No description available.

No description available.

No description available.

Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / The human population in sub-Saharan Africa has been increasing due to decreases in mortality rates and increases in average human age; in turn increasing poverty and pressure placed on agriculture and agricultural production. However, livestock production in South Africa, and globally, is declining due to disease and parasite prevalence, lack of feed, poor breeding, marketing management, change in nutrition in both livestock and humans, rapid urbanization, encroachment on wildlife and unfavourable climatic conditions brought about by global change. One unintended consequence has been the emergence and spread of transboundary animal diseases and, more specifically, the resurgence and emergence of zoonotic disease. Zoonotic diseases are sicknesses transmissible from animals to humans, resulting from direct contact or environmental reservoirs. Previous studies have identified small-scale farmers as the group most prevalent to contracting zoonotic diseases, especially those working in a communal dispensation. Therefore, this study focused on the communal farming area of Steinkopf in the semi-arid Namaqualand region of South Africa. Steinkopf is one of the largest Act 9 areas, with communal land tenure and a mixed farming system, sheep and goats, on about 759 ha. Steinkopf is divided into two rainfall regions, the Succulent Karoo (winter rainfall region) and the Nama Karoo (summer rainfall region). This study aims to identify and characterise the bacterial microbial communities found in the topsoil layer and faecal matter (dung) within the winter and summer rainfall regions of Steinkopf communal rangeland using Next-generation sequencing. Further, the aim is to assess whether pathogenic bacteria are present within the rangeland and what their potential impact on the local farming community might be if present. A high-throughput sequencing technique (Next-generation sequencing) was used to amplify 16S rRNA targeting the V3-V4 hypervariable regions. The phylotypes produced were 37 phyla, 353 families and 634 genera of which the most abundant bacterial phyla were Planctomycetes, Firmicutes and Bacteroidetes and the most abundant genera were Gemmata, Akkermansia and Arthrobacter. Alpha diversity indices showed a variation in species diversity, evenness and richness between soil and dung samples, it shows a higher species richness, evenness and unique OTUs detected in summer soil samples and at natural water holes. Through these analysis soil samples were regarded as superior to dung samples within this particular environment and for this particular study. Natural water holes were identified as a safer option when compared to man-made water holes as there are natural systems in place that combat the spread and growth of harmful bacterial microbes. It was found that seasonality has a great impact on the development and growth of environmental bacterial microbiota and that the current randomness of grazing routes and migrations within the Steinkopf communal rangeland is not a detriment but instead acts as a benefits to environmental and livestock health. Furthermore, a total of three pathogenic bacteria were identified however, they occurred at relatively low abundances. It can thus be concluded that this study thoroughly describes the usefulness of using a high-throughput sequencing technique such as Next-generation sequencing when amplifying a small sample size in order to achieve a large volume of information; and that currently the Steinkopf communal rangeland is not subjected to or at risk of a potential zoonotic threat.

No description available.

Between 60-70% of Namibia’s population practice subsistence agro-pastoralism on communal land that constitutes 41% of the total land area. Cysticercosis bovis is found worldwide, but most often in rural developing countries, where unhygienic conditions are coupled with poor cattle management practices and lack or absence of meat inspection. Because livestock is so important to the economy and social structure of the majority of people in Namibia, risks from zoonotic diseases transmitted from domestic animals to humans are a constant threat and are therefore of major concern. In addition, C.bovis is also emerging as a public health risk not only in these rural communities but also in urban areas where many infected cattle are transported, informally slaughtered and consumed. This disease has a negative impact on food safety, and thus is related to Veterinary Public Health (VPH) strategies in Namibia. Over the period from 2000 to 2004, 3232 (8%) measles detections were recorded from the 40 373 cattle slaughtered at Meatco Oshakati Abattoir. C.bovis is considered important from both an economic (loss of income to cattle owners) and human health (it is a zoonosis) point of view. The aim of the study was to do an analysis of the level of C.bovis in bovine carcasses at the abattoir, in order to identify geographical areas where the disease is prevalent in cattle in North Central Namibia and to develop a risk communication strategy, to improve the control of this disease in the target population (subsistence cattle farmers in the study area). Meat inspection was carried out for a period of 12 months and the abattoir records examined covered two years (2004 –2005). Results showed that incidence for C.bovis of cattle originating from Oshikoto Region were high: (12%). Omusati and Oshana Regions had an incidence of 7% and a much lower incidence of C.bovis (5%) was reported in cattle from the Ohangwena Region. Structured interviews with 95 farmers (99% male and 1% female) in all the four Regions of the study area, were carried out using a set of questionnaires (Appendix A). The questionnaires had provision for numerical data and comments concerning changes, constraints and suggestions for improving dissemination of information and extension services in the target areas. It was noted that between 5% and 13 % of respondents had neither pit latrines nor waterborne sewage. This leads to the conclusion that a significant proportion of the rural population is defecating in an area which is available to the cows grazing close to the homestead or cattle post. In addition, 61% of cattle from this area are marketed through informal marketing and many of them are slaughtered informally with no meat inspection taking place. This provides a high risk of infestation for the consumer, which perpetuates the parasite in the rural population. The educational level showed that 24% had no formal education and 33% had only primary school education. The language spoken by 93% of respondents is Oshiwambo and although only 20% speak English or Afrikaans, extension materials, including visual material, is not available in the vernacular. Between 58% and 96% of the respondents from the four Regions had no knowledge of the disease and how it could be diagnosed and controlled in both people and cattle. In Oshikoto Region, where the incidence in slaughtered cattle was the highest, only 4% of the respondents knew about C.bovis in cattle. The results obtained for language proficiency advocates for extension materials to be developed in Oshiwambo (which 93% of the target population are able to read and write). Skills training using visual aids and personal communication in Oshiwambo would be needed for other 7% who are illiterate. From the above, it was concluded that extension is needed to reduce the incidence of C.bovis in cattle. The most important extension messages, as determined by an expert opinion survey of veterinarians in Namibia, were firstly that families should be treated for tapeworms and secondly that they should only buy meat that has been inspected after slaughter at an abattoir. It was recommended that stakeholders in the livestock industry, and the state as well as the Department of Health should be made aware of the high level of cysticercosis and the equally high level of ignorance about the disease in rural areas of North Central Namibia. Veterinary and agriculture staff should be motivated to communicate and combine efforts to assist each other, as transport is expensive and one of the main constraints to successful extension because of the great distances in North Central Namibia. Funding should also be found for production of extension materials in the vernacular. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2007. / Paraclinical Sciences / MSc / unrestricted

Os parasitas pertencentes ao gênero Leishmania têm distribuição ubíqua. Este táxon inclui Leishmania infantum chagasi, agente etiológico da leishmaniose visceral nas Américas, uma zoonose negligenciada cujas metodologias diagnósticas acumulam uma série de limitações, requerendo a validação e padronização de metodologias diagnósticas satisfatórias. Vários fatores estão relacionados à patogênese causada por este protozoário, entre eles a catepsina L-like, uma cisteíno protease envolvida em processos regulatórios metabólicos e infecciosos. Portanto, este trabalho teve como objetivo avaliar a eficácia do gene de catepsina L-like isoforma CPA como alvo de diagnóstico molecular e como marcador filogenético que permita a compreensão das variações intraespecíficas e elucidem a história evolutiva de L. infantum chagasi no Brasil. Foram utilizados 44 isolados de L. infantum chagasi de diferentes estados brasileiros. Os fragmentos do gene de catepsina L-like foram amplificados, purificados, sequenciados, alinhados manualmente e analisados por métodos filogenéticos de máxima parcimônia e inferência bayesiana. As sequências geradas foram usadas para pesquisar e sintetizar iniciadores a serem usados em reações específicas para o parasita alvo. O gene de catepsina L-like não mostrou variabilidade intraespecífica entre os isolados analisados, sugerindo um evento recente de introdução do mesmo nas Américas. O par de iniciadores propostos amplificou o DNA alvo de isolados de L. infantum chagasi, sendo efetivo na amplificação de DNA em concentrações de até 10-11g / µl. O marcador proposto não apresentou reações cruzadas com outros hemoparasitas de importância clínica. Quando utilizado para o diagnóstico em um painel de amostras clínicas de cães, obteve-se uma frequência de positividade de 49,03% (102/208), contrastando com o valor de 14,42% (30/208) obtido com o marcador para o gene do espaçador ribossomal interno ITS. Quando testado em amostras de flebotomíneos se obteve um valor de 6,25% e em amostras de pacientes humanos o valor foi de 14,28%. Os marcadores também foram eficazes em amplificar DNA extraído de amostras de urina, de sangue fixado em papel filtro e mesmo em amostras de swab de lesões conjuntivas. Este conjunto de parâmetros permite inferir que o CatLeish- PCR é sensível e específico para o diagnóstico de L. infantum chagasi podendo ser aplicado tanto em pesquisas clínicas quanto em inquéritos epidemiológicos de vigilância. / The parasites belonging to the Leishmania genus have a wide distribution. This taxon includes Leishmania infantum chagasi, the etiologic agent of Visceral Leishmaniasis in the Americas, a neglected zoonosis that requires the validation and standardization of satisfactory diagnostic methodologies. Several factors are related to the pathogenesis caused by this protozoan, as Catepsin L-like, a cysteine protease involved in regulatory and infectious processes. Given this information this work aimed to evaluate the effectiveness of Cathepsin L-like isoform CPA as a target for molecular diagnosis and as a phylogenetic marker that allows understanding the intraspecific variations and the evolutionary history of L. infantum chagasi in Brazil. We used 44 isolates of L. infantum chagasi from different Brazilian states. The cathepsin L-like gene fragments were amplified, purified, sequenced, manually aligned and analyzed by maximum parsimony and Bayesian inference methods. The sequences generated were researched to construction of oligonucleotide primers to be used in reactions specific to the target parasite. The Cathepsin L-like gene did not show intraspecific variability among the isolates analyzed, suggesting a recent event of introduction of the same in the Americas. The pair of proposed primers amplified the target DNA of L. infantum chagasi isolates, being effective in DNA amplification at concentrations of up to 10-11g/µl. The proposed marker did not present cross-reactions with other hemoparasites of clinical importance. When used for the diagnosis in a panel of clinical samples of dogs obtained a positive frequency of 49.03% (102/208), against the 14.42% (30/208) to ribosomal ITS marker. Samples of sandflies obtained a value of 6.25% and in humans the value was 14.28%. The markers were also effective in blood samples fixed on filter paper and even in samples from conjunctival lesion swabs. This set of parameters allows to infer that CatLeish-PCR is a sensitive and specific marker for the diagnosis of L. infantum chagasi in clinical and epidemiological surveys.

The global disease scape is constantly shifting, influenced by demographic transitions, altering the balance of the burden of infectious and non‐communicable diseases. The epidemiological transitions can be divided into three stages: the first, an increase in infectious disease burden as populations settled, then grew into towns and cities providing conditions for infectious agents to maintain spread; the second transition follows industrialisation, changes in lifestyle, diet and improved sanitation whereby infectious diseases are reduced and non‐communicable disease (NCD) prevalence increases; the third transition describes the re‐emergence of infectious diseases as the AIDS epidemic and other emerging and re‐emerging disease outbreaks lead to an increasing burden of infectious diseases, particularly in developing countries. Analysis of the disease‐scape has been carried out using WHO Global Burden of Disease data and correlation to demographic factors calculated using World Bank Development Indicators. The balance of chronic NCDs and infectious diseases can be represented numerically as the unit rate of infectious to non‐communicable diseases. The rate, which indicates at which end the continuum lies can then be correlated to these demographic development indicators to assess the factors which are influential to the continuum. As the balance of infectious and non‐communicable diseases around the world alters, the focus of the advocacy at the global health level has been examined to assess if the trends follow that of the shifting continuum. This has been carried out through an assessment of the WHO World Health Assembly (WHA) resolutions adopted annually between 1948 and 2013 on the subject of infectious and/or non-communicable diseases. The principle of International health stemmed from the need to contain the international spread of communicable diseases, so it is not surprising that in the first decade of the WHO, 88% of the resolutions adopted for infectious and non‐communicable disease were adopted for infectious diseases. In the latest ten years of the WHO, 72% of the Assembly resolutions for infectious and non‐communicable diseases were focused on infectious diseases; this indicates that while there has been a shift in the balance, the adopted resolutions still focus heavily on infectious diseases. An example of how advocacy can elevate diseases to a higher position on the global health agenda is that of the Neglected Tropical Diseases. Following the Millennium Development Goals, this group of seventeen diseases has been highlighted as being “neglected” in terms of funding, research and political will. A review of the campaign to highlight this shows how global health advocacy can elevate diseases to a prominent position on the global health agenda. With this in mind, the advocacy for a sub‐group of Neglected Zoonotic Diseases has been examined at the WHA level. The results highlight the sporadic nature of support to control these diseases, and that activism for control of some of the major zoonotic diseases remains lacking. Rabies is explored as an example of a disease for which there are recommendations and support at the global level for the control and elimination of the disease, but for which barriers to control exist locally in endemic countries. The advocacy for diseases at the global health level has the possibility to impact the priorities of health care within individual nations. However the advocacy at this level may take time to reflect the changes within the disease‐scape. The impact of such advocacy is also limited by local political will, availability of resources and local cultural implications. Therefore there is a need to ensure that efforts to control diseases are tailored to specific populations and that resources are made available to support the advocacy.

Scant attention has been given to occupational health hazards of Australian veterinarians. This study aimed to identify the major risk factors for occupational injury and disease, emotional health and suicide rates of veterinarians. Qualitative in-depth interviews with 45 veterinarians were carried out which revealed that a significant proportion of veterinarians were both injured, stressed and had incurred zoonotic diseases. Data linkage of the names of registered veterinarians in Western Australia with four Health Department of Western Australia databases was undertaken to provide supportive statistics on the conditions identified as being important in the interviews. The results of this latter analysis were inconclusive. Therefore a self-administered questionnaire was developed, which collected quantitative data on injuries, disease, stress and risk factors from 419 veterinarians. Since the in-depth interviews had identified stress and suicide ideation as being very significant for many of those interviewed, the Kessler 10+ scale for measuring psychological distress was included in the self-administered questionnaire. The data linkage was unable to provide accurate data about numbers of deaths of veterinarians and the records of coroners in Victoria and Western Australia which provided data on 89 veterinarians, were analysed to determine suicide rates. Despite the interviews providing considerable information about rates and risk factors for injuries, disease and stress, no statistical analyses were undertaken because they provided insufficient data for quantitative analyses. / Nevertheless, statistics derived from the morbidity database using data-linkage, will be useful in comparing injuries in any future studies of this type. Data collected from the self-administered questionnaire were subjected to Chi square, and non-parametric tests and logistic regression analyses using multiple imputation for missing values. Age-standardised and age-specific rates (ASR) were calculated for data on suicide in veterinarians derived from coroners' records obtained from Western Australia and Victoria using the Rates Calculator developed by Codde.' The interviews and the survey of 464 veterinarians showed that a significant proportion of veterinarians incurred injuries and zoonotic diseases, and were highly stressed and distressed. The interviews showed that a significant proportion of veterinarians expected to be injured and/or contract zoonotic diseases. It is suggested that this acceptance may, in part, account for the number of injuries that occur. Some of these injuries, especially in mixed animal veterinarians, may be attributable to poor facilities on farms and a lack of competent support in restraint of animals. There needs to be a cultural change with regard to safety if injury is to be reduced. Using the Chi-squared analyses of the survey data, injury was associated with several risk factors including being a practice owner and being in mixed animal practice, being younger and with having taken drugs such as marijuana in the past 12 months. / When all these variables were input into a logistic regression model, several of these risk factors were eliminated providing only three risk factors as predictors of injury. These were: having a back injury; taking drugs in the previous 12 months; and being between 35 and 54 years of age. Having high distress levels was not a predictor for injury. Analyses of responses to the KlOi- scale in the self-administered questionnaire revealed that the proportion of highly distressed respondents was double that of the Western Australian, New South Wales and Australian general populations which supports the findings from the interviews. Logistic regression provided three predictors for distress: being less than 35 years of age, having taken drugs in the past 12 months, and having a back injury, however having other workplace injuries was not a predictor. The findings that the suicide rate in this study was about four times that of the general Australian adult population, should be of major concern and signal that there may be factors specific to the veterinary profession that account for this high rate. This study has shown that there are high levels of psychological distress in veterinarians, especially practitioners, which suggests that veterinary practice may, in itself, be a stressful occupation. However, it may also be that some individuals with a predilection for distress, are being recruited into the veterinary profession. / Better selection techniques for recruiting veterinary students using an aptitude test as well as interviews, could identify those who were unsuited for becoming veterinarians or who required additional mentoring and support upon graduation. This could reduce stress, distress and suicide in the veterinary profession. Overall, 17 recommendations were made directed at improving the quality of data collection to obtain more reliable statistical outcomes, and suggesting ways of reducing injury, distress and zoonotic disease in veterinarians.

Os parasitas pertencentes ao gênero Leishmania têm distribuição ubíqua. Este táxon inclui Leishmania infantum chagasi, agente etiológico da leishmaniose visceral nas Américas, uma zoonose negligenciada cujas metodologias diagnósticas acumulam uma série de limitações, requerendo a validação e padronização de metodologias diagnósticas satisfatórias. Vários fatores estão relacionados à patogênese causada por este protozoário, entre eles a catepsina L-like, uma cisteíno protease envolvida em processos regulatórios metabólicos e infecciosos. Portanto, este trabalho teve como objetivo avaliar a eficácia do gene de catepsina L-like isoforma CPA como alvo de diagnóstico molecular e como marcador filogenético que permita a compreensão das variações intraespecíficas e elucidem a história evolutiva de L. infantum chagasi no Brasil. Foram utilizados 44 isolados de L. infantum chagasi de diferentes estados brasileiros. Os fragmentos do gene de catepsina L-like foram amplificados, purificados, sequenciados, alinhados manualmente e analisados por métodos filogenéticos de máxima parcimônia e inferência bayesiana. As sequências geradas foram usadas para pesquisar e sintetizar iniciadores a serem usados em reações específicas para o parasita alvo. O gene de catepsina L-like não mostrou variabilidade intraespecífica entre os isolados analisados, sugerindo um evento recente de introdução do mesmo nas Américas. O par de iniciadores propostos amplificou o DNA alvo de isolados de L. infantum chagasi, sendo efetivo na amplificação de DNA em concentrações de até 10-11g / µl. O marcador proposto não apresentou reações cruzadas com outros hemoparasitas de importância clínica. Quando utilizado para o diagnóstico em um painel de amostras clínicas de cães, obteve-se uma frequência de positividade de 49,03% (102/208), contrastando com o valor de 14,42% (30/208) obtido com o marcador para o gene do espaçador ribossomal interno ITS. Quando testado em amostras de flebotomíneos se obteve um valor de 6,25% e em amostras de pacientes humanos o valor foi de 14,28%. Os marcadores também foram eficazes em amplificar DNA extraído de amostras de urina, de sangue fixado em papel filtro e mesmo em amostras de swab de lesões conjuntivas. Este conjunto de parâmetros permite inferir que o CatLeish- PCR é sensível e específico para o diagnóstico de L. infantum chagasi podendo ser aplicado tanto em pesquisas clínicas quanto em inquéritos epidemiológicos de vigilância. / The parasites belonging to the Leishmania genus have a wide distribution. This taxon includes Leishmania infantum chagasi, the etiologic agent of Visceral Leishmaniasis in the Americas, a neglected zoonosis that requires the validation and standardization of satisfactory diagnostic methodologies. Several factors are related to the pathogenesis caused by this protozoan, as Catepsin L-like, a cysteine protease involved in regulatory and infectious processes. Given this information this work aimed to evaluate the effectiveness of Cathepsin L-like isoform CPA as a target for molecular diagnosis and as a phylogenetic marker that allows understanding the intraspecific variations and the evolutionary history of L. infantum chagasi in Brazil. We used 44 isolates of L. infantum chagasi from different Brazilian states. The cathepsin L-like gene fragments were amplified, purified, sequenced, manually aligned and analyzed by maximum parsimony and Bayesian inference methods. The sequences generated were researched to construction of oligonucleotide primers to be used in reactions specific to the target parasite. The Cathepsin L-like gene did not show intraspecific variability among the isolates analyzed, suggesting a recent event of introduction of the same in the Americas. The pair of proposed primers amplified the target DNA of L. infantum chagasi isolates, being effective in DNA amplification at concentrations of up to 10-11g/µl. The proposed marker did not present cross-reactions with other hemoparasites of clinical importance. When used for the diagnosis in a panel of clinical samples of dogs obtained a positive frequency of 49.03% (102/208), against the 14.42% (30/208) to ribosomal ITS marker. Samples of sandflies obtained a value of 6.25% and in humans the value was 14.28%. The markers were also effective in blood samples fixed on filter paper and even in samples from conjunctival lesion swabs. This set of parameters allows to infer that CatLeish-PCR is a sensitive and specific marker for the diagnosis of L. infantum chagasi in clinical and epidemiological surveys.