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The prevalence and distribution of <i>Argas walkerae</i> (Acari: Argasidae) in the eastern region of the Eastern Cape Province, South Africa : research communications
2008
N. Nyangiwe | B. Gummow | I.G. Horak
The prevalence and geographic distribution of the fowl tampan, Argas walkerae Kaiser & Hoogstraal, 1969 was determined in the eastern region of the Eastern Cape Province, South Africa by inspecting two fowl houses in the vicinity of each of 72 randomly selected communal cattle dip-tanks. Tampans were collected from 102 (70.8 %) of the 144 fowl houses in the neighbourhood of 57 (79.2 %) of the 72 selected dip-tanks, and the localities of the collections were mapped. Argas walkerae was present in fowl houses from the warm coastal regions of the Indian Ocean in the south to the cold and mountainous Drakensberg in the north-east of the Province. Taking into account the probable sensitivity of the sampling method, it is estimated that A. walkerae is likely to be present in fowl houses belonging to between 74 and 84 % of communities making use of cattle dip-tanks in the eastern region of the Eastern Cape Province, and that when it is present, between 64 and 75 % of fowl houses will be infested. The geographic distribution of A. walkerae seemed to be more strongly associated with the presence of fowls and fowl houses containing raw or processed wood in their structure than with climate.
Show more [+] Less [-]Naturally acquired antibodies to <i>Bacillus anthracis</i> protective antigen in vultures of southern Africa
2008
P. C.B. Turnbull | M. Diekman | J. W. Killian | W. Versfeld | V. De Vos | L. Arntzen | K. Wolter | P. Bartels | A. Kotze
TURNBULLP, P.C.B. DIEKMANNM,M., KILIAN, J.W., VERSFELDW, W.,DE VOS, V., ARNTZENL, L.,WOLTER, K., BARTELS, P. & KOTZE, A. 2008.N aturally acquired antibodies to Bacillusa nthracisp rotective antigeni n vultureso f southern Africa. Onderstepoort Journal of Veterinary Research, T5:95-102 Sera from 19 wild caught vultures in northern Namibia and 15 (12 wild caught and three captive bred but with minimal histories) in North West Province, South Africa, were examined by an enzyme-linked immunosorbenats say( ELISA)f or antibodiesto the Bacillus anthracis toxin protective antigen (PA). As assessed from the baseline established with a control group of ten captive reared vultures with well-documented histories, elevated titres were found in 12 of the 19 (63%) wild caught Namibian birds as compared with none of the 15 South African ones. There was a highly significant difference between the Namibian group as a hole and the other groups (P < 0.001) and no significant difference between the South African and control groups (P > 0.05). Numbers in the Namibian group were too small to determine any significances in species-, sex- or age-related differences within the raw data showing elevated titres in four out of six Cape Vultures, Gyps coprotheress, six out of ten Whitebacked Vultures, Gyps africanus, and one out of three Lappet-faced Vultures, Aegypiust racheliotus, or in five of six males versus three of seven females, and ten of 15 adults versus one of four juveniles. The results are in line with the available data on the incidence of anthrax in northern Namibia and South Africa and the likely contact of the vultures tested with anthrax carcasses. lt is not known whether elevated titre indicates infection per se in vultures or absorption of incompletely digested epitopes of the toxin or both. The results are discussed in relation to distances travelled by vultures as determined by new tracking techniques, how serology can reveal anthrax activity in an area and the issue of the role of vultures in transmission of anthrax.
Show more [+] Less [-]Studies on effects of lactose on experimental <i>Trypanosoma vivax</i> infection in Zebu cattle. 1. Plasma kinetics of intravenously administered lactose at onset of infection and pathology
2008
M. Y. Fatihu | S. Adamu | I. A. Umar | N. D.G. Ibrahim | L. O. Eduvie | K. A.N. Esievo
Lactose in normal saline was administered intravenously to a group of Zebu cattle infected with Trypanosoma vivax to determine the bloodplasma kinetics at onset of an experimental infection and its ability to protect tissues against damage as part of preliminary studies to determine its suitability for use in the treatment of trypanosomosis. Significant (P <0.01) higher lactose concentrations were observed in the T. vivax-intecled bulls at 30 min and 1h (P< 0.05) post-infectio (p.i.) and by 4 h p.i. the plasma lactose remained above the level prior to infusion, after which it fell slightly below the preinfusion level in the uninfected group. Calculated pharmacokinetic parameters revealed delayed excretion of lactose in the T. vivax-intected group soon after infection. The total body clearance (C/B )was significantly (P < 0.05) reduced. The biological half-life (t1/2), elimination rate constant (kel) and apparent volume of distribution (Vd) were relatively decreased (P > 0.05) as a result of the T. vivax infection. Retention of lactose in the plasma was attributed to decreased plasma clearance l.t is suggested that the presence of trypanosomes in circulation rather than organic lesions could have been responsible for the delay observed in the excretion of lactose. At 12 weeks p.i., when the experiment was terminated, the group infected and given lactose infusion (despiteh igherp arasitaemia) had no gross or histopathological lesions in the brain, spleen, lymphnodes, heart, kidneys, liver and testes. However, the group infected but not infused with lactose were emaciated, had pale mucosae, watery blood, general muscular atrophy, serous atrophy of coronary fat and other adiposet issue, hepatomegalys, plenomegalys, wollen and oedematous lymph nodes, all of which are suggestive of trypanosomosis. Histopathological lesions included arrowing of Bowman's space and hypercellularity of glomerular tufts in the kidneys with the mean glomerula truft nucleairn dices (GTNs) in the group significantly higher (P <0.01)than the mean GTNs of the lactoseinfused and control bulls. Degenerative changes occurred in the myocardium, spleen, testes and epididymides. The tesicular and epididymal lesions are indicative of male reproductive dysfunction.
Show more [+] Less [-]2-Phenoxyethanol as anaesthetic in removing and relocating 102 species of fishes representing 30 families from Sea World to uShaka Marine World, South Africa
2008
D.B. Vaughan | M.R. Penning | K.W. Christison
2-Phenoxyethanol was used as an anaesthetic to translocate 102 species of fishes representing 30 families from the Sea World aquarium on Durban's beachfront to uShaka Marine World. Most fishes responded well to a final anaesthetic concentration of 0,150 mℓ / ℓ and there were no mortalities.
Show more [+] Less [-]Naturally acquired antibodies to Bacillus anthracis protective antigen in vultures of southern Africa
2008
Turnbull, P.C.B.(Arjemptur Technology Ltd) | Diekmann, M.(Rare and Endangered Species Trust) | Kilian, J.W.(Etosha Ecological Institute) | Versfeld, W.(Etosha Ecological Institute) | De Vos, V. | Arntzen, L.(National Institute for Communicable Diseases) | Wolter, K.(Rhino and Lion Wildlife Conservation NPO Nyoka Ridge) | Bartels, P.(National Zoological Gardens of SA) | Kotze, A.(National Zoological Gardens of SA ,University of the Free State)
Sera from 19 wild caught vultures in northern Namibia and 15 (12 wild caught and three captive bred but with minimal histories) in North West Province, South Africa, were examined by an enzyme-linked immunosorbent assay (ELISA) for antibodies to the Bacillus anthracis toxin protective antigen (PA). As assessed from the baseline established with a control group of ten captive reared vultures with well-documented histories, elevated titres were found in 12 of the 19 (63 %) wild caught Namibian birds as compared with none of the 15 South African ones. There was a highly significant difference between the Namibian group as a whole and the other groups (P < 0.001) and no significant difference between the South African and control groups (P > 0.05). Numbers in the Namibian group were too small to determine any significances in species-, sex- or age-related differences within the raw data showing elevated titres in four out of six Cape Vultures, Gyps coprotheres, six out of ten White-backed Vultures, Gyps africanus, and one out of three Lappet-faced Vultures, Aegypius tracheliotus, or in five of six males versus three of seven females, and ten of 15 adults versus one of four juveniles. The results are in line with the available data on the incidence of anthrax in northern Namibia and South Africa and the likely contact of the vultures tested with anthrax carcasses. It is not known whether elevated titre indicates infection per se in vultures or absorption of incompletely digested epitopes of the toxin or both. The results are discussed in relation to distances travelled by vultures as determined by new tracking techniques, how serology can reveal anthrax activity in an area and the issue of the role of vultures in transmission of anthrax.
Show more [+] Less [-]Bovine intestinal cellular responses following primary and challenge infections with Calicophoron microbothrium metacercariae
2008
Mavenyengwa, M.(University of Zimbabwe Department of Paraclinical Veterinary Studies Faculty of Veterinary Science) | Mukaratirwa, S.(University of KwaZulu-Natal School of Biological and Conservation Sciences) | Obwolo, M.(University of Zimbabwe Department of Paraclinical Veterinary Studies Faculty of Veterinary Science) | Monrad, J.(Danish Centre for Experimental Parasitology)
This study was carried out to establish whether cattle can develop resistance to re-infection by Calicophoron microbothrium by assessing the response of intestinal mucosal globule leukocytes, eosinophils, mast cells and basophils, and the establishment of the parasite in the host. A total of 24 1-year-old Tuli steers were randomly divided into four groups of six animals each and infected with C. microbothrium metacercariae. On the first day of the study, animals in Groups I and II were immunized with 5 000 metacercariae and then challenged with 15 000 metacercariae on Day 150 post-immunization. Animals in Group III were immunized with 15 000 metacercariae at the same time that Groups I and II animals were challenged to act as a positive control group. Animals in Group IV were left uninfected and acted as a negative control group. Three animals from each group were slaughtered on Day 28 post-challenge and the remainder were slaughtered on Day 42 post-challenge. The established amphistomes were recovered and histopathological and cytological examinations were done on the jejunum, duodenum, abomasum and the rumen. The establishment rates of the challenge infection in the immunized and challenged groups were lower and ranged from 0 to 0.2 % as compared to 6 %> from naive animals infected as positive controls. Animals immunized and then challenged with C. microbothrium had significantly higher eosinophil, mast cell and globule leukocytes counts in the intestinal mucosa (P < 0.05) as compared to those of the control group. The study indicates that cattle can develop resistance to C. microbothrium re-infection and that eosinophils and mast cells may be important cells in the rejection of the parasite.
Show more [+] Less [-]Experimental infections of baboons (Papio spp.) and vervet monkeys (Cercopithecus aethiops) with Trichinella zimbabwensis and successful treatment with ivermectin
2008
Mukaratirwa, S.(University of Zimbabwe Faculty of Veterinary Science Department of Paraclinical Veterinary Studies) | Dzoma, B.M.(University of Zimbabwe Faculty of Veterinary Science Department of Paraclinical Veterinary Studies) | Matenga, E.(University of Zimbabwe Faculty of Veterinary Science Department of Paraclinical Veterinary Studies) | Ruziwa, S.D.(University of Zimbabwe Faculty of Veterinary Science Department of Paraclinical Veterinary Studies) | Sacchi, L.(University of Pavia Department of Animal Biology) | Pozio, E.(Istituto Superiore di Sanità Parasitic and Immunomediated Diseases Department of Infectious)
Experimental Trichinella zimbabwensis infections were established in three baboons (Papio sp.) and four vervet monkeys (Cercopithecus aethiops) and the clinical-pathological manifestations assessed. The infected animals showed clinical signs ranging from fever, diarrhoea, periorbital oedema and muscular pain in varying degrees. One baboon became blind due to the infection. Levels of creatinine phosphokinase and lactate dehydrogenase increased to reach a peak on Day 42 post-infection (pi) for both baboons and monkeys. Blood parameters such as packed cell volume, levels of red blood cells and white blood cells did not change significantly from the normal ranges except for the levels of eosinophils which peaked above the normal ranges at Day 28 and 56 pi in baboons and at Day 56 pi in monkeys. Two baboons and two monkeys died during the course of the experiment. They were emaciated and showed lesions such as ascites, hydropericardium, congested liver and enlarged gall bladder. Histopathological findings of various muscles included a basophilic transformation of muscle cells, the disappearance of sarcomere myofibrils and basophilic sarcoplasm with the presence of Trichinella larvae in the sarcoplasm. These changes were mainly in the massetter and were of various intensities in the tail, gastrocnemius and biceps muscles. Five consecutive treatments with an oxfendazole-levamisole combination on surviving animals failed to clear the infection whereas ivermectin cleared the infection after one treatment in two monkeys and after two treatments in a baboon.
Show more [+] Less [-]Evaluation of different adjuvants for foot-and-mouth disease vaccine containing all the SAT serotypes
2008
Cloete, M.(Onderstepoort Veterinary Institute) | Dungu, B.(Onderstepoort Veterinary Institute ,Onderstepoort Biological Products) | Van Staden, L.I.(Onderstepoort Veterinary Institute) | Ismail-Cassim, N.(Onderstepoort Veterinary Institute) | Vosloo, W.(Onderstepoort Veterinary Institute)
Foot-and-mouth disease (FMD) is an economically important disease of cloven-hoofed animals that is primarily controlled by vaccination of susceptible animals and movement restrictions for animals and animal-derived products in South Africa. Vaccination using aluminium hydroxide gel-saponin (AS) adjuvanted vaccines containing the South African Territories (SAT) serotypes has been shown to be effective both in ensuring that disease does not spread from the endemic to the free zone and in controlling outbreaks in the free zone. Various vaccine formulations containing antigens derived from the SAT serotypes were tested in cattle that were challenged 1 year later. Both the AS and ISA 206B vaccines adjuvanted with saponin protected cattle against virulent virus challenge. The oil-based ISA 206B-adjuvanted vaccine with and without stimulators was evaluated in a field trial and both elicited antibody responses that lasted for 1 year. Furthermore, the ISA 206 adjuvanted FMD vaccine protected groups of cattle against homologous virus challenge at very low payloads, while pigs vaccinated with an emergency ISA 206B-based FMD vaccine containing the SAT 1 vaccine strains were protected against the heterologous SAT 1 outbreak strain.
Show more [+] Less [-]The financial cost implications of the highly pathogenic notifiable avian influenza H5N1 in Nigeria
2008
Fasina, F.O.(National Veterinary Research Institute Viral Research Department ,University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Sirdar, M.M.(Military Cooperative Corporation) | Bisschop, S.P.R.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies)
Nigeria and several other nations have recently been affected by outbreaks of the Asian H5N1 strain of highly pathogenic notifiable avian influenza (HPNAI) virus, which affects the pou sts associated with the current avian influenza outbreaks. The evaluation used epidemiological data, production figures and other input parameters to determine the final costs. An infection involving 10 % of the commercial bird population will cost Nigeria about $245 million and a worse scenario may lead to a loss of around $700 million. The results urge governments to invest more in measures aimed at the effective prevention of HPNAI and to consider the huge economic losses associated with the disease. Finally, an inter-disciplinary approach to managing and controlling HPNAI outbreaks is encouraged.
Show more [+] Less [-]Preliminary survey of ticks (Acari: Ixodidae) on cattle in Central Equatoria State, Southern Sudan
2008
Salih, D.A.(Central Veterinary Research Laboratories) | Julla, I.I.(University of Bahr El Ghazal College of Veterinary Science) | Hassan, S.M.(University of Khartoum Faculty of Veterinary Medicine Department of Parasitology) | El Hussein, A.M.(Central Veterinary Research Laboratories) | Jongejan, F.(Utrecht University Faculty of Veterinary Medicine Department of Infectious Diseases and Immunology,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases,)
In a preliminary survey conducted in 2005, the species composition and seasonality of ticks infesting cattle in Central Equatoria State, Southern Sudan was determined. Three locations were selected (Gumbo, Khor Rumla and Nyaing) and surveyed every 3 months. Two cattle herds in each of the three locations were visited four times during the study period. Total body collections of ticks were made from each of five cattle (Nilotic Zebu breed) kept in six different herds. Four tick genera and ten species were identified. The tick species identified were Amblyomma lepidum, Amblyomma variegatum, Boophilus annulatus, Boophilus decoloratus, Hyalomma marginatum rufipes, Hyalomma truncatum, Rhipicephalus appendiculatus, Rhipicephalus evertsi evertsi, Rhipicephalus praetextatus and Rhipicephalus sanguineus group. The highest number of ticks was collected in October during the rainy season. A finding of great significance was that R. appendiculatus, vector of East Coast fever, has now firmly established itself throughout the year with possible implications for cattle production in Central Equatoria State.
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