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Economic impacts of tick-borne diseases in Africa : tick-borne diseases 全文
2009
B.D. Perry
As we join Onderstepoort in celebrating its centenary, it is worth reflecting that tick-borne infections of wildlife and livestock have been part of everyday life in Africa for many, many generations. While much has changed since Watkins-Pitchford started developing short-interval dipping trials with arsenicals to contain the new epidemic of East Coast fever in southern Africa 100 years ago, when it comes to the impacts of tick-borne infections, many of the same challenges remain.
显示更多 [+] 显示较少 [-]Theiler and the 'Spirit of Onderstepoort' Introductory keynote address : historical overview : Onderstepoort and veterinary research in Africa 全文
2009
R.D. Bigalke
Although Theiler became internationally known for his pioneering veterinary research a distant century ago, there are probably few veterinary researchers today who have not heard of him. Onderstepoort, the research institute he created, is equally well, if not even better, known. Moreover, the name Onderstepoort is not only associated with his institute but also with the only South African faculty of veterinary science, another Theiler 'baby'. The purpose of this presentation is to determine why this was so, and to what extent the fame was justified. Was it due to the 'Spirit of Onderstepoort' sometimes referred to by Theiler in the early as well as later stages of his career, or was there perhaps more to it, and what was Theiler's share in the development of that spirit, that fame
显示更多 [+] 显示较少 [-]More appropriate disease control policies for the developing world 全文
2009
Mariner, J.C.(International Livestock Research Institute)
Investment in disease control should be targeted to critical points that provide the greatest benefit to the livelihoods of livestock-dependent stakeholders. Risk-based targeting should balance the impacts of diseases against the feasibility of their control. This requires sensitive and specific surveillance systems that provide representative overviews of the animal health situation for accurate assessment of disease impact and transmission patterns. Assessment of impact should include household and market effects. The key in surveillance is involving livestock owners using active methods that ensure their disease priorities are addressed. Epidemiological targeting of interventions to critical points in disease transmission cycles should be done to obtain maximal disease reduction. Interventions should be delivered in full partnership with both private and community-based stakeholders to assure high uptake and sustainability. In developing countries, approaches such as participatory disease surveillance and community-based animal health programs have been effective and comply with international animal health standards.
显示更多 [+] 显示较少 [-]The comparative prevalence of five ixodid tick species infesting cattle and goats in Maputo Province, Mozambique 全文
2009
De Matos, C.(Instituto de Investigação Agrária de Mozambique ,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Sitoe, C.(Instituto de Investigação Agrária de Mozambique) | Neves, L.(Universidade Eduardo Mondlane Faculdade de Veterinária) | Nöthling, J.O.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Horak, I.G.(University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases,University of the Free State Department of Zoology and Entomology)
Tick infestation, and udder and teat damage in selected cattle herds of Matabeleland South, Zimbabwe 全文
2009
Ndhlovu, D.N.(Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Makaya, P.V.(Central Veterinary Laboratory Division of Veterinary Services) | Penzhorn, B.L.(Faculty of Veterinary Science Department of Veterinary Tropical Diseases)
A cross-sectional survey was conducted to determine tick infestation, and udder and teat damage in 286 lactating cows and heifers at six properties in the smallholder and commercial sectors in Gwanda district of Matabeleland South Province, Zimbabwe. Eight tick species were identified: Amblyomma hebraeum, Hyalomma truncatum, Hyalomma marginatum rufipes, Rhipicephalus evertsi evertsi, Rhipicephalus (Boophilus) decoloratus, Rhipicephalus appendiculatus, Rhipicephalus zambeziensis and Rhipicephalus simus. Overall, 81.5 % of the cattle were tick infested; prevalence of tick-infested cattle was significantly higher on communal land (93.8 %) and recently claimed land (85.1 %) than on commercial farms. The mean tick load on infested cattle on communal land was significantly higher than in the other two sectors. Although 53 % of the sampled cattle had some degree of udder and teat damage, very few farmers (2.6 %) treated their cattle for these conditions. Udder damage was ca. two times and three times, respectively, more likely to occur in cattle on communal land compared to cattle on recently claimed land and commercial farms. The occurrence of R. appendiculatus and R. zambeziensis indicate that the cattle population in the study area is at high risk of a theileriosis outbreak, a tick-borne disease that has not been reported from this area.
显示更多 [+] 显示较少 [-]Study on the efficacy and safety of different antigens and oil formulations of infectious coryza vaccines containing an NAD-independent strain of Avibacterium paragallinarum 全文
2009
Dungu, B.(Onderstepoort Biological Products) | Brett, B.(Onderstepoort Biological Products) | Macdonald, R.(Onderstepoort Biological Products) | Deville, S.(SEPPIC) | Dupuis, L.(SEPPIC) | Theron, J.(University of Pretoria Department of Microbiology and Plant Pathology) | Bragg, R.R.(University of the Free State)
The present study was designed to assess and compare three different formulations of the new Onderstepoort infectious coryza (IC) quadrivalent vaccine, which contain an NAD-independent strain of Avibacterium paragallinarum (previously known as Haemophilus paragallinarum), and a commercial IC vaccine, not containing an NAD-independent strain, for their safety and ability to protect chickens of varying ages against virulent challenges with four different serovars of A. paragallinarum, including the NAD-independent strain of the C-3 serovar. Four groups of 140 chickens each were vaccinated at the age of 17 weeks and revaccinated at the age of 19 weeks with each of the four vaccine formulations. A similar sized group of non-vaccinated chickens was used as control. Two rounds of challenge were conducted: a group of chicken in each vaccination group was challenged between 31 and 35 weeks of age, while another group was challenged between 51 and 55 weeks of age. The "in-contact" challenge model was used in this experiment. For each vaccination group, the four challenge strains representing four local serovars were used in each challenge round. The efficacy of the vaccines was compared based on overall protection levels obtained and the duration of protection. The safety of the different vaccines was determined by the severity of post-vaccination reactions. The need for the incorporation of the NAD-independent strain in the vaccine was evidenced by the low protection level against NAD-independent challenge recorded in the group of birds vaccinated with the commercial vaccine. The results obtained confirmed not only the variation in virulence of different South African serovars, with serovar C-3 being the most virulent and serovar B having almost no virulence but also the age related increase in susceptibility. The importance of a suitable formulation of the vaccine is discussed.
显示更多 [+] 显示较少 [-]Morphology of the tongue of the emu (Dromaius novaehollandiae). I. Gross anatomical features and topography 全文
2009
Crole, M.R.(University of Pretoria Faculty of Veterinary Science Department of Anatomy and Physiology) | Soley, J.T.(University of Pretoria Faculty of Veterinary Science Department of Anatomy and Physiology)
Despite numerous papers addressing the topic, the gross morphology of the ratite tongue and more specifically that of the emu, has been superficially or poorly described. This paper presents the first definitive macroscopic description of the emu tongue and reviews, consolidates and compares the scattered information on the gross morphology of the ratite tongue available in the literature. Twenty-three heads obtained from birds at slaughter were used for this study. Specimens were fixed in 10 % neutral buffered formalin, rinsed and the gross anatomy described. The emu tongue is divided into a body and a root. The body is triangular, dorsoventrally flattened, pigmented and displays caudally directed lingual papillae on both the lateral and caudal margins. The root, a more conspicuous structure in comparison to other ratites, is triangular, with a raised bulbous component folding over the rostral part of the laryngeal fissure. Following the general trend in ratites, the emu tongue is greatly reduced in comparison to the bill length and is specifically adapted for swallowing during the cranioinertial method of feeding employed by palaeognaths. This study revealed that it is not only the shape of the tongue that differs between ratites, as previously reported, but also its colour, appearance of its margins and root, and its length in comparison to the bill, and the shape of the paraglossum.
显示更多 [+] 显示较少 [-]Comparative histopathology of the lymph nodes, spleen, liver and kidney in experimental ovine trypanosomosis 全文
2009
Omotainse, S.O.(University of Agriculture College of Veterinary Medicine Department of Veterinary Pathology) | Anosa, V.O.(University of Ibadan Faculty of Veterinary Medicine Department of Veterinary Pathology)
The infection of Yankassa rams with three important trypanosome species affecting livestock, namely, Trypanosoma congolense, T. vivaxand T. bruceiproduced both acute and chronic fatal conditions. Chronic infections were induced in the three infections by the application of subcurative doses of diaminazene aceturate (Berenil®). Pathological changes in the infected animals included splenomegaly and hepatomegaly which were more pronounced in acute than in chronic T. congolense infection. However, these changes were more severe in chronic than in acute T. vivax infection. While splenomegaly was more pronounced in chronic T. brucei infection than in acute, hepatomegaly and lymphadenopathy were more severe in acute than in the chronic condition. The increases in size of the spleen, lymph nodes and liver were associated with congestion, increases in cell density related to increased immunological reactions in the spleen and lymph nodes as well as increase in numbers, size and activity of the phagocytic cells in these organs.
显示更多 [+] 显示较少 [-]Traditional remedies used for the treatment of cattle wounds and myiasis in Amatola Basin, Eastern Cape Province, South Africa 全文
2009
Soyelu, O.T.(University of Fort Hare Faculty of Science and Agriculture Department of Animal Science) | Masika, P.J.(University of Fort Hare Agricultural and Rural Development Research Institute)
A questionnaire survey was carried out to document traditional remedies used in the treatment of cattle wounds and myiasis in Amatola Basin. Eighty-three cattle farmers from nine villages were interviewed. The majority of respondents (67.9 %) use traditional remedies for treatment of these conditions. However, 25.9 % of them use a combination of traditional remedies with conventional medicines. The survey revealed that 13 medicinal plants belonging to 11 families were used. Aloe ferox, Prunus persica and Phytolacca heptandra were, however, the most commonly used. Leaves are the most frequently used plant part, often prepared as an infusion. Other non-plant remedies used include disinfectants, antiseptics as well as diesel and petrol. Manual removal of maggots from wounds was also practise and treatment is usually continued until the wound heals.
显示更多 [+] 显示较少 [-]The pathology of tuberculosis caused by Mycobacterium tuberculosis in a herd of semi-free-ranging springbok (Antidorcas marsupialis) 全文
2009
Gous, T.A.(University of Pretoria Faculty of Veterinary Science Department of Paraclinical Sciences) | Williams, M.C.(University of Pretoria Faculty of Veterinary Science Department of Paraclinical Sciences)
The first detailed description of the pathology of tuberculosis, caused by Mycobacterium tuberculosis, in springbok is reported. The springbok were part of a semi-free-ranging herd kept on the grounds of iThemba Laboratory for Accelerator Based Science (LABS) in the Kuils River district of the Western Cape Province, South Africa. Mycobacterium tuberculosis was isolated from three animals out of a total of 33 sampled, with two animals showing tuberculosis lesions. The index case was an adult ewe that showed advanced miliary tuberculosis with marked macroscopic and microscopic lesions in the lungs, pleura and respiratory lymph nodes, and numerous acid-fast bacilli. Six healthy rams were sampled nine months later and a pilot study indicated miliary tuberculosis lesions in one ram, which again were macroscopically most prominent in the lungs, pleura and respiratory lymph nodes. Macroscopic lesions were also noted in the sternal, iliac, prefemoral and retropharyngeal lymph nodes. Microscopy in this animal revealed lesions in the macroscopically affected organs as well as numerous other lymph nodes, and suspected lesions occurred in the testicle and colon. Acid-fast bacilli were scarce to moderate in affected organs. Because of the miliary nature of the lesions in both affected animals, the route of infection could not be established conclusively. The lesions in most affected organs of both animals resembled classical tuberculous granulomas. A main study conducted on healthy animals 19 months after the pilot study failed to find any animal with tuberculosis lesions in the group of 25 sampled, and all were negative for mycobacteria via mycobacterial culture.
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