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Epidemiological study of Rift Valley fever virus in Kigoma, Tanzania Full text
2014
Emmanuel G. Kifaro | Japhet Nkangaga | Gradson Joshua | Raphael Sallu | Mmeta Yongolo | George Dautu | Christopher J. Kasanga
Epidemiological study of Rift Valley fever virus in Kigoma, Tanzania Full text
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.
Show more [+] Less [-]Epidemiological study of Rift Valley fever virus in Kigoma, Tanzania Full text
2014
Kifaro, Emmanuel G(Sokoine University of Agriculture) | Nkangaga, Japhet(Tanzania Veterinary Laboratory Agency) | Joshua, Gradson(Tanzania Veterinary Laboratory Agency) | Sallu, Raphael(Tanzania Veterinary Laboratory Agency) | Yongolo, Mmeta(Tanzania Veterinary Laboratory Agency) | Dautu, George(Central Veterinary Research Institute) | Kasanga, Christopher J(Sokoine University of Agriculture)
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.
Show more [+] Less [-]Rapid, sensitive and effective diagnostic tools for foot-and-mouth disease virus in Africa Full text
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
Rapid, sensitive and effective diagnostic tools for foot-and-mouth disease virus in Africa Full text
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.
Show more [+] Less [-]Rapid, sensitive and effective diagnostic tools for foot-and-mouth disease virus in Africa Full text
2014
Kasanga, Christopher J.(Sokoine University of Agriculture) | Yamazaki, Wataru(University of Miyazaki Department of Microbiology) | Mioulet, Valerie(The Pirbright Institute) | King, Donald P.(The Pirbright Institute) | Mulumba, Misheck(Southern African Development Community Secretariat) | Ranga, Ezekia(Ministry of Livestock Development and Fisheries) | Deve, Jimis(Southern African Development Community Transboundary Animal Diseases Section) | Mundia, Cornelius(Southern African Development Community Transboundary Animal Diseases Section) | Chikungwa, Patrick(Southern African Development Community Transboundary Animal Diseases Section) | Joao, Laureta(Southern African Development Community Transboundary Animal Diseases Section) | Wambura, Philemon N.(Sokoine University of Agriculture Faculty of Veterinary Medicine) | Rweyemamu, Mark M.(Sokoine University of Agriculture)
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.
Show more [+] Less [-]Practice of One Health approaches: Bridges and barriers in Tanzania Full text
2014
Kim A. Kayunze | Angwara Kiwara | Eligius Lyamuya | Dominic M. Kambarage | Jonathan Rushton | Richard Coker | Richard Kock
Practice of One Health approaches: Bridges and barriers in Tanzania Full text
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.
Show more [+] Less [-]Practice of One Health approaches: Bridges and barriers in Tanzania Full text
2014
Kayunze, Kim A.(Sokoine University of Agriculture) | Kiwara, Angwara(Muhimbili University of Health and Allied Sciences (MUHAS)) | Lyamuya, Eligius(Muhimbili University College of Health and Allied Sciences (MUHAS)) | Kambarage, Dominic M.(Sokoine University of Agriculture) | Rushton, Jonathan(Royal Veterinary College) | Coker, Richard(London School of Hygiene & Tropical Medicine) | Kock, Richard(Royal Veterinary College)
The practice of One Health approaches in human and animal health programmes is influenced by type and scope of bridges for and barriers to 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 intersectoral partnership. The nature of collaborative arrangement was assessed, and the respective bridges and barriers over a period of 12 months (July 2011 - June 2012) were identified. The specific objectives were to: (1) determine the proportions of health experts who had collaborated with other experts of disciplines different from theirs, (2) rank the general bridges for and barriers to collaboration according to the views of the health experts, and (3) find the actual bridges for and barriers to 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 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 impact and availability of funding. The main barriers to collaboration were lack of knowledge about animal or human health issues, lack of networks for collaboration and lack of plans to collaborate. This situation calls for the need to curb barriers in order to enhance intersectoral collaboration for more effective management of risks attributable to infectious diseases of humans and animals.
Show more [+] Less [-]Bovine trypanosomosis prevalence at the edge of Hluhluwe-iMfolozi Park, KwaZulu-Natal, South Africa Full text
2014
Lundi Ntantiso | Chantel de Beer | Tanguy Marcotty | Abdalla A. Latif
Bovine trypanosomosis prevalence at the edge of Hluhluwe-iMfolozi Park, KwaZulu-Natal, South Africa Full text
2014
Lundi Ntantiso | Chantel de Beer | Tanguy Marcotty | Abdalla A. Latif
The northern KwaZulu-Natal (NKZN) region of South Africa is the southern limit of the African tsetse belt. Entomological information on Glossina brevipalpis and Glossina austeni was generated following the outbreak of trypanosomosis in cattle in 1990. However, these data have not been supported by parallel studies on epidemiology of the disease and therefore there has been no control policy in place. This study presented the first intensive investigations to address the epidemiology of trypanosomosis in NKZN. Tsetse abundance, trypanosome herd average prevalence (HAP), herd average anaemia (HAA) and herd average packed cell volume (HA-PCV) were investigated at three communal diptanks located at the edge of Hluhluwe-iMfolozi Park by monthly sampling from June 2006 – November 2007. Seasonal trypanosome surveys were conducted at seven other communal diptanks. Glossina brevipalpis prevalence was high at two of the diptanks, Mvutshini and Ekuphindisweni, but low at Ocilwane, whilst G. austeni was only collected from Mvutshini. This high and low tsetse challenge presented different disease scenarios. Cattle at Mvutshini and Ekuphindisweni had the highest HAP of 12.3% and 8.9% respectively, both significantly different (p = 0.001) from the HAP obtained from cattle at Ocilwane (2.9%). These two cattle herds also had the highest HAA, 27.7% and 33.4% respectively, whilst cattle at Ocilwane had the lowest, 11.1% (p = 0.001). Conversely, cattle at Ocilwane had the highest HA-PCV, ranging between 29.0% and 32.0%, whilst cattle at Mvutshini and Ekuphindisweni had the lowest HA-PCV (24.0% – 29.0%). By combining the data from the three diptanks (1318 observations), 62.0% of the infected cattle were found anaemic, compared to 20.0% in the uninfected group. Trypanosome seasonal surveys showed that cattle at all the seven diptanks were infected with trypanosomes; mean HAP, HAA and HA-PCV of 10.2%, 46.6% and 23.7%, respectively. This study generated information on the epidemiological factors related to the wide spread of trypanosome-infected cattle and tsetse flies. Trypanosomosis is a disease of economic importance impacting the livelihood of resource-poor farmers in NKZN.
Show more [+] Less [-]Spatial and temporal distribution of foot-and-mouth disease virus in the lake zone of Tanzania Full text
2014
Genchwere, Joseph M(Tanzania Veterinary Laboratory Agency) | Kasanga, Christopher J(University of Agriculture)
Spatial and temporal distribution of foot-and-mouth disease virus in the lake zone of Tanzania Full text
2014
Genchwere, Joseph M(Tanzania Veterinary Laboratory Agency) | Kasanga, Christopher J(University of Agriculture)
This study was conducted to determine the spatiotemporal distribution of foot-and-mouth disease (FMD) virus (FMDV) serotypes and evaluate the awareness of livestock keepers about FMD in Tanzania. An observational prospective study involving serological analysis, FMDV antigen detection and questionnaire survey was carried out in the lake zone of Tanzania. Seroprevalence of antibodies to the nonstructural protein 3ABC of FMDV and serotype- specific antigen detection were investigated by using SVANOVIR® FMDV 3ABC-Ab ELISA and indirect-sandwich ELISA (sELISA), respectively, whilst a structured questionnaire was used to evaluate the awareness of livestock keepers about FMD. During the period of 2010-2011, both serum and tissue (foot-and-mouth epithelia) samples were collected from cattle suspected of FMD in 13 districts of the four regions of the lake zone. A total of 107 (80.5%) out of 133 tested serum samples were seropositive to nonstructural protein 3ABC, with at least one sample being positive from all 10 districts screened. Fifteen (53.6%) out of 28 tissue epithelial samples collected from FMD cases in eight districts during the course of this study were positive to serotype O FMDV antigen. Of these eight districts, serotype O FMDV antigens were detected from seven districts and no other serotypes were recovered from animal samples screened. Questionnaire surveys in six districts indicated that livestock keepers in the lake zone were aware of the clinical manifestations (26/29 = 90.0%) and economic impact (23/29 = 79.0%) of FMD in the region. The questionnaire data showed that FMD outbreaks often occurred after rainy seasons (22/29 = 75.9%), with the highest peaks predominantly occurring just after the long rains in May and June, and at the end of the short rains in November and December of each year. The spatial distribution of the FMD cases suggested that serotype O virus exposure was the only widespread cause of the 2010-2011 outbreaks in the lake zone.
Show more [+] Less [-]Spatial and temporal distribution of foot-and-mouth disease virus in the lake zone of Tanzania Full text
2014
Joseph M. Genchwere | Christopher J. Kasanga
This study was conducted to determine the spatiotemporal distribution of foot-and-mouth disease (FMD) virus (FMDV) serotypes and evaluate the awareness of livestock keepers about FMD in Tanzania. An observational prospective study involving serological analysis, FMDV antigen detection and questionnaire survey was carried out in the lake zone of Tanzania. Seroprevalence of antibodies to the nonstructural protein 3ABC of FMDV and serotype-specific antigen detection were investigated by using SVANOVIR® FMDV 3ABC-Ab ELISA and indirect-sandwich ELISA (sELISA), respectively, whilst a structured questionnaire was used to evaluate the awareness of livestock keepers about FMD. During the period of 2010–2011, both serum and tissue (foot-and-mouth epithelia) samples were collected from cattle suspected of FMD in 13 districts of the four regions of the lake zone. A total of 107 (80.5%) out of 133 tested serum samples were seropositive to nonstructural protein 3ABC, with at least one sample being positive from all 10 districts screened. Fifteen (53.6%) out of 28 tissue epithelial samples collected from FMD cases in eight districts during the course of this study were positive to serotype O FMDV antigen. Of these eight districts, serotype O FMDV antigens were detected from seven districts and no other serotypes were recovered from animal samples screened. Questionnaire surveys in six districts indicated that livestock keepers in the lake zone were aware of the clinical manifestations (26/29 = 90.0%) and economic impact (23/29 = 79.0%) of FMD in the region. The questionnaire data showed that FMD outbreaks often occurred after rainy seasons (22/29 = 75.9%), with the highest peaks predominantly occurring just after the long rains in May and June, and at the end of the short rains in November and December of each year. The spatial distribution of the FMD cases suggested that serotype O virus exposure was the only widespread cause of the 2010–2011 outbreaks in the lake zone.
Show more [+] Less [-]The changing landscape of public health in sub-Saharan Africa: Control and prevention of communicable diseases needs rethinking Full text
2014
Mboera, Leonard E.G.(National Institute for Medical Research) | Mfinanga, Sayoki G.(Muhimbili Medical Research Centre) | Karimuribo, Esron D.(Sokoine University of Agriculture) | Rumisha, Susan F.(National Institute for Medical Research) | Sindato, Calvin(Tabora Medical Research Centre)
The changing landscape of public health in sub-Saharan Africa: Control and prevention of communicable diseases needs rethinking Full text
2014
Mboera, Leonard E.G.(National Institute for Medical Research) | Mfinanga, Sayoki G.(Muhimbili Medical Research Centre) | Karimuribo, Esron D.(Sokoine University of Agriculture) | Rumisha, Susan F.(National Institute for Medical Research) | Sindato, Calvin(Tabora Medical Research Centre)
In sub-Saharan Africa, communicable diseases (CDs) are the leading public health problems and major causes of morbidity and mortality. CDs result in significant individual suffering, disrupting daily life, threatening livelihoods and causing one-third of the years lost to illness or death worldwide. This paper aims to analyse the current strategies in the control and prevention of CDs in sub-Saharan Africa and proposes an ecohealth approach in relation to current changing epidemiological profiles. Whilst in recent years the burden of HIV and AIDS, tuberculosis and malaria have helped to mobilise large amounts of funding and expertise to help address them, many CDs, particularly those affecting the poor, have been neglected. People living in rural areas are also likely to be politically marginalised and living in degraded environments. They often lack assets, knowledge and opportunities to gain access to health care or protect themselves from infections. New diseases are also emerging at unprecedented rates and require attention. Many CDs are rooted in environmental and livelihood conditions and mediated by social and individual determinants. It is now increasingly recognised that a much broader, coordinated and multi-sectoral ecohealth approach is required to address CDs in sub-Saharan Africa. An ecohealth approach has been shown to be more robust in public health interventions than the traditional medical approach. The approach helps to generate an understanding of ecosystem factors that influence the emergence and spread of both old and new diseases, considers temporal and spatial dimensions of disease infection and allows systems thinking. In conclusion, establishing intersectoral and multisectoral linkages is important to facilitate joint efforts to address CDs at the national, district and community levels.
Show more [+] Less [-]The changing landscape of public health in sub-Saharan Africa: Control and prevention of communicable diseases needs rethinking Full text
2014
Leonard E.G. Mboera | Sayoki G. Mfinanga | Esron D. Karimuribo | Susan F. Rumisha | Calvin Sindato
In sub-Saharan Africa, communicable diseases (CDs) are the leading public health problems and major causes of morbidity and mortality. CDs result in significant individual suffering, disrupting daily life, threatening livelihoods and causing one-third of the years lost to illness or death worldwide. This paper aims to analyse the current strategies in the control and prevention of CDs in sub-Saharan Africa and proposes an ecohealth approach in relation to current changing epidemiological profiles. Whilst in recent years the burden of HIV and AIDS, tuberculosis and malaria have helped to mobilise large amounts of funding and expertise to help address them, many CDs, particularly those affecting the poor, have been neglected. People living in rural areas are also likely to be politically marginalised and living in degraded environments. They often lack assets, knowledge and opportunities to gain access to health care or protect themselves from infections. New diseases are also emerging at unprecedented rates and require attention. Many CDs are rooted in environmental and livelihood conditions and mediated by social and individual determinants. It is now increasingly recognised that a much broader, coordinated and multi-sectoral ecohealth approach is required to address CDs in sub-Saharan Africa. An ecohealth approach has been shown to be more robust in public health interventions than the traditional medical approach. The approach helps to generate an understanding of ecosystem factors that influence the emergence and spread of both old and new diseases, considers temporal and spatial dimensions of disease infection and allows systems thinking. In conclusion, establishing intersectoral and multisectoral linkages is important to facilitate joint efforts to address CDs at the national, district and community levels.
Show more [+] Less [-]Drivers of disease emergence and spread: Is wildlife to blame? Full text
2014
Kock, Richard(Royal Veterinary College Department of Pathology and Pathogen Biology)
Drivers of disease emergence and spread: Is wildlife to blame? Full text
2014
Kock, Richard(Royal Veterinary College Department of Pathology and Pathogen Biology)
The global focus on wildlife as a major contributor to emerging pathogens and infectious diseases (EIDs) in humans and domestic animals is not based on field, experimental or dedicated research, but mostly on limited surveys of literature, opinion and the assumption that biodiversity harbours pathogens. The perceived and direct impacts of wildlife, from being a reservoir of certain human and livestock pathogens and as a risk to health, are frequently overstated when compared to the Global burden of disease statistics available from WHO, OIE and FAO. However organisms that evolve in wildlife species can and do spill-over into human landscapes and humans and domestic animal population and, where these organisms adapt to surviving and spreading amongst livestock and humans, these emerging infections can have significant consequences. Drivers for the spill-over of pathogens or evolution of organisms from wildlife reservoirs to become pathogens of humans and domestic animals are varied but almost without exception poorly researched. The changing demographics, spatial distribution and movements, associated landscape modifications (especially agricultural) and behavioural changes involving human and domestic animal populations are probably the core drivers of the apparent increasing trend in emergence of new pathogens and infectious diseases over recent decades.
Show more [+] Less [-]Drivers of disease emergence and spread: Is wildlife to blame? Full text
2014
Richard Kock
The global focus on wildlife as a major contributor to emerging pathogens and infectious diseases (EIDs) in humans and domestic animals is not based on field, experimental or dedicated research, but mostly on limited surveys of literature, opinion and the assumption that biodiversity harbours pathogens. The perceived and direct impacts of wildlife, from being a reservoir of certain human and livestock pathogens and as a risk to health, are frequently overstated when compared to the Global burden of disease statistics available from WHO, OIE and FAO. However organisms that evolve in wildlife species can and do spill-over into human landscapes and humans and domestic animal population and, where these organisms adapt to surviving and spreading amongst livestock and humans, these emerging infections can have significant consequences. Drivers for the spill-over of pathogens or evolution of organisms from wildlife reservoirs to become pathogens of humans and domestic animals are varied but almost without exception poorly researched. The changing demographics, spatial distribution and movements, associated landscape modifications (especially agricultural) and behavioural changes involving human and domestic animal populations are probably the core drivers of the apparent increasing trend in emergence of new pathogens and infectious diseases over recent decades.
Show more [+] Less [-]<i>Fusarium</i> species isolated from <i>Pennisetum clandestinum</i> collected during outbreaks of kikuyu poisoning in cattle in South Africa Full text
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.
Show more [+] Less [-]Modulation of growth and immunity by dietary supplementation with resveratrol in young chickens receiving conventional vaccinations Full text
2014
Zhang, Caiyun | Tian, YaDong | Yan, FengBin | Kang, XiangTao | Han, RuiLi | Sun, Guirong | Zhang, Huiru
Objective—To determine the effects of resveratrol (RES) on growth and immune status in chickens receiving conventional vaccinations. Animals—Two hundred forty 1-day-old layer chickens. Procedures—Chickens received conventional vaccinations throughout the study and were randomly assigned to 1 of 4 treatments in 6 replicate pens/treatment. Treatments included 1 control group (basal diet) and 3 experimental groups fed the basal diet plus 200, 400, and 800 mg of RES/kg of diet. At 40 days of age, 1 bird/pen was randomly selected to have blood and tissues collected to determine serum immunity indices; mRNA relative expression of proinflammatory cytokines in splenocytes; mRNA relative expression of nuclear transcription factor-κB, growth hormone receptor, and insulin-like growth factor-1 in hepatocytes; cell proliferation; and apoptosis. Results—Average daily gain, antibody titers against Newcastle disease virus and avian influenza viruses H5 and H9, and insulin-like growth factor-1 expression were quadratically increased with increasing RES concentration. In hepatocytes, growth hormone receptor gene mRNA relative expression was quadratically increased and nuclear transcription factor-κB gene mRNA relative expression was linearly decreased with increasing RES concentration. In splenocytes, nterleukin-1β and tumor necrosis factor-α mRNA relative expression was linearly decreased with increasing RES concentration. Resveratrol supplementation delayed cell proliferation and reduced apoptosis in immunocytes. With increasing RES concentration, proliferation index and relative weight of the thymus, ratio of CD4+ to CD8+ cells, and CD4+ cell count were quadratically increased, and IgM concentration was linearly increased. Conclusions and Clinical Relevance—Dietary resveratrol supplementation improved growth, protected immunocytes against antigen-induced apoptosis, and upregulated immune response in chickens that received conventional vaccinations.
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