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Full genome sequencing to study the evolutionary characteristics of foot-and-mouth disease virus in southern Africa
2014
Christopher J. Kasanga | Begoña Valdazo-González | Rahana Dwarka | Jemma Wadsworth | Nick J. Knowles | Philemon N. Wambura | Mark M. Rweyemamu | Misheck Mulumba | Jimis Deve | Donald P. King
Molecular biological characteristics of foot-and-mouth disease virus in the African buffalo in southern Africa
2014
Christopher J. Kasanga | Rahana Dwarka | Gaothlele Thobokwe | Jemma Wadsworth | Nick J. Knowles | Misheck Mulumba | Ezekia Ranga | Jimis Deve | Cornelius Mundia | Patrick Chikungwa | Laureta Joao | Raphael Sallu | Mmeta Yongolo | Philemon N. Wambura | Mark M. Rweyemamu | Donald P. King
Serosurveillance of foot-and-mouth disease virus in selected livestock-wildlife interface areas of Tanzania
2014
Mathias Mkama | Christopher J. Kasanga | Raphael Sallu | Ezekia Ranga | Mmeta Yongolo | Misheck Mulumba | Mark Rweyemamu | Philemon Wambura
Foot-and-mouth disease (FMD) is caused by a virus of the genus Aphthorvirus of the family Picornaviridae. There is great scientific need for determining the transmission dynamics of FMD virus (FMDV) by drawing more attention to the livestock-wildlife interface areas. A variety of literature suggests that buffalo could serve as reservoir of FMDV in wildlife and cattle. However, many FMDV research studies conducted on experimentally infected cattle as carriers and groups of animal highly susceptible to FMDV (i.e. bovine calves) have shown lower chances of transmission of the virus between carriers and the susceptible groups. These findings underscore the importance of continued research on the role played by carrier animals on FMDV transmission dynamics under natural conditions. The aim of this research study was to determine FMDV infection status among buffalo and cattle herds in selected livestock-wildlife interface areas. The sampled areas included Mikumi, Mkomazi and Ruaha national parks, where a total of 330 buffalo and bovine sera samples were collected. Laboratory analysis of the samples was done through the NSP ELISA technique using the PrioCHECK® FMDV NS Kit for detection of antibodies directed against 3ABC non-structural proteins and confirming natural infections. Results showed that 76.3% of tested sera samples were positive for FMDV. However, serotyping of NSP ELISA seroreactors with LPBE is yet to be done. This information is important for further epidemiological studies towards developing effective FMD control strategies.
Afficher plus [+] Moins [-]Validation of an ELISA for the concurrent detection of total antibodies (IgM and IgG) to Rift Valley fever virus
2014
Charlotte E. Ellis | Vuyokazi E. Mareledwane | Roy Williams | David B. Wallace | Phelix A.O. Majiwa
Rift Valley fever virus (RVFV) infects humans and livestock, causing haemorrhaging andabortions in animals. Three major RVF epizootics have occurred in South Africa since the1950s and the outbreak in 2010 had a mortality rate of 10.7% in humans. Accurate and earlydetection is therefore essential for management of this zoonotic disease. Enzyme-linkedimmunosorbent assays (ELISAs) have been developed for the detection of either IgM or IgGantibodies to RVFV in animal sera. In this study, data are presented on the validation of adouble-antigen ELISA for the simultaneous detection of both classes of antibodies to RVFV ina single test. ELISA plates were coated with a recombinant nucleoprotein. The nucleoprotein,conjugated to horseradish peroxidase, was used as the detecting reagent. A total of 534 serafrom sheep and cattle were used in the validation. The sheep sera were collected during a RVFpathogenesis study at the Agricultural Research Council (ARC) – Onderstepoort VeterinaryInstitute and the cattle sera were collected during an outbreak of RVF in 2008 at the ARC –Animal Production Institute in Irene, Pretoria. The ELISA had a diagnostic sensitivity of 98.4%and a specificity of 100% when compared to a commercial cELISA. This convenient and fastassay is suitable for use in serological surveys or monitoring immune responses in vaccinatedanimals.
Afficher plus [+] Moins [-]The quest for One Health: Human Resource training aspects
2014
Angwara Kiwara | Ave-Maria Semakafu | Gasto Frumence
Appropriately trained Human Resources for Health (HRH) are key inputs into One Health. ‘… more than 50% of all infectious diseases of humans originate from animals and that, of the emerging diseases about 75% could be traced back to animal origin’ (Rweyemamu et al. 2006). A comprehensive understanding of the social determinants of health, through an appropriate training model for HRH, is a key input. This study aimed to explore if human and veterinary medical schools were using such a model or providing time for this model in their curricula. Specific objectives were to: determine the time that human and veterinary medical schools’ curricula provide for subjects or courses related to the social determinants of health; analyse the curricula contents to establish how they relate to the social determinants of health; and explore how a bio-medical model may influence the graduates’ understanding and practice of One Health. A review of human and veterinary graduate-level medical schools’ curricula in East Africa was performed in April 2013 and May 2013. The findings were: in the curricula, SDH contents for knowledge enhancement about One Health are minimal and that teaching is Germ Theory model-driven and partisan. Out of the total training time for physicians and veterinarians, less than 10% was provided for the social determinants of health-related courses. In conclusion, the curricula and training times provided are inadequate for graduates to fully understand the social determinants of health and their role in One Health. Furthermore, the Germ Theory model that has been adopted addresses secondary causes and is inappropriate. There is a need for more in-depth model. This article suggests that a vicious cycle of ill-health model must be taught.
Afficher plus [+] Moins [-]Rapid, sensitive and effective diagnostic tools for foot-and-mouth disease virus in Africa
2014
Christopher J. Kasanga | Wataru Yamazaki | Valerie Mioulet | Donald P. King | Misheck Mulumba | Ezekia Ranga | Jimis Deve | Cornelius Mundia | Patrick Chikungwa | Laureta Joao | Philemon N. Wambura | Mark M. Rweyemamu
Speed is paramount in the diagnosis of highly infectious diseases, such as foot-and-mouth disease (FMD), as well as for emerging diseases; however, simplicity is required if a test is to be deployed in the field. Recent developments in molecular biology have enabled the specific detection of FMD virus (FMDV) by reverse-transcription loop-mediated isothermal amplification (RT-LAMP), real-time reverse-transcription polymerase chain reaction (RT-qPCR) and sequencing. RT-LAMP enables amplification of the FMDV RNA-dependent RNA polymerase 3D(pol) gene at 63 °C (in the presence of a primer mixture and both reverse transcriptase and Bst DNA polymerase) for 1 h, whilst RT-qPCR amplifies the same gene in approximately 2 h 30 min. In this study, we compared the sensitivity and effectiveness of RT-LAMP against RT-qPCR for the detection of the FMDV 3D(pol) gene in 179 oesophageal-pharyngeal scraping samples (collected by probang) obtained from clinically healthy cattle and buffalo in Malawi, Mozambique and Tanzania in 2010. The FMDV detection rate was higher with RT-LAMP (30.2%; n = 54) than with RT-qPCR (17.3%; n = 31). All samples positive by RT-qPCR (Cq ≤ 32.0) were also positive for the RT-LAMP assay; and both assays proved to be highly specific for the FMDV target sequence. In addition, the VP1 sequences of 10 viruses isolated from positive samples corresponded to the respective FMDV serotypes and genotypes. Our findings indicate that the performance of RT-LAMP is superior to RT-qPCR. Accordingly, we consider this test to have great potential with regard to the specific detection and surveillance of infectious diseases of humans and animals in resource-compromised developing countries.
Afficher plus [+] Moins [-]Genetic diversity of <i>Ehrlichia ruminantium</i> strains in Cameroon
2014
Seraphine N. Esemu | Roland N. Ndip | Lucy M. Ndip
In order to investigate the extent of genetic diversity among Ehrlichia ruminantium strains in Cameroon, a partial fragment (800 bp) of the E. ruminantium map1 gene was amplified by nested polymerase chain reaction in 121 of 156 E. ruminantium pCS20-positive DNA samples extracted from ticks and cattle collected from two ranches. Deoxyribonucleic acid sequencing of the map1 gene products indicated the presence of at least 21 genotypes at the nucleotide level and 16 genotypes at the amino acid level circulating within the study sites. Some of the genotypes were identical to Antigua (U50830), Blaaukrans (AF368000) or UmBanein (U50835), whilst the others were new genotypes. Twenty-four representative sequences were deposited in GenBank and given accession numbers JX477663 – JX477674 (for sequences of tick origin) and JX486788 – JX486799 (for sequences of cattle origin). Knowledge of E. ruminantium strain diversity could be important in understanding the epidemiology of heartwater
Afficher plus [+] Moins [-]Preliminary investigation on presence of peste des petits ruminants in Dakawa, Mvomero district, Morogoro region, Tanzania
2014
Tebogo Kgotlele | Christopher J. Kasanga | Lughano J.M. Kusiluka | Gerald Misinzo
Peste des petits ruminants (PPR) is an acute viral disease of small ruminants characterised by the sudden onset of depression, fever, oculonasal discharges, sores in the mouth, foul-smelling diarrhoea and death. For many years, in Africa, the disease was mainly confined to West and Central Africa but it has now spread southwards to previously PPR-free countries including Tanzania, Democratic Republic of Congo and Angola. The disease was first reported in Tanzania in 2008 when it was confined to the Northern Zone districts bordering Kenya. Presence of the disease has also been confirmed in southern Tanzania especially Mtwara region. Recently, a suspected outbreak of PPR in Dakawa area, Mvomero district, Morogoro region was reported. Clinical samples (lungs, intestines, lymph nodes, whole blood and sera) from suspected goats (n = 8) and sheep (n = 1) were submitted to Sokoine University of Agriculture for analysis. Molecular diagnosis by amplification of the nucleoprotein gene and the fusion gene of PPR virus (PPRV) using PPRV specific primers was done. Five goats and the sheep were positive for PPRV after performing RT-PCR. To our knowledge, this is the first report confirming the presence of PPR in the Mvomero district of the Morogoro region, Tanzania. Hence, more efforts should be put in place to prevent the spread of PPR in Tanzania.
Afficher plus [+] Moins [-]Quantification of tissue shrinkage in canine small intestinal specimens after resection and fixation
2014
Clarke, B.S. | Banks, T.A. | Findji, L.
The aim of this study was to quantify the longitudinal shrinkage of canine small intestinal specimens after resection and fixation in 10% formalin. Samples were obtained from 12 clinically normal dogs of medium to large breed via ventral midline coeliotomy and enterectomy. The length of each sample was measured before excision, immediately after excision, and after 24 h in 10% formalin. The results were interpreted with the use of single-sample t-tests of the average changes; P-values of less than 0.01 were considered significant. The samples indicated a significant decrease in length after resection and fixation. The mean shrinkage from the pre-excision state was 28.3% immediately after excision (P < 0.0001) and 26.3% after 24 h of fixation (P < 0.0001). There was a small but not significant increase in the length of the specimens between the 2nd and 3rd measurement points. Quantification of the longitudinal shrinkage of resected intestinal specimens may improve interpretation of the distance of surgical margins from abnormal tissue in histopathology reports and allow investigation of the margins required for the clearance of specific tumors.
Afficher plus [+] Moins [-]Efficacy and safety of tranexamic acid as an emetic in dogs
2014
Kakiuchi, Hitoshi | Kawarai-Shimamura, Asako | Fujii, Yoko | Aoki, Takuma | Yoshiike, Masaki | Arai, Hayato | Nakamura, Atsushi | Orito, Kensuke
Objective—To determine dose dependency of tranexamic acid–induced emesis and the time course of the antifibrinolytic potency of tranexamic acid in dogs. Animals—10 Beagles. Procedures—In a dose-escalating experiment, ascending doses of tranexamic acid (10, 20, and 30 mg/kg, IV) were administered at 5-minute intervals until vomiting was observed. In a separate single-dose experiment, ascending doses of tranexamic acid (20, 30, 40, and 50 mg/kg, IV) were administered at 1-week intervals until vomiting was observed. Time to onset of vomiting and number of vomiting episodes were measured in both experiments. In a coagulation experiment, a single 50 mg/kg bolus of tranexamic acid was administered, and blood was obtained 1 hour before and 20 minutes, 3 hours, and 24 hours after administration. Antifibrinolytic potency of tranexamic acid was evaluated by use of a modified rotational thromboelastography method. Results—Tranexamic acid induced vomiting in a dose-dependent manner. Vomiting frequency was < 2 episodes, and vomiting concluded < 250 seconds after administration. Antifibrinolytic potency of tranexamic acid was significantly higher at 20 minutes following administration, but not different by 24 hours, when compared with the potency measured before administration. No adverse effects were observed in any experiment. Conclusions and Clinical Relevance—IV administration of tranexamic acid induced emesis in a dose-dependent manner. The antifibrinolytic potency of tranexamic acid decreased in a time-dependent manner and was resolved < 24 hours after administration. Further studies are warranted to investigate the emetic and other adverse effects of tranexamic acid in dogs of various breeds and ages.
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