Three ASF/SF2-like alternative splicing genes from maize were identified, cloned, and analyzed. Each of these genes (zmSRp30, zmSRp31, and zmSRp32) contains two RNA binding domains, a signature sequence SWQDLKD, and a characteristic serine/ariginine-rich domain. There is a strong structural similarity to the human ASF/SF2 splicing factor and to the Arabidopsis atSRp34/p30 proteins. Similar to ASF/SF2-like genes in other organisms, the maize pre-mRNA messages are alternatively spliced. They are differentially expressed in maize tissues with relatively uniform levels of zmSRp30 and zmSRp31 messages being observed throughout the plant, while zmSRp32 messages preferentially accumulated in the meristematic regions. Overexpression of zmSRp32 in maize cells leads to the enhanced selection of weak 5' intron splice sites during the processing of pre-mRNA molecules. Overexpression of the zmSRp31 or zmSRp32 gene affects regulation of wheat dwarf virus rep gene pre-mRNA splicing, presumably by interacting with the weak 5' splice site, CCGU. Our results suggest that the described genes are functional homologues of the human ASF/SF2 alternative splicing factor and they indicate a diversity of the ASF/SF2-like alternative splicing factors in monocot plant cells.

Mutations in codon 133 of p53, which cause the loss of the Delta 133 isoform(s) expression, are very frequent in the Li-Fraumeni (LF) and Li-Fraumeni-like (LFL) syndromes. In sporadic cancers, silent p53 mutations are correlated with exonic splicing enhancers (ESEs) and exonic methylated sites. The present study shows that mutations in splice sites are also very frequent in LF/LFL syndromes, while missense mutations are less common compared to other familial or sporadic cancers (P = 0 in both cases). Furthermore, it is shown that the codons at which LF/LFL germline missense mutations occur, correlate with CpG-containing ESEs (r = 0.181, P = 0.014) which are all methylated in p53. While both silent and LF/LFL missense mutations correlate with SC35 motifs, only the latter are associated with SRp55. On the contrary, only silent mutations in sporadic cancers correlate with SF2/ASF motifs in p53. Moreover, 12.1% of LF/LFL missense mutations involve the formation of potential splice sites of considerable splicing scores. Finally, mutations that are not at, or adjacent to CpGs (+/-1 codon, 34% of all LF/LFL mutated sites), introduce considerable changes of the ESE scores (>1.3 score change). The above data verify that LF/LFL missense mutations probably result also in splicing deregulation, in addition to any changes of the protein function and are mostly associated with alterations of the exonic methylation landscape. Some of the ESEs affected in LF/LFL syndromes are also genetically unstable in sporadic cancers but non-CpG cytosine instability, which is predominantly associated with specific ESEs, is only common in sporadic cancers.

This update on the African swine fever (ASF) outbreaks in the EU demonstrated that out of all tested wild boar found dead, the proportion of positive samples peaked in winter and summer. For domestic pigs only, a summer peak was evident. Despite the existence of several plausible factors that could result in the observed seasonality, there is no evidence to prove causality. Wild boar density was the most influential risk factor for the occurrence of ASF in wild boar. In the vast majority of introductions in domestic pig holdings, direct contact with infected domestic pigs or wild boar was excluded as the route of introduction. The implementation of emergency measures in the wild boar management zones following a focal ASF introduction was evaluated. As a sole control strategy, intensive hunting around the buffer area might not always be sufficient to eradicate ASF. However, the probability of eradication success is increased after adding quick and safe carcass removal. A wider buffer area leads to a higher success probability; however it implies a larger intensive hunting area and the need for more animals to be hunted. If carcass removal and intensive hunting are effectively implemented, fencing is more useful for delineating zones, rather than adding substantially to control efficacy. However, segments of fencing will be particularly useful in those areas where carcass removal or intensive hunting is difficult to implement. It was not possible to demonstrate an effect of natural barriers on ASF spread. Human-mediated translocation may override any effect of natural barriers. Recommendations for ASF control in four different epidemiological scenarios are presented.

Keywords: African swine fever; domestic pigs; epidemiology; management; prevention; risk factor; seasonality; wild boar.

In this study, we have investigated the motion of polystyrene microparticles inside a sessile droplet of water actuated by surface acoustic waves (SAWs), which produce an acoustic streaming flow (ASF) and impart an acoustic radiation force (ARF) on the particles. We have categorized four distinct regimes (R1-R4) of particle aggregation that depend on the particle diameter, the SAW frequency, the acoustic wave field (travelling or standing), the acoustic waves' attenuation length, and the droplet volume. The particles are concentrated at the centre of the droplet in the form of a bead (R1), around the periphery of the droplet in the form of a ring (R2), at the side of the droplet in the form of an isolated island (R3), and close to the centre of the droplet in the form of a smaller ring (R4). The ASF-based drag force, the travelling or standing SAW-based ARF, and the centrifugal force are utilized in various combinations to produce these distinct regimes. For simplicity, we fixed the fluid volume at 5 μL, varied the SAW actuation frequency (10, 20, 80, and 133 MHz), and tested several particle diameters in the range 1-30 μm to explicitly demonstrate the regimes R1-R4. We have further demonstrated the separation of particles (1 and 10 μm, 3 and 5 μm) using mixed regime configurations (R1 and R2, R2 and R4, respectively).

African swine fever (ASF) is a notifiable viral disease affecting domestic pigs and wild boars that has been endemic in Sardinia since 1978. Several risk factors complicate the control of ASF in Sardinia: generally poor level of biosecurity, traditional breeding practices, illegal behaviour in movements and feeding of pigs, and sporadic occurrence of long-term carriers. A previous study describes the disease in Sardinia during 1978-2013. The aim of this study was to gain more in-depth knowledge of the spatio-temporal pattern of ASF in Sardinia during 2012 to May 2014, comparing patterns of occurrence in domestic pigs and wild boar and identifying areas of local transmission. African swine fever notifications were studied considering seasonality, spatial autocorrelation, spatial point pattern and spatio-temporal clusters. Results showed differences in temporal and spatial pattern of wild boar and domestic pig notifications. The peak in wild boar notifications (October 2013 to February 2014) occurred six months after than in domestic pig (May to early summer 2013). Notifications of cases in both host species tended to be clustered, with a maximum significant distance of spatial association of 15 and 25 km in domestic pigs and wild boars, respectively. Five clusters for local ASF transmission were identified for domestic pigs, with a mean radius and duration of 4 km (3-9 km) and 38 days (6-55 days), respectively. Any wild boar clusters were found. The apparently secondary role of wild boar in ASF spread in Sardinia could be explained by certain socio-economic factors (illegal free-range pig breeding or the mingling of herds. The lack of effectiveness of previous surveillance and control programmes reveals the necessity of employing a new approach). Results present here provide better knowledge of the dynamics of ASF in Sardinia, which could be used in a more comprehensive risk analysis necessary to introduce a new approach in the eradication strategy.

Due to the current unavailability of vaccines or treatments for African swine fever (ASF), which is caused by African swine fever virus (ASFV), rapid and reliable detection of the virus is essential for timely implementation of emergency control measures and differentiation of ASF from other swine diseases with similar clinical presentations. Here, an improved PCR assay was developed and evaluated for sensitive and universal detection of ASFV. Primers specific for ASFV were designed based on the highly conserved region of the vp72 gene sequences of all ASFV strains available in GenBank, and the PCR assay was established and compared with two OIE-validated PCR tests. The analytic detection limit of the PCR assay was 60 DNA copies per reaction. No amplification signal was observed for several other porcine viruses. The novel PCR assay was more sensitive than two OIE-validated PCR assays when testing 14 strains of ASFV representing four genotypes (I, V, VIII and IX) from diverse geographical areas. A total of 62 clinical swine blood samples collected from Uganda were examined by the novel PCR, giving a high agreement (59/62) with a superior sensitive universal probe library-based real-time PCR. Eight out of 62 samples tested positive, and three samples with higher Ct values (39.15, 38.39 and 37.41) in the real-time PCR were negative for ASFV in the novel PCR. In contrast, one (with a Ct value of 29.75 by the real-time PCR) and two (with Ct values of 29.75 and 33.12) ASFV-positive samples were not identified by the two OIE-validated PCR assays, respectively. Taken together, these data show that the novel PCR assay is specific, sensitive, and applicable for molecular diagnosis and surveillance of ASF.

The aim of this paper is to evaluate the African swine fever (ASF) outbreak that began in 1978 in Paracambi municipality, Rio de Janeiro State, Brazil, and the steps taken by the Brazilian authorities to eradicate the disease. The presence of ASF in the country was confirmed by isolating the virus, and its pathogenicity was certified by the laboratory of the Plum Island Disease Center, New York, United States. Even before the laboratory results became available, the Brazilian Agriculture Ministry declared an Animal Health Emergency, in which the official Veterinary Services adopted rapid control measures to restrain and eradicate the disease. These control measures contributed to the reorganisation of the national swine industry and stimulated the use of high-technology production techniques, as well as an improvement in herd health consciousness. All this contributed to Brazil becoming the largest meat exporter in the world.

This review evaluates evidence for benefits of including animal source foods (ASF) in the diets of children in developing countries. In observational studies, a higher usual intake of ASF in such countries is associated with better growth, status of some micronutrients, cognitive performance, motor development and activity. Only three randomized trials supplemented children with milk and compared outcomes with a nonintervention control group. Both height and weight growth were improved, although in Kenya height was increased only in younger schoolers who were stunted at baseline. Meat supplements have been evaluated in only two randomized controlled trials, in Kenya and Guatemala (mean baseline age 8 years and 1 year, respectively); growth was no better than in an equicaloric control group. Meat improved cognitive function and activity in Kenya; milk was less effective than meat for improving cognitive function and physical activity, perhaps due to its lower content of iron, zinc, or riboflavin. Meat and especially cow's milk are excellent sources of vitamin B(12), a micronutrient commonly deficient in populations which consume low amounts of ASF. Other micronutrients such as iron have been added to cow's milk and resulted in improved nutritional outcomes for children.

African swine fever (ASF) is a virulent infectious disease of pigs. As there is no effective vaccine and treatment method at present, it poses a great threat to the pig industry once it breaks out. In this paper, we used ASF outbreak data and the WorldClim database meteorological data, and selected the CfsSubset Evaluator-Best First feature selection method combined with the random forest algorithms to construct an African swine fever outbreak prediction model. Subsequently, we also established a test set for data other than modeling, and the accuracy ACC value range of the model on the independent test set was 76.02%-84.64%, which indicated that the modeling effect was better and the prediction accuracy was higher than previous estimates. In addition, logistic regression analysis was conducted on 12 features used for modeling and the ROC curves were drawn. The results showed that the bio14 features (precipitation of driest month), had the largest contribution to the outbreak of ASF, and it was speculated that the outbreak of the epidemic was significantly related to precipitation. Finally, we used this qualitative prediction model to build a global online prediction system for ASF outbreaks, in the hope that this study will help to decision-makers who can then take the relevant prevention and control measures in order to prevent the further spread of future epidemics of the disease.

: African swine fever (ASF) is a viral disease of domestic and wild suids for which there is currently no vaccine or treatment available. The recent spread of ASF virus (ASFV) through Europe and Asia is causing enormous economic and animal losses. Unfortunately, the measures taken so far are insufficient and an effective vaccine against ASFV needs to be urgently developed. We hypothesized that immunization with a cocktail of thirty-five rationally selected antigens would improve the protective efficacy of subunit vaccine prototypes given that the combination of fewer immunogenic antigens (between 2 and 22) has failed to elicit protective efficacy. To this end, immunogenicity and efficacy of thirty-five adenovirus-vectored ASFV antigens were evaluated in wild boar. The treated animals were divided into different groups to test the use of BioMize adjuvant and different inoculation strategies. Forty-eight days after priming, the nine treated and two control wild boar were challenged with the virulent ASFV Arm07 isolate. All animals showed clinical signs and pathological findings consistent with ASF. This lack of protection is in line with other studies with subunit vaccine prototypes, demonstrating that there is still much room for improvement to obtain an effective subunit ASFV vaccine.

African swine fever (ASF) is a contagious, notifiable viral disease, which is considered a significant threat not only for European, but also for worldwide pork production, since recently the virus emerged within numerous Chinese pig herds. The disease was introduced in Poland in 2014 and up to the end of 2018, 213 outbreaks in pigs and 3347 cases in wild boars have been reported. The presented study describes the whole genome sequencing of seven Polish isolates, collected between 2016 and 2017, using next generation sequencing (NGS) technology. The complete, genomic sequences of these isolates were compared against five other closely related ASFV genomes, annotated in the NCBI database. The obtained sequences were from 189.393 to 189.405 bp long and encoded 187-190 open reading frames (ORFs). The isolates were grouped within genotype II and showed 99.941 to 99.956% nucleotide identity to the Georgia 2007/1 reference strain.

African swine fever (ASF) is a severe disease of suids caused by African swine fever virus (ASFV). Its dsDNA genome (170-194 kbp) is scattered with homopolymers and repeats as well as inverted-terminal-repeats (ITR), which hamper whole-genome sequencing. To date, only a few genome sequences have been published and only for some are data on sequence quality available enabling in-depth investigations. Especially in Europe and Asia, where ASFV has continuously spread since its introduction into Georgia in 2007, a very low genetic variability of the circulating ASFV-strains was reported. Therefore, only whole-genome sequences can serve as a basis for detailed virus comparisons. Here, we report an effective workflow, combining target enrichment, Illumina and Nanopore sequencing for ASFV whole-genome sequencing. Following this approach, we generated an improved high-quality ASFV Georgia 2007/1 whole-genome sequence leading to the correction of 71 sequencing errors and the addition of 956 and 231 bp at the respective ITRs. This genome, derived from the primary outbreak in 2007, can now serve as a reference for future whole-genome analyses of related ASFV strains and molecular approaches. Using both workflow and the reference genome, we generated the first ASFV-whole-genome sequence from Moldova, expanding the sequence knowledge from Eastern Europe.

African swine fever (ASF) is a fatal disease for domestic pigs, leading to serious economic losses in countries where ASF is endemic. Despite extensive research, efficient vaccines against ASF are lacking. Since peripheral blood cells are important mediators for vaccines, we study the impact of ASF on blood parameters in pigs with different ages and infected with different doses of ASF virus. Four different groups were studied: (1) 12 weeks of age/low virus dose; (2) 12 weeks of age/high virus dose; (3) 18 weeks of age/low virus dose; and (4) 18 weeks of age/high virus dose. By varying in age and/or ASFV inoculation dose, we monitor blood parameters during different degrees of disease. Thirty percent of the pigs survived the infection with a moderately virulent strain of African swine fever virus (ASFV). Animals that did survive infection were generally older, independent from the inoculation dose used. A firm reduction in many different cell types at 3-5 days postinfection (DPI) was accompanied by an increase in body temperature, followed by clinical signs and mortality from day 6 PI. While blood parameters generally normalized in survivors, γδ T cells and IL-10 levels could be related to mortality. These conclusions should be considered in new approaches for protection against ASF.

Chronic pneumonia experimentally produced in 14 pigs with African swine fever (ASF) virus was studied by immunofluorescene (IF) and histopathologic techniques. Frozen sections prepared from pulmonary tissues of the infected pigs were stained with fluorescein-conjugated antiserums against ASF viral antigen, porcine immunoglobulin G (IgG), procine complement (C), and porcine fibrinogen. The viral antigen(s) was mainly seen in macrophages and cell debris in alveolar walls and lumens. This finding indicates that the virus replicated in the cytoplasm of alveolar macrophages that subsequently degenerated and released the viral antigen. Diffuse immunoglobulin (Ig) deposition was found in necrotic cells and debris. Immunoglobulin also was seen bound to intracytoplasmic inclusion bodies in some degenerating alveolar macrophages. This finding indicates that antibody against ASF viral antigen(s) excluded from blood circulation or produced by local immunocytes (or both) reacted with viral antigen at intramacrophage and extramacrophage levels and resulted in the formation of insoluble antigen-antibody (Ag-Ab) complexes. The participation of C in the immune complex was evident in the early stage of the pneumonia, but was less evident in the subsequent extensive, progressive necrotic processes. Fibrin deposits were visible only in the early necrotic area of alveolar walls and lumens. Possible mechanisms inducing extensive necrosis are discussed.

African swine fever (ASF) is one of the most threatening diseases for the pig farming sector worldwide. As an effective vaccine is lacking, strict application of control measures is the only way to fight the disease in both industrial farms and backyard holdings. With generally low biosecurity standards, the latter are at particular risk for disease introduction and offer challenging conditions for disease control. In the following case report, we describe the overall course of an ASF outbreak in a Bulgarian backyard farm and the implemented control measures. Farm facilities and available data have been investigated to estimate the possible source, spread and time point of virus introduction. Contact with contaminated fomites entering the stable via human activities was regarded to be the most likely introduction route. The slow disease spread within the farm contributes to the hypothesis of a moderate contagiosity. As no further ASF outbreaks have been detected in domestic pig farms in the region, it could be demonstrated that successful disease control in small-scale farms can be reached. Thus, the report contributes to a better understanding of ASF in the backyard sector.

The need to consider the role of social factors in the efficacy of farm management and, consequently, in the onset and persistence of diseases typical to animal farms is increasingly being realized increasingly worldwide. Many risk analysis studies have been conducted to assess the role of various factors in the development of animal diseases; however, very few have accounted for the role of social factors. The aim of this work was to bridge this gap, with the main hypothesis that different socio-economic factors could be valid indicators for the occurrence of different animal diseases. A socio-economic analysis was performed using demographic characteristics of the farmers and data from 44 social indicators released by the Italian Statistician National Institute of Statistics (ISTAT) database. African swine fever (ASF) in wild boars (WB) and domestic pigs and other endemic animal diseases and zoonoses in Sardinia were considered, such as cistic echinococcosis (CE), contagious agalactia (CA), trichinellosis, West Nile disease (WND), and bluetongue (BT). Seven different negative binomial regression models were fitted using the number of cases between 2011-2017. Three indicators-cultural demand, employment rate, and legality-showed a statistically significant association with risk for all the diseases considered, but with varying effects. Some indicators, such as the age and sex of the farmer, material deprivation index, number of farms and animals, micro-criminality index, and rate of reported thefts were common to ASF, CA, trichinellosis, and CE cases. Others such as the forest surface and the energy produced from renewable sources were common to BT, WND, and ASF in WB. Tourism in seasons other than summer was a valid predictor of ASF and trichinellosis, while out-of-region hospital use had a statistically significant role in CE risk identification. These results may help understand the social context in which these diseases may occur and thus guide the design and implementation of additional risk management measures that go beyond well-known veterinary measures.

Six strains of African swine fever (ASF) virus were propagated in culture of primary pig kidney (PK) cells. The course of virus growth was followed by means of the fluorescent antibody staining technique. All 6 strains multiplied in the cultures, and 5 of these eventually showed cytopathic effects leading to cell death. Three of the strains were tested for pathogenicity in pigs at various passage levels. Each showed evidence of modification in virulence after a relatively few passages in PK cells. In one case modified virus produced resistance to challenge with homologous virulent virus. All strains rendered the PK cultures capable of hemadsorption of pig erythrocytes.

Temporal patterns and spatial distribution of African swine fever (ASF) were studied through the analysis of routinely collected data in the ASF-endemic area of the Province of Nuoro, Sardinia. During 1993-1996, ASF outbreaks were reported from 45 out of the 82 municipalities of the study area. Overall farm-level incidence rate (IR) was 1.3 outbreaks per 100 farms-year. ASF peaked in 1995 (IR = 1.8) and declined in 1996 (IR = 0.82). Significant (P < 0.05) spring peaks of ASF outbreaks and affected municipalities were detected using statistical methods for circular distributions. Spatial clustering of ASF-affected municipalities, as evaluated by join-count statistics, was significant in 1993 (Zjc = -3.0, P < 0.01) and 1994 (Zjc = -3.2, P < 0.01) but not in 1995 (Zjc = -0.6, P = 0.55) and 1996 (Zjc = -1.2, P = 0.23). Extensive pig farming and ASF were spatially co-distributed (kappa = 0.51, 95% CI = 0.33-0.70).

The purpose of this retrospective study was to demonstrate the surgical outcomes of anterior spinal fusion (ASF) and posterior subtraction osteotomy (PSO) for osteoporotic vertebral collapse (OVC). Forty patients who underwent surgery for OVC at the thoracolumbar junction with neurological deficits were included in this study. ASF was primarily chosen for patients without vertebral compression fracture at other levels, and PSO was chosen for patients with more severe kyphosis or with multiple vertebral fractures. ASF was performed in 26 patients and PSO was performed in 14 patients. We evaluated the pre- and postoperative clinical status consisting of pain, gait, paralysis, and bladder function analysis. Additionally, pre- and postoperative kyphosis, correction angle, correction loss, and upright balance were investigated radiologically. Improvements in pain level, gait, paralysis, and bladder function were obtained in both groups. Average correction angles in the ASF and PSO groups were 16 and 37, respectively. Average correction losses at the final follow-up in the ASF and PSO groups were 7 and 13, respectively. Newly developed postsurgical vertebral compression fracture adjacent to the level of instrumentation was observed in four patients (15%) in the ASF group and in 11 patients (79%) from the PSO group. ASF provided satisfactory outcomes for patients with thoracolumbar OVC, who have no vertebral compression fracture at other levels. Although PSO has benefits for the correction of kyphosis, several problems persist with this procedure, especially for patients with severe osteoporosis.

BACKGROUND

Insulin resistance is related to central obesity and the amount of skeletal muscle. A simple and practical anthropometric marker for muscle mass is not known, although waist circumference (WC) is used as an indicator of abdominal obesity. The aims of this study were to investigate whether arm (AC) and thigh circumferences (TC) can be used as an indicator of muscle mass and if they are related to muscle strength.

METHODS

A total of 110 obese (body mass index [BMI]≥25 kg/m(2)) women with type 2 diabetes were enrolled, and WC, AC, and TC were measured. Abdominal visceral fat (AVF), subcutaneous fat (ASF), and total fat (ATF) were assessed by computed tomography, regional muscle (MM), and fat mass by dual-energy X-ray absorptiometry, muscle strength by one repetition maximum (1RM) of both extremities (chest and leg press) and insulin resistance by K(ITT).

RESULTS

The mean age was 56.2±7.3 years, duration of diabetes was 4.2±4.4 years, and BMI was 27.2±2.8 kg/m(2). WC was correlated with ATF, AVF, and ASF (r=0.728, P<0.001; r=0.515, P<0.001; r=0.608, P<0.001, respectively). Arm MM was correlated with AC (r=0.500, P<0.001), and leg MM with TC (r=0.291, P=0.002). Upper 1RM was related to AC/WC ratio (r=0.359, P<0.001), and lower 1RM was to TC/WC ratio (r=0.286, P=0.003). Insulin resistance had significant relations with AVF, WC, and total MM (r=-0.262, P=0.008; r=-0.217, P=0.029; r=0.160, P=0.031, respectively).

CONCLUSIONS

The muscle mass was related to extremity circumferences, and muscle strength was to extremity/waist circumference ratio in obese women with type 2 diabetes.

African swine fever (ASF) is a highly lethal contagious disease of swine caused by African swine fever virus (ASFV). At present, it is listed as a notifiable disease reported to the World Organization for Animal Health (OIE) and a class one animal disease ruled by Chinese government. ASF has brought significant economic losses to the pig industry since its outbreak in China in August 2018. In this review, we recapitulated the epidemic situation of ASF in China as of July 2020 and analyzed the influencing factors during its transmission. Since the situation facing the prevention, control, and eradication of ASF in China is not optimistic, safe and effective vaccines are urgently needed. In light of the continuous development of ASF vaccines in the world, the current scenarios and evolving trends of ASF vaccines are emphatically analyzed in the latter part of the review. The latest research outcomes showed that attempts on ASF gene-deleted vaccines and virus-vectored vaccines have proven to provide complete homologous protection with promising efficacy. Moreover, gaps and future research directions of ASF vaccine are also discussed.

Keywords: ASFV; African swine fever; China; epidemic situation; progress; vaccines.

The activity of several proteins involved in fibrinolysis and the morphological changes in the blood vessel walls of pigs infected with highly virulent (Malawi'83) and moderately virulent (Dominican Republic '78-DR'78) ASF virus isolates were determined. Pigs infected with the Malawi'83 virus developed an increased fibrinolytic activity due to high plasma levels of tissue-plasminogen activator (t-PA) of 71.3 +/- 22.8 IU/ml (mean +/- SD), which correlated well with an increased activation of interstitial capillary endothelial cells and high levels of 1150 +/- 73.6 nM of fibrin monomer in the circulation. Animals infected with DR'78 virus, in contrast, showed an inhibition of fibrinolysis in the late stages of disease with almost a 5-fold increase of plasminogen activator inhibitor (PAI) activity of 196.0 AU/ml. These results suggest that activation of the fibrinolytic system in pigs infected with the Malawi'83 virus is probably due to increased formation and deposition of fibrin in the circulation, contributing to an increased bleeding tendency and higher mortality. On the contrary, animals infected with DR'78 virus developed an inhibition of fibrinolysis and thus a reduction in bleeding.

The effect of African swine fever (ASF) virus infection on reproductive performance of recovered sows and their pigs was investigated. Six sows were inoculated with a 1979 ASF isolate from the Dominican Republic. One sow was bred on postinoculation day (PID) 58 and killed on PID 148. Four sows were bred between PID 368 and 419 and were allowed to farrow. One sow did not conceive. Samples collected during pregnancy, at farrowing, and during lactation were tested for virus by tissue culture and animal inoculations to determine whether ASF virus recrudesced during these natural stresses. Virus was recovered only from tissues of the sow killed on PID 148. Virus was not detected in tissue samples from the 4 other sows or from any fetus or neonate. Sow and neonatal pig sera, colostral whey, and milk whey were assayed for antibodies against ASF viral antigens, using an enzyme-linked immunosorbent assay. Antibody values in sows' sera did not change appreciably during pregnancy, farrowing, or lactation. One litter of pigs was raised with their sow. Weekly serum samples were tested for passively acquired antibodies. At 7 weeks of age, the litter was challenge inoculated with the same virus as that used initially to infect their dam. Viremia titers, duration of viremias, and clinical course were reduced. One young pig did not develop fever, viremia, clinical disease, or antibody response to virus challenge exposure. The altered course of infection was attributed to protective effect of passively acquired antibodies.

African swine fever causes substantial economic losses in the swine industry in affected countries. Traditionally confined to Africa with only occasional incursions into other regions, ASF began spreading into Caucasian countries and Eastern Europe in 2007, followed by Western Europe and Asia in 2018. Such a dramatic change in the global epidemiology of ASF has resulted in concerns that the disease may continue to spread into disease-free regions such as the US. In this study, we estimated the risk of introduction of ASF virus into the US through smuggling of pork in air passenger luggage. Results suggest that the mean risk of ASFV introduction into the US via this route has increased by 183.33% from the risk estimated before the disease had spread into Western Europe or Asia. Most of the risk (67.68%) was associated with flights originating from China and Hong Kong, followed by the Russian Federation (26.92%). Five US airports accounted for >90% of the risk. Results here will help to inform decisions related to the design of ASF virus surveillance strategies in the US.