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The history of the emergence and transmission of human coronaviruses Full text
2021
Mulabbi, Elijah N.(Makerere University Faculty of Veterinary Medicine, Animal Resources and Biosecurity Department of Veterinary Medicine) | Tweyongyere, Robert(Makerere University Faculty of Veterinary Medicine, Animal Resources and Biosecurity Department of Veterinary Medicine) | Byarugaba, Denis K.(Makerere University Faculty of Veterinary Medicine, Animal Resources and Biosecurity Department of Veterinary Medicine)
The history of the emergence and transmission of human coronaviruses Full text
2021
Mulabbi, Elijah N.(Makerere University Faculty of Veterinary Medicine, Animal Resources and Biosecurity Department of Veterinary Medicine) | Tweyongyere, Robert(Makerere University Faculty of Veterinary Medicine, Animal Resources and Biosecurity Department of Veterinary Medicine) | Byarugaba, Denis K.(Makerere University Faculty of Veterinary Medicine, Animal Resources and Biosecurity Department of Veterinary Medicine)
Human coronaviruses are known respiratory pathogens associated with a range of respiratory illnesses, and there are considerable morbidity and hospitalisation amongst immune-compromised individuals of all age groups. The emergence of a highly pathogenic human coronavirus in China in 2019 has confirmed the long-held opinion that these viruses are important emerging and re-emerging pathogens. In this review article, we trace the discovery and emergence of coronaviruses (CoVs) over time since they were first reported. The review article will enrich our understanding on the host range, diversity and evolution, transmission of human CoVs and the threat posed by these viruses circulating in animal populations but overtime have spilled over to humans because of the increased proximity between humans and animals.
Show more [+] Less [-]The history of the emergence and transmission of human coronaviruses Full text
2021
Elijah N. Mulabbi | Robert Tweyongyere | Denis K. Byarugaba
Human coronaviruses are known respiratory pathogens associated with a range of respiratory illnesses, and there are considerable morbidity and hospitalisation amongst immune-compromised individuals of all age groups. The emergence of a highly pathogenic human coronavirus in China in 2019 has confirmed the long-held opinion that these viruses are important emerging and re-emerging pathogens. In this review article, we trace the discovery and emergence of coronaviruses (CoVs) over time since they were first reported. The review article will enrich our understanding on the host range, diversity and evolution, transmission of human CoVs and the threat posed by these viruses circulating in animal populations but overtime have spilled over to humans because of the increased proximity between humans and animals.
Show more [+] Less [-]Table of Contents Vol 88, No 1 (2021) Full text
2021
Editorial Office
No abstract is available.
Show more [+] Less [-]Finding of a two-headed green turtle embryo during nest monitoring in Baa Atoll, Maldives Full text
2021
Stephanie Köhnk | Rosie Brown | Amelia Liddell
Finding of a two-headed green turtle embryo during nest monitoring in Baa Atoll, Maldives Full text
2021
Stephanie Köhnk | Rosie Brown | Amelia Liddell
Green sea turtles are one of the two species of marine turtles known to nest in the Maldives. The prevalent time of nesting seems to be inconsistent throughout the island nation. In this study, sea turtle nesting activity was monitored on the island of Coco Palm Dhuni Kolhu in Baa Atoll over a period of 12 months. A total of 13 nests were confirmed with a median hatching success rate of 89.58% as ascertained by nest excavation. In one of the nests, a severely deformed hatchling with polycephaly, an opening in the neck area and a lordotic spine was found, and we investigated in detail with radiographic images and a necropsy. Our findings support the importance of consistent nesting activity and nest monitoring efforts in the country as a basis for conservation efforts.
Show more [+] Less [-]Finding of a two-headed green turtle embryo during nest monitoring in Baa Atoll, Maldives Full text
2021
Köhnk,Stephanie | Brown,Rosie | Liddell,Amelia
Green sea turtles are one of the two species of marine turtles known to nest in the Maldives. The prevalent time of nesting seems to be inconsistent throughout the island nation. In this study, sea turtle nesting activity was monitored on the island of Coco Palm Dhuni Kolhu in Baa Atoll over a period of 12 months. A total of 13 nests were confirmed with a median hatching success rate of 89.58% as ascertained by nest excavation. In one of the nests, a severely deformed hatchling with polycephaly, an opening in the neck area and a lordotic spine was found, and we investigated in detail with radiographic images and a necropsy. Our findings support the importance of consistent nesting activity and nest monitoring efforts in the country as a basis for conservation efforts.
Show more [+] Less [-]Plasmodium berghei-induced malaria decreases pain sensitivity in mice Full text
2021
Aboyeji L. Oyewole | Oluwole Akinola | Bamidele V. Owoyele
Plasmodium berghei-induced malaria decreases pain sensitivity in mice Full text
2021
Aboyeji L. Oyewole | Oluwole Akinola | Bamidele V. Owoyele
Various types of pain were reported by people with Plasmodium falciparum and were mostly attributed to a symptom of malarial infection. Neural processes of pain sensation during malarial infection and their contributions to malaria-related death are poorly understood. Thus, these form the focus of this study. Swiss mice used for this study were randomly divided into two groups. Animals in the first group (Pb-infected group) were inoculated with Plasmodium berghei to induce malaria whilst the other group (intact group) was not infected. Formalin test was used to assess pain sensitivity in both groups and using various antagonists, the possible mechanism for deviation in pain sensitivity was probed. Also, plasma and brain samples collected from animals in both groups were subjected to biochemical and/or histological studies. The results showed that Pb-infected mice exhibited diminished pain-related behaviours to noxious chemical. The observed parasite-induced analgesia appeared to be synergistically mediated via µ-opioid, α2 and 5HT2A receptors. When varied drugs capable of decreasing pain threshold (pro-nociceptive drugs) were used, the survival rate was not significantly different in the Pb-infected mice. This showed little or no contribution of the pain processing system to malaria-related death. Also, using an anti-CD68 antibody, there was no immunopositive cell in the brain to attribute the observed effects to cerebral malaria. Although in the haematoxylin and eosin-stained tissues, there were mild morphological changes in the motor and anterior cingulate cortices. In conclusion, the pain symptom was remarkably decreased in the animal model for malaria, and thus, the model may not be appropriate for investigating malaria-linked pain as reported in humans. This is the first report showing that at a critical point, the malaria parasite caused pain-relieving effects in Swiss mice.
Show more [+] Less [-]Plasmodium berghei-induced malaria decreases pain sensitivity in mice Full text
2021
Oyewole, Aboyeji L.(University of Ilorin Faculty of Basic Medical Sciences College of Health Sciences,Bioresearch Hub Laboratory) | Akinola, Oluwole(University of Ilorin Faculty of Basic Medical Sciences College of Health Sciences) | Owoyele, Bamidele V.(University of Ilorin Faculty of Basic Medical Sciences College of Health Sciences)
Various types of pain were reported by people with Plasmodium falciparum and were mostly attributed to a symptom of malarial infection. Neural processes of pain sensation during malarial infection and their contributions to malaria-related death are poorly understood. Thus, these form the focus of this study. Swiss mice used for this study were randomly divided into two groups. Animals in the first group (Pb-infected group) were inoculated with Plasmodium berghei to induce malaria whilst the other group (intact group) was not infected. Formalin test was used to assess pain sensitivity in both groups and using various antagonists, the possible mechanism for deviation in pain sensitivity was probed. Also, plasma and brain samples collected from animals in both groups were subjected to biochemical and/or histological studies. The results showed that Pb-infected mice exhibited diminished pain-related behaviours to noxious chemical. The observed parasite-induced analgesia appeared to be synergistically mediated via µ-opioid, α2 and 5HT2A receptors. When varied drugs capable of decreasing pain threshold (pro-nociceptive drugs) were used, the survival rate was not significantly different in the Pb-infected mice. This showed little or no contribution of the pain processing system to malaria-related death. Also, using an anti-CD68 antibody, there was no immunopositive cell in the brain to attribute the observed effects to cerebral malaria. Although in the haematoxylin and eosin-stained tissues, there were mild morphological changes in the motor and anterior cingulate cortices. In conclusion, the pain symptom was remarkably decreased in the animal model for malaria, and thus, the model may not be appropriate for investigating malaria-linked pain as reported in humans. This is the first report showing that at a critical point, the malaria parasite caused pain-relieving effects in Swiss mice.
Show more [+] Less [-]Updated distribution and host records for the argasid tick Ornithodoros (Pavlovskyella) zumpti: A potential vector of African swine fever virus in South Africa Full text
2021
Anthony F. Craig | Livio Heath | Jan E. Crafford | Juergen A. Richt | Robert Swanepoel
Updated distribution and host records for the argasid tick Ornithodoros (Pavlovskyella) zumpti: A potential vector of African swine fever virus in South Africa Full text
2021
Anthony F. Craig | Livio Heath | Jan E. Crafford | Juergen A. Richt | Robert Swanepoel
African swine fever virus (ASFV) causes a lethal and contagious disease of domestic pigs. In South Africa, the virus historically circulated in warthogs and ornithodorid ticks that were only found in warthog burrows in the north of the country. Regulations implemented in 1935 to prevent transfer of infected animals or products to the south initially proved effective but from 2016 there have been outbreaks of disease in the south that cannot be traced to transfer of infection from the north. From 1963 there were widespread translocations of warthogs to the south, initially from a source considered to be free of ornithodorid ticks. We undertook to determine whether sylvatic circulation of ASFV occurs in the south, including identification of potential new vectors, through testing extralimital warthogs for antibody and ticks for virus. Results of testing warthogs for antibody and other species of ticks for virus will be presented separately. Here we report finding Ornithodoros (Pavlovskyella) zumpti ticks in warthog burrows for the first time. This occurred in the Eastern Cape Province (ECP) in 2019. Since African swine fever was recognised in the ECP for the first time in 2020 and outbreaks of the disease in domestic pigs continue to occur there, priority should be given to determining the distribution range and vector potential of O. (P.) zumpti for ASFV.
Show more [+] Less [-]Acknowledgement to reviewers Full text
2021
Editorial Office
No abstract available.
Show more [+] Less [-]Wide circulation of peste des petits ruminants virus in sheep and goats across Nigeria Full text
2021
Samuel E. Mantip | Anthony Sigismeau | Maurice Nanven | Atuman Joel | Abayomi M. Qasim | Sada Aliyu | Ibrahim Musa | Ogechukwu Ezeanyika | Ibikunle Faramade | Garba Ahmed | Timothy Y. Woma | David Shamaki | Genevieve Libeau | Souaibou Farougou | Arnaud Bataille
Wide circulation of peste des petits ruminants virus in sheep and goats across Nigeria Full text
2021
Samuel E. Mantip | Anthony Sigismeau | Maurice Nanven | Atuman Joel | Abayomi M. Qasim | Sada Aliyu | Ibrahim Musa | Ogechukwu Ezeanyika | Ibikunle Faramade | Garba Ahmed | Timothy Y. Woma | David Shamaki | Genevieve Libeau | Souaibou Farougou | Arnaud Bataille
Peste des petits ruminants (PPR) is a highly contagious viral disease that mainly affects goats and sheep in Asia, Africa and the Middle East, and threatens Europe [R.E.1]. The disease is endemic on the African continent, particularly in West Africa, and is a major factor driving food insecurity in low-income populations. The aim of this research study was to carry out surveillance, genetic characterisation and isolation of recently circulating PPR viruses (PPRV) in sheep and goats from the six agro-ecological zones of Nigeria. A total of 268 post-mortem tissue samples of lung and mesenteric ganglia were collected from clinically suspected sheep and goats in 18 different states, of which five never previously sampled. The presence of PPRV was confirmed using a reverse-transcription coupled with a polymerase chain reaction (RT-PCR) assay. A total of 72 samples, 17 sheep (6%) and 55 goats (21%), were found to be PPR positive. Positive samples were distributed in almost all states, except Kano, where PPR was detected in previous studies. The PPRV-positive samples were further confirmed by sequencing or virus isolation in areas where the infection had never previously been detected. These results confirm the active circulation of PPRV across all six agro-ecological zones of Nigeria, and consequently, the need for introducing strict measures for the control and prevention of the disease in the country.
Show more [+] Less [-]Wide circulation of peste des petits ruminants virus in sheep and goats across Nigeria Full text
2021
Mantip, Samuel | Sigismeau, Anthony | Nanven, Maurice | Joel, Atuman | Qasim, Abayomi | Aliyu, Sada | Musa, Ibrahim | Ezeanyika, Ogechukwu | Faramade, Ibikunle | Ahmed, Garba | Woma, Timothy | Shamaki, David | Libeau, Genevieve | Farougou, Souaibou | Bataille, Arnaud | National Veterinary Research Institute [Nigeria] (NVRI) | Université d’Abomey-Calavi = University of Abomey Calavi (UAC) | Animal, Santé, Territoires, Risques et Ecosystèmes (UMR ASTRE) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Département Systèmes Biologiques (Cirad-BIOS) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | This research article was funded by the European Commission Directorate General for Health and Food Safety (Grant No. SI2.756606) awarded to the European Union Reference Laboratory for Peste des Petits Ruminants (EURL-PPR) and by a grant from European Commission (Development Cooperation Instruments) awarded to the project ‘EU Support to Livestock Disease Surveillance Knowledge Integration – LIDISKI’ (FOOD/2019/410-957) in the framework of the Development of Smart Innovation through Research in the Agriculture (DeSIRa) programme.
International audience | Peste des petits ruminants (PPR) is a highly contagious viral disease that mainly affects goats and sheep in Asia, Africa and the Middle East, and threatens Europe [R.E.1]. The disease is endemic on the African continent, particularly in West Africa, and is a major factor driving food insecurity in low-income populations. The aim of this research study was to carry out surveillance, genetic characterisation and isolation of recently circulating PPR viruses (PPRV) in sheep and goats from the six agro-ecological zones of Nigeria. A total of 268 post-mortem tissue samples of lung and mesenteric ganglia were collected from clinically suspected sheep and goats in 18 different states, of which five never previously sampled. The presence of PPRV was confirmed using a reverse-transcription coupled with a polymerase chain reaction (RT-PCR) assay. A total of 72 samples, 17 sheep (6%) and 55 goats (21%), were found to be PPR positive. Positive samples were distributed in almost all states, except Kano, where PPR was detected in previous studies. The PPRV-positive samples were further confirmed by sequencing or virus isolation in areas where the infection had never previously been detected. These results confirm the active circulation of PPRV across all six agro-ecological zones of Nigeria, and consequently, the need for introducing strict measures for the control and prevention of the disease in the country.
Show more [+] Less [-]Wide circulation of peste des petits ruminants virus in sheep and goats across Nigeria Full text
2021
Mantip, Samuel | Sigismeau, Anthony | Nanven, Maurice | Atuman, Joel | Qasim, Abayomi M. | Aliyu, Sada | Musa, Ibrahim | Ezeanyika, Ogechukwu | Faramade, Ibikunle | Ahmed, Garba | Woma, Timothy Yusuf | Shamaki, David | Libeau, Geneviève | Farougou, Souabou | Bataille, Arnaud
Peste des petits ruminants (PPR) is a highly contagious viral disease that mainly affects goats and sheep in Asia, Africa and the Middle East, and threatens Europe [R.E.1]. The disease is endemic on the African continent, particularly in West Africa, and is a major factor driving food insecurity in low-income populations. The aim of this research study was to carry out surveillance, genetic characterisation and isolation of recently circulating PPR viruses (PPRV) in sheep and goats from the six agro-ecological zones of Nigeria. A total of 268 post-mortem tissue samples of lung and mesenteric ganglia were collected from clinically suspected sheep and goats in 18 different states, of which five never previously sampled. The presence of PPRV was confirmed using a reverse-transcription coupled with a polymerase chain reaction (RT-PCR) assay. A total of 72 samples, 17 sheep (6%) and 55 goats (21%), were found to be PPR positive. Positive samples were distributed in almost all states, except Kano, where PPR was detected in previous studies. The PPRV-positive samples were further confirmed by sequencing or virus isolation in areas where the infection had never previously been detected. These results confirm the active circulation of PPRV across all six agro-ecological zones of Nigeria, and consequently, the need for introducing strict measures for the control and prevention of the disease in the country.
Show more [+] Less [-]Wide circulation of peste des petits ruminants virus in sheep and goats across Nigeria Full text
2021
Mantip,Samuel E. | Sigismeau,Anthony | Nanven,Maurice | Joel,Atuman | Qasim,Abayomi M. | Musa,Sada Aliyu Ibrahim | Ezeanyika,Ogechukwu | Faramade,Ibikunle | Ahmed,Garba | Woma,Timothy Y. | Shamaki,David | Libeau,Genevieve | Farougou,Souaibou | Bataille,Arnaud
Peste des petits ruminants (PPR) is a highly contagious viral disease that mainly affects goats and sheep in Asia, Africa and the Middle East, and threatens Europe [R.E.1]. The disease is endemic on the African continent, particularly in West Africa, and is a major factor driving food insecurity in low-income populations. The aim of this research study was to carry out surveillance, genetic characterisation and isolation of recently circulating PPR viruses (PPRV) in sheep and goats from the six agro-ecological zones of Nigeria. A total of 268 post-mortem tissue samples of lung and mesenteric ganglia were collected from clinically suspected sheep and goats in 18 different states, of which five never previously sampled. The presence of PPRV was confirmed using a reverse-transcription coupled with a polymerase chain reaction (RT-PCR) assay. A total of 72 samples, 17 sheep (6%) and 55 goats (21%), were found to be PPR positive. Positive samples were distributed in almost all states, except Kano, where PPR was detected in previous studies. The PPRV-positive samples were further confirmed by sequencing or virus isolation in areas where the infection had never previously been detected. These results confirm the active circulation of PPRV across all six agro-ecological zones of Nigeria, and consequently, the need for introducing strict measures for the control and prevention of the disease in the country.
Show more [+] Less [-]The spread and antimicrobial resistance of Staphylococcus aureus in South African dairy herds – A review Full text
2021
Joanne Karzis | Inge-Marie Petzer | Vinny Naidoo | Edward F. Donkin
The spread and antimicrobial resistance of Staphylococcus aureus in South African dairy herds – A review Full text
2021
Joanne Karzis | Inge-Marie Petzer | Vinny Naidoo | Edward F. Donkin
Staphylococcus aureus is internationally recognised as a principal agent of mastitis and the foremost reason for economic loss in the dairy industry. The limited data available on organism-specific antibiotic resistance surveillance in dairy cattle have stimulated the need for such a review article. The objective of this study was to review relevant literature on antimicrobial resistance of mastitis-causing staphylococci isolated from dairy cows in South Africa compared to other countries. Factors relating to the incidence of mastitis and treatment strategies in terms of the One Health concept and food security were included. The Web of Science (all databases) and relevant websites were used, and articles not written in English were excluded. The incidence of mastitis varied between South Africa and other countries. Antimicrobial resistance patterns caused by S. aureus also varied in regions within Southern Africa and those of other countries although some similarities were shown. Antimicrobial resistance differed between S. aureus bacteria that were maltose positive and negative (an emerging pathogen). The results highlighted the importance of the availability of organism-specific surveillance data of the incidence of mastitis and antibiotic resistance for specific countries and within similar climatic conditions. Accurate knowledge about whether a specific pathogen is resistant to an antibiotic within a certain climate, country, area or farm should reduce the incidence of unnecessary or incorrect treatment with antibiotics. This should enable dairy farmers to deal with these organisms in a more effective manner. Therefore such research should be ongoing.
Show more [+] Less [-]Review of African swine fever outbreaks history in South Africa: From 1926 to 2018 Full text
2021
Ciza A. Mushagalusa | Eric Etter | Mary-Louise Penrith
Review of African swine fever outbreaks history in South Africa: From 1926 to 2018 Full text
2021
Ciza A. Mushagalusa | Eric Etter | Mary-Louise Penrith
The article reviews the outbreaks and distribution of African swine fever (ASF) in South Africa since the first probable outbreak that occurred in the Koedoesrand Ward in 1926. Retrospective data on the ASF outbreaks in South Africa were obtained from the World Organisation for Animal Health (OIE) disease database and the South African veterinary services annual reports in addition to published articles and online sources. South Africa has experienced many outbreaks that can be divided into 2 time periods: the period before the development of the OIE diseases database (1993) and the period after. More than 141 outbreaks of ASF were reported during the first period. Since the development of OIE disease database, 72 outbreaks directly involving 2968 cases, 2187 dead and 2358 killed pigs mainly in smallholder pig farms were reported. The median number of cases for a given ASF outbreak is 17, but in 50% of outbreaks no pigs were killed for prevention. The most important ASF outbreak was reported in April 2014 in the Greater Zeerust district (North West province) involving 326 cases and 1462 killed pigs. However, the outbreak with highest mortality involving 250 pigs was reported in 2016 (Free State province). According to phylogenetic analysis, nine p72 genotypes (I, III, IV, VII, VIII, XIX, XX, XXI and XXII) have been identified in South Africa. Season-wise, more outbreaks were recorded during summer. It was also observed that the OIE disease database could contain errors that would have been introduced through compiled forms at country level. Spatiotemporal studies on ASF outbreaks in South Africa are therefore required in order to assess statistically and quantitatively the clustering of outbreaks over space and time.
Show more [+] Less [-]Review of African swine fever outbreaks history in South Africa: From 1926 to 2018 Full text
2021
Mushagalusa, Ciza A. | Etter, Eric | Penrith, Mary-Louise
The article reviews the outbreaks and distribution of African swine fever (ASF) in South Africa since the first probable outbreak that occurred in the Koedoesrand Ward in 1926. Retrospective data on the ASF outbreaks in South Africa were obtained from the World Organisation for Animal Health (OIE) disease database and the South African veterinary services annual reports in addition to published articles and online sources. South Africa has experienced many outbreaks that can be divided into 2 time periods: the period before the development of the OIE diseases database (1993) and the period after. More than 141 outbreaks of ASF were reported during the first period. Since the development of OIE disease database, 72 outbreaks directly involving 2968 cases, 2187 dead and 2358 killed pigs mainly in smallholder pig farms were reported. The median number of cases for a given ASF outbreak is 17, but in 50% of outbreaks no pigs were killed for prevention. The most important ASF outbreak was reported in April 2014 in the Greater Zeerust district (North West province) involving 326 cases and 1462 killed pigs. However, the outbreak with highest mortality involving 250 pigs was reported in 2016 (Free State province). According to phylogenetic analysis, nine p72 genotypes (I, III, IV, VII, VIII, XIX, XX, XXI and XXII) have been identified in South Africa. Season-wise, more outbreaks were recorded during summer. It was also observed that the OIE disease database could contain errors that would have been introduced through compiled forms at country level. Spatiotemporal studies on ASF outbreaks in South Africa are therefore required in order to assess statistically and quantitatively the clustering of outbreaks over space and time.
Show more [+] Less [-]Review of African swine fever outbreaks history in South Africa: From 1926 to 2018 Full text
2021
Mushagalusa,Ciza A. | Etter,Eric | Penrith,Mary-Louise
The article reviews the outbreaks and distribution of African swine fever (ASF) in South Africa since the first probable outbreak that occurred in the Koedoesrand Ward in 1926. Retrospective data on the ASF outbreaks in South Africa were obtained from the World Organisation for Animal Health (OIE) disease database and the South African veterinary services annual reports in addition to published articles and online sources. South Africa has experienced many outbreaks that can be divided into 2 time periods: the period before the development of the OIE diseases database (1993) and the period after. More than 141 outbreaks of ASF were reported during the first period. Since the development of OIE disease database, 72 outbreaks directly involving 2968 cases, 2187 dead and 2358 killed pigs mainly in smallholder pig farms were reported. The median number of cases for a given ASF outbreak is 17, but in 50% of outbreaks no pigs were killed for prevention. The most important ASF outbreak was reported in April 2014 in the Greater Zeerust district (North West province) involving 326 cases and 1462 killed pigs. However, the outbreak with highest mortality involving 250 pigs was reported in 2016 (Free State province). According to phylogenetic analysis, nine p72 genotypes (I, III, IV, VII, VIII, XIX, XX, XXI and XXII) have been identified in South Africa. Season-wise, more outbreaks were recorded during summer. It was also observed that the OIE disease database could contain errors that would have been introduced through compiled forms at country level. Spatiotemporal studies on ASF outbreaks in South Africa are therefore required in order to assess statistically and quantitatively the clustering of outbreaks over space and time.
Show more [+] Less [-]Review of African swine fever outbreaks history in South Africa: From 1926 to 2018 Full text
2021
Mushagalusa, Ciza A. | Etter, Eric | Penrith, Mary-Louise | Université évangélique en Afrique | Animal, Santé, Territoires, Risques et Ecosystèmes (UMR ASTRE) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Département Systèmes Biologiques (Cirad-BIOS) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | University of Pretoria [South Africa] | The Ecology and Evolution of Infectious Diseases Program, grant no. 2019-67015-28981 from the United States Department of Agriculture National Institute of Food and Agriculture.
International audience | The article reviews the outbreaks and distribution of African swine fever (ASF) in South Africa since the first probable outbreak that occurred in the Koedoesrand Ward in 1926. Retrospective data on the ASF outbreaks in South Africa were obtained from the World Organisation for Animal Health (OIE) disease database and the South African veterinary services annual reports in addition to published articles and online sources. South Africa has experienced many outbreaks that can be divided into 2 time periods: the period before the development of the OIE diseases database (1993) and the period after. More than 141 outbreaks of ASF were reported during the first period. Since the development of OIE disease database, 72 outbreaks directly involving 2968 cases, 2187 dead and 2358 killed pigs mainly in smallholder pig farms were reported. The median number of cases for a given ASF outbreak is 17, but in 50% of outbreaks no pigs were killed for prevention. The most important ASF outbreak was reported in April 2014 in the Greater Zeerust district (North West province) involving 326 cases and 1462 killed pigs. However, the outbreak with highest mortality involving 250 pigs was reported in 2016 (Free State province). According to phylogenetic analysis, nine p72 genotypes (I, III, IV, VII, VIII, XIX, XX, XXI and XXII) have been identified in South Africa. Season-wise, more outbreaks were recorded during summer. It was also observed that the OIE disease database could contain errors that would have been introduced through compiled forms at country level. Spatiotemporal studies on ASF outbreaks in South Africa are therefore required in order to assess statistically and quantitatively the clustering of outbreaks over space and time.
Show more [+] Less [-]The Medical Applications of Transmission Electron Microscope: Subject Review Full text
2021
Aseel Hameed | Jihad Aahmed
Transmission electron microscope TEM is a tool used to visualization intracellular components of certain samples ranging from very little dimension one micrometer up to one nanometer, Therefore, TEM can reveal a tiny detail that can’t investigate through the light microscope. The application of TEM in the medical field may help the researchers to analyze the morphological structure of samples obtained from small organisms like bacteria and viruses, as well as study the samples of cellular inclusions on basis of three-dimensional images.
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