Challenging boundaries: is cross-protection evaluation necessary for African swine fever vaccine development? A case of oral vaccination in wild boar.

African swine fever (ASF) poses a significant threat to domestic pigs and wild boar (Sus scrofa) populations, with the current epidemiological situation more critical than ever. The disease has spread across five continents, causing devastating losses in the swine industry. Although extensive research efforts are ongoing to develop an effective and safe vaccine, this goal remains difficult to achieve. Among the potential vaccine candidates, live attenuated viruses (LAVs) have emerged as the most promising option due to their ability to provide strong protection against experimental challenges. However, ASF virus (ASFV) is highly diverse, with genetic and phenotypic variations across different isolates, which differ in virulence. This study highlights the limitations of a natural LAV strain (Lv17/WB/Rie1), which showed partial efficacy against a highly virulent and partially heterologous isolate (Arm07; genotype II). However, the LAV's effectiveness was incomplete when tested against a more phylogenetically distant virus (Ken06.Bus; genotype IX). These findings raise concerns about the feasibility of developing a universal vaccine for ASFV in the near future, emphasizing the urgent need to assess the protective scope of LAV candidates across different ASFV isolates to better define their limitations.

Stiffness-induced modulation of ERG transcription factor in chronic liver disease.

Chronic liver disease (CLD) is characterised by liver sinusoidal endothelial cells (LSECs) dysfunction. Mechanical forces and inflammation are among the leading factors. ETS-related gene (ERG) is an endothelial-specific transcription factor, involved in maintaining cell quiescence and homeostasis. Our study aimed to understand the expression and modulation of ERG in CLD. ERG expression was characterised and correlated to clinical data in human liver cirrhosis at different disease stages. ERG dynamics in response to stiffness and inflammation were investigated in primary healthy and cirrhotic rat LSEC and in human umbilical vein endothelial cells (HUVECs). ERG is markedly downregulated in cirrhosis independently of disease stage or aetiology and its expression is modulated by substrate stiffness in ECs. Inflammation downregulates ERG in cells on physiological stiffness, but not on high stiffness, suggesting a complementary role of inflammation and stiffness in suppressing ERG. This study outlines ERG as an LSEC inflammation and stiffness-responsive transcription factor in cirrhosis.

Identifying sites where wild boars can consume anthropogenic food waste with implications for African swine fever.

Wild boar population dynamics promote the increase in numbers and distribution of the species in Eurasia, leading to a rise in the interaction with human activities, as well as generating problems with the management of certain infectious diseases, most notably African swine fever (ASF). ASF virus possesses high stability in several contaminated pork and pork products that can be a source of indirect transmission to susceptible hosts habituated to anthropogenic food waste. This transmission route is a concerning threat for the dispersion of the disease, primarily into unaffected areas given the worldwide widespread distribution of the disease and the increase of wild boar contact with humans. Thus, in this study, a straightforward tool to assess the relative risk of wild boar natural populations potentially consuming food waste is presented using synthetic data. Three risk groups were defined related to urban areas, travel, and leisure. The surrounding quality of habitat of wild boar was used to obtain the relative risk of wild boar potentially consuming anthropogenic food waste. To assign the relative risk to the corresponding risk unit, we also included the population for the urban areas group, and traffic volume for the travel risk group. The leisure group had higher scaled risk scores, followed by the urban areas group. Higher risk was found in the edges of the study area where more natural landscapes are found. The implications of this risk are discussed focusing on the context of ASF transmission. The outputs can help prioritize decision-making in terms of the improvement of preventive measures against the habituation of wild boar to anthropogenic food waste and ASFV introduction in a given study area.

Hepatic Venous Pressure Gradient: Measurement and Pitfalls.

Measurement of hepatic venous pressure gradient (HVPG) effectively mirrors the severity of portal hypertension (PH) and offers valuable insights into prognosis of liver disease, including the risk of decompensation and mortality. Additionally, HVPG offers crucial information about treatment response to nonselective beta-blockers and other medications, with its utility demonstrated in clinical trials in patients with PH. Despite the widespread dissemination and validation of noninvasive tests, HVPG still holds a significant role in hepatology. Physicians treating patients with liver diseases should comprehend the HVPG measurement procedure, its applications, and how to interpret the results and potential pitfalls.

Geospatial analysis for strategic wildlife disease surveillance: African swine fever in South Korea (2019-2021).

Since the confirmation of African swine fever (ASF) in South Korea in 2019, its spread, predominantly in wild boars, has been a significant concern. A key factor in this situation is the lack of identification of risk factors by surveillance bias. The unique orography, characterized by high mountains, complicates search efforts, leading to overlooked or delayed case detection and posing risks to the swine industry. Additionally, shared rivers with neighboring country present a continual threat of virus entry. This study employs geospatial analysis and statistical methods to 1) identify areas at high risk of ASF occurrence but possibly under-surveilled, and 2) indicate strategic surveillance points for monitoring the risk of ASF virus entry through water bodies and basin influences. Pearson's rho test indicated that elevation (rho = -0.908, p-value < 0.001) and distance from roads (rho = -0.979, p-value < 0.001) may have a significant impact on limiting surveillance activities. A map of potential under-surveilled areas was created considering these results and was validated by a chi-square goodness-of-fit test (X-square = 208.03, df = 1, p-value < 0.001). The strong negative correlation (rho = -0.997, p-value <0.001) between ASF-positive wild boars and distance from water sources emphasizes that areas surrounding rivers are one of the priority areas for monitoring. The subsequent hydrological analyses provided important points for monitoring the risk of virus entry via water from the neighboring country. This research aims to facilitate early detection and prevent further spread of ASF.

Metabolic phenotyping of patients with advanced chronic liver disease for better characterization of cirrhosis regression.

BACKGROUND & AIMS: Regression of cirrhosis has been observed in patients with viral and non-viral etiologies of liver disease in whom the underlying cause of liver injury was effectively suppressed. However, the understanding of the factors contributing to reversibility of fibrosis and cirrhosis is limited. Our aims were to assess clinical factors, perform genotyping of known variants, and comprehensive metabolic phenotyping to characterize the regression of fibrosis in patients with compensated advanced chronic liver disease (cACLD). METHODS: In a case-control pilot study of 81 patients with cACLD, we compared individuals exhibiting histological or clinical evidence of cACLD regression ("regressors"; n = 44) with those showing no improvement ("non-regressors"; n = 37) after a minimum of 24 months of successful treatment of the cause of liver disease. Data were validated using an external validation cohort (n = 30). RESULTS: Regardless of the cause of cACLD, the presence of obesity (odds ratio [OR] 0.267 95% CI 0.072-0.882; p = 0.049), high liver stiffness (OR 0.960, 95% CI 0.925-0.995; p = 0.032), and carriage of GCKR variant rs1260326 (OR 0.148, 95% CI 0.030-0.773; p = 0.019) are associated with a reduced likelihood of fibrosis regression in a subgroup of 60 patients with ACLD genotyped for known genetic variants. Using liver tissue transcriptomics, we identified metabolic pathways differentiating regressors from non-regressors, with top pathways associated with lipid metabolism - especially fatty acids, bile acids, phospholipids, triacylglycerides (biosynthesis), and the carnitine shuttle. In the entire discovery cohort, we further measured metabolites within the defined pathways, which led to the identification of 33 circulating markers differentiating regressors from non-regressors after etiological therapy. The validation cohort confirmed 14 of the differentially expressed markers. CONCLUSIONS: We identified and validated a group of lipid biomarkers associated with regression of fibrosis that could be used as non-invasive biomarkers for detecting regression of fibrosis in cACLD. IMPACT AND IMPLICATIONS: Regression of cirrhosis/advanced chronic liver disease (ACLD) after removal of the underlying cause of liver injury has been observed in human cirrhosis. However, detailed characterization of ACLD regression remains an unmet need. In this study, we provide a comprehensive phenotyping of individuals likely to experience ACLD regression. While obesity, carriage of GCKR variant rs1260326 and high liver stiffness were associated with lower likelihood of regression of ACLD, a signature of circulating lipid metabolites enabled differentiation of regressors from non-regressors after effective etiologic therapy. The lipid signature we discovered and externally validated could be used as non-invasive biomarker to detect regression of fibrosis in patients with compensated ACLD.

Combination of Model for End-Stage Liver Disease (MELD) and Sarcopenia predicts mortality after transjugular intrahepatic portosystemic shunt (TIPS).

TIPS is the most effective treatment for portal hypertension. Patient selection remains important to achieving optimal post-TIPS outcomes. The study evaluates 1-year mortality factors in cirrhotic patients receiving TIPS. METHODS: 87 cirrhotic patients received a TIPS between 2015 - 2021. Predictors of 1-year and overall mortality were assessed by estimating cumulative incidence functions and Grey's test to adjust for liver transplantation as a risk competing with mortality. Variables with p < 0.05 were checked for collinearity and included in the multivariate Cox proportional hazards model. Model discrimination was evaluated by calculating the area under the ROC curve. RESULTS: 87 patients were included (68% men; 22% ≥70 years). ALD was the primary cirrhosis cause. Most patients were Child-Pugh class B, MELD-Na score was 13.6 ± 6.0 points. The most frequent indication for TIPS was bleeding (51.7%), followed by refractory ascites (42.5%). The variables positively associated with mortality in univariate analysis were ascites, clinically overt sarcopenia and MELD-Na score, while ongoing nutritional supplementation improved survival. In the multivariate analysis, only clinically overt sarcopenia and MELD-Na score remained independently associated with mortality. A MELD-Na/sarcopenia model demonstrated a good discrimination, AUROC: 0.86 (95% CI 0.77 - 0.95). CONCLUSION: MELD-Na score, and sarcopenia were significantly associated with 1-year survival in cirrhotic patients who received TIPS.

Chemical disinfection as a simple and reliable method to control the amphibian chytrid fungus at breeding points of endangered amphibians.

Chytridiomycosis caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is pushing amphibians towards extinction. Whilst mitigation methods were suggested a decade ago, we lack field trials testing their efficacy. We used the agrochemical fungicide, tebuconazole, to treat Bd infected breeding waterbodies of an endangered species that is highly susceptible to the fungus. Just two applications of tebuconazole led to a significant reduction in infection loads in the vast majority of sites, and at six sites the disinfection remained one/two-years post-application. Tebuconazole values drastically decreased in the waterbodies within a week after application, with no significant effects on their hydrochemical and hydrobiological characteristics. Although the use of chemicals in natural populations is undesirable, the growing existential threat to amphibians all over the world indicates that effective interventions in selected populations of endangered species are urgently needed.

Application of machine learning with large-scale data for an effective vaccination against classical swine fever for wild boar in Japan.

Classical swine fever has been spreading across the country since its re-emergence in Japan in 2018. Gifu Prefecture has been working diligently to control the disease through the oral vaccine dissemination targeting wild boars. Although vaccines were sprayed at 14,000 locations between 2019 and 2020, vaccine ingestion by wild boars was only confirmed at 30% of the locations. Here, we predicted the vaccine ingestion rate at each point by Random Forest modeling based on vaccine dissemination data and created prediction surfaces for the probability of vaccine ingestion by wild boar using spatial interpolation techniques. Consequently, the distance from the vaccination point to the water source was the most important variable, followed by elevation, season, road density, and slope. The area under the curve, model accuracy, sensitivity, and specificity for model evaluation were 0.760, 0.678, 0.661, and 0.685, respectively. Areas with high probability of wild boar vaccination were predicted in northern, eastern, and western part of Gifu. Leave-One-Out Cross Validation results showed that Kriging approach was more accurate than the Inverse distance weighting method. We emphasize that effective vaccination strategies based on epidemiological data are essential for disease control and that our proposed tool is also applicable for other wildlife diseases.

Landscape connectivity for predicting the spread of ASF in the European wild boar population.

African swine fever (ASF) is an infectious and highly fatal disease affecting wild and domestic swine, which is unstoppably spreading worldwide. In Europe, wild boars are one of the main drivers of spread, transmission, and maintenance of the disease. Landscape connectivity studies are the main discipline to analyze wild-species dispersal networks, and it can be an essential tool to predict dispersal-wild boar movement routes and probabilities and therefore the associated potential ASF spread through the suitable habitat. We aimed to integrate wild boar habitat connectivity predictions with their occurrence, population abundance, and ASF notifications to calculate the impact (i.e., the capacity of a landscape feature to favor ASF spread) and the risk (i.e., the likelihood of a habitat patch becoming infected) of wild boar infection across Europe. Furthermore, we tested the accuracy of the risk of infection by comparing the results with the temporal distribution of ASF cases. Our findings identified the areas with the highest impact and risk factors within Europe's central and Eastern regions where ASF is currently distributed. Additionally, the impact factor was 31 times higher on habitat patches that were infected vs non-infected, proving the utility of the proposed approach and the key role of wild boar movements in ASF-spread. All data and resulting maps are openly accessible and usable.

Pre-emptive TIPS in high-risk acute variceal bleeding. An updated and revised individual patient data meta-analysis.

BACKGROUND AND AIMS: A previous individual patient data meta-analysis (IPD-MA) showed that compared with drugs+endoscopy, the placement of transjugular portosystemic shunt within 72 hours of admission (pre-emptive transjugular intrahepatic portosystemic shunt: p-TIPS) increases the survival of high-risk patients (Child-Pugh B+ active bleeding and Child-Pugh C<14 points) with cirrhosis and acute variceal bleeding. However, the previous IPD-MA was not a two-stage meta-analysis, did not consider the potential risk of selection bias of observational studies, and did not include the most recent randomized clinical trial. We performed an updated and revised IPD-MA to reassess the efficacy of p-TIPS, addressing all previous issues. APPROACH AND RESULTS: We included all studies from the previous IPD-MA and searched for other possible eligible publications until September 2022. We performed a two-stage IPD-MA of data from 8 studies (4 randomized clinical trials and 4 observational). In addition, we performed a sensitivity analysis excluding those patients dying up to the first 72 hours after admission in the Drugs+Endoscopy arms of the 4 observational studies. The primary end point was the effects of p-TIPS versus Drugs+Endoscopy on 1-year survival.We identified 1389 patients (342 p-TIPS and 1047 Drugs+Endoscopy). The two-stage IPD-MA showed that p-TIPS significantly reduced the mortality in the overall population (HR=0·43, 95% CI: 0.32-0.60, p <0.001. This effect was observed in both subgroups of patients with Child-Pugh. The sensitivity analysis confirmed the survival benefit of p-TIPS. CONCLUSIONS: The updated two-stage IPD-MA confirms the significant survival advantage of p-TIPS in high-risk patients with cirrhosis and acute variceal bleeding. As a result, we recommend p-TIPS as the preferred first-choice treatment for these patients.

What can we learn from the five-year African swine fever epidemic in Asia?

Today's global swine industry is exposed to the unprecedented threat of African swine fever (ASF). Asia, the site of the most recent epidemics, could serve as a huge viral reservoir for the rest of the world given the severity of the damage, the huge swine industry, and the high volume of trade with other countries around the world. As the majority of ASF notifications in Asia today originate from pig farms, the movement of live pigs and associated pork products are considered critical control points for disease management. Particularly, small-scale or backyard farms with low biosecurity levels are considered major risk factors. Meanwhile, wild boars account for most notified cases in some countries and regions, which makes the epidemiological scenario different from that in other Asian countries. As such, the current epidemic situation and higher risk factors differ widely between these countries. A variety of studies on ASF control have been conducted and many valuable insights have been obtained in Asia; nevertheless, the overall picture of the epidemic is still unclear. The purpose of this review is to provide an accurate picture of the epidemic situation across Asia, focusing on each subregion to comprehensively explain the disease outbreak. The knowledge gained from the ASF epidemics experienced in Asia over the past 5 years would be useful for disease control in areas that are already infected, such as Europe, as well as for non-affected areas to address preventive measures. To this end, the review includes two aspects: a descriptive analytical review based on publicly available databases showing overall epidemic trends, and an individualized review at the subregional level based on the available literature.

Relationship between two pathogens in an amphibian community that experienced mass mortalities.

Because host species tend to harbor multiple parasitic species, coinfection in a host is common. The chytrid fungus Batrachochytrium dendrobatidis (Bd) and the viruses in the genus Ranavirus (Rv) are responsible for the decline of amphibians worldwide. Despite wide geographical co-occurrence and the serious conservation problem that coinfection with these pathogens could represent, little is known about their possible synergistic interactions and effects in a host community. We investigated the occurrence and associations between these two pathogens in an amphibian community after Rv-driven disease outbreaks were detected in four populations of the Iberian ribbed newt (Pleurodeles waltl) in northwestern Spain. We collected tissue samples from amphibians and fish and estimated Bd and Rv infection loads by qPCR. A few months after the most recent mass mortality event, Rv infection parameters at the affected sites decreased significantly or were lower than such registered at the sites where no outbreaks were recorded. Both pathogens were simultaneously present in almost all sites, but coinfection in a single host was rare. Our findings suggest that the co-occurrence of Bd and Rv does not predict adverse outcomes (e.g., enhanced susceptibility of hosts to one pathogen due to the presence or infection intensity of the other) following an outbreak. Other variables (such as species identity or site) were more important than infection with a pathogen in predicting the infection status and severity of infection with the other pathogen. Our results highlight the importance of host-specific and environmental characteristics in the dynamics of infections, coinfection patterns, and their impacts.

Relaciones entre dos patógenos en una comunidad anfibia que experimentó mortalidad masiva Resumen La coinfección es común en especies hospederas ya que estas especies tienden a albergar muchas especies parasíticas. El hongo quitridio Batrachochytrium dendrobatidis (Bd) y los virus del género Ranavirus (Rv) son responsables de la declinación mundial de anfibios. A pesar de la amplia co-ocurrencia geográfica y el problema serio de conservación que podría representar la coinfección con estos patógenos, se conoce muy poco sobre sus posibles interacciones sinérgicas y sus efectos en una comunidad hospedera. Investigamos la incidencia y las asociaciones entre estos dos patógenos en una comunidad anfibia después de que se detectaron brotes de enfermedades causados por Rv en cuatro poblaciones del tritón estriado ibérico (Pleurodeles waltl) en el noroeste de España. Recolectamos muestras de tejido de anfibios y peces y estimamos la carga infecciosa de Bd y Rv con una qPCR. Unos meses después del evento de mortalidad masiva más reciente, los parámetros de infección de Rv en los sitios afectados disminuyeron significativamente o fueron más bajos que los registrados en sitios sin brotes. Ambos patógenos estuvieron presentes de forma simultánea en casi todos los sitios, pero fue raro encontrar la coinfección en un solo hospedero. Nuestros descubrimientos sugieren que la coocurrencia de Bd y Rv no pronostica resultados adversos (aumento en la susceptibilidad de los hospederos a un patógeno debido a la presencia o intensidad de infección del otro patógeno) después de un brote. Otras variables, como la identidad de la especie o el sitio, fueron más importantes que la infección con un patógeno en la predicción del estado de infección y la severidad de la infección con otro patógeno. Nuestros resultados resaltan la importancia de las características ambientales y aquellas específicas del hospedero en las dinámicas de infección, los patrones de coinfección y sus impactos.