Bottlenose dolphins (Tursiops truncatus) aggressive behavior towards other cetacean species in the western Mediterranean.

Aggressive behavior of bottlenose dolphins (Tursiops truncatus) towards conspecifics is widely described, but they have also often been reported attacking and killing harbour porpoises (Phocoena phocoena) around the world. However, very few reports exist of aggressive interactions between bottlenose dolphins and other cetacean species. Here, we provide the first evidence that bottlenose dolphins in the western Mediterranean exhibit aggressive behavior towards both striped dolphins (Stenella coeruleoalba) and Risso's dolphins (Grampus griseus). Necropsies and visual examination of stranded striped (14) and Risso's (2) dolphins showed numerous lesions (external rake marks and different bone fractures or internal organ damage by blunt trauma). Indicatively, these lessons matched the inter-tooth distance and features of bottlenose dolphins. In all instances, these traumatic interactions were presumed to be the leading cause of the death. We discuss how habitat changes, dietary shifts, and/or human colonization of marine areas may be promoting these interactions.

Gaps in African swine fever: Analysis and priorities.

African swine fever (ASF) causes greater sanitary, social and economic impacts on swine herds than many other swine diseases. Although ASF was first described in 1921 and it has affected more than fifty countries in Africa, Europe and South America, several key issues about its pathogenesis, immune evasion and epidemiology remain uncertain. This article reviews the main characteristics of the causative virus, its molecular epidemiology, natural hosts, clinical features, epidemiology and control worldwide. It also identifies and prioritizes gaps in ASF from a horizontal point of view encompassing fields including molecular biology, epidemiology, prevention, diagnosis and vaccine development. The purpose of this review is to promote ASF research and enhance its control.

Understanding African Swine Fever infection dynamics in Sardinia using a spatially explicit transmission model in domestic pig farms.

African swine fever virus (ASFV) has been endemic in Sardinia since 1978, resulting in severe losses for local pig producers and creating important problems for the island's veterinary authorities. This study used a spatially explicit stochastic transmission model followed by two regression models to investigate the dynamics of ASFV spread amongst domestic pig farms, to identify geographic areas at highest risk and determine the role of different susceptible pig populations (registered domestic pigs, non-registered domestic pigs [brado] and wild boar) in ASF occurrence. We simulated transmission within and between farms using an adapted version of the previously described model known as Be-FAST. Results from the model revealed a generally low diffusion of ASF in Sardinia, with only 24% of the simulations resulting in disease spread, and for each simulated outbreak on average only four farms and 66 pigs were affected. Overall, local spread (indirect transmission between farms within a 2 km radius through fomites) was the most common route of transmission, being responsible for 98.6% of secondary cases. The risk of ASF occurrence for each domestic pig farm was estimated from the spread model results and integrated in two regression models together with available data for brado and wild boar populations. There was a significant association between the density of all three populations (domestic pigs, brado, and wild boar) and ASF occurrence in Sardinia. The most significant risk factors were the high densities of brado (OR = 2.2) and wild boar (OR = 2.1). The results of both analyses demonstrated that ASF epidemiology and infection dynamics in Sardinia create a complex and multifactorial disease situation, where all susceptible populations play an important role. To stop ASF transmission in Sardinia, three main factors (improving biosecurity on domestic pig farms, eliminating brado practices and better management of wild boars) need to be addressed.

Why is African swine fever still present in Sardinia?

African swine fever (ASF) is an infectious disease of swine that has been present in Sardinia since 1978. Soon after introduction of the disease, several control and eradication programmes were established with limited success. Some researchers attributed the persistence of the disease in central and eastern areas to certain socio-economic factors, the existence of some local and traditional farming practices (i.e., unregistered free-ranging pigs known as brado animals) and the high density of wild boar in the region. In the past, scarcity of swine data in Sardinia complicated the evaluation and study of ASF on the island. More complete, accurate and reliable information on pig farms has become available as a result of the most recent eradication programmes. Here, we perform statistical modelling based on these data and the known distribution of domestic pig and wild boar to identify the main risk factors that have caused ASF persistence in Sardinia. Our results categorized, identified and quantified nine significant risk factors, six of which have not been previously described. The most significant factors were the number of medium-sized farms, the presence of brado animals and the combination of estimated wild boar density and mean altitude above sea level. Based on these factors, we identified regions in eastern and central Sardinia to be at greatest risk of ASF persistence; these regions are also where the disease has traditionally been endemic. Based on these risk factors, we propose specific control measures aimed at mitigating such risks and eradicating ASF from the island.

Serological Surveillance and Direct Field Searching Reaffirm the Absence of Ornithodoros Erraticus Ticks Role in African Swine Fever Cycle in Sardinia.

African swine fever (ASF), one of the most important diseases of swine, has been endemic in the Italian island of Sardinia for more than 35 years. During these decades, several strategies and eradication efforts have been implemented in the island with limited success. Strong climatic and ecological similarities exist between Sardinia and one area of the Iberian Peninsula where Ornithodoros erraticus ticks were involved in the persistence of ASF from 1960 to 1995. This fact leads to the hypothesis that, potentially, Ornithodoros ticks could be also involved in the ASF cycle in Sardinia, thus accounting for some of the reoccurring ASF outbreaks in this island. Initial efforts aimed at detection of Ornithodoros ticks in Sardinia were performed during the 1970s/1980s with no positive results. Accordingly, the absence of Ornithodoros ticks in Sardinia has been generally accepted. However, since a new and reinforced ASF eradication programme has been recently launched in Sardinia, it is essential to clarify the presence and role of these soft ticks in the epizootiology of ASF in this island. For that purpose, 1767 porcine serum samples collected from all around the island (1261 from domestic and 506 from wild boar) were analysed by ELISA for antibodies to salivary antigens of Ornithodoros erraticus. In addition, Ornithodoros ticks were directly searched in a number of pig premises that have suitable habitats for these ticks and were located in areas repeatedly affected by ASF. Only one serum sample resulted positive in the serological assay, and no Ornithodoros ticks were collected in none of the premises. These results indicate that these soft tick species are not involved in the epizootic cycle of ASF in Sardinia and highlight the importance of controlling other risk factors still present in the island for effectively eradicate the disease.

Update on the Risk of Introduction of African Swine Fever by Wild Boar into Disease-Free European Union Countries.

Despite efforts to prevent the appearance and spread of African swine fever (ASF) in the European Union, several Member States are now affected (Lithuania, Poland, Latvia and Estonia). Disease appearance in 2014 was associated with multiple entrances linked to wild boar movement from endemic areas (EFSA Journal, 8, 2015, 1556), but the risk of new introductions remains high (Gallardo et al., Porcine Health Management, 1, and 21) as ASF continues to be active in endemic countries (Russian Federation, Belarus and Ukraine). Since 2014, the number of ASF notifications has increased substantially, particularly in wild boar (WB), in parallel with slow but constant geographical advance of the disease. This situation suggests a real risk of further disease spread into other Member States, posing a great threat to pig production in the EU. Following the principles of the risk-based veterinary surveillance, this article applies a methodology developed by De la Torre et al. (Transboundary and Emerging Diseases, 62, and 272) to assess the relative risk of new introductions of ASF by natural movements of WB according to the current epidemiological situation. This update incorporates the most recent available data and an improved version of the most important risk estimator: an optimized cartographic tool of WB distribution to analyse wild boar suitable habitat. The highest relative risk values were estimated for Slovakia (5) and Romania (5), followed by Finland (4), Czech Republic (3) and Germany (3). Relative risk for Romania and Finland is associated mainly with disease entrance from endemic areas such as the Russian Federation and Ukraine, where the disease is currently spreading; relative risk for Germany and Czech Republic is associated mainly with the potential progress of the disease through the EU, and relative risk for Slovakia is associated with both pathways. WB habitat is the most important risk estimator, whereas WB density is the least significant, suggesting that WB presence is more relevant than density. These results can provide actionable advice for dealing with risk. They can be directly used to inform risk-based national strategies and identify countries that may need to pay greater attention to surveillance or conduct additional evaluations at the subnational level.

Identification of a New Genotype of African Swine Fever Virus in Domestic Pigs from Ethiopia.

African swine fever (ASF) is an important emerging transboundary animal disease (TAD), which currently has an impact on many countries in Africa, Eastern Europe, the Caucasus and the Russian Federation. The current situation in Europe shows the ability of the virus to rapidly spread, which stands to threaten the global swine industry. At present, there is no viable vaccine to minimize spread of the disease and stamping out is the main source of control. In February 2011, Ethiopia had reported its first suspected outbreaks of ASF. Genomic analyses of the collected ASF virus (ASFV) strains were undertaken using 23 tissue samples collected from domestic swine in Ethiopia from 2011 to 2014. The analysis of Ethiopian ASFVs partial p72 gene sequence showed the identification of a new genotype, genotype XXIII, that shares a common ancestor with genotypes IX and X, which comprise isolates circulating in Eastern African countries and the Republic of Congo. Analysis of the p54 gene also followed the p72 pattern and the deduced amino acid sequence of the central variable region (CVR) of the B602L gene showed novel tetramer repeats not previously characterized.

Early Detection of Infection in Pigs through an Online Monitoring System.

Late detection of emergency diseases causes significant economic losses for pig producers and governments. As the first signs of animal infection are usually fever and reduced motion that lead to reduced consumption of water and feed, we developed a novel smart system to monitor body temperature and motion in real time, facilitating the early detection of infectious diseases. In this study, carried out within the framework of the European Union research project Rapidia Field, we tested the smart system on 10 pigs experimentally infected with two doses of an attenuated strain of African swine fever. Biosensors and an accelerometer embedded in an eartag captured data before and after infection, and video cameras were used to monitor the animals 24 h per day. The results showed that in 8 of 9 cases, the monitoring system detected infection onset as an increase in body temperature and decrease in movement before or simultaneously with fever detection based on rectal temperature measurement, observation of clinical signs, the decrease in water consumption or positive qPCR detection of virus. In addition, this decrease in movement was reliably detected using automatic analysis of video images therefore providing an inexpensive alternative to direct motion measurement. The system can be set up to alert staff when high fever, reduced motion or both are detected in one or more animals. This system may be useful for monitoring sentinel herds in real time, considerably reducing the financial and logistical costs of periodic sampling and increasing the chances of early detection of infection.

Technological advances in veterinary diagnostics: opportunities to deploy rapid decentralised tests to detect pathogens affecting livestock.

Sustainable food production capable of feeding a growing human population is a significant global challenge, and is a priority encompassed within the United Nations Millennium Development Goal to 'eradicate extreme poverty and hunger'. Infectious diseases reduce the productivity of farm animals, and the globalised trade of animals and their products increases the threat of disease incursion. Accurate and rapid diagnostic tests are an essential component of contingency plans to detect, control and eradicate such diseases. Diagnosis involves a 'pipeline' that normally starts with clinical suspicion, followed by collecting samples, transporting specimens to a centralised laboratory setting (e.g. national/international Reference Laboratories), analysing these samples using a range of diagnostic tests and reporting the results. However, the transport of specimens from the field to the laboratory can be a lengthy process that can delay critical decision-making and severely affect the quality of the samples. This important limitation of centralised diagnostic testing has motivated the development of tools for the rapid, simple detection of livestock pathogens. Recent advances in the development of technologies for personalised human medicine have motivated the development of prototype diagnostic tests for a wide selection of diseases of livestock. However, many of these tests are not yet routinely used or commercially available. This paper critically reviews the most promising examples of such assays, and highlights the challenges that remain to transition these tests from applied research and development into routine use.

La production durable de denrées alimentaires pour nourrir une population humaine en constante augmentation constitue un vaste enjeu planétaire ainsi que l'une des priorités définies par les Nations Unies dans le cadre des Objectifs du Millénaire pour le développement visant à « éradiquer l'extrême pauvreté et la faim dans le monde ¼. D'une part, les maladies animales réduisent la productivité des animaux d'élevage ; d'autre part, la mondialisation des échanges d'animaux et de produits d'origine animale intensifie les risques d'incursion de maladies. L'utilisation de tests de diagnostic rapides et fiables est une composante essentielle des plans d'urgence visant à détecter, contrôler et éradiquer ces maladies. Une procédure de diagnostic est généralement constituée de plusieurs opérations, depuis la suspicion clinique, la collecte d'échantillons, leur transport vers un laboratoire central (par exemple un laboratoire de référence national/international), jusqu'à l'analyse de ces échantillons au moyen d'une série de tests diagnostiques et la notification des résultats. Néanmoins, le transport des échantillons depuis le terrain jusqu'au laboratoire est parfois un processus très long qui peut retarder la prise de décisions cruciales, voire compromettre gravement la qualité des échantillons. Cette limitation importante des procédures diagnostiques centralisées a incité à mettre au point des outils permettant une détection rapide et aisée des agents pathogènes affectant le bétail. Les progrès récents accomplis dans les technologies relevant de la médecine humaine personnalisée ont encouragé le développement de prototypes d'épreuves de diagnostic pour nombre de maladies du bétail. Toutefois, plusieurs de ces tests ne sont pas encore utilisés en routine ni disponibles commercialement. Les auteurs font le point sur les exemples les plus prometteurs de ces tests et soulignent les difficultés restant à résoudre pour que ces tests puissent évoluer d'une application en recherche et développement à une utilisation en routine.

El logro de una producción sostenible de alimentos en cantidad suficiente para abastecer a una población humana cada vez más numerosa es una difícil empresa que el mundo tiene ante sí, que además entronca con una de las prioridades plasmadas en los Objetivos de Desarrollo del Milenio de las Naciones Unidas: «erradicar la pobreza extrema y el hambre¼. Las enfermedades infecciosas merman la productividad de los animales de granja, al tiempo que el comercio mundializado de animales y sus derivados amplifica la amenaza de incursiones infecciosas. La existencia de pruebas de diagnóstico rápidas y exactas es un elemento básico de todo plan de emergencia encaminado a detectar, controlar y erradicar esas enfermedades. Las labores de diagnóstico entrañan un «circuito¼ que normalmente empieza con la sospecha clínica, sigue con la obtención de muestras, su transporte a un laboratorio central (como un laboratorio de referencia nacional o internacional) y su análisis mediante diversas pruebas de diagnóstico y culmina con la notificación de los resultados. Sin embargo, el transporte hasta un laboratorio de las muestras obtenidas sobre el terreno es a veces un proceso lento, que puede retrasar la adopción de decisiones cruciales y mermar sensiblemente la calidad de las muestras. Este importante inconveniente derivado de la realización centralizada de pruebas ha llevado a concebir herramientas que permitan detectar de forma rápida y sencilla patógenos presentes en el ganado. Los avances registrados últimamente en la obtención de tecnologías destinadas a la medicina humana personalizada han propiciado también la elaboración de prototipos de pruebas para diagnosticar numerosas enfermedades del ganado, aunque muchas de ellas todavía no se utilizan sistemáticamente ni están comercializadas. Los autores, tras examinar en clave crítica los más prometedores ejemplos de estos nuevos ensayos, señalan las dificultades que aún subsisten para que estas pruebas puedan pasar del ámbito de la investigación aplicada y el desarrollo al de su utilización sistemática.

Effectiveness and practicality of control strategies for African swine fever: what do we really know?

African swine fever (ASF) is a major pig health problem, and the causative virus is moving closer to Western European regions where pig density is high. Stopping or slowing down the spread of ASF requires mitigation strategies that are both effective and practical. Based on the elicitation of ASF expert opinion, this study identified surveillance and intervention strategies for ASF that are perceived as the most effective by providing the best combination between effectiveness and practicality. Among the 20 surveillance strategies that were identified, passive surveillance of wild boar and syndromic surveillance of pig mortality were considered to be the most effective surveillance strategies for controlling ASF virus spread. Among the 22 intervention strategies that were identified, culling of all infected herds and movement bans for neighbouring herds were regarded as the most effective intervention strategies. Active surveillance and carcase removal in wild boar populations were rated as the most effective surveillance and intervention strategies, but were also considered to be the least practical, suggesting that more research is needed to develop more effective methods for controlling ASF in wild boar populations.

Development of a Luminex-Based DIVA Assay for Serological Detection of African Horse Sickness Virus in Horses.

African horse sickness (AHS) is considered a fatal re-emergent vector-borne disease of horses. In the absence of any effective treatment for AHS, vaccination remains the most effective form of disease control. The new generation of vaccines, such as one based on purified, inactivated AHS virus (AHSV, serotype 4), which does not induce antibodies against non-structural protein 3 (NS3), enables the development of diagnostic methods that differentiate infected from vaccinated animals (DIVA assays). As detecting AHS in AHSV-free countries may lead to restrictions on international animal movements and thereby cause significant economic damage, these DIVA assays are crucial for reducing movement restrictions. In this article, we describe a Luminex-based multiplex assay for DIVA diagnosis of AHS, and we validate it in a duplex format to detect antibodies against structural protein 7 (VP7) and NS3 in serum samples from horses vaccinated with inactivated AHSV4 vaccine or infected with a live virus of the same serotype. Results of the Luminex-based assay for detecting anti-NS3 antibodies showed good positive correlation with results from an in-house enzyme-linked immunosorbent assay (ELISA). Thus, the Luminex-based technique described here may allow multiplex DIVA antibody detection in a single sample in less than 2 h, and it may prove adaptable for the development of robust, multiplex serological assays.

Implementation and validation of an economic module in the Be-FAST model to predict costs generated by livestock disease epidemics: Application to classical swine fever epidemics in Spain.

Be-FAST is a computer program based on a time-spatial stochastic spread mathematical model for studying the transmission of infectious livestock diseases within and between farms. The present work describes a new module integrated into Be-FAST to model the economic consequences of the spreading of classical swine fever (CSF) and other infectious livestock diseases within and between farms. CSF is financially one of the most damaging diseases in the swine industry worldwide. Specifically in Spain, the economic costs in the two last CSF epidemics (1997 and 2001) reached jointly more than 108 million euros. The present analysis suggests that severe CSF epidemics are associated with significant economic costs, approximately 80% of which are related to animal culling. Direct costs associated with control measures are strongly associated with the number of infected farms, while indirect costs are more strongly associated with epidemic duration. The economic model has been validated with economic information around the last outbreaks in Spain. These results suggest that our economic module may be useful for analysing and predicting economic consequences of livestock disease epidemics.

Detection of African Swine Fever Antibodies in Experimental and Field Samples from the Russian Federation: Implications for Control.

African swine fever (ASF) re-entered in Europe in 2007 by Georgia rapidly affecting neighbouring countries. Since then, ASF has caused severe problems to the Russian Federation (RF) and spread to Northern and Western regions, including Ukraine (2012 and 2014) and Belarus (2013). At the beginning of 2014, dead wild boars were found in Lithuania and Poland. Several outbreaks have been later notified in the European Union(EU), affecting domestic pigs and wild boar of Latvia, Lithuania and Poland, and also wild boar in Estonia, causing major problems for the EU pig sector. Some studies have been performed with this ASFV isolate, revealing that it belongs to genotype II and causes an acute form of the disease. However, few data are available about the presence of antibodies in field and experimental samples from the affected area. This study analysed samples from experimental infections with ASFV isolated from the RF in 2013 (74 sera and 3 tissue exudates), and field samples from the RF from 2013 to 2014 (266 samples, including 32 and 7 tissue exudates from domestic pigs and wild boar, respectively). All samples were tested by a commercial ELISA and, some of them (79), also by immunochromatographic tests. Positive and doubtful samples were confirmed by immunoblotting test. Positive results were found in experimental and field samples, which confirm the presence of antibodies against ASFV in the RF. Antibodies were detected in animals inoculated with three different ASFV isolates, with some differences found among them. Only a small percentage of field samples was positive for ASF antibodies (3.7%), in agreement with other observations that reported a high virulence for the ASFV isolates in the area. These results confirm the potential presence of survivor animals that should be considered in affected areas to help design effective control and eradication plans against ASF.

Identification of Suitable Areas for African Horse Sickness Virus Infections in Spanish Equine Populations.

African horse sickness (AHS) is one of the most important vector-borne viral infectious diseases of equines, transmitted mainly by Culicoides spp. The re-emergence of Culicoides-borne diseases in Europe, such as the recent bluetongue (BT) or Schmallenberg outbreaks, has raised concern about the potential re-introduction and further spread of AHS virus (AHSV) in Europe. Spain has one of the largest European equine populations. In addition, its geographical, environmental and entomological conditions favour AHSV infections, as shown by the historical outbreaks in the 1990s. The establishment of risk-based surveillance strategies would allow the early detection and rapid control of any potential AHSV outbreak. This study aimed to identify the areas and time periods that are suitable or at high risk for AHS occurrence in Spain using a GIS-based multicriteria decision framework. Specifically risk maps for AHS occurrence were produced using a weighted linear combination of the main risk factors of disease, namely extrinsic incubation period, equine density and distribution of competent Culicoides populations. Model results revealed that the south-western and north-central areas of Spain and the Balearic Islands are the areas at the highest risk for AHSV infections, particularly in late summer months. Conversely, Galicia, Castile and Leon and La Rioja can be considered as low-risk regions. This result was validated with historical AHS and BT outbreaks in Spain, and with the Culicoides vector distribution area. The model results, together with current Spanish equine production features, should provide the foundations to design risk-based and more cost-effective surveillance strategies for the early detection and rapid control potential of AHS outbreaks in Spain.

Constant Hepatitis E Virus (HEV) Circulation in Wild Boar and Red Deer in Spain: An Increasing Concern Source of HEV Zoonotic Transmission.

Hepatitis E is a viral zoonosis that affects multiple hosts. The complete dynamics of infection in wildlife are still unknown, but the previous fact facilitates the maintenance and circulation of the virus, posing a risk to human health in the case of meat consumption from susceptible animals. In Spain, it has been shown how domestic pigs, cattle and wildlife (i.e. wild boar and red deer) clearly interact in hunting farms, generating a complex epidemiological situation in terms of interspecies pathogen transmission. Therefore, in this study, we aimed to (i) evaluate the circulation of the virus in geographically close domestic (Iberian pigs) and wild animals (wild boar and deer) living in hunting areas from central Spain over an 8-year period (2003-2010) and (ii) to determine whether HEV could be used as a marker of domestic-wildlife contact. For these purposes, a longitudinal analysis of Iberian pig, wild boar and red deer samples (n = 287) through virological and serological tests was conducted to shed light upon the circulation events of HEV. Regarding HEV RNA detection by real-time RT-PCR, 10.12% samples (95% CI: 5.44-14.8) from wild boar and 16.05% samples (95% CI: 8.06-24.04) from red deer were positive. As for the Iberian pigs, none of the 48 samples was positive for HEV RNA detection. In the serological analysis, 43.75% (95% CI: 29.75-57.75) from Iberian pig, 57.40% (95% CI: 48.10-66.70) from wild boar and 12.85% (95% CI: 5.01-20.69) samples from red deer presented anti-HEV antibodies. Positive samples were distributed among all study years (2003-2010). These results depict the urgent need to improve the inspection and surveillance of these species and their products. In the case of HEV, it is clear that the stable and constant presence of the virus in wildlife and its contact with Iberian pigs pose a risk for human health as they are all destined for human consumption.

Thirty-Five-Year Presence of African Swine Fever in Sardinia: History, Evolution and Risk Factors for Disease Maintenance.

Despite the implementation of control efforts and funds to fight against the disease, African swine fever (ASF) has been present in Sardinia since 1978. It has caused serious problems for both the industrial pig sector and the regional authorities in Sardinia, as well as the economy of Italy and the European Union, which annually supports the costly eradication programme. During this time, ASF has persisted, especially in the central-east part of Sardinia where almost 75% of the total outbreaks are concentrated. The Sardinian pig sector is clearly divided into two categories based on the specialization and industrialization of production: industrial farms, which represents only 1.8% of the farms in the island and non-professional holdings, which are comprised of small producers (90% of pig holdings have <15 pigs) and apply little to no biosecurity measures. Additionally, illegally raised pigs are still bred in free-ranging systems in certain isolated parts of the island, despite strict regulations. The illegal raising of pigs, along with other high-risk management practices (e.g., use of communal areas) are likely the primary reasons for endemic persistence of the virus in this area. The compensation provided to the farmers, and other aspects of the eradication programme have also negatively influenced eradication efforts, indicating that socio-cultural and economic factors play an important role in the epidemiology of ASF on the island. The aim of this study was to comprehensively review the evolution of the 35-year presence of ASF in Sardinia, including control measures, and the environmental and socio-economic factors that may have contributed to disease endemicity on the island. The present review highlights the need for a coordinated programme that considers these socio-economic and environmental factors and includes an assessment of new cost-effective control strategies and diagnostic tools for effectively controlling ASF in Sardinia.

Development of a Microsphere-based Immunoassay for Serological Detection of African Horse Sickness Virus and Comparison with Other Diagnostic Techniques.

African horse sickness (AHS) is a viral disease that causes high morbidity and mortality rates in susceptible Equidae and therefore significant economic losses. More rapid, sensitive and specific assays are required by diagnostic laboratories to support effective surveillance programmes. A novel microsphere-based immunoassay (Luminex assay) in which beads are coated with recombinant AHS virus (AHSV) structural protein 7 (VP7) has been developed for serological detection of antibodies against VP7 of any AHSV serotype. The performance of this assay was compared with that of a commercial enzyme-linked immunosorbent assay (ELISA) and commercial lateral flow assay (LFA) on a large panel of serum samples from uninfected horses (n = 92), from a reference library of all AHSV serotypes (n = 9), on samples from horses experimentally infected with AHSV (n = 114), and on samples from West African horses suspected of having AHS (n = 85). The Luminex assay gave the same negative results as ELISA when used to test the samples from uninfected horses. Both assays detected antibodies to all nine AHSV serotypes. In contrast, the Luminex assay detected a higher rate of anti-VP7 positivity in the West African field samples than did ELISA or LFA. The Luminex assay detected anti-VP7 positivity in experimentally infected horses at 7 days post-infection, compared to 13 days for ELISA. This novel immunoassay provides a platform for developing multiplex assays, in which the presence of antibodies against multiple ASHV antigens can be detected simultaneously. This would be useful for serotyping or for differentiating infected from vaccinated animals.

New insights into the role of ticks in African swine fever epidemiology.

African swine fever (ASF), one of the most important diseases of swine, is present in many African countries, as well as in eastern Europe, Russia and Sardinia. It is caused by a complex virus, ASF virus (ASFV), for which neither vaccine nor treatment is available. ASFV affects swine of all breeds and ages, and also replicates in soft ticks of the genus Ornithodoros, facilitating ASFV persistence and reocurrence of disease. Depending on the involvement of these ticks, and the presence or not of sylvatic asymptomatic animals, several epidemiological cycles have been identified. The disease persists in East and southern African countries in a sylvatic cycle between O. porcinus (of the O. moubata species complex) and common warthogs. In some countries a domestic pig-tick cycle exists, whereas in other regions, notably West Africa, the role of soft ticks has not been demonstrated, and ASFV is transmitted between domestic pigs in the absence of tick vectors. Even in several East and Central African countries which have the sylvatic or domestic cycle, the majority of outbreaks are not associated with ticks or wild suids. In Europe, O. erraticus was detected and identified as a crucial vector for ASF maintenance in outdoor pig production on the Iberian Peninsula. However, in most parts of Europe, there is a lack of information about the distribution and role of Ornithodoros ticks in ASF persistence, particularly in eastern regions. This article reviews ASF epidemiology and its main characteristics, with a special focus on the distribution and role of soft ticks in ASF persistence in different settings. Information abouttick detection, control measures and future directions for research is also included.

First Detection of Antibodies Against African Swine Fever Virus in Faeces Samples.

African swine fever (ASF) is a viral, highly lethal haemorrhagic disease of swine with no available vaccine or effective treatment. Introduction of ASF into a country triggers immediate restriction measures that cause significant economic losses and threatens spread to neighbouring countries. Wild boar populations have been recently assigned an essential role in the spread of African swine fever virus (ASFV) to European countries. Therefore, effective surveillance and monitoring of wild boar populations is required, but sampling wild boar is logistically challenging and expensive. This study assessed the feasibility of detecting antibodies against ASFV in faeces for later implementation in surveillance and control programmes. Two groups of pigs were experimentally infected with an attenuated ASFV isolate Ken05, and blood, oral fluid and faecal samples were tested for the presence of viral DNA using quantitative real-time polymerase chain reaction (qPCR) to monitor infection progress. Faecal samples were analysed using two indirect enzyme-linked immunosorbent assays (ELISAs) based on semipurified viral protein (vp) 72 or purified recombinant vp30 expressed in mammalian cells. Faecal samples from 9 of 10 pigs with non-haemorrhagic diarrhoea tested positive for antibodies against ASFV using the two ELISA tests that showed a positive correlation. The serum sample results from the two indirect ELISAs were compared against results from the reference ELISA technique and the immunoperoxidase test. Our findings indicate the feasibility of faecal sampling for detecting anti-ASFV antibodies, which may provide a practical non-invasive alternative for sampling wild boar populations. In conclusion, the application of these ELISA tests to faecal field samples could be particularly useful to screen for the presence of ASF in field conditions.

Experimental Transmission of African Swine Fever (ASF) Low Virulent Isolate NH/P68 by Surviving Pigs.

African swine fever (ASF) has persisted in Eastern Europe since 2007, and two endemic zones have been identified in the central and southern parts of the Russian Federation. Moderate- to low-virulent ASF virus isolates are known to circulate in endemic ASF-affected regions. To improve our knowledge of virus transmission in animals recovered from ASF virus infection, an experimental in vivo study was carried out. Four domestic pigs were inoculated with the NH/P68 ASF virus, previously characterized to develop a chronic form of ASF. Two additional in-contact pigs were introduced at 72 days post-inoculation (dpi) in the same box for virus exposure. The inoculated pigs developed a mild form of the disease, and the virus was isolated from tissues in the inoculated pigs up to 99 dpi (pigs were euthanized at 36, 65, 99 and 134 dpi). In-contact pigs showed mild or no clinical signs, but did become seropositive, and a transient viraemia was detected at 28 days post-exposure (dpe), thereby confirming late virus transmission from the inoculated pigs. Virus transmission to in-contact pigs occurred at four weeks post-exposure, over three months after the primary infection. These results highlight the potential role of survivor pigs in disease maintenance and dissemination in areas where moderate- to low-virulent viruses may be circulating undetected. This study will help design better and more effective control programmes to fight against this disease.