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First molecular assessment of the African swine fever virus status of <i>Ornithodoros</i> ticks from Swaziland
2014
Carin I. Boshoff | Armanda D.S. Bastos | Mzwandi M. Dube | Livio Heath
African swine fever (ASF) is an economically significant haemorrhagic disease of domestic pigs. It is caused by the African swine fever virus (ASFV), a deoxyribonucleic acid (DNA)arbovirus. Argasid ticks of the genus Ornithodoros, which are widely distributed throughout southern Africa, play a primary role in virus maintenance and spread within the endemic sylvatic cycle. The ASF status of Swaziland is unknown, but this land-locked country is surrounded by ASF-positive countries, has a burgeoning pig industry and sylvatic cycle hosts present within its borders. In this first assessment of ASF status, warthog burrows in seven nature reserves and game management areas in Swaziland were investigated for tick and virus presence. Tick infestation rates of between 33.3% – 88.8% were recovered for the four Ornithodoros-infested reserves. A total of 562 ticks were screened for virus genome presence using a duplex Polymerase Chain Reaction (PCR) that targets the C-terminal end of the p72 gene of the ASFV and confirms DNA integrity through amplification of the 16S rRNA tick host gene. All samples were negative for virus genome presence and positive for the tick genome target. Nucleotide sequencing of the latter confirmed that Ornithodoros ticks from Swaziland are identical to those from the Kruger National Park in South Africa across the gene region characterised. Whilst this first evaluation of ASF presence in Swaziland indicates that the virus does not appear to be present in the key virus vector, the presence of sylvatic cycle hosts, together with the country’s proximity to ASF-affected countries calls for expanded investigations and regular monitoring of the ASF status of Swaziland.
Afficher plus [+] Moins [-]Practice of One Health approaches: Bridges and barriers in Tanzania
2014
Kim A. Kayunze | Angwara Kiwara | Eligius Lyamuya | Dominic M. Kambarage | Jonathan Rushton | Richard Coker | Richard Kock
The practice of one health approaches in human and animal health programmes is influenced by type and scope of bridges and barriers for partnerships. It was thus essential to evaluate the nature and scope of collaborative arrangements among human, animal, and wildlife health experts in dealing with health challenges which demand inter-sectoral partnership. The nature of collaborative arrangement was assessed, and the respective bridges and barriers over a period of 12 months (July 20011 to June 2012) were identified. The specific objectives were to: (1) determine the proportion of health experts who had collaborated with other experts of disciplines different from theirs, (2) rank the general bridges for and barriers against collaboration according to the views of the health experts, and (3) find the actual bridges for and barriers against collaboration among the health experts interviewed. It was found that 27.0% of animal health officers interviewed had collaborated with medical officers while 12.4% of the medical officers interviewed had collaborated with animal health experts. Only 6.7% of the wildlife officers had collaborated with animal health experts. The main bridges for collaboration were instruction by upper level leaders, zoonotic diseases of serious impacts, and availability of funding. The main barriers for collaboration were lack of knowledge about animal/human health issues, lack of networks for collaboration, and lack of plans to collaborate. This thus calls for the need to curb barriers in order to enhance inter-sectoral collaboration for more effective management of risks attributable to infectious diseases of humans and animals.
Afficher plus [+] Moins [-]Multitoxin analysis of <i>Aspergillus clavatus</i>-infected feed samples implicated in two outbreaks of neuromycotoxicosis in cattle in South Africa
2014
Christo J. Botha | Matthew J. Legg | Mariëtte Truter | Michael Sulyok
Aspergillus clavatus intoxication is a highly fatal neuromycotoxicosis of ruminants, especially cattle. It is caused by the ingestion of infected sprouting grain and sorghum beer residue. Locomotor disturbances, tremors and paralysis are observed. Histologically, degeneration and necrosis of larger neurons in the medulla oblongata, the midbrain, the thalamus and the ventral horns of the spinal cord are observed. Although a range of mycotoxins such as patulin, cytochalasin E and pseurotin A have been isolated, there is limited information on which specific mycotoxin or group of mycotoxins are involved during outbreaks of intoxication in livestock. In the present study, two outbreaks of A. clavatus poisoning in cattle are briefly described. Feed samples were collected for fungal identification, and culture and multitoxin analysis. A range of fungal metabolites were detected, and the estimated concentrations (μg/kg) are provided. Both the sprouting barley and brewer’s grain were predominantly infected with A. clavatus and, to a lesser extent, Rhizopus arrhizus. The only common Aspergillus secondary metabolite present in all the samples was pseurotin A. Patulin and cytochalasin E were present in the sprouting barley samples, as well as the A. clavatus isolates cultured on malt extract agar for 2 weeks; however, neither of these mycotoxins could be detected in the brewer’s grain sample.
Afficher plus [+] Moins [-]Screening for foot-and-mouth disease virus in livestock-wildlife interface areas of Tanzania
2014
Emma Peter | Christopher J. Kasanga | Raphael Sallu | Mkama Mathias | Mmeta Yongolo | Misheck Mulumba | Ezekia Ranga | Philemon N. Wambura | Mark M. Rweyemamu
Antigenic characterisation of lyssaviruses in South Africa
2014
Ernest Ngoepe | Christine Fehlner-Gardiner | Alex Wandeler | Claude Sabeta
There are at least six Lyssavirus species that have been isolated in Africa, which include classical rabies virus, Lagos bat virus, Mokola virus, Duvenhage virus, Shimoni bat virus and Ikoma lyssavirus. In this retrospective study, an analysis of the antigenic reactivity patterns of lyssaviruses in South Africa against a panel of 15 anti-nucleoprotein monoclonal antibodies was undertaken. A total of 624 brain specimens, collected between 2005 and 2009, confirmed as containing lyssavirus antigen by direct fluorescent antibody test, were subjected to antigenic differentiation. The lyssaviruses were differentiated into two species, namely rabies virus (99.5%) and Mokola virus (0.5%). Furthermore, rabies virus was further delineated into two common rabies biotypes in South Africa: canid and mongoose. Initially, it was found that the canid rabies biotype had two reactivity patterns; differential staining was observed with just one monoclonal antibody. This difference was likely to have been an artefact related to sample quality, as passage in cell culture restored staining. Mongoose rabies viruses were more heterogeneous, with seven antigenic reactivity patterns detected. Although Mokola viruses were identified in this study, prevalence and reservoir host species are yet to be established. These data demonstrate the usefulness of monoclonal antibody typing panels in lyssavirus surveillance with reference to emergence of new species or spread of rabies biotypes to new geographic zones.
Afficher plus [+] Moins [-]First report of a mixed infection of <i>Trichinella nelsoni</i> and <i>Trichinella</i> T8 in a leopard (<i>Panthera pardus</i>) from the Greater Kruger National Park, South Africa
2014
Louis J. La Grange | Björn Reininghaus | Samson Mukaratirwa
At least three Trichinella species, namely Trichinella nelsoni, Trichinella britovi and Trichinella zimbabwensis, and one genotype (Trichinella T8), have been isolated from sylvatic carnivores on the African continent. With the exception of T. britovi, the other species are known to circulate in wildlife of the Kruger National Park (KNP), South Africa, and KNP neighbouring game reserves (collectively known as the greater KNP area). Lions (Panthera leo) and spotted hyenas (Crocuta crocuta) appear to be the most important reservoirs of T. nelsoni and Trichinella T8 in the KNP and surrounding areas. Interspecies predation between lions and hyenas has been implicated as a primary mode of maintaining the life cycles of these two Trichinella species. This is the first report of a mixed natural infection of T. nelsoni and Trichinella T8 in a leopard (Panthera pardus) from South Africa. Trichinella muscle larvae were identified to species level by multiplex polymerase chain reaction (PCR). Probable sources of infection, based on the known dietary preference and prey species’ range of leopards, are also discussed. The described occurrence of Trichinella species in a leopard from the greater KNP area raises the question of possible sources of infection for this predator species.
Afficher plus [+] Moins [-]<i>Fusarium</i> species isolated from <i>Pennisetum clandestinum</i> collected during outbreaks of kikuyu poisoning in cattle in South Africa
2014
Christo J. Botha | Mariëtte Truter | Adriaana Jacobs
Kikuyu poisoning occurs sporadically in South Africa. It is of major economic importance, as valuable dairy cows are often poisoned by it, and once affected, the mortality rate is high. Pennisetum clandestinum samples were collected during eight outbreaks of kikuyu poisoning in cattle in the Eastern Cape Province of South Africa from 2008 to 2010. The kikuyu grass samples were submitted specifically for the isolation and molecular identification of Fusarium species, as it was recently suggested that mycotoxins synthesised by Fusarium torulosum could be the cause of this intoxication. Ninety-four Fusarium isolates were retrieved from the grass samples, of which 72 were members of the Fusarium incarnatum/Fusarium equiseti species complex based on morphology and phylogenetic analyses of the translation elongation factor 1α sequence data. The South African isolates from kikuyu identified as members of the F. incarnatum/F. equiseti species complex grouped together in six separate clades. The other isolates were Fusarium culmorum (n = 3), Fusarium redolens (n = 4) and Fusarium oxysporum (n = 15). Although F. torulosum could not be isolated from P. clandestinum collected during kikuyu poisoning outbreaks in South Africa, the mycotoxicosis theory is still highly plausible.
Afficher plus [+] Moins [-]Constraints in animal health service delivery and sustainable improvement alternatives in North Gondar, Ethiopia
2014
Hassen Kebede | Achenef Melaku | Elias Kebede
Poor livestock health services remain one of the main constraints to livestock production in many developing countries, including Ethiopia. A study was carried out in 11 districts of North Gondar, from December 2011 to September 2012, with the objective of identifying the existing status and constraints of animal health service delivery, and thus recommending possible alternatives for its sustainable improvement. Data were collected by using pre-tested questionnaires and focus group discussion. Findings revealed that 46.34% of the responding farmers had taken their animals to government veterinary clinics after initially trying treatments with local medication. More than 90.00% of the clinical cases were diagnosed solely on clinical signs or even history alone. The antibacterial drugs found in veterinary clinics were procaine penicillin (with or without streptomycin), oxytetracycline and sulphonamides, whilst albendazole, tetramisole and ivermectin were the only anthelmintics. A thermometer was the only clinical aid available in all clinics, whilst only nine (45.00%) clinics had a refrigerator. In the private sector, almost 95.00% were retail veterinary pharmacies and only 41.20% fulfilled the requirement criteria set. Professionals working in the government indicated the following problems: lack of incentives (70.00%), poor management and lack of awareness (60.00%) and inadequate budget (40.00%). For farmers, the most frequent problems were failure of private practitioners to adhere to ethical procedures (74.00%) and lack of knowledge of animal diseases and physical distance from the service centre (50.00%). Of all responding farmers, 58.54% preferred the government service, 21.14% liked both services equally and 20.33% preferred the private service. Farmers’ indiscriminate use of drugs from the black market (23.00%) was also mentioned as a problem by private practitioners. Sustainable improvement of animal health service delivery needs increased awareness for all stakeholders and a well-regulated private service in order to mitigate the constraints apparent in the government service.
Afficher plus [+] Moins [-]Epidemiological study of Rift Valley fever virus in Kigoma, Tanzania
2014
Emmanuel G. Kifaro | Japhet Nkangaga | Gradson Joshua | Raphael Sallu | Mmeta Yongolo | George Dautu | Christopher J. Kasanga
Rift Valley fever virus (RVFV) is an acute, zoonotic viral disease caused by a Phlebovirus, which belongs to the Bunyaviridae family. Among livestock, outbreaks of the disease are economically devastating. They are often characterised by large, sweeping abortion storms and have significant mortality in adult livestock. The aim of the current study was to investigate RVFV infection in the Kigoma region, which is nestled under the hills of the western arm of the Great Rift Valley on the edge of Lake Tanganyika, Tanzania. A region-wide serosurvey was conducted on non-vaccinated small ruminants (sheep and goats, n = 411). Sera samples were tested for the presence of anti-RVFV antibodies and viral antigen, using commercial enzyme-linked immunosorbent assay and reverse transcriptase polymerase chain reaction, respectively. The overall past infections were detected in 22 of the 411 animals, 5.4% (Confidence Interval (CI) 95% = 3.5% – 8.1%). The Kigoma rural area recorded the higher seroprevalence of 12.0% (CI 95% = 7.3% – 18.3%; p < 0.0001), followed by Kibondo at 2.3% (CI 95% = 0.5% – 6.5%; p > 0.05) and the Kasulu district at 0.8% (CI 95% = 0.0% – 4.2%; p > 0.05). The prevalence was 12.5% and 4.7% for sheep and goats, respectively. Reverse transcriptase polymerase chain reaction results indicated that only eight samples were found to be positive (n = 63). This study has confirmed, for the first time, the presence of the RVFV in the Kigoma region four years after the 2007 epizootic in Tanzania. The study further suggests that the virus activity exists during the inter-epizootic period, even in regions with no history of RVFV.
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