ABSTRACT
Foot-and-mouth disease (FMD) is an ailment that causes serious damage to the productive chain, and its control through vaccination is of utmost importance for its eradication. Brazil initiated the National Foot-and-Mouth Disease Surveillance Program (PNEFA) with the aim of making the country FMD-free by 2026. As part of the program, notifications of vesicular lesions became mandatory for the Official Veterinary Service (OVS), which is responsible for verifying them. Due to its size, border areas with countries that do not have FMD-free status pose a risk to Brazil and require greater attention. This study described the profile of notifications of suspected outbreaks of vesicular syndrome in Brazil and analyzed the performance of the surveillance system. The results showed 7134 registered notifications of suspected vesicular syndrome outbreaks from 2018 to 2022, with 2022 having the highest number (n = 2343 or 32.85â¯%). The species that generated the most notifications were swine (90.99â¯%), cattle and buffaloes (7.54â¯%), goats and sheep (1.44â¯%), and others (0.03â¯%). The sources of notification were "Veterinary medicine professionals" (61.82â¯%), "Owners or employees" (13.66â¯%), "Third parties" (8.90â¯%), "OVS" (7.20â¯%), and "others" (2.66â¯%). 41.69â¯% of notifications originated from non-border municipalities, and 58.32â¯% from border areas. Only the state of Paraná account for 51.73â¯% of the total notifications. This state also accounted for 66.70â¯% of the 32.47â¯% of notifications with a final diagnosis of "absence of clinically compatible signs or susceptible animals", indicating a certain lack of knowledge in the area, leading to unnecessary notifications and system overload. The performance of the OVS was evaluated based on the service response time from notification registration trough Logistic and Negative binomial regressions. A total of 27.83â¯% of notifications did not meet the Brazilian legally specified time, and the zone related to the state of Parana needs improvements in performance. The presence and peaks of Senecavirus A cases may have influenced an increased number of swine notifications and led to a decrease in OVS response time. The results demonstrate better performance of surveillance in border areas. Given the vast territory of Brazil, it is not expected that 100â¯% of responses occur within the legal timeframe, however, the performance of the surveillance system proved to be adequate, with 86â¯% complied to the legislation. The performance indicators could be used as a monitoring tool, along with indicators to demonstrate system overload. Continued education actions are crucial for strengthening PNEFA.
Subject(s)
Cattle Diseases , Disease Outbreaks , Foot-and-Mouth Disease , Brazil/epidemiology , Animals , Foot-and-Mouth Disease/epidemiology , Foot-and-Mouth Disease/prevention & control , Disease Outbreaks/veterinary , Disease Outbreaks/prevention & control , Cattle , Cattle Diseases/epidemiology , Cattle Diseases/virology , Cattle Diseases/prevention & control , Swine , Disease Notification/statistics & numerical data , Sheep , Swine Diseases/epidemiology , Swine Diseases/virology , Swine Diseases/prevention & control , Population Surveillance/methods , Sheep Diseases/epidemiology , Sheep Diseases/virology , Sheep Diseases/prevention & control , Goat Diseases/epidemiology , Goat Diseases/virology , Goat Diseases/prevention & control , Goats , Buffaloes , Epidemiological Monitoring/veterinaryABSTRACT
BACKGROUND: Senecavirus A (SV-A) is an RNA virus that belongs to the genus Senecavirus within the family Picornaviridae. This study aimed to analyze factors that can influence the molecular diagnosis of Senecavirus A, such as oligonucleotides, RNA extraction methods, and RT-qPCR kits. METHODS: Samples from suspected cases of vesicular disease in Brazilian pigs were analyzed for foot-and-mouth disease, swine vesicular disease, and vesicular stomatitis. All tested negative for these diseases but positive for SV-A. RT-qPCR tests were used, comparing different reagent kits and RNA extraction methods. Sensitivity and repeatability were evaluated, demonstrating efficacy in detecting SV-A in clinical samples. RESULTS: In RNA extraction, significant reduction in Cq values was observed with initial dilutions, particularly with larger supernatant volumes. Trizol and Maxwell showed greater sensitivity in automated equipment protocols, though results varied in tissue tests. RT-qPCR kit comparison revealed differences in amplification using viral RNA but minimal differences with plasmid DNA. Sensitivity among methods was comparable, with slight variations in non-amplified samples. Repeatability tests showed consistent results among RT-qPCRs, demonstrating similarity between methods despite minor discrepancies in Cq values. CONCLUSIONS: Trizol, silica columns, and semi-automated extraction were compared, as well as different RT-qPCR kits. The study found significant variations that could impact the final diagnosis.
Subject(s)
Picornaviridae Infections , Picornaviridae , RNA, Viral , Swine Diseases , Animals , Picornaviridae/genetics , Picornaviridae/isolation & purification , Swine , Picornaviridae Infections/diagnosis , Picornaviridae Infections/veterinary , Picornaviridae Infections/virology , RNA, Viral/genetics , Swine Diseases/virology , Swine Diseases/diagnosis , Sensitivity and Specificity , Real-Time Polymerase Chain Reaction/methods , Swine Vesicular Disease/diagnosis , Swine Vesicular Disease/virology , Foot-and-Mouth Disease/diagnosis , Foot-and-Mouth Disease/virology , Brazil , Reproducibility of ResultsABSTRACT
This study aims to analyze if the results from different serological assays, used alone or combined, could match the outcome of challenge infection with foot-and-mouth disease virus (FMDV) after vaccination in cattle. Day-of-challenge sera from animals that had been vaccinated 21 days before with monovalent formulations containing inactivated A Iran 96 or A Iran 99 virus strains were used. Challenge and serology were performed with A22 Iraq strain. IgG1 titers and total-IgG avidity indexes were significantly higher in protected animals (p < 0.01) while IgG2-titers were not related to protection (p > 0.05). An IgG1 avidity ELISA was developed to analyze in one step, IgG1 levels and avidity. This assay estimated protection with 96 % accuracy. A strong agreement with challenge results was achieved (K = 0.85), suggesting a role of high-affinity IgG1 in protection against FMDV. These results support the assessment of the single dilution IgG1-Avidity ELISA to predict cross-protection in FMDV-vaccinated cattle.
Subject(s)
Antibodies, Viral , Antibody Affinity , Cattle Diseases , Cross Protection , Enzyme-Linked Immunosorbent Assay , Foot-and-Mouth Disease Virus , Foot-and-Mouth Disease , Immunoglobulin G , Vaccination , Viral Vaccines , Animals , Foot-and-Mouth Disease/prevention & control , Foot-and-Mouth Disease/immunology , Enzyme-Linked Immunosorbent Assay/methods , Cattle , Immunoglobulin G/blood , Immunoglobulin G/immunology , Foot-and-Mouth Disease Virus/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Viral Vaccines/immunology , Cattle Diseases/prevention & control , Cattle Diseases/immunology , Cross Protection/immunology , Vaccination/methodsABSTRACT
[Objective] After more than 50 years of struggle, the delegates from each COSALFA member country and the invited experts bring to the table a history of the fight against the disease in their countries, the current scenario, and the challenges that are required to maintain or advance the recognized status of free from foot-and-mouth disease, in the current context and the different strategies, for each situation. That through the discussions present the opportunity to assess current and future challenges to meet the objectives of the PHEFA Action Plan 2021-2025
Subject(s)
Veterinary Public Health , Congress , Foot-and-Mouth DiseaseABSTRACT
[Objetivo] Pasados más de 50 años de lucha, que los delegados de cada país miembro de la COSALFA y los expertos invitados traigan a la mesa una breve historia del combate a la enfermedad en sus países; el escenario presente y los desafíos que se imponen tanto para mantener o avanzar en el estatus reconocido de libre de fiebre aftosa, en el contexto actual y las diferentes estrategias, para cada situación. Que a través de las discusiones se presente la oportunidad para evaluar los desafíos actuales y futuros a fin de cumplir con los objetivos del Plan de Acción 2021-2025 del PHEFA.
Subject(s)
Foot-and-Mouth Disease , Veterinary Public Health , Disease Eradication , Congresses as TopicABSTRACT
[Objetivo] Após mais de 50 anos de luta, que os delegados de cada país membro da COSALFA e os especialistas convidados tragam à mesa um histórico do combate à doença em seus países, o cenário presente e os desafios que se impõem para manter ou avançar no status reconhecido de livre de febre aftosa, no contexto atual e as diferentes estratégias, para cada situação. Que através das discussões se apresente a oportunidade para avaliação dos desafios atuais e futuros a fim de cumprir com os objetivos do Plano de Ação 2021-2025 do PHEFA
Subject(s)
Foot-and-Mouth Disease , Veterinary Public Health , Congresses as Topic , AmericasABSTRACT
Resoluciones de la Resoluciones de la 50a COSALFA. Reunión ordinaria de la Comisión Sudamericana para la Lucha contra la Fiebre Aftosa. (Rio de Janeiro, Brasil - 25 y 26 de abril de 2024)
Subject(s)
Foot-and-Mouth Disease , Veterinary Public Health , South America , ResolutionsABSTRACT
It is acknowledged that the technical coordination and cooperation provided by PANAFTOSA/PAHO within the framework of the Hemispheric Program for the Eradication of Foot-and-Mouth Disease (PHEFA) has been decisive for the progress made and it is still necessary for the complete eradication of the disease in the continent, without jeopardizing the progress made. The PHEFA remains in effect although the region reflected its best historical record in 2023, consecutively, regarding areas recognized as free by the World Organization for Animal Health (WOAH). Additionally, the countries continue to be oriented toward the execution of the PHEFA Plan of Action 2021-2025 to complete the eradication of foot-and-mouth disease, while also seeking to strengthen prevention and the capacity of veterinary services of the countries of the continent to respond to a potential foot-and-mouth disease emergency. The funding modality of PANAFTOSA/PAHO’s technical cooperation for the PHEFA is based on PAHO’s contribution with international professionals responsible of the foot-and-mouth disease (FMD) area and the reference laboratory, as well as the resources obtained from the reference material supplied to the countries. Additionally, it includes a model of voluntary contributions linked to specific projects with the countries. Therefore, the aforementioned is reflected in the costs referred to for this Biennial Plan 2024-2025. The expected outcomes of the mentioned plan will contribute to the goals outlined in the PHEFA Plan of Action 2021-2025, with a priority vision from PANAFTOSA/PAHO that takes into account COSALFA resolutions, aiming to prepare the countries for the final stage of the PHEFA. Based on these guidelines, and considering the current situation, PANAFTOSA/PAHO has elaborated the present proposal of the Biennial Technical Cooperation Plan 2024-2025 to consolidate the PHEFA.
Subject(s)
Veterinary Public Health , Foot-and-Mouth Disease , Disease EradicationABSTRACT
[Introducción] El informe presenta un resumen de las acciones para la erradicación y prevención de la Fiebre Aftosa (FA) en Sudamérica y Panamá, que incluye una evaluación del cumplimiento de las resoluciones de la 49ª COSALFA, celebrada el 25 de agosto de 2022, por parte de los países y del Centro Panamericano de Fiebre Aftosa y Salud Pública Veterinaria de la Organización Panamericana de la Salud/Organización Mundial de la Salud (PANAFTOSA/SPV-OPS/OMS). Además, se informa sobre las actividades generales de cooperación técnica, los resultados de acuerdos y proyectos, y los esfuerzos interinstitucionales y de colaboración con otras agencias de cooperación llevados a cabo por PANAFTOSA-OPS para apoyar a los países.
Subject(s)
Foot-and-Mouth Disease , Veterinary Public Health , South AmericaABSTRACT
[Introduction] The report of the ex officio Secretariat presents a summary of the actions taken for the eradication and prevention of foot-and-mouth disease (FMD) in South America and Panama during the period July 2022- December 2023. It includes an assessment of compliance with the resolutions of the 49th COSALFA, held on August 25, 2022, by the countries and the Pan American Center for Foot-and-Mouth Disease and Veterinary Public Health (PANAFTOSA/VPH-PAHO/WHO). Also, information is provided on general technical cooperation activities, the outcome of agreements and projects, and interinstitutional and collaborative efforts with other cooperation agencies undertaken by PANAFTOSA-PAHO in support of the countries. The regional situation of foot-and-mouth disease relies on the reports sent by the countries to PANAFTOSA-PAHO, and the information gathered by the Center, complemented by analyses of relevant data published in several media. The compliance with Resolutions is assessed based on the information gathered by the ex officio Secretariat within the framework of the commitments to the Hemispheric Program for the Eradication on Foot-and-Mouth Disease (PHEFA), and it can be improved with the contributions of delegates
Subject(s)
Foot-and-Mouth Disease , Veterinary Public HealthABSTRACT
La modalidad de financiación para la cooperación técnica de PANAFTOSA/OPS para el PHEFA se basa en el aporte por parte de la OPS de los profesionales internacionales responsables del área de Fiebre Aftosa (FA) y del laboratorio de referencia y en los recursos obtenidos por el material de referencia suministrado a los países. Se incluye, además, un modelo de contribuciones voluntarias vinculadas a proyectos específicos con países. Por lo tanto, lo mencionado anteriormente se refleja en los costos referidos para este Plan Bienal 2024-2025. Los resultados esperados del mencionado plan contribuirán a las metas previstas en el Plan de Acción 2021-2025 del PHEFA, con una visión de prioridades por parte de PANAFTOSA/OPS que toma en cuenta las resoluciones de la COSALFA, que apunta a preparar a los países para la fase final del PHEFA. Con base en estas directrices, y considerando la situación actual, PANAFTOSA/OPS ha elaborado la presente propuesta de Plan Bienal 2024-2025 de cooperación técnica para consolidación del PHEFA.
Subject(s)
Foot-and-Mouth Disease , Disease Eradication , Pan American Foot-and-Mouth Disease CenterABSTRACT
Foot-and-mouth disease is a highly contagious disease that affects cloven-hoofed animals. It has an important socio-economic impact on the livestock industry because it produces a drastic decrease of productivity. The disease has been successfully eradicated from some regions, including North America and Western Europe, but it is still endemic in developing countries. Agriculture plays an important role in the national economy of Vietnam, to which animal production contributes a great proportion. The concurrent circulation of foot-and-mouth disease virus (FMDV) serotypes O, A, and Asia 1 has been detected in recent years, but serotype O remains the most prevalent and is responsible for the highest numbers of outbreaks. Appropriate vaccine strain selection is an important element in the control of FMD and is necessary for the application of vaccination programs in FMD-affected regions. Here, we present updated information about the genetic and antigenic characteristics of circulating strains, collected from endemic outbreaks involving types O and A, between 2010 and 2019. Neutralizing assays showed a good in vitro match between type O strains and the monovalent O1 Campos vaccine strain. High r1 values were obtained (above 0.7) when testing a swine serum pool collected 21 days after vaccination, but the O/VTN/2/2019 strain was an exception. An EPP estimation resulted in a median neutralizing titre of about 1.65 log10, indicating that good protection could be achieved. For type A Asia SEA 97 lineage strains, acceptable individual neutralizing titres were obtained with estimated EPP values over 80% for different combinations of vaccine strains. Taking into account that the r1 value is one tool of a battery of tests that should be considered for estimating the cross-protection of a field strain against a vaccine strain, an in vivo challenge experiment was also performed, yielding a PD50 value of 8.0. The results indicate that South American strains could be potentially used for controlling outbreaks involving these lineages. This study demonstrates the importance of considering strain characteristics when choosing vaccine strains and controls.
Subject(s)
Foot-and-Mouth Disease Virus , Foot-and-Mouth Disease , Viral Vaccines , Animals , Swine , Vietnam/epidemiology , Viral Vaccines/genetics , Foot-and-Mouth Disease/epidemiology , Foot-and-Mouth Disease/prevention & control , Antigens, Viral/genetics , SerogroupABSTRACT
Fasciola hepatica, a worldwide distributed helminth, has a robust immunoregulatory effect in the host, increasing the susceptibility to secondary infections. Foot and mouth disease (FMD) is a highly contagious acute vesicular viral disease effectively controlled by vaccination in endemic regions. Despite the evidence of immunoregulatory effects, the impact of fasciolosis on the immune response induced by FMD vaccination in cattle has never been assessed. Our objective was to evaluate whether the infection by F. hepatica in cattle influences the long-term immunity elicited by the currently used commercial FMD-inactivated vaccines. Aberdeen Angus steers negative for F. hepatica were vaccinated twice against FMD virus (FMDV) during the first 6 months of age using a commercial oil vaccine formulated with A24/Cruzeiro and O1/Campos strains. When maternal antibodies against F. hepatica were weaned (18--20 months of age) animals were divided into groups of 12 and infected or mock-infected with 500 metacercariae/animal. Individual serum samples were collected at 0-, 28-, 59-, 87- and 157-days post-infection (dpi). Indirect ELISAs were used to detect A24/Cruzeiro specific bovine IgG and IgG subtypes. The total IgG antibody levels and avidity against FMDV did not show significant differences between all the groups. The commercial vaccine induced higher IgG2 than IgG1 titers in vaccinated animals. Anti-FMDV IgG1 levels significantly decreased in the infected group at 28 dpi. In addition, the avidity of IgG1 FMDV-specific antibodies at day 28 in the infected group was reduced compared to the control. These results show that F. hepatica infection modified anamnestic responses against FMDV, reducing serum IgG1 titers and avidity. To our knowledge, this is the first report of immune-regulation of F. hepatica altering the immune response of FMD vaccines, one of the most globally used animal vaccines.
Subject(s)
Cattle Diseases , Fasciola hepatica , Fascioliasis , Foot-and-Mouth Disease Virus , Foot-and-Mouth Disease , Viral Vaccines , Animals , Cattle , Immunoglobulin G , Antibodies, Viral , Foot-and-Mouth Disease/prevention & control , Fascioliasis/prevention & control , Fascioliasis/veterinary , Vaccination/veterinary , ImmunityABSTRACT
Foot and mouth disease is a highly contagious viral disease that poses a significant economic threat to cloven-hoofed animals, including cattle and sheep. The emergence of a novel foot and mouth disease virus-A isolate, FMDV-A-Egy-AHRI-RL385-Ven-2022, in Egypt in 2022 has raised concerns about its potential impact on existing vaccination programs. Given that vaccination is a key strategy for foot and mouth disease virus control, the present study was aimed to assess the cross-protective efficacy of both local and imported inactivated vaccines against this new threat. Through challenge experiments and serum neutralization tests, we observed limited effectiveness of both vaccine types. The calculated r1-values at 28 days post-vaccination indicated a minimal immune response to FMDV-A-Egy-AHRI-RL385-Ven-2022 (0.176 and 0.175 for local and imported vaccines, respectively). Challenge experiments further confirmed these findings, revealing 0percent protection from the local vaccine and only 20percent rotection from imported vaccines by day 7 post-challenge. These results underscore the urgent need to update existing foot and mouth disease virus vaccines in Egypt by incorporating the newly circulating FMDV-A-Egy-AHRI-RL385-Ven-2022 strain. This proactive measure is crucial to prevent future outbreaks and ensure effective disease control(AU)
La fiebre aftosa es una enfermedad vírica muy contagiosa que supone una importante amenaza económica para los animales biungulados, entre ellos el ganado vacuno y ovino. La aparición de un nuevo aislado del virus A de la fiebre aftosa, el FMDV-A-Egy-AHRI-RL385-Ven-2022, en Egipto en 2022 ha suscitado preocupación por su posible impacto en los programas de vacunación existentes. Dado que la vacunación es una estrategia clave para el control del virus de la fiebre aftosa, el objetivo del presente estudio fue evaluar la eficacia protectora cruzada de las vacunas inactivadas locales e importadas frente a esta nueva amenaza. Mediante experimentos de desafío y pruebas de seroneutralización, observamos una eficacia limitada de ambos tipos de vacuna. Los valores r1 calculados a los 28 días posvacunación indicaron una respuesta inmunitaria mínima frente a FMDV-A-Egy-AHRI-RL385-Ven-2022 (0,176 y 0,175 para las vacunas local e importada, respectivamente). Los experimentos de provocación confirmaron aún más estos resultados, revelando un 0 por ciento de protección de la vacuna local y sólo un 20 por ciento de protección de las vacunas importadas al séptimo día después de la provocación. Estos resultados subrayan la urgente necesidad de actualizar las vacunas existentes contra el virus de la fiebre aftosa en Egipto incorporando la nueva cepa circulante FMDV-A-Egy-AHRI-RL385-Ven-2022. Esta medida proactiva es crucial para prevenir futuros brotes y garantizar un control eficaz de la enfermedad(AU)
Subject(s)
Animals , Disease Outbreaks , Livestock , Foot-and-Mouth Disease/epidemiology , Vaccines , EgyptABSTRACT
Foot-and-mouth disease is responsible for severe economic losses to the livestock industry of Pakistan. This study aimed to use Swiss albino mice as a cost-effective experimental animal model to study different immunological and histopathological aspects of FMDV instead of natural targeted species like cattle. After isolation of field isolates FMDV on BHK-21 cell line, biological titer of the virus and mice infectious dose50 was calculated. Virus was injected in 45 Swiss albino mice (group A) through intraperitoneal route. The gross, histopathological and immunopathological lesions in heart, trachea and lungs were recorded at different day's intervals. Histopathologically, the heart showed congestion, hemorrhages and necrosis of cardiac muscles. Trachea showed deciliated epithelium and lungs showed hemorrhages, bronchial edema and alveolar emphysema. Immunohistochemical studies revealed the presence of virus in cardiac muscles, tracheal and bronchial epithelium and alveolar lumen. The findings evoked a thought that laboratory animals could be an alternative to large animals to meet budget limitations for further research on foot-and-mouth-disease.
A febre aftosa (FMD) é responsável por graves perdas econômicas para a indústria pecuária do Paquistão. Este estudo teve como objetivo usar camundongos albinos suíços como um modelo animal experimental de baixo custo para estudar diferentes aspectos imunológicos e histopatológicos do FMDV em vez de espécies naturais como o gado. Após o isolamento dos isolados de campo do FMDV na linhagem celular BHK-21, calculou-se o título biológico do vírus e a dose infecciosa dos camundongos50. O vírus foi injetado em 45 camundongos albinos suíços (grupo A) por via intraperitoneal. As lesões macroscópicas, histopatológicas e imunopatológicas no coração, traqueia e pulmões foram registradas em diferentes intervalos de dias. Histopatologicamente, o coração apresentava congestão, hemorragias e necrose dos músculos cardíacos. A traqueia apresentava epitélio deciliado e os pulmões apresentavam hemorragias, edema brônquico e enfisema alveolar. Estudos imuno-histoquímicos revelaram a presença de vírus em músculos cardíacos, epitélio traqueal e orçamentárias para pesquisas adicionais sobre a febre aftosa
Subject(s)
Rats , Foot-and-Mouth Disease Virus/pathogenicity , Foot-and-Mouth Disease , Animals, Laboratory/anatomy & histologyABSTRACT
Conmemorar los 50 años de las Reuniones Ordinarias de la Comisión Sudamericana de Lucha Contra la Fiebre Aftosa – COSALFA – es una ocasión propicia para conocer y reconocer el trabajo y los desafíos que enfrentamos en la construcción de esa historia. En esa edición especial en la cual presentamos el Resumen Histórico de la COSALFA 1973-2022, agradecimos especialmente la posibilidad de recorrer la historia de los resultados de esa Comisión que PANAFTOSA/OPS lideró para aportar a la construcción de memoria, pero fundamentalmente para poder pensar, mirando la realidad de hoy, qué nuevas formas puedan tomar y cuáles son los nuevos retos que hay por delante para alcanzar la erradicación de la fiebre aftosa en nuestro continente. Las alianzas estratégicas son fundamentales para configurar políticas y procesos de transformación eficaces. Esto queda notoriamente demostrado por la asociación que líderes visionarios promovieron al proponer la creación de esa Comisión en 1972 que fue acogida con entusiasmo por la Organización Panamericana de Salud (OPS). Claramente, las nuevas generaciones, las actuales y las por venir tienen y tenemos hoy la responsabilidad de que esto así suceda. Debemos continuar fortaleciéndonos sobre la base de nuestra historia, de lo que fueron construyendo los que nos antecedieron y lo que construimos en distintos escenarios de dirección en las diferentes organizaciones. Es allí donde nuestra cooperación tiene más vigencia que nunca: en el hoy, sustentado en el ayer y con perspectiva de futuro. Estos cincuenta años de colaboración permanente dan testimonio del perseverante trabajo de hombres y mujeres que han puesto lo mejor de sí para conseguir estos resultados. PANAFTOSA/OPS ha sido un pionero en la cooperación técnica entre los países. Medio siglo de historia demuestra que esta cooperación es necesaria y realizable y que se inspira en el trabajo en red, la solidaridad y la gestión del conocimiento.
Subject(s)
Veterinary Public Health , Foot-and-Mouth Disease , Technical CooperationABSTRACT
FMD remains endemic in many Asian and African countries where multiple variants of serotypes O and A, among others, currently circulate. Due to lack of cross-protection between serotypes and incomplete protection between some strains even within a serotype, an important challenge for the application of effective vaccination programs is to select highly immunogenic and widely cross-reactive vaccine strains. Adaptation of a candidate field virus for use as a vaccine can be quite complex, so that whenever possible, the use of well-established vaccine viruses could have enormous advantages. FMD vaccine strains harmonized for use in South America have shown excellent results in FMD control, not only in the region, where it is still used systematically as a preventive measure, but also more recently in some Asian countries. To gain further insight into the immunogenic spectrum of these strains, VN tests (VNT) were performed with sera from cattle and/or pigs vaccinated with monovalent (type O) or trivalent (types O and A) formulations against 122 type O and 32 type A field viruses isolated from 35 countries in Asia and Africa, belonging to different lineages. Almost all VNT titers obtained were within the expected protective level, indicating the wide immunogenic spectrum of high potency FMD vaccines formulated with O1 Campos, A24 Cruzeiro and A Argentina 2001 South American vaccine strains belonging to EURO-SA topotypes against currently active viruses from other topotypes. These in vitro results are in line with previously reported in vivo challenge tests in pigs against three A/ASIA/Sea-97 isolates and two isolates belonging to type O lineages O/SEA/Mya-98 and O/ME-SA/Ind-2001e.
Subject(s)
Cattle Diseases , Foot-and-Mouth Disease Virus , Foot-and-Mouth Disease , Viral Vaccines , Cattle , Animals , Swine , Foot-and-Mouth Disease/epidemiology , Argentina/epidemiology , Antigens, Viral , Serogroup , Antibodies, ViralABSTRACT
Quantitative risk assessment was used to estimate the risk of introducing foot-and-mouth disease (FMD) through bone-in beef from Argentina (FMD-free with vaccination status) into other FMD-free countries. A stochastic model was built to characterize all the steps from primary production to bone-in beef export and introduction into an FMD-free country. The probability that bone-in beef from at least one animal infected with the FMD virus (FMDV) was exported during a year was 5.27 × 10-3 (95% CI <10-10 - 5.19 x 10-2) or in other words one case in 190 years. The risk of FMDV introduction was sensitive to the probability of an outbreak occurring in Argentina (r [Spearman´s rank correlation] = 0.99) and the number of herds affected during an outbreak (r = 0.10). Additionally, the probability that susceptible animals in the importing country came into contact with infective material (bones) and generated an outbreak was 6.16 × 10-4 (95% CI <10-10 - 6.20 ×10-3) or one FMD outbreak every 1623 years on average. Based on the quantitative risk assessment results, the probability of FMDV introduction into a FMD-free country where vaccination is not practiced from a FMD-free country where vaccination is practiced associated with bone-in beef trade from Argentina was negligible. The risk of an FMD outbreak caused by the potential introduction of the FMDV was associated with the existing conditions in the country. Thus, maintaining the FMD-free status with or without vaccination would not be relevant.
Subject(s)
Cattle Diseases , Foot-and-Mouth Disease Virus , Foot-and-Mouth Disease , Animals , Cattle , Foot-and-Mouth Disease/epidemiology , Foot-and-Mouth Disease/prevention & control , Argentina/epidemiology , Risk Assessment , Vaccination/veterinary , Cattle Diseases/epidemiology , Cattle Diseases/prevention & controlABSTRACT
Nesta nota do Centro Pan-Americano de Febre Aftosa e Saúde Pública Veterinária é realizada uma análise comparativa entre os status estabelecidos pela Organização Mundial de Saúde Animal para febre aftosa, livre com vacinação e livre sem vacinação, com foco especial no uso da vacinação sistemática nos países sul-americanos.
Subject(s)
Foot-and-Mouth Disease , Vaccination , Veterinary Public HealthABSTRACT
The techinical note of the Pan American Center for foot-and-mouth disease and veterinary public health: Comparative analysis between with and without vaccination statuses is aimed at conducting a comparative analysis between the statuses established by WOAH for foot-and-mouth disease, free with vaccination and free without vaccination, with special focus on the use of systematic vaccination in South American countries. The foot-and-mouth disease vaccine has been a major cornerstone in the fight against the disease since the onset of the PHEFA. At present, the risk of disease is mainly concentrated in the Andean region, particularly in the Bolivarian Republic of Venezuela and the bordering region with the Republic of Colombia, which questions the need of maintaining systematic vaccination in the other disease-free countries of South America. The foot-and-mouth disease vaccine is a control tool, but it is not necessary to maintain in the foot-and-mouth disease-free zones as a prevention strategy. Besides, it should be remembered that it only provides protection against vaccine serotypes, while animals remain susceptible to other serotypes. Countries with robust surveillance systems and no cases for a long period of time can progress towards eradication, suspending vaccination and gaining the foot-and-mouth disease-free status without vaccination, as outlined in the PHEFA. Several differences exist between the two statuses, which are translated into two different epidemiological contexts, with different health requirements for trade, as showed in Chart 1. Thus, foot-and-mouth disease-free zones with vaccination require improved surveillance efforts since they should demonstrate the absence of both infection and transmission. Besides, these vaccinated populations are not the end of the eradication process, which is completed by eliminating control measures. These factors result in significant differences in the maintenance costs of the two statuses (Perry et al., 2020). Decision-makers in each country, both of the public and private sectors, should take into account available scientific and technical information to start a planned transition process and achieve disease eradication in their territories. The key to eradicating foot-and-mouth disease in South America has been the collaboration and coordination of countries, orchestrated under the umbrella of the PHEFA. Joint work is essential to achieve eradication in the entire continent. The countries should address the transition to the status of foot-and-mouth disease-free without vaccination in a responsible manner, grounded on available scientific and technical evidence, with transparency in all the involved sectors to seek alternatives that foster progress and ensure sustainability of the progress achieved so far.