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Estimates of the pharmacokinetics of famciclovir and its active metabolite penciclovir in young Asian elephants (Elephas maximus) 全文
2012
Brock, A Paige | Isaza, Ramiro | Hunter, Robert P. | Richman, Laura K. | Koch, David E. | Schmitt, Dennia L. | Montali, Richard J. | Lindsay, William A.
Objective: To determine plasma pharmacokinetics of penciclovir following oral and rectal administration of famciclovir to young Asian elephants (Elephas maximus). Animals: 6 healthy Asian elephants (5 females and 1 male), 4.5 to 9 years old and weighing 1,646 to 2,438 kg. Procedures: Famciclovir was administered orally or rectally in accordance with an incomplete crossover design. Three treatment groups, each comprising 4 elephants, received single doses of famciclovir (5 mg/kg, PO, or 5 or 15 mg/kg, rectally); there was a minimum 12-week washout period between subsequent famciclovir administrations. Serial blood samples were collected after each administration. Samples were analyzed for famciclovir and penciclovir with a validated liquid chromatography–mass spectroscopy assay. Results: Famciclovir was tolerated well for both routes of administration and underwent complete biotransformation to the active metabolite, penciclovir. Mean maximum plasma concentration of penciclovir was 1.3 μg/mL at 1.1 hours after oral administration of 5 mg/kg. Similar results were detected after rectal administration of 5 mg/kg. Mean maximum plasma concentration was 3.6 μg/mL at 0.66 hours after rectal administration of 15 mg/kg; this concentration was similar to results reported for humans receiving 7 mg/kg orally. Conclusions and Clinical Relevance: Juvenile Asian elephants are susceptible to elephant endotheliotropic herpesvirus. Although most infections are fatal, case reports indicate administration of famciclovir has been associated with survival of 3 elephants. In Asian elephants, a dose of 8 to 15 mg of famciclovir/kg given orally or rectally at least every 8 hours may result in penciclovir concentrations that are considered therapeutic in humans.
显示更多 [+] 显示较少 [-]Genomic sequence of infectious bursal disease virus from Zambia suggests evidence for genome re-assortment in nature 全文
2012
Christopher J. Kasanga | T. Yamaguchi | H.M. Munang’andu | P.N. Wambura | K. Ohya | H. Fukushi
Infectious bursal disease virus (IBDV) is a bi-segmented RNA virus, which belongs to the genus Avibirnavirus of the family Birnaviridae. Two serotypes, 1 and 2, exist in IBDV. The serotype 1 IBDVs are the causative agents of infectious bursal disease (IBD) in chickens worldwide and lead to immunosuppression in young birds. Genome re-assortment has been speculated to occur and contribute to the emergence of new IBDV strains. However, evidence was lacking until recently when two re-assortant viruses were detected in China. In this study, we determined the complete nucleotide sequence of an IBDV, designated KZC-104, from a confirmed natural IBD outbreak in Lusaka, Zambia in 2004. The genome consisted of 3074 and 2651 nucleotides in the coding regions of segments A and B, respectively. Alignment of both nucleotide and deduced amino acid sequences, and phylogenetic analysis revealed that the genome segment A of KZC-104 was derived from a very virulent strain, whereas its segment B was derived from a classical attenuated strain. On BLAST search, the full-length segments A and B sequences showed 98% closest nucleotide homology to the very virulent strain D6948 and 99.8% closest nucleotide homology to the classical attenuated strain D78, respectively. This is a unique IBDV reassortant strain, which has emerged in nature involving segment B of a live attenuated vaccine. This observation provides direct evidence for the involvement of vaccine strains in the emergence of reassortant IBDV in the field. Taken together, these findings suggest an additional risk of using live IBDV vaccines, which may act as genetic donors for genome re-assortment. Further studies are required to investigate the epidemiology and biological characteristics of reassortant strains so that the appropriate and safe IBDV vaccines can be recommended.
显示更多 [+] 显示较少 [-]Epidemiological perspectives of ticks and tick-borne diseases in South Sudan: Cross-sectional survey results 全文
2012
Fredrick M. Kivaria | Angolwisye M. Kapaga | Gabriel K. Mbassa | Paul F. Mtui | Rhombe J. Wani
A cross-sectional study was conducted between September and October 2010 in five states of South Sudan that were selected on the basis of the perceived risk of tick-borne diseases. The purpose was to investigate epidemiological parameters of tick-borne diseases in South Sudan and their uses in future control strategies. A total of 805 calves were assessed by clinical, microscopic and serological examination and tick counts. The indirect Enzyme-Linked Immuno-Sorbent Assay (ELISA) was used to detect antibodies to<em> Theileria parva</em>, <em>Theileria mutans</em>, <em>Anaplasma marginale</em> and <em>Babesian bigemina</em>. Sero-conversion risks for <em>T. parva</em> and <em>T. mutans</em> were 27.3% and 31.3% respectively, whilst the risk was 57.6% and 52.8% for <em>A. marginale</em> and <em>B. bigemina</em>, respectively. Major tick species identified include <em>Rhipicephalus appendiculatus</em>, <em>Rhipicephalus decoloratus</em>, <em>Rhipicephalus microplus</em>, <em>Amblyomma variegatum</em>, and <em>Rhipicephalus evertsi</em>. There was great variation (<em>P</em> ≤ 0.001) in the number of all these ticks, both between herds in a state and between calves in an individual herd. The low and intermediate sero-conversion risks observed in the study states suggest that immunisation against East Coast fever (ECF) is justified. Fortunately, three major genotypes that were identified by applying Polymerase Chain Reaction Restriction Fragment Length Polymorphism (PCRRFLP) analysis on the p104 to the blood samples and T. parva Muguga, matched very well with <em>T. parva</em> Kiambu 5 and <em>T. parva</em> Muguga; therefore the Muguga cocktail can be used for the immunisation of cattle in South Sudan. However, prospective studies are required to develop optimal control measures for tick-borne diseases under different ecological and husbandry practices in South Sudan.
显示更多 [+] 显示较少 [-]Unexpectedly low seroprevalence of toxoplasmosis in South Africa 全文
2012
K. Kistiah | John Frean | J. Winiecka-Krusnell | A. Barragan
Toxoplasmosis is an infection of warm-blooded vertebrates caused by the obligate intracellular protozoan parasite, Toxoplasma gondii. It is one of the most common parasitic diseases of humans, infecting approximately one-third of the world’s population. In persons with advanced HIV, toxoplasmosis represents a major opportunistic infection of the central nervous system. Approximately two-thirds of all people living with HIV live in sub-Saharan Africa. In areas such as this, toxoplasmosis could theoretically pose a huge threat. There is little known about T. gondii prevalence in humans in Africa. Geographically, prevalences vary widely on this continent, as observed in other parts of the world. There is limited historical information about the disease in South Africa. More knowledge is needed at a regional level about the risk of toxoplasmosis, diagnostic issues, and measures to reduce the risk to susceptible persons. The seroprevalence of T. gondii in selected populations, namely HIV-positive and HIV-negative individuals, and a more general sample biased towards pregnant women, was therefore investigated and found to be 9.8% (37/376), 12.8% (48/376) and 6.4% (32/497) respectively. Compared with historical data from South Africa, the prevalence has decreased substantially; however, the incidence of clinical disease is unknown, despite the very high burden of HIV and AIDS cases (5.9 million and 0.7 million, respectively in 2009). This study provided information relating to the diagnosis and current seroprevalence of T. gondii in South Africa. Many questions still remain to be answered however, to fully understand the impact of this parasite on the country’s population.
显示更多 [+] 显示较少 [-]The African buffalo: A villain for inter-species spread of infectious diseases in southern Africa 全文
2012
Anita L. Michel | Roy G. Bengis
The African buffalo: A villain for inter-species spread of infectious diseases in southern Africa 全文
2012
Anita L. Michel | Roy G. Bengis
The African buffalo (Syncerus caffer) is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after ‘Big Five’ in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD), Corridor disease (theileriosis), bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population’s survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations.
显示更多 [+] 显示较少 [-]The African buffalo: A villain for inter-species spread of infectious diseases in southern Africa 全文
2012
Michel, Anita L.(University of Pretoria Department of Veterinary Tropical Diseases) | Bengis, Roy G(Directorate Veterinary Services)
The African buffalo (Syncerus caffer) is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after 'Big Five' in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD), Corridor disease (theileriosis), bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population's survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations.
显示更多 [+] 显示较少 [-]First International One Health congress 全文
2012
Martyn H. Jeggo
More than 650 people from around 60 countries attended the 1st International One Health Conference, held in Melbourne from 14 to 16 February 2011. Scientists, clinicians, government and community members from a range of disciplines came together to discuss the benefits of working together to promote a One Health approach to human, animal and environmental health. One Health embraces systems thinking and recognising the interdependence of people, animals and environment. The conference was hosted by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and was supported by international agencies, the Australian and Canadian governments, and industry. The Organising Committee recognised from the outset, the need to provide a forum not just for scientific presentation, but for open discussion and dialogue around the policy and political issues, as well as the science that drives the One Health agenda. The Committee was also cognizant of the need to embrace a definition of One Health that includes food security and food safety and included the social and economic pressures that shapes this area. The meeting was therefore organised under four themes with plenary sessions followed by breakout parallel sessions for each of these. The themes covered Disease Emergence, Environmental Drivers, Trade, Food Security and Food Safety, and Science Policy and Political Action. The plenary session commenced with one or two keynote presentations by world leaders on the topic being covered, followed by panel discussions involving six to eight experts and involving all participants at the congress. Each of the panel members spoke briefly on the topic covered by the keynote speaker and were asked to be as provocative as possible. The discussions that followed allowed debate and discussion on the keynote presentations and the panel members comments. This was followed by six to eight parallel breakout sessions involving in depth papers on the session’s topic. Throughout the conference at various times, sponsored sessions dealt with particular areas of science or policy providing a further framework not only to learn current science but for debate and discussion. A full copy of all abstracts is available on the web at http://www.springerlink.com. In concluding the Congress recognised the interdependence of, and seeks to improve human, animal and environmental health; recognised that communication, collaboration and trust between human and animal health practitioners is at the heart of the One Health concept; agreed that a broad vision that includes other disciplines such as economics and social behaviour is essential to success. The Congress stressed the need to promote the ‘do-able’ such as improving surveillance and response for emerging infectious diseases whilst developing the broader approach. It identified a need to emphasise community participation and development of community capacity, and especially, an open transparent dialogue with both a ‘ground up’ and ‘top down’ approach that would lead to an improved understanding of our ecosystems, including molecular ecobiology, are an essential part of One Health.
显示更多 [+] 显示较少 [-]A Lean Six Sigma approach to the improvement of the selenium analysis method 全文
2012
Bronwyn C. Cloete | André Bester
Reliable results represent the pinnacle assessment of quality of an analytical laboratory, and therefore <em>variability</em> is considered to be a critical quality problem associated with the selenium analysis method executed at Western Cape Provincial Veterinary Laboratory (WCPVL). The elimination and control of variability is undoubtedly of significant importance because of the narrow margin of safety between toxic and deficient doses of the trace element for good animal health. A quality methodology known as Lean Six Sigma was believed to present the most feasible solution for overcoming the adverse effect of variation, through steps towards analytical process improvement. Lean Six Sigma represents a form of scientific method type, which is empirical, inductive and deductive, and systematic, which relies on data, and is fact-based. The Lean Six Sigma methodology comprises five macro-phases, namely Define, Measure, Analyse, Improve and Control (DMAIC). Both qualitative and quantitative laboratory data were collected in terms of these phases. Qualitative data were collected by using quality-tools, namely an Ishikawa diagram, a Pareto chart, Kaizen analysis and a Failure Mode Effect analysis tool. Quantitative laboratory data, based on the analytical chemistry test method, were collected through a controlled experiment. The controlled experiment entailed 13 replicated runs of the selenium test method, whereby 11 samples were repetitively analysed, whilst Certified Reference Material (CRM) was also included in 6 of the runs. Laboratory results obtained from the controlled experiment was analysed by using statistical methods, commonly associated with quality validation of chemistry procedures. Analysis of both sets of data yielded an improved selenium analysis method, believed to provide greater reliability of results, in addition to a greatly reduced cycle time and superior control features. Lean Six Sigma may therefore be regarded as a valuable tool in any laboratory, and represents both a management discipline, and a standardised approach to problem solving and process optimisation.
显示更多 [+] 显示较少 [-]Development of a curriculum for training in One Health analytical epidemiology at the University of Zambia 全文
2012
J. Muma | Martin Simuunza | K. Mwachalimba | M. Munyeme | B. Namangala | C. Hankanga | G. Sijumbila | R. Likwa Ndonyo | Yona Sinkala | A. Mwanza | A. Simanyengwe Mweene
Development of a curriculum for training in One Health analytical epidemiology at the University of Zambia 全文
2012
J. Muma | Martin Simuunza | K. Mwachalimba | M. Munyeme | B. Namangala | C. Hankanga | G. Sijumbila | R. Likwa Ndonyo | Yona Sinkala | A. Mwanza | A. Simanyengwe Mweene
Recently, the world has witnessed emergence of novel diseases such as avian influenza, HIV and AIDS, West Nile Virus and Ebola. The evolution of these pathogens has been facilitated mainly by a constantly evolving animal-human interface. Whilst infectious disease control was previously conceptualised as either public health or animal health related issues, the distinction between disciplinary foci have been blurred by multiple causal factors that clearly traverse traditional disciplinary divides. These multiple evolutionary pressures have included changes in land use, ecosystems, human-livestock-wildlife interactions and antibiotic use, representing novel routes for pathogen emergence. With the growing realisation that pathogens do not respect traditional epistemological divides, the ‘One Health’ initiative has emerged to advocate for closer collaboration across the health disciplines and has provided a new agenda for health education. Against this background, the One Health Analytical Epidemiology course was developed under the auspices of the Southern African Centre for Infectious Diseases Surveillance by staff from the University of Zambia with collaborators from the London School of Hygiene and Tropical Medicine and the Royal Veterinary College in London. The course is aimed at equipping scientists with multidisciplinary skill sets to match the contemporary challenges of human, animal and zoonotic disease prevention and control. Epidemiology is an important discipline for both public and animal health. Therefore, this two-year programme has been developed to generate a cadre of epidemiologists with a broad understanding of disease control and prevention and will be able to conceptualise and design holistic programs for informing health and disease control policy decisions.
显示更多 [+] 显示较少 [-]Development of a curriculum for training in One Health analytical epidemiology at the University of Zambia 全文
2012
Muma, J.B.(University of Zambia Department of Disease Control) | Simuunza, Martin(University of Zambia Department of Disease Control) | Mwachalimba, K.(University of Zambia Department of Disease Control) | Munyeme, M.(University of Zambia Department of Disease Control) | Namangala, B.(University of Zambia Department of Paraclinical Studies) | Hankanga, C.(University of Zambia Department of Clinical Studies) | Sijumbila, G.(University of Zambia School of Medicine) | Ndonyo, R. Likwa(University of Zambia School of Medicine) | Sinkala, Yona(Department of Veterinary and Livestock Development) | Mwanza, A.(University of Zambia Department of Clinical Studies) | Mweene, A. Simanyengwe(University of Zambia Department of Disease Control)
Recently, the world has witnessed emergence of novel diseases such as avian influenza, HIV and AIDS, West Nile Virus and Ebola. The evolution of these pathogens has been facilitated mainly by a constantly evolving animal-human interface. Whilst infectious disease control was previously conceptualised as either public health or animal health related issues, the distinction between disciplinary foci have been blurred by multiple causal factors that clearly traverse traditional disciplinary divides. These multiple evolutionary pressures have included changes in land use, ecosystems, human-livestock-wildlife interactions and antibiotic use, representing novel routes for pathogen emergence. With the growing realisation that pathogens do not respect traditional epistemological divides, the 'One Health' initiative has emerged to advocate for closer collaboration across the health disciplines and has provided a new agenda for health education. Against this background, the One Health Analytical Epidemiology course was developed under the auspices of the Southern African Centre for Infectious Diseases Surveillance by staff from the University of Zambia with collaborators from the London School of Hygiene and Tropical Medicine and the Royal Veterinary College in London. The course is aimed at equipping scientists with multidisciplinary skill sets to match the contemporary challenges of human, animal and zoonotic disease prevention and control. Epidemiology is an important discipline for both public and animal health. Therefore, this two-year programme has been developed to generate a cadre of epidemiologists with a broad understanding of disease control and prevention and will be able to conceptualise and design holistic programs for informing health and disease control policy decisions.
显示更多 [+] 显示较少 [-]Filoviral haemorrhagic fevers: A threat to Zambia? 全文
2012
Katendi Changula | A.S. Mweene
Filoviral haemorrhagic fevers (FVHF) are caused by agents belonging to Filoviridae family, Ebola and Marburg viruses. They are amongst the most lethal pathogens known to infect humans. Incidence of FVHF outbreaks are increasing, with affected number of patients on the rise. Whilst there has been no report yet of FVHF in Zambia, its proximity to Angola and Democratic Republic of Congo, which have recorded major outbreaks, as well as the open borders, increased trade and annual migration of bats between these countries, puts Zambia at present and increased risk. Previous studies have indicated bats as potential reservoir hosts for filoviruses. An increasing population with an increasing demand for resources has forced incursion into previously uninhabited land, potentially bringing them into contact with unknown pathogens, reservoir hosts and/or amplifying hosts. The recent discovery of a novel arenavirus, Lujo, highlights the potential that every region, including Zambia, has for being the epicentre or primary focus for emerging and re-emerging infections. It is therefore imperative that surveillance for potential emerging infections, such as viral haemorrhagic fevers be instituted. In order to accomplish this surveillance, rapid detection, identification and monitoring of agents in patients and potential reservoirs is needed. International co-operation is the strategy of choice for the surveillance and fight against emerging infections. Due to the extensive area in which filoviral infections can occur, a regional approach to surveillance activities is required, with regional referral centres. There is a need to adopt shared policies for the prevention and control of infectious diseases. There is also need for optimisation of currently available tests and development of new diagnostic tests, in order to have robust, highly sensitive and specific diagnostic tests that can be used even where there are inadequate laboratories and diagnostic services.
显示更多 [+] 显示较少 [-]Vector competence of <i>Glossina austeni</i> and <i>Glossina brevipalpis</i> for <i>Trypanosoma congolense</i> in KwaZulu-Natal, South Africa 全文
2012
Makhosazana Motloang | Justin Masumu | Barend Mans | Peter van den Bossche | Abdalla Latif
Tsetse-transmitted trypanosomosis (nagana) has been the cause of stock losses in the recent past and still presents a major problem to livestock owners in certain areas of KwaZulu- Natal, South Africa. Over 10 000 cattle mortalities were reported in the 1990 nagana outbreak. Although information on the distribution and abundance of the tsetse flies Glossina brevipalpis and Glossina austeni in KwaZulu-Natal exists, data on their vector competence are lacking. This study aimed to determine the rate of natural Trypanosoma congolense infection by field-collected as well as colony-reared flies of these species. A total of 442 field-collected G. brevipalpis and 40 G. austeni flies were dissected immediately after collection to determine their infection rates, whilst 699 G. brevipalpis and 49 G. austeni flies were fed on susceptible animals in 10 and four batches, respectively, for use in xenodiagnosis experiments. Teneral colony flies were fed on infected animals and dissected 21 days post infection to confirm their infectivity testing. Glossina austeni harboured 8% immature and mature infections. In G. brevipalpis, the infection with the immature stages was lower (1%) and no mature infections were observed. Although all four batches of G. austeni transmitted T. congolense to four susceptible animals, no transmission resulted from 10 batches of G. brevipalpis fed on susceptible cattle. Colony-derived G. austeni (534) and G. brevipalpis (882) were fed on four bovines infected with different T. congolense isolates. Both G. austeni and G. brevipalpis acquired trypanosome infection from the bovines, with immature infection ranges of 20% – 33% and 1% – 4%, respectively. Parasites, however, only matured in G. austeni (average = 4%). Glossina austeni plays a larger role in the epidemiology of animal trypanosomosis in KwaZulu-Natal than G. brevipalpis and therefore more focus should be aimed at the former when control measures are implemented.
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