems, devastate economies and cause global health insecurity. These public health challenges arising from the interaction of humans-animals-environment link require a holistic approach referred to as One Health (OH). OH is the collaborative effort of multiple disciplines working locally, nationally, and globally, to attain optimal health for people, animals, and the environment. Given its situation, Uganda has embraced the OH approach in order to be able to predict, prepare and respond to these public health challenges effectively, though still in infancy stages. In this paper, we present major achievements and challenges of OH implementation, and make recommendations for systematic and sustainable OH implementation. Achievements include: formation of the National One Health (NOH) platform with a Memorandum of Understanding between sectors; a national priority list of zoonotic diseases, the NOH Strategic Plan and a One Health communication strategy to strengthen engagement across sectors and stakeholders. There have also been efforts to integrate OH in academia. The challenges are related to inadequate; coordination across sectors, government commitment, advocacy and awareness creation and research. For systematic and sustainable OH engagements, urgent efforts should be made through government support to address current and related future challenges.
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Doenças Transmissíveis Emergentes , Saúde Única , Saúde Pública , Animais , Doenças Transmissíveis Emergentes/epidemiologia , Doenças Transmissíveis Emergentes/prevenção & controle , Humanos , Saúde Pública/métodos , Uganda/epidemiologia , ZoonosesRESUMO
The interconnections of humans, domestic animals, wildlife and the environment have increasingly become complex, requiring innovative and collaborative approaches (One Health approach) for addressing global health challenges. One Health is a multidisciplinary and multi-sectoral collaborative approach to human, animal, plant and environmental health. The role of academia in training professionals oriented in One Health is critical in building a global workforce capable of enhancing synergies of various sectors in improving health. Makerere University, Uganda has implemented pre-service capacity building initiatives aimed to foster One Health competencies among students who are future practitioners. In addition to incorporating the One Health concept in didactic curricula, Student One Health Innovation Clubs, undergraduate field placements in 11 demonstration sites, graduate fellowships, small grants to support research and innovations, and cross-college collaborative training approaches have greatly aided the assimilation of One Health into the fabric of university offerings. Partnerships with government ministries, private sector and international agencies were initiated to benefit the students, as well as chart a path for experiential learning and in-service offerings in the future. One major challenge, however, has been the tendency to focus on infectious diseases, especially zoonoses, with less consideration of other health issues. The opportunity for improvement, nonetheless, lies in the increasing emerging and re-emerging health concerns including epidemics, environmental pollution and related challenges which justify the need for countries and institutions to focus on building and strengthening multidisciplinary health systems.
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This paper describes an assessment of the patterns of peste des petits ruminants virus circulation in the Karamoja subregion of Uganda conducted to identify the communities that maintain the virus and inform the development of a targeted vaccination strategy. Participatory epidemiological methods were used to develop an operational hypothesis for the patterns of PPR in Karamoja that was subsequently validated through outbreak investigation and genomics. The participatory epidemiological assessment included risk mapping with livestock owners, community animal health workers and veterinarians and indicated there were two critical foci of virus transmission on the Uganda-Kenya border. One was located in two adjacent subcounties of Kotido and Kaabong Districts in northern Karamoja and the other in Loroo subcounty of Amudat District in southern Karamoja. Participants reported that these were locations where outbreaks were usually first observed in Karamoja and subsequently spread to other areas. Following the participatory assessment, surveillance activities were implemented across the Karamoja subregion in 2018. Three outbreak were detected, investigated and sampled. Two outbreaks were located in the northern and one on the southern focus of transmission. No Outbreaks were diagnosed in Karamoja outside of these foci during 2018. Genomics indicated different clusters of viruses were associated with the northern and southern foci that were more closely related to other East African isolates than to each other. This indicates these are two separate systems of virus circulation which should be explicitly addressed in eradication as separate cross-border systems that require integrated cross-border interventions.
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The genetic diversity of the three Southern African Territories (SAT) types of foot-and-mouth disease virus (FMDV) reflects high antigenic variation, and indications are that vaccines targeting each SAT-specific topotype may be needed. This has serious implications for control of FMD using vaccines as well as the choice of strains to include in regional antigen banks. Here, we investigated an intra-serotype chimeric virus, vSAT2(ZIM14)-SAT2, which was engineered by replacing the surface-exposed capsid-coding region (1B-1D/2A) of a SAT2 genome-length clone, pSAT2, with that of the field isolate, SAT2/ZIM/14/90. The chimeric FMDV produced by this technique was viable, grew to high titres and stably maintained the 1B-1D/2A sequence upon passage. Chemically inactivated, oil adjuvanted vaccines of both the chimeric and parental immunogens were used to vaccinate cattle. The serological response to vaccination showed the production of strong neutralizing antibody titres that correlated with protection against homologous FMDV challenge. We also predicted a good likelihood that cattle vaccinated with an intra-serotype chimeric vaccine would be protected against challenge with viruses that caused recent outbreaks in southern Africa. These results provide support that chimeric vaccines containing the external capsid of field isolates induce protective immune responses in FMD host species similar to the parental vaccine.