Suidae Research Articles

Stability of African swine fever virus on spiked spray-dried porcine plasma.

African swine fever (ASF) is a viral disease that affects members of the Suidae family. The notifiable disease is considered a major threat to the pig industry, animal health, and food security worldwide. According to the European Food Safety Authority, ASF virus (ASFV) survival and transmission in feed and feed materials is a major research gap. Against this background, the objective of this study was to determine the survival of ASFV on spiked spray-dried porcine plasma (SDPP) when stored at two different temperatures. To this means, commercial SDPP granules were contaminated with high titers of ASFV in a worst-case external contamination scenario. Three samples per time point and temperature condition were subjected to blind passaging on macrophage cultures and subsequent haemadsorption test to determine residual infectivity. In addition, viral genome was detected by real-time PCR. The results indicate that heavily contaminated SDPP stored at 4°C remains infectious for at least 5 weeks. In contrast, spiked SDPP stored at room temperature displayed a distinct ASFV titer reduction after 1 week (>2.8 log levels) and complete inactivation after 2weeks (>5.7 log levels). In conclusion, the residual risk of ASFV transmission through externally contaminated SDPP is low if SDPP is stored at room temperature (21 ± 2°C) for a period of at least 2weeks before feeding.

Computational Genomics of RELA gene of Pig and its protein prescription

RELA gene is a pleiotropic transcription that is present in almost all living cells where several signal transduction events end points were initiated by many arrays of stimuli that were related to many biological processes such as inflammation, immunity, differentiation, cell growth, tumorigenesis and apoptosis in the cells. The nucleotide and amino acid sequence (AAS) of RELA gene of pig and other mammalian species were downloaded from the National Center for Biotechnology information (NCBI) data base, United State of America and Universal protein resources (Uniprot) database, United Kingdom. Data generated were analyzed by bioinformatics tools. The results showed a high variation of AAS among the mammals where only four mammals have the same AAS length (551) with pig while others were not. The RELA gene of pig shared very high percent identity with all mammals ranging from 95.5% (warthog) to 83.5% (guinea pig) and similarity percentage ranged from 85.1 to 99.5% where the warthog had the highest percentage value while the least mammal was Guinea pig. The tree showed RELA gene with two clades; the first for mammals and the second for non-mammals. The RELA gene of pig was in the same cluster with the other Suidae family, warthog and babirusa. For the protein structure obtained, only 43% can be meaningfully predicted from the 61% residues modelled at more than 90%. The domain architecture of RELA protein structure contained mainly RNA Recognition motif and region of low complexity. The domainstarting position of all the organisms ranged from 191 to 210 while the termination of all the mammals ranged from 102 to 306 amino acids.The region of low complexity starting point ranged from position 173 to 462while termination positions ranged from 184 to 474. The evolution relationship of RELA gene of pig and other mammalian species were highly related and conserved among the mammalian species; they have high comparability and they evolved from common ancestors.

Genetic origins and diversity of bushpigs from Madagascar (Potamochoerus larvatus, family Suidae)

The island of Madagascar, situated off the southeast coast of Africa, shows the first evidence of human presence ~ 10,000 years ago; however, other archaeological data indicates a settlement of the modern peoples of the island distinctly more recent, perhaps > 1500 years ago. Bushpigs of the genus Potamochoerus (family Suidae), are today widely distributed in Madagascar and presumed to have been introduced from Africa at some stage by human immigrants to the island. However, disparities about their origins in Madagascar have been presented in the literature, including the possibility of endemic subspecies, and few empirical data are available. Furthermore, the separation of bushpigs in Madagascar from their mainland relatives may have favoured the evolution of a different repertoire of immune genes first due to a founder effect and then as a response to distinct pathogens compared to their ancestors. Molecular analysis confirmed the species status of the bushpig in Madagascar as P. larvatus, likely introduced from the central region of southern Africa, with no genetic evidence for the recognition of eastern and western subspecies as suggested from previous cranial morphology examination. Investigation of the immunologically important SLA-DQB1 peptide-binding region showed a different immune repertoire of bushpigs in Madagascar compared to those on the African mainland, with seventeen exon-2 haplotypes unique to bushpigs in Madagascar (2/28 haplotypes shared). This suggests that the MHC diversity of the Madagascar populations may have enabled Malagasy bushpigs to adapt to new environments.

Role of the DNA-Binding Protein pA104R in ASFV Genome Packaging and as a Novel Target for Vaccine and Drug Development.

The recent incursions of African swine fever (ASF), a severe, highly contagious, transboundary viral disease that affects members of the Suidae family, in Europe and China have had a catastrophic impact on trade and pig production, with serious implications for global food security. Despite efforts made over past decades, there is no vaccine or treatment available for preventing and controlling the ASF virus (ASFV) infection, and there is an urgent need to develop novel strategies. Genome condensation and packaging are essential processes in the life cycle of viruses. The involvement of viral DNA-binding proteins in the regulation of virulence genes, transcription, DNA replication, and repair make them significant targets. pA104R is a highly conserved HU/IHF-like DNA-packaging protein identified in the ASFV nucleoid that appears to be profoundly involved in the spatial organization and packaging of the ASFV genome. Here, we briefly review the components of the ASFV packaging machinery, the structure, function, and phylogeny of pA104R, and its potential as a target for vaccine and drug development.

Comparative Pathology and Pathogenesis of African Swine Fever Infection in Swine.

African Swine Fever (ASF) is a viral disease that affects animals of the Suidae family, and soft ticks from the genus Ornithodoros can also be infected by the ASF virus (ASFV). The disease was first described in Africa at the beginning of the twentieth century as an acute disease characterized by high mortality and fatal hemorrhages. ASF has caused outbreaks in numerous countries and it continues to be devastating nowadays for the porcine sector in those countries affected, and a massive threat for those free of the disease. ASF can follow clinical courses from peracute to chronic in domestic pigs (Sus scrofa) depending on a variety of factors, including the immune status of the animals and the virulence of the ASFV strain. The key features of the pathogenesis of the disease in domestic swine are a) a severe lymphoid depletion including lymphopenia and a state of immunodeficiency, and b) hemorrhages. However, African wild swine like bushpigs (Potamochoerus larvatus), red river hogs (Potamochoerus porcus), and warthogs (Phacochoerus africanus) can be infected by ASFV showing no clinical signs of disease and acting as natural reservoir hosts. In this article we review the key features of the gross and microscopic pathology together with a description of the pathogenesis of ASFV infection in domestic pigs following the different clinical courses. The pathogenesis of ASF in wild and domestic swine is also described, what can provide important information for the design of control strategies, such as vaccines.

Survey for pestiviruses in backyard pigs in southern Brazil.

The Pestivirus genus comprises species that affect animal health and productivity worldwide. Members of the Suidae family are hosts for classical swine fever virus (CSFV), an important pathogen tracked by the World Organization for Animal Health (OIE). However, swine are also susceptible to other pestivirus species that can result in disease or compromise CSFV detection. We searched for pestivirus infection in swine sera collected from 320 backyard pig herds in southern Brazil. We used reverse-transcription PCR primers for Bungowannah virus; atypical porcine pestivirus (APPV); and a panpestivirus pair that detects bovine viral diarrhea virus (BVDV)-1, -2, and HoBi-like pestivirus (HoBiPeV), border disease virus (BDV), and CSFV. Two samples were positive using the panpestivirus primer pair and were classified as BVDV-1d and -2a, respectively. Serum samples were tested for virus neutralization against BVDV-1a, -1b, and -2 strains, resulting in 28 (4.4%) positive samples. Of those, 16 samples had the highest titers against BVDV-1a (2), BVDV-1b (5), and BVDV-2 (9). Our results indicate that Bungowannah virus, APPV, CSFV, BDV, and HoBiPeV have not been circulating in these specific backyard swine populations. However, ruminant pestiviruses were detected and must be considered in future pestivirus control programs conducted in Brazil.

Computational Molecular Analysis of the 5 Candidate Genes of Suidae Family Related to African Swine Fever Occurrence

Suidae family consisting, domestic pig, warthog and babyrousa are identified with even hooves and snout nose. They have been reported to be tolerant to African swine fever virus (ASFV) with the exception of the domestic pig. Domestic pig is valuable for humans as a source of protein all over the world, but is more susceptible to this disease. ASFV has been found in warthog and bush pig. Five candidate genes, RELA, PPP3CB, PPIA, NFKBIA, and NFATC1 have been suggested to be responsible for the genetic variation between the components of Suidae family, which may contribute to the species-specific responses to ASFV infection. This study aims to investigate the evolution, differentiation and functional function of these five genes in three species of Suidae family that are either susceptible or tolerant to ASFV using molecular computational genetics.
 The nucleotide and amino acid sequence (aas) of the 5 genes of pig, warthog and babyrousa were downloaded from NCBI, Essembel geneome browser, and Uniprot database. They were aligned and analysed to predict functional effect of amino acid substitution as deleterious or neutral for small insertions and deletions.
 The candidate genes were observed to have variants with the exception of NFKBIA. They were observed to have deleterious variants. These deleterious variants may be responsible for the susceptibility or tolerance of this family to ASF disease.

Ecology of Wild Hogs in Florida

Florida's wild hogs (Figure 1) are often referred to as feral hogs or swine and are of three general types. These include free-ranging swine that come from domesticated stock, Eurasian wild boar, and hybrids of the two. Although technically, feral refers to free-ranging animals from domesticated stock, all wild hogs are typically referred to as feral in Florida and all are considered the same species, Sus scrofa. Wild hogs are in the family Suidae (true wild pigs), none of which are native to the Americas. Although not found in Florida, the only native pig-like mammal found in the United States is the collared peccary or javelina (Tayassu tajacu; Figure 2). These are not true pigs, in the family Tayassuidae, and about half the size of typical wild hogs. This document is WEC 191 and is one of a series of the Department of Wildlife Ecology and Conservation, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences (IFAS), University of Florida. First published: April 2005.

<p class="Body">DNA segments of African Swine Fever Virus detected for the first time in hard ticks from sheep and bovines

In this study, we detected African Swine Fever Virus (ASFV) in Dermacentor (Ixodidae) from sheep and bovines using small RNA sequencing. To validate this result, a 235-bp DNA segment was detected in a number of DNA samples from D. silvarum and sheep blood. This 235-bp segment had an identity of 99% to a 235-bp DNA segment of ASFV and contained three single nucleotide mutations (C38T, C76T and A108C). C38T, resulting in a single amino acid mutation G66D, suggests the existence of a new ASFV strain, which is different from all reported ASFV strains in the NCBI GenBank database and the ASFV strain (GenBank: MH713612.1) reported in China in 2018. To further confirm the existence of ASFV in Dermacentor ticks, three DNA segments of ASFV were detected in D. niveus females from bovines and their first generation ticks reared in our lab. These results also proved that transovarian transmission of ASFV occurs in hard ticks. This study revealed for the first time that ASFV has a wider range of hosts (e.g. sheep and bovines) and vectors (e.g. hard ticks), beyond the well-known Suidae family and Argasidae (soft ticks). Our findings pave the way toward further studies on ASFV transmission and the development of prevention and control measures.

High seroprevalence of Toxoplasma gondii antibodies in wild boars hunted in the Game Breeding Center in north-eastern Poland

Toxoplasmosis is a cosmopolitan zoonotic disease caused by Toxoplasma gondii, an intracellular protozoan. The main source of infection for humans is meat contaminated with tissue cysts, the main invasive form of the parasite. The muscle tissue of seropositive animals of the family Suidae, subfamily Sus (domestic pig, wild boar) are the most common sources of infections with Toxoplasma gondii. The aim of this study was to determine the prevalence of T. gondii infections in the meat of wild boars (Sus scrofa) based on measurements of T. gondii antibodies in the enzyme-linked immunosorbent assay (ELISA). One hundred samples of muscle tissue were obtained from wild boars hunted in the Game Breeding Center in north-eastern Poland. The animals were divided into three age groups: weaners (27), subadults (38) and adults (35). The prevalence of toxoplasmosis was very high in the analyzed population, and 71% of the animals were classified as seropositive in ELISA. Antibodies against T. gondii were detected in 62.9% of weaners, 73.6% of subadults and 74.2% of adult boars. The seroprevalence of T. gondii antibodies was significantly higher in the animals hunted in the Game Breeding Center in comparison with the national average determined by other authors. Such extensive spread of the parasite in the natural environment can be attributed to geographic location, landform, presence of waterbodies, local climate, the size of the wild boar population and the spread of castor bean ticks (Ixodes ricinus).

Current Knowledge on Porcine circovirus 3 (PCV-3): A Novel Virus With a Yet Unknown Impact on the Swine Industry.

Porcine circovirus 3 (PCV-3) is a recently described virus belonging to the family Circoviridae. It represents the third member of genus Circovirus able to infect swine, together with PCV-1, considered non-pathogenic, and PCV-2, one of the most economically relevant viruses for the swine worldwide industry. PCV-3 was originally found by metagenomics analyses in 2015 in tissues of pigs suffering from porcine dermatitis and nephropathy syndrome, reproductive failure, myocarditis and multisystemic inflammation. The lack of other common pathogens as potential infectious agents of these conditions prompted the suspicion that PCV-3 might etiologically be involved in disease occurrence. Subsequently, viral genome was detected in apparently healthy pigs, and retrospective studies indicated that PCV-3 was already present in pigs by early 1990s. In fact, current evidence suggests that PCV-3 is a rather widespread virus worldwide. Recently, the virus DNA has also been found in wild boar, expanding the scope of infection susceptibility among the Suidae family; also, the potential reservoir role of this species for the domestic pig has been proposed. Phylogenetic studies with available PCV-3 partial and complete sequences from around the world have revealed high nucleotide identity (>96%), although two main groups and several subclusters have been described as well. Moreover, it has been proposed the existence of a most common ancestor dated around 50 years ago. Taking into account the economic importance and the well-known effects of PCV-2 on the swine industry, a new member of the same family like PCV-3 should not be neglected. Studies on epidemiology, pathogenesis, immunity and diagnosis are guaranteed in the next few years. Therefore, the present review will update the current knowledge and future trends of research on PCV-3.

The intracellular proteome of African swine fever virus

African swine fever (ASF) is a viral disease that affects members of the Suidae family such as African bush pigs, warthogs, but also domestic pigs, and wild boar. It is transmitted by direct contact of naïve with infected animals, by soft ticks of the Ornithodoros genus, or indirectly by movement of infected animals, improper disposal of contaminated animal products or other sources related to human activity. The recent spread of ASF into Eastern and Central European countries is currently threatening the European pig industry. The situation is aggravated as to-date no efficient vaccine is available. African swine fever virus (ASFV) is a large enveloped ds DNA-virus encoding at least 150 open reading frames. Many of the deduced gene products have not been described, less functionally characterized. We have analysed ASFV protein expression in three susceptible mammalian cell lines representing a susceptible host (wild boar) and two non-susceptible species (human and green monkey) by mass spectrometry and provide first evidence for the expression of 23 so far uncharacterized ASFV ORFs. Expression levels of several newly identified ASFV proteins were remarkably high indicating importance in the viral replication cycle. Moreover, expression profiles of ASFV proteins in the three cell lines differed markedly.

ARCHAEOZOOLOGICAL MATERIALS FROM SHESTOVYTSIA NECROPOLIS IN THE COLLECTIONS OF THE INSTITUTE OF ARCHAEOLOGY

A long-term archaeological study at Shestovytsia necropolis accumulated a significant collection, an important part of which are archaeozoological materials. Most of the finds are stored at the Institute of Archaeology of the National Academy of Sciences of Ukraine. V. I. Bibikova determined the bones from 35 Shestovytsia’s burial mounds, excavated in the 1940s—1950s and published by D. I. Blifeld. Currently in the collection, there are osteological remains from 28 complexes and 3 bones without the catalogue numbers, they were identified by Ye. Yu. Yanish. The sample from this site includes 454 fragments of animal origin from 61 individuals minimum.
 All animal remains belong to the category of «ritually used», because they originate from inventory of burials. These are the animal for sacrific buried along with the human body, the remains of funeral feast and of food placed into the grave, and the personal belongings of the dead, i. e. things of everyday use (combs, pointed tools (fids or marlinspikes), needle- and awl-cases, etc.), amulets, and gaming pieces. They are ranged by degree of treatment from bones without any treatment to complicated bone products. Animals which bones were used for further treatment were adult species. The bones of young individuals, apparently, belonged to the animals used for funeral feast.
 Total of 11 representative mammal species belong to 3 Oders — Artiodactyla: Bovidae family, Cervidae family, Suidae family; Perissodactyla: Equidae family; Carnivora: Canidae family and Ursidae family; and also Rodentia. In addition, in several graves, chicken bones (Gallus gallusdomesticus), bird’s (obviously chicken) eggs, as well as the shell of the Unio crassus were detected. There are no fish remains in the materials from the necropolis. Domestic species accounted for 68.3 % of the determined mammalian remains. The largest variety is registered in the materials from the burial mound 21 (the mound 22 (121), according to the report, excavations in 1956) and the burial 1 and 4 of the mound 61 (the mound 52 (51), according to the report, excavations in 1957).
 87 bones contain traces of influence: the effects of fire, the traces of chopping, cutting, and gnawing by dogs. In the investigated material, there is a bone of small cattle with pathological enlargements, which are the result of the inflammatory process, in this case, most probably after trauma. In addition, the enamel of the horse’s tooth is damaged, which is likely a result of the certain types of feed usage.

Porcine macrophage-like cells permit viral replication, produce inflammatory mediators, and undergo apoptosis following infection with Rift Valley fever virus MP-12

Abstract Rift Valley fever virus (RVFV) is a mosquito-borne virus that can cause severe disease in a variety of domestic animal species as well as in humans. Outbreaks occur primarily in Sub-Saharan Africa with ruminant livestock most affected and outcomes that include abortion storms and high mortality among young animals. Clinical disease is not known to occur in domestic pigs (Sus scrofa); however, a limited number of studies have detected circulating antibodies to RVFV among wild and domestic members of the pig family (Suidae). Experimentally, RVFV has been shown to replicate in some porcine epithelial and neuronal cells in vitro, and induce a viremia in a fraction of pigs inoculated in vivo. No studies to date have investigated the behavior of RVFV in porcine cells of immune origin, whereas in humans and mice, macrophages and dendritic cells have been implicated as having roles in RVFV pathogenicity. Here, we use a porcine monocyte-derived macrophage-like cell line, CΔ2+, to investigate porcine innate immune cell permissiveness to MP-12, an attenuated form of RVFV. MP-12 caused observable cytopathic effects in CΔ2+ cells and reduced cell viability in dose- and time-dependent manners. At 24 hours, the reduced viability was coincident with apoptosis, with necrosis also occurring at a higher multiplicity of infection. At early time points, MP-12 replicated at levels comparable to cells derived from sheep kidney—a target organ of a highly susceptible host species. Infected CΔ2+ cells also upregulated transcription of inflammatory mediators. This work provides the first evidence that porcine immune cells are permissive to RVFV, and indicates that additional studies are warranted to better understand the dynamics of RVFV in suids.

Inferring the evolution of the major histocompatibility complex of wild pigs and peccaries using hybridisation DNA capture-based sequencing.

The major histocompatibility complex (MHC) is a key genomic model region for understanding the evolution of gene families and the co-evolution between host and pathogen. To date, MHC studies have mostly focused on species from major vertebrate lineages. The evolution of MHC classical (Ia) and non-classical (Ib) genes in pigs has attracted interest because of their antigen presentation roles as part of the adaptive immune system. The pig family Suidae comprises over 18 extant species (mostly wild), but only the domestic pig has been extensively sequenced and annotated. To address this, we used a DNA-capture approach, with probes designed from the domestic pig genome, to generate MHC data for 11 wild species of pigs and their closest living family, Tayassuidae. The approach showed good efficiency for wild pigs (~80% reads mapped, ~87× coverage), compared to tayassuids (~12% reads mapped, ~4× coverage). We retrieved 145 MHC loci across both families. Phylogenetic analyses show that the class Ia and Ib genes underwent multiple duplications and diversifications before suids and tayassuids diverged from their common ancestor. The histocompatibility genes mostly form orthologous groups and there is genetic differentiation for most of these genes between Eurasian and sub-Saharan African wild pigs. Tests of selection showed that the peptide-binding region of class Ib genes was under positive selection. These findings contribute to better understanding of the evolutionary history of the MHC, specifically, the class I genes, and provide useful data for investigating the immune response of wild populations against pathogens.

Sympatry among Three Suid Species (Family Suidae) on the North Coast of Kenya

ABSTRACT Three species of suids occur on the broad coastal plain of Kenya east and north of the Tana River; desert warthog Phacochoerus aethiopicus, common warthog Phacochoerus africanus, and bushpig Potamochoerus larvatus. Systematic cameratrap surveys, comprising 9229 camera-trap days on grids at six study sites, were used to determine the distribution and relative abundance of these three suids in the Boni-Dodori Forest Complex (ca. 4000 km2) and in Arabuko-Sokoke Forest Reserve (416 km2) on Kenya's north and central coasts, respectively. In the Boni-Dodori Forest Complex, desert warthog was captured at one camera site, common warthog at four camera sites, and bushpig at 33 camera sites. In Arabuko-Sokoke Forest Reserve, only bushpig was captured (seven camera sites). Sympatry of desert warthog and common warthog seems limited in the Boni-Dodori Forest Complex. Here, desert warthog appears to be narrowly sympatric with bushpig whereas common warthog is broadly sympatric with bushpig. Sympatry of the th...

Prevalence of Antibodies to Aujeszky's Disease Virus in Wild Boar in Poland, Between 2011 and 2014: A Retrospective Study.

IntroductionAujeszky’s disease virus (ADV) infects a wide range of animals, including members of the Suidae family, i.e. domestic and wild pigs, as well as wild boar. Since wild boar are a potential ADV reservoir and a source of infection for domestic pigs, the aim of the study was to evaluate ADV antibody prevalence in the Polish wild boar population, during the years 2011 to 2014.Material and MethodsWild boar blood samples were collected during three consecutive hunting seasons; i.e. 2011/2012, 2012/2013, and 2013/2014, and tested for ADV antibodies by ELISA.ResultsADV antibodies were detected in samples from all tested voivodships. The average seroprevalence reached 32.2%. Seroprevalence, over the examined hunting seasons, was 27.4% in 2011/2012, 32.4% in 2012/2013, and 35.5% in 2013/2014. The highest percentage of seroreagents was detected in four voivodships, situated along the western border of Poland, i.e. Zachodnio-Pomorskie (ZP), Lubuskie (LB), Dolnośląskie (DS), and Opolskie (OP). This area is positively correlated with the highest density of the wild boar population and the highest wild boar hunting bag.ConclusionThe results of this study confirm that the wild boar population may still pose a threat to domestic pigs, which is of special importance at the final stage of Aujeszky’s disease eradication programme in Poland.

Reconstitution of UCP1 using CRISPR/Cas9 in the white adipose tissue of pigs decreases fat deposition and improves thermogenic capacity

Uncoupling protein 1 (UCP1) is localized on the inner mitochondrial membrane and generates heat by uncoupling ATP synthesis from proton transit across the inner membrane. UCP1 is a key element of nonshivering thermogenesis and is most likely important in the regulation of body adiposity. Pigs (Artiodactyl family Suidae) lack a functional UCP1 gene, resulting in poor thermoregulation and susceptibility to cold, which is an economic and pig welfare issue owing to neonatal mortality. Pigs also have a tendency toward fat accumulation, which may be linked to their lack of UCP1, and thus influences the efficiency of pig production. Here, we report application of a CRISPR/Cas9-mediated, homologous recombination (HR)-independent approach to efficiently insert mouse adiponectin-UCP1 into the porcine endogenous UCP1 locus. The resultant UCP1 knock-in (KI) pigs showed an improved ability to maintain body temperature during acute cold exposure, but they did not have alterations in physical activity levels or total daily energy expenditure (DEE). Furthermore, ectopic UCP1 expression in white adipose tissue (WAT) dramatically decreased fat deposition by 4.89% (P < 0.01), consequently increasing carcass lean percentage (CLP; P < 0.05). Mechanism studies indicated that the loss of fat upon UCP1 activation in WAT was linked to elevated lipolysis. UCP1 KI pigs are a potentially valuable resource for agricultural production through their combination of cold adaptation, which improves pig welfare and reduces economic losses, with reduced fat deposition and increased lean meat production.

Bacterial pathogens of pigs with particular reference to Escherichia coli: A systematic review and meta-analysis

Pigs are ungulate animals of the genus Suis and family Suidae. They are globally spread but restricted in certain countries due to religious and cultural beliefs. Pork serves as an important source of protein (38% of meat consumed in the world). While pig production remains a profitable enterprise, commercial and particularly the small-scale farmers face huge constraint in this husbandry practice, one of the most important being bacterial infections and its associated with morbidity and mortality. In this work, we reviewed the prevalence of bacterial infections in pigs with particular reference to Escherichia coli, a bacterium that is regularly isolated and can lead to multiple infections in pigs. Literatures were searched on selected veterinary and biological data bases in 2016 with focus on natural infections and isolates from natural infections with epidemiological details. Pathotypes, serotypes and serogroups of E. coli, the country of origin, source, growth stage, age of pigs infected, disease outbreak, the number of samples and type of samples, numbers and percentage of positive samples and isolates were used as filters. Pathotypes reported include enterotoxigenic E. coli (ETEC) 66.7%, enterotoxigenic E. coli and shiga toxigenic E. coli (ETEC and STEC) 14.3%, STEC only (7.9%), enterotoxigenic E. coli/enteropathogenic E. coli/enteroaggregative E. coli (ETEC/EPEC/EAE) 31.7%. Others were enterohaemorrhagic E. coli (EHEC), diffusely adherent E. coli (DAEC) (ETEC, EPEC, STEC) and extra-intestinal pathogenic E. coli (ExPEC). Twenty-nine countries with documented records of cases of E. coli were included with the USA reporting, the highest number followed by China. About 74% of the samples were taken from farms and others were from samples submitted to research laboratories and veterinary faculties for necropsy. Serogroups O141, O149, O139, O138, O8 and O9 were most common. Piglets were most affected (52.3%) followed by weaners (39.6%) and porkers (7.9%) with age ranging from 1 to 392 days old. A total of 24,854 isolates were considered, 10477 (42.2%) were positives and the following genes were carried: STa, STb, LT, stx1, stx2, Stx-2e, F4, F5, F6, F18, F41, AIDA, EAST1, eae, paa and hlyA. The diseases produced by E. coli were neonatal diarrhoea, colibacillosis, post-weaning diarrhoea and edema disease. The associated risk factors were poor housing, management and feed changes, extensive use of antibiotics as prophylaxis, overcrowding, and high humidity and temperature changes. India, USA, Japan, Slovakia, Denmark Sweden and Poland were countries with significant reports and high detection of virulence factors (72 to 100%). Key words: Escherichia coli, diarrhea, serogroups, enterotoxigenic, colibacillosis.

The African swine fever epidemic in West Africa, 1996-2002

African swine fever (ASF) is a contagious, highly fatal, haemorrhagic viral disease that only affects members of the Suidae family. Currently, no vaccine or treatment exists, so the disease has potentially devastating consequences for the pig industries, availability of affordable protein livelihoods and trade. This study aimed to consolidate historical information generated by working towards the control and eradication of ASF in previously unaffected countries in West Africa during 1996-2002. This descriptive analysis entailed the evaluation and review of archived records and reports of outbreaks, data from veterinary services, veterinary consultants and peer-reviewed publications. Specifically, the analysis focused on establishing the sequence of events in the spread of the disease throughout the region, as well as the possible sources and pathways (mostly human-driven, i.e., movement of pigs and swill feeding). The socio-economic aspects of the epidemic were also assessed. Finally, the prevention and control measures applied were described and evaluated. Major challenges for control that were identified involved lack of capacity to respond to an outbreak of animal disease and the nature of the pig sector in the affected countries. Most of the pigs were produced in low biosecurity subsistence husbandry systems. Actions taken by producers to limit economic losses due to the epidemic (e.g., illegal selling of pigs and infected pork, hiding of outbreaks) increased the risk of spread and frustrated control efforts. The disease has persisted in an endemic state ever since and has negatively affected pig production and marketing in most of these countries. The analysis of this information will allow a better understanding of the disease dynamics in a region infected for the first time, and learning how the prevention and control interventions that were implemented worked or failed. This will help the development of better tailored, sustainable and locally sound interventions. The authors provide a set of recommendations for ASF prevention and control.