| african swine fever: pathogenicity and immunogenicity of two non-haemadsorbing viruses. | the virulence of 2 non-haemadsorbing african swine fever virus isolates were compared with 2 haemodsorbing viruses. while 3 of these isolates usually produced acute death in pigs, 1 non-haemadsorbing virus caused either a fatal infection with an extended course, or few or no obvious signs of infection. pigs that survived infection with the latter virus were resistant to the lethal effects of the other 3 strains as well as to a pool of 7 isolates made from ornithodorus porcinus porcinus (senus wa ... | 1979 | 551362 |
| absence of ornithodoros moubata, the vector of african swine fever virus, from the main pig producing area of cameroon. | no evidence for the presence of soft ticks of the ornithodoros moubata complex was found during a survey of african swine fever carried out between 1985 and 1988 in the west province and southern parts of the north west and south west provinces of cameroon. the survey consisted of interviews of veterinary assistants and farmers, distribution of a questionnaire and tick searches both manually and with carbon dioxide traps. the absence of warthogs (phacochoerus aethiopicus) from these areas was al ... | 1990 | 2371751 |
| genetic diversity of african swine fever virus isolates from soft ticks (ornithodoros moubata) inhabiting warthog burrows in zambia. | the genomes of african swine fever virus isolates collected from soft ticks (ornithodoros moubata) inhabiting warthog burrows in four areas of zambia were compared by restriction enzyme site mapping. isolates from different areas showed considerable diversity. the regions of genomes that differed between isolates were distributed throughout the virus genome, although some more conserved regions were identified, such as the right-hand third of the genome. the genomes of seven isolates from neighb ... | 1988 | 3199101 |
| isolation of african swine fever virus from ticks of the ornithodoros moubata complex (ixodoidea: argasidae) collected within the african swine fever enzootic area of malawi. | ticks of the ornithodoros moubata complex were collected from domestic pig sties and dwelling houses, and from a warthog habitat, and tested for the presence of african swine fever (asf) virus. collections were made in 9 of the 24 districts of malawi, these being primarily the districts in which o. moubata is most numerous. asf virus was isolated from ticks collected in both domestic pig sties and houses in certain villages in mchinji district where asf outbreaks had recently occurred. mchinji d ... | 1988 | 3402546 |
| the excretion of two virulent strains of african swine fever virus by domestic pigs. | daily observations were made on the excretion of african swine fever (asf) virus by pigs infected intranasally or by contact. two strains of virus having mean death times of approximately 3 and 6 days were used, the latter being recently isolated from a warthog.first excretion usually occurred by the nasopharyngeal route, as early as 1 or 2 days before the onset of fever in many cases. the titres of pharyngeal and nasal swabs rose rapidly to reach mean levels of about 10(4)-10(5) had 50 at 48-72 ... | 1970 | 5276336 |
| epizootiology of african swine fever virus in warthogs. | | 1969 | 5386390 |
| experimental infection of warthos (phacochoerus aethiopicus) with african swine fever virus. | although there were no obvious signs of illness following experimental infection of young warthog with african swine fever virus, the animals developed viraemias between 10(2,4) and 10(3,6) hd50/ml within the first week of infection, and virus concentrations in a number of lymphatic tissues attained high levels (greater than or equal to 10(6) hd50/g). unlike in blood, and to some extent in the spleen, virus titres in lymph nodes did not decline appreciable during the 33-day observation period, s ... | 1980 | 7454231 |
| an ikappab homolog encoded by african swine fever virus provides a novel mechanism for downregulation of proinflammatory cytokine responses in host macrophages. | cytokines stimulate inflammatory defenses against viral infections. in order to evade host defenses, viruses have developed strategies to counteract antiviral cytokines. african swine fever virus (asfv) is a large, double-stranded dna virus that infects macrophages. this study demonstrates that asfv effectively inhibited phorbol myristic acid-induced synthesis of antiviral, proinflammatory cytokines alpha interferon, tumor necrosis factor alpha, and interleukin-8 in infected macrophages as asses ... | 1996 | 8970976 |
| a conserved african swine fever virus ikappab homolog, 5el, is nonessential for growth in vitro and virulence in domestic swine. | an african swine fever virus (asfv) gene with similarity to the cellular inhibitor of nfkappab (ikappab) was described in the pathogenic african isolate malawi lil-20/1 (orf 5el) and a cell-culture-adapted european virus, ba71v (orf a238l). recently, this gene was shown to be a functional ikappab homolog capable of downregulating nfkappab-regulated gene expression. this observation suggests the gene may be of significance to aspects of asfv pathogenesis and virulence in domestic swine by interfe ... | 1997 | 9281518 |
| deletion of a cd2-like gene, 8-dr, from african swine fever virus affects viral infection in domestic swine. | an african swine fever virus (asfv) gene with similarity to the t-lymphocyte surface antigen cd2 has been found in the pathogenic african isolate malawi lil-20/1 (open reading frame [orf] 8-dr) and a cell culture-adapted european virus, ba71v (orf ep402r) and has been shown to be responsible for the hemadsorption phenomenon observed for asfv-infected cells. the structural and functional similarities of the asfv gene product to cd2, a cellular protein involved in cell-cell adhesion and t-cell-med ... | 1998 | 9525608 |
| the pathogenesis of african swine fever in the resistant bushpig. | bushpigs and warthogs are natural reservoir hosts of african swine fever virus (asfv) in the wild, showing no clinical signs of disease when infected with the same highly virulent isolates of asfv that induce rapid, haemorrhagic death in domestic pigs. in contrast to domestic pigs, infection of bushpigs with malawi isolate results in low levels of virus replication and lymphocyte apoptosis within the spleen, and a relatively low spread of virus to other lymphoid tissues. however, at 10 days post ... | 1998 | 9634086 |
| african swine fever virus infection of the bushpig (potamochoerus porcus) and its significance in the epidemiology of the disease. | warthog (phacochoerus aethiopicus), giant forest hog (hylochoerus meinertzhageni) and bushpig (potamochoerus porcus) are known to be susceptible to infection with african swine fever (asf) virus. little however, is known about the ecology of the disease in the bushpig. this study has shown that the bushpig remains viraemic for between 35 and 91 days following infection during which time it is able to infect the tick vector o. moubata. these ticks were able to transmit the disease to pigs. the vi ... | 1998 | 9659687 |
| detection of african swine fever virus in infected pig tissues by immunocytochemistry and in sity hybridisation. | the techniques for determining cellular sites of establishment and persistence of african swine fever virus (asfv) were established in susceptible domestic pigs and the resistant african reservoir hosts, the warthog and bushpig. detection, both in vitro and in vivo, was achieved by in situ hybridisation and immunocytochemistry, focusing principally on specific probes for vp73, a major capsid protein. hybridisation of radio-labelled probes for dna and rna was relatively insensitive and time consu ... | 1998 | 9694328 |
| african swine fever virus infection of porcine aortic endothelial cells leads to inhibition of inflammatory responses, activation of the thrombotic state, and apoptosis. | african swine fever (asf) is an asymptomatic infection of warthogs and bushpigs, which has become an emergent disease of domestic pigs, characterized by hemorrhage, lymphopenia, and disseminated intravascular coagulation. it is caused by a large icosohedral double-stranded dna virus, african swine fever virus (asfv), with infection of macrophages well characterized in vitro and in vivo. this study shows that virulent isolates of asfv also infect primary cultures of porcine aortic endothelial cel ... | 2001 | 11581405 |
| pathogenesis of african swine fever virus in ornithodoros ticks. | african swine fever virus (asfv) is the only known dna arbovirus and the sole member of the family asfarviridae. it causes a lethal, hemorrhagic disease in domestic pigs. asfv is enzootic in sub-saharan africa and is maintained in a sylvatic cycle by infecting both wild members of the suidae (e.g. warthogs) and the argasid tick ornithodoros porcinus porcinus. the pathogenesis of asfv in o. porcinus porcinus ticks is characterized by a low infectious dose, lifelong infection, efficient transmissi ... | 2001 | 11831434 |
| african swine fever virus proteins involved in evading host defence systems. | african swine fever virus (asfv) can cause an acutely fatal haemorrhagic fever in domestic pigs although in its natural hosts, warthogs, bushpigs and the soft tick vector, ornithodoros moubata, asfv causes inapparent persistent infections. the virus is a large, cytoplasmic, double-stranded dna virus which has a tropism for macrophages. as it is the only member of the asfarviridae family, asfv encodes many novel genes not encoded by other virus families. the ability of the virus to persist in its ... | 2004 | 15207450 |
| a host species-informative internal control for molecular assessment of african swine fever virus infection rates in the african sylvatic cycle ornithodoros vector. | african swine fever virus (asfv) infection in adult ornithodoros porcinus (murry 1877, sensuwalton 1979) ticks collected from warthog burrows in southern and east africa was assessed using a duplex genomic amplification approach that is informative with respect to the invertebrate host species and infecting sylvatic cycle virus. dna extracted from individual ticks was used as template for the simultaneous amplification of a c-terminal 478-bp asfv p72 gene region and a approximately 313-bp fragme ... | 2009 | 19941606 |
| phylogenomic analysis of 11 complete african swine fever virus genome sequences. | viral molecular epidemiology has traditionally analyzed variation in single genes. whole genome phylogenetic analysis of 123 concatenated genes from 11 asfv genomes, including e75, a newly sequenced virulent isolate from spain, identified two clusters. one contained south african isolates from ticks and warthog, suggesting derivation from a sylvatic transmission cycle. the second contained isolates from west africa and the iberian peninsula. two isolates, from kenya and malawi, were outliers. of ... | 2010 | 20171711 |
| african swine fever viruses with two different genotypes, both of which occur in domestic pigs, are associated with ticks and adult warthogs, respectively, at a single geographical site. | the role of the ancestral sylvatic cycle of the african swine fever virus (asfv) is not well understood in the endemic areas of eastern africa. we therefore analysed the asf infection status on samples collected from 51 free-ranging warthogs (phacocherus africanus) and 1576 ornithodorus porcinus ticks from 26 independent warthog burrows at a single ranch in kenya. abattoir samples from 83 domestic pigs without clinical symptoms, originating from specific locations with no recent reported asf out ... | 2010 | 20965989 |
| cloning, characterization and diagnostic performance of the salivary lipocalin protein tsgp1 from ornithodoros moubata. | the argasid tick ornithodoros moubata is distributed throughout south and east africa and madagascar, where it colonizes wild and domestic habitats and feeds on warthogs, domestic swine, and humans. this argasid transmits the spirochete borrelia duttonii, causing east african tick-borne relapsing fever in humans, and the african swine fever virus, which causes a highly lethal haemorrhagic disease in pigs. tick surveillance and the elimination of o. moubata from synanthropic environments (human d ... | 2010 | 21216104 |
| molecular monitoring of african swine fever virus using surveys targeted at adult ornithodoros ticks: a re-evaluation of mkuze game reserve, south africa. | the mkuze game reserve (mgr), in north-eastern kwazulu-natal province, south africa is an african swine fever virus (asf) controlled area. in a survey conducted in 1978, asf prevalence in warthogs and ornithodoros ticks in mgr was determined to be 2% and 0.06%, respectively. these values, acknowledged as being unusually low compared to other east and southern african asf-positive sylvatic-cycle host populations, have not been assessed since. the availability of a sensitive pcr-based virus detect ... | 2009 | 21344788 |
| species-specific variation in rela underlies differences in nf-?b activity: a potential role in african swine fever pathogenesis. | african swine fever virus (asfv) is a highly infectious disease of domestic pigs, with virulent isolates causing a rapidly fatal hemorrhagic fever. in contrast, the porcine species endogenous to africa tolerate infection. the ability of the virus to persist in one host while killing another genetically related host implies that disease severity may be, in part, modulated by host genetic variation. to complement transcription profiling approaches to identify the underlying genetic variation in th ... | 2011 | 21450812 |
| molecular characterization of african swine fever virus from domestic pigs in northern tanzania during an outbreak in 2013. | african swine fever (asf) is an acute, highly contagious and deadly viral hemorrhagic fever of domestic pigs caused by african swine fever virus (asfv), a double-stranded dna virus of the family asfarviridae. in this study, molecular diagnosis and characterization of outbreak asfv in northern tanzania, was performed on spleen, lymph node, kidney, and heart samples collected in june and july 2013 from domestic pigs that died during a hemorrhagic disease outbreak. confirmatory diagnosis of asf was ... | 2014 | 24996815 |
| investigation into the epidemiology of african swine fever virus at the wildlife - domestic interface of the gorongosa national park, central mozambique. | an epidemiological study of african swine fever (asf) was conducted between march 2006 and september 2007 in a rural area adjacent to the gorongosa national park (gnp) located in the central mozambique. domestic pigs and warthogs were sampled to determine the prevalence of antibodies against asf virus and the salivary antigens of ornithodoros spp. ticks, while ticks collected from pig pens were tested for the presence of asfv. in addition, 310 framers were interviewed to gain a better understand ... | 2016 | 25483914 |
| first molecular assessment of the african swine fever virus status of ornithodoros ticks from swaziland. | african swine fever (asf) is an economically significant haemorrhagic disease of domestic pigs. it is caused by the african swine fever virus (asfv), a deoxyribonucleic acid (dna)arbovirus. argasid ticks of the genus ornithodoros, which are widely distributed throughout southern africa, play a primary role in virus maintenance and spread within the endemic sylvatic cycle. the asf status of swaziland is unknown, but this land-locked country is surrounded by asf-positive countries, has a burgeonin ... | 2014 | 26304186 |
| african swine fever virus eradication in africa. | african swine fever was reported in domestic pigs in 26 african countries during the period 2009-2011. the virus exists in an ancient sylvatic cycle between warthogs (phacochoerus africanus) and argasid ticks of the ornithodoros moubata complex in many of the countries reporting outbreaks and in two further countries in the region. eradication of the virus from the countries in eastern and southern africa where the classic sylvatic cycle occurs is clearly not an option. however, the virus has be ... | 2013 | 23142552 |
| african swine fever virus serodiagnosis: a general review with a focus on the analyses of african serum samples. | african swine fever (asf) is an infectious disease that causes heavy mortality in domestic pigs. at present there is no vaccine against asf, and eradication in countries where the disease is endemic is based only on competent diagnosis programs and the sacrifice of infected animals. due to the presence of natural attenuated strains, certain infection conditions may result in reduced mortality. in these situations, the disease can be diagnosed by detection of specific antibodies. the use of class ... | 2013 | 23131491 |
| detection of african swine fever virus in the tissues of asymptomatic pigs in smallholder farming systems along the kenya-uganda border: implications for transmission in endemic areas and asf surveillance in east africa. | the persistence of african swine fever virus (asfv) in endemic areas, with small-scale but regular outbreaks in domestic pigs, is not well understood. asfv has not been detected using conventional diagnosis in these pigs or adjacent populations of resistant african wild pigs, that could act as potential carriers during the outbreaks. however, such data are crucial for the design of evidence-based control strategies. we conducted cross-sectional (1107 pigs) and longitudinal (100 pigs) monitoring ... | 2017 | 28721858 |
| host and viral traits predict zoonotic spillover from mammals. | the majority of human emerging infectious diseases are zoonotic, with viruses that originate in wild mammals of particular concern (for example, hiv, ebola and sars). understanding patterns of viral diversity in wildlife and determinants of successful cross-species transmission, or spillover, are therefore key goals for pandemic surveillance programs. however, few analytical tools exist to identify which host species are likely to harbour the next human virus, or which viruses can cross species ... | 2017 | 28636590 |