Foot-and-mouth Disease Virus Research Articles

Foot-and-mouth disease attributed to serotype A in sheep flocksof Jammu and Kashmir, India

The present study investigates the suspected FMD outbreak in sheep flock in Jammu and Kashmir Union Territory of India during May 2021. Swab materials, saliva and serum samples from symptomatic and in-contact apparently healthy animals were collected. A total of 13, 41 and 15 serum samples from Beerwah Budgam, Poshnar sheep farm, and Gundipora/Shalkani Budgam and Dara Srinagar, respectively were collected. Also 360 serum samples were collected from the districts of Pulwama, Ananthnag, Shopian, Kupwara, Baramulla and Bandipora. The serum samples were subjected to the in-house indirect 3AB3 NSP ELISA, while the swab and saliva samples were processed and subjected to serotyping ELISA and multiplex RT-PCR. One sample from Gundipora/Shalkani Budgam and Dara Srinagar was found positive for FMDV serotype A in multiplex RT-PCR. FMD virus serotype A was last documented in Jammu and Kashmir pretty long years ago. In NSP serology, 53.8%, 26.8% and 33.3% serum samples from Beerwah Budgam, Poshnar farm and Gundipora/Shalkani Budgam and Dara Srinagar, respectively were found positive for 3AB NSP antibodies of FMDV. Further, 119 out of 360 (32.5%) serum samples collected from affected flock of different districts were also found positive for 3AB NSP antibodies suggesting a high level of virus circulation. Introduction of infected animals and intermixing of animals while sharing common pasture land followed by the unrestricted movement of diseased/ subclinically infected animals might have been the probable reason behind the origin and spread of the outbreak.

Chrysin Inhibits Indonesian Serotype Foot-and-Mouth-Disease Virus Replication: Insights from DFT, Molecular Docking and Dynamics Analyses

Chrysin, a predominant compound in Propolis, possesses diverse bioactivities, including antiviral properties. However, its antiviral efficacy against the Indonesian Foot-and-Mouth Disease Virus (FMDV) serotype remains unexplored. This study investigates Chrysin's inhibitory potential against FMDV Indonesian serotype by targeting the 3C Protease (3CP), a vital enzyme for viral replication. Multiple sequence alignment was used to reveal unique characteristics of the Indonesian serotype's 3CP compared to global serotypes. Density Functional Theory (DFT) calculations assessed Chrysin's interaction with 3CP based on electronegativity. Molecular docking and molecular dynamics analyses evaluated Chrysin's inhibitory activity against 3CP, using homology modeling for the Indonesian serotype's 3CP structure. Luteolin, a known FMDV 3CP inhibitor with a similar structure to Chrysin, served as a reference. Results showed distinct 3CP sequences in the Indonesian serotype compared to O serotypes and others. Chrysin exhibited potential electron-donor activity with lower HOMO and LUMO values than Luteolin, but they had similar energy gaps, i.e., 4.016 and 4.044 eV, respectively. Molecular docking indicated similar binding affinities, with Chrysin (-6.365 kcal/mol) and Luteolin (-6.864 kcal/mol) bound to active site residues. Molecular dynamics analysis demonstrated stable 3CP-Chrysin and 3CP-Luteolin complexes, with minor differences in Radius of gyration (Rg) and Root-Mean-Square Fluctuation (RMSF) below 1 Å. From the ligand stability point of view, Chrysin had comparable stability with Luteolin. However, Chrysin formed fewer hydrogen bonds and displayed greater free-binding energy than Luteolin during simulation periods. These findings suggest that Chrysin holds promise as an inhibitor of the Indonesian serotype's FMDV 3C Protease.

Inferring transmission routes for foot-and-mouth disease virus within a cattle herd using approximate Bayesian computation

To control an outbreak of an infectious disease it is essential to understand the different routes of transmission and how they contribute to the overall spread of the pathogen. With this information, policy makers can choose the most efficient methods of detection and control during an outbreak. Here we assess the contributions of direct contact and environmental contamination to the transmission of foot-and-mouth disease virus (FMDV) in a cattle herd using an individual-based model that includes both routes. Model parameters are inferred using approximate Bayesian computation with sequential Monte Carlo sampling (ABC-SMC) applied to data from transmission experiments and the 2007 epidemic in Great Britain. This demonstrates that the parameters derived from transmission experiments are applicable to outbreaks in the field, at least for closely related strains. Under the assumptions made in the model we show that environmental transmission likely contributes a majority of infections within a herd during an outbreak, although there is a lot of variation between simulated outbreaks. The accumulation of environmental contamination not only causes infections within a farm, but also has the potential to spread between farms via fomites. We also demonstrate the importance and effectiveness of rapid detection of infected farms in reducing transmission between farms, whether via direct contact or the environment.

Detection of foot-and-mouth disease viruses from the A/AFRICA/G-I genotype in the Sultanate of Oman

Rapid identification and characterization of circulating foot-and-mouth disease virus (FMDV) strains is crucial for effective disease control. In Oman, a few serological and molecular studies have been conducted to identify the strains of FMDV responsible for the outbreaks that have been occurring within the country. In this study, 13 oral epithelial tissue samples from cattle were collected from suspected cases of FMD in Ash Sharqiyah North, Al Batinah North, Dhofar and Ad Dhakhyilia governorates of Oman between 2018 and 2021. FMDV RNA was detected in all samples by real-time RT-PCR and viruses were isolated after one- or two-blind passages in the porcine Instituto Biologico-Rim Suino-2 cell line. Antigen capture ELISA characterized all isolates as serotype A and VP1 phylogenetic analysis placed all sequences within a single clade of the G-I genotype within the A/AFRICA topotype. These sequences shared the closest nucleotide identities to viruses circulating in Bahrain in 2021 (93.5% to 99.5%) and Kenya in 2017 (93.4% to 99.1%). To the best of our knowledge, this is the first time that A/AFRICA/G-I viruses have been detected in Oman. Together with the closely related viruses detected recently in Bahrain, these findings reinforce the importance of deploying effective quarantine control measures to minimize the risks of transboundary transmission of FMD associated with the importation of cattle from East Africa.

Susceptibility of primary ovine dorsal soft palate and palatine tonsil cells to FMDV infection.

Foot and mouth disease (FMD) is a highly contagious viral disease affecting cloven-hoofed animals. This disease is one of the most important in animal health due to its significant socio-economic impact, especially in case of an outbreak. One important challenge associated with this disease is the ability of the FMD virus (FMDV) to persist in its hosts through still unresolved underlying mechanisms. The absence of relevant in vitro models is one factor preventing advancement in our understanding of FMDV persistence. While a primary bovine cell model has been established using cells from FMDV primary and persistence site in cattle, it appeared interesting to develop a similar model based on ovine anatomical sites of interest to compare host-pathogen interactions. Thus, epithelial cells derived from the palatine tonsils and the dorsal soft palate were isolated and cultured. Their epithelial nature was confirmed using immunofluorescence. Following monolayer infection with FMDV O/FRA/1/2001 Clone 2.2, the FMDV-sensitivity of these cells was evaluated. Dorsal soft palate (DSP) cells were also expanded in multilayers at the air-liquid interface to mimic a stratified epithelium sensitive to FMDV infection. Our investigation revealed the presence of infectious virus, as well as viral antigens and viral RNA, up to 35 days after infection of the cell multilayers. Further experiment with DSP cells from different individuals needs to be reproduced to confirm the robustness of the new model of persistence in multilayer DSP. The establishment of such primary cells creates new opportunities for FMDV research and analysis in sheep cells.

Multiple pathogens co-exposure and associated risk factors among cattle reared in a wildlife-livestock interface area in Kenya.

Understanding multi-pathogen infections/exposures in livestock is critical to inform prevention and control measures against infectious diseases. We investigated the co-exposure of foot-and-mouth disease virus (FMDV), Brucella spp., Leptospira spp., and Coxiella burnetii in cattle in three zones stratified by land use change and with different wildlife-livestock interactions in Narok county, Kenya. We also assessed potential risk factors associated with the transmission of these pathogens in cattle. We identified five villages purposively, two each for areas with intensive (zone 1) and moderate wildlife-livestock interactions (zone 2) and one for locations with low wildlife-livestock interactions (zone 3). We sampled 1,170 cattle from 390 herds through a cross-sectional study and tested the serum samples for antibodies against the focal pathogens using enzyme-linked immunosorbent assay (ELISA) kits. A questionnaire was administered to gather epidemiological data on the putative risk factors associated with cattle's exposure to the investigated pathogens. Data were analyzed using the Bayesian hierarchical models with herd number as a random effect to adjust for the within-herd clustering of the various co-exposures among cattle. Overall, 88.0% (95% CI: 85.0-90.5) of the cattle tested positive for at least one of the targeted pathogens, while 41.7% (95% CI: 37.7-45.8) were seropositive to at least two pathogens. FMDV and Brucella spp. had the highest co-exposure at 33.7% (95% CI: 30.9-36.5), followed by FMDV and Leptospira spp. (21.8%, 95% CI: 19.5-24.4), Leptospira spp. and Brucella spp. (8.8%, 95% CI: 7.2-10.6), FMDV and C. burnetii (1.5%, 95% CI: 0.7-2.8), Brucella spp. and C. burnetii (1.0%, 95% CI: 0.3-2.2), and lowest for Leptospira spp. and C. burnetii (0.3%, 95% CI: 0.0-1.2). Cattle with FMDV and Brucella spp., and Brucella spp. and Leptospira spp. co-exposures and those simultaneously exposed to FMDV, Brucella spp. and Leptospira spp. were significantly higher in zone 1 than in zones 2 and 3. However, FMDV and Leptospira spp. co-exposure was higher in zones 1 and 2 than zone 3. We recommend the establishment of a One Health surveillance system in the study area to reduce the morbidity of the targeted zoonotic pathogens in cattle and the risks of transmission to humans.

Fasciola hepatica infection modifies IgG1 specific immune response to foot-and-mouth disease virus induced by vaccination

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.

Analysis of Coinfection Pathogens From Foot‐and‐Mouth Disease Virus Persistently Infected Cattle Using Oxford Nanopore Sequencing

The persistent infection caused by foot‐and‐mouth disease virus (FMDV) still lacks a reliable explanation, as its etiology and maintenance are intricate and potentially involve concurrent infections with multiple pathogens. In this study, we utilized the nanopore platform for direct sequencing of clinical samples obtained from cattle persistently infected with FMDV serotype O and investigated the distribution characteristics of coinfecting pathogens in their pharyngeal region. Briefly, we exploited Oxford Nanopore sequencing technology to generate high‐quality and sufficient sequence data for the comprehensive characterization of microbial genomes. Furthermore, we performed sequence comparison, alignment, and phylogenetic tree construction. Our findings revealed a total of 23 viruses in FMDV carrier bovine, with FMDV, bovine orthopneumovirus, and Choristoneura fumiferana granulovirus emerging as the top three identified pathogens. The analysis unexpectedly revealed the presence of porcine circovirus type 2 and pepper mild mottle virus among the viral genes detected in the bovine FMDV carrier. Compared to noncarrier, carrier bovine of FMDV exhibited a greater diversity and abundance of mycoplasma types as well as reads counts. Therefore, we propose that the establishment and perpetuation of persistent FMDV infection may be attributed to the simultaneous presence of other viral agents and mycoplasmas. These findings highlight the significance of investigating multipathogen coinfection in elucidating the etiology of persistent FMD virus infection.

Direct RNA Sequencing of Foot-and-mouth Disease Virus Genome Using a Flongle on MinION.

Foot-and-mouth disease (FMD) is a severe and extremely contagious viral disease of cloven-hoofed domestic and wild animals, which leads to serious economic losses to the livestock industry globally. FMD is caused by the FMD virus (FMDV), a positive-strand RNA virus that belongs to the genus Aphthovirus, within the family Picornaviridae. Early detection and characterization of FMDV strains are key factors to control new outbreaks and prevent the spread of the disease. Here, we describe a direct RNA sequencing method using Oxford Nanopore Technology (ONT) Flongle flow cells on MinION Mk1C (or GridION) to characterize FMDV. This is a rapid, low cost, and easily deployed point of care (POC) method for a near real-time characterization of FMDV in endemic areas or outbreak investigation sites. Key features • Saves ~35 min of the original protocol time by omitting the reverse transcription step and lowers the costs of reagents and consumables. • Replaces the GridION flow cell from the original protocol with the Flongle, which saves ~90% on the flow cell cost. • Combines the NGS benchwork with a modified version of our African swine fever virus (ASFV) fast analysis pipeline to achieve FMDV characterization within minutes. Graphical overview Schematic of direct RNA sequencing of foot-and-mouth disease virus (FMDV) process, which takes ~50 min from extracted RNA to final loading, modified from the ONT SQK-RNA002 protocol (Version: DRS_9080_v2_revO_14Aug2019).

Effect of different inactivants and preservatives on the stability of 146S fraction of foot-and-mouth diseases virus.

Foot-and-mouth disease virus (FMDV) cripples livestock by imparting devastating effects to economy. A good vaccine is the key to stopping it, but due to instability of 146S of FMDV, it is becoming difficult. This is bad because only 146S can fight against disease and its dissociation ultimately leads to decreased potency of vaccine. This study aimed to preserve the integrity of 146S in vaccine using different inactivators and preservatives. Foot-and-mouth Disease virus type 'O' was propagated on baby hamster kidney 21 cell lines and inactivated using formalin or binary ethylenimine (BEI). Size exclusion high performance liquid chromatography analysis revealed minimal 146S loss after double inactivation with formalin and BEI. This inactivated virus was further formulated into oil-based vaccine with sodium thiomersal or chloroform as a preservative. Our findings demonstrated that chloroform outperformed thiomersal in maintaining shelf life of vaccine. This claims that the combined approach of double inactivation with formalin and BEI followed by chloroform as preservative offered a promising strategy for developing efficacious FMDV.

Beyond the Magic of Moringa oleifera: Its Potential to Control Indonesian Serotype of Footand-Mouth-Disease Virus Replication through Inhibition of 3-Cysteine Protease

Foot-and-Mouth Disease (FMD) poses a significant threat to livestock worldwide, necessitating innovative approaches to combat its causative agent, the FMD virus (FMDV). On the other hand, Moringa oleifera is a feed alternative for cattles with numerous bioactive compounds. This paper delves into the captivating realm of Moringa oleifera (MO) bioactives and their potential in thwarting FMDV replication by targeting the essential enzyme, 3C Protease (3CP). To elucidate the inhibitory potential of these bioactives, a rigorous investigation involving molecular docking and molecular dynamics simulations was conducted. Specifically, the 3CP was modeled based on the amino acid sequence of FMDV Indonesian Serotype. Results showed that most of the compounds from MO outperformed Ribavirin as the standard therapy for FMD. Among them, Baicalin, Chlorogenic Acid, and Rutin have binding affinity -9.1, -8.1, and -8.1 kcal/mol, respectively. Those compounds also formed more hydrogen bonds than Ribavirin through their binding sites. Molecular dynamics simulation also revealed that interaction of 3CP with those compounds had minor influence on its structural stability. The conformation of those compounds is also more stable than Ribavirin, supported by more hydrogen bonds. In summary, this research highlighted the potential mechanism of MO bioactives in preventing severe FMDV infection through inhibition of viral replication.

Evaluation of vaccine efficacy with 2B/T epitope conjugated porcine IgG-Fc recombinants against foot-and-mouth disease virus.

The inactivated vaccine is effective in controlling foot-and-mouth disease (FMD), but it has drawbacks such as the need for a biosafety level 3 laboratory facility to handle live foot-and-mouth disease virus (FMDV), high production costs, and biological safety risks. In response to these challenges, we developed a new recombinant protein vaccine (2BT-pIgG-Fc) containing porcine IgG-Fc to enhance protein stability in the body. This vaccine incorporates two-repeat B-cell and one-single T-cell epitope derived from O/Jincheon/SKR/2014. Our study confirmed that 2BT-pIgG-Fc and a commercial FMDV vaccine induced FMDV-specific antibodies in guinea pigs at 28 days post-vaccination. The percentage inhibition (PI) value of 2BT-pIgG-Fc was 90.43%, and the commercial FMDV vaccine was 81.75%. The PI value of 2BT-pIgG-Fc was 8.68% higher than that of commercial FMDV vaccine. In pigs, the primary target animals for FMDV, all five individuals produced FMDV-specific antibodies 42 days after vaccination with 2BT-pIgG-Fc. Furthermore, serum from 2BT-pIgG-Fc-vaccinated pigs exhibited neutralizing ability against FMDV infection. Intriguingly, the 2BT-pIgG-Fc recombinant demonstrated FMDV-specific antibody production rates and neutralization efficiency similar to commercial inactivated vaccines. This study illustrates the potential to enhance vaccine efficacy by strategically combining well-known antigenic domains in the development of recombinant protein-based vaccines.

Extracellular vesicles derived from antigen-presenting cells pulsed with foot and mouth virus vaccine-antigens act as carriers of viral proteins and stimulate B cell response.

Foot and mouth disease (FMD) is a highly contagious infection caused by FMD-virus (FMDV) that affects livestock worldwide with significant economic impact. The main strategy for the control is vaccination with FMDV chemically inactivated with binary ethylenimine (FMDVi). In FMDV infection and vaccination, B cell response plays a major role by providing neutralizing/protective antibodies in animal models and natural hosts. Extracellular vesicles (EVs) and small EVs (sEVs) such as exosomes are important in cellular communication. EVs secreted by antigen-presenting cells (APC) like dendritic cells (DCs) participate in the activation of B and T cells through the presentation of native antigen membrane-associated to B cells or by transferring MHC-peptide complexes to T cells and even complete antigens from DCs. In this study, we demonstrate for the first time that APC activated with the FMDVi O1 Campos vaccine-antigens secrete EVs expressing viral proteins/peptides that could stimulate FMDV-specific immune response. The secretion of EVs-FMDVi is a time-dependent process and can only be isolated within the first 24 h post-activation. These vesicles express classical EVs markers (CD9, CD81, and CD63), along with immunoregulatory molecules (MHC-II and CD86). With an average size of 155 nm, they belong to the category of EVs. Studies conducted in vitro have demonstrated that EVs-FMDVi express antigens that can stimulate a specific B cell response against FMDV, including both marginal zone B cells (MZB) and follicular B cells (FoB). These vesicles can also indirectly or directly affect T cells, indicating that they express both B and T epitopes. Additionally, lymphocyte expansion induced by EVs-FMDVi is greater in splenocytes that have previously encountered viral antigens in vivo. The present study sheds light on the role of EVs derived from APC in regulating the adaptive immunity against FMDV. This novel insight contributes to our current understanding of the immune mechanisms triggered by APC during the antiviral immune response. Furthermore, these findings may have practical implications for the development of new vaccine platforms, providing a rational basis for the design of more effective vaccines against FMDV and other viral diseases.

The Pathogenesis of Foot-and-Mouth Disease Virus Infection: How the Virus Escapes from Immune Recognition and Elimination.

Foot-and-mouth disease virus (FMDV) is a highly contagious and economically devastating pathogen that affects cloven-hoofed animals worldwide. FMDV infection causes vesicular lesions in the mouth, feet, and mammary glands, as well as severe systemic symptoms such as fever, salivation, and lameness. The pathogenesis of FMDV infection involves complex interactions between the virus and the host immune system, which determine the outcome of the disease. FMDV has evolved several strategies to evade immune recognition and elimination, such as antigenic variation, receptor switching, immune suppression, and subversion of innate and adaptive responses. This review paper summarizes the current knowledge on the pathogenesis of FMDV infection and the mechanisms of immune evasion employed by the virus. It also discusses the challenges and opportunities for developing effective vaccines and therapeutics against this important animal disease.

A Fluorescent Immunochromatography Test Strip for the Rapid Identification of SVV and FMDV

Seneca Valley virus (SVV) and foot‐and‐mouth disease virus (FMDV) belong to the Picornaviridae family, which can cause similar symptoms. After infection, pigs will develop fever; loss of appetite; blister lesions on the skin and mucous membrane of the mouth, nose, and hoof; and other similar diseases, and the spread is very fast, causing major economic losses to the pig industry. Therefore, a rapid, accurate, and sensitive diagnostic method is necessary to enable rapid prevention and control measures for preventing the spread of these diseases. Here, a fluorescent immunochromatography test strip, using Eu‐doped fluorescence beads and monoclonal antibody, was developed for the simultaneous determination of FMDV and SVV. The test process for the assay could be completed in 12 min, which avoided the time cost of the current methods for FMDV/SVV detection. Under optimized conditions, the limit of detection of SVV is 5 × 104 PFU/mL, and that of FMDV is 5 × 104 PFU/mL under the Fluorescence Immunoassay Analyzer. Our assay results showed a good linear correlation with RT‐PCR installed in the clinical laboratory. The species design has a promising application prospect in the surveillance and control of the outbreak of idiopathic blister.

Detection of antibodies against structural proteins of foot-and-mouth disease virus in bovines of western Uttar Pradesh, India.

Foot-and-mouth disease (FMD) is considered as one of the most important contagious viral diseases affecting cloven-footed animals. For effective control of FMD, immunization along with herd immunity is essential in the field conditions. To assure and track the coverage and effectiveness of the vaccination program, the serological studies are very much required after the vaccination program. The present study was aimed to investigate the prevalence of antibodies against structural proteins of FMD virus (FMDV) serotypes of O, A and Asia-1 in seven districts of western Uttar Pradesh, India, and assure the efficacy of vaccination under National Animal Disease Control Program. A total of 308 sera samples were collected from apparent healthy vaccinated cattle and buffaloes from seven districts including Amroha, Baghpat, Bareilly, Bulandsahar, Gautam Budh Nagar, Meerut and Muzaffarnagar of western Uttar Pradesh, India. Determination of antibodies against structural proteins of FMDV was carried out using solid-phase blocking enzyme-linked immunosorbent assay. The protective level of the FMDV serotypes O, A and Asia-1 included in the inactivated trivalent vaccine was 66.55, 48.05 and 47.08% in bovines, respectively. To provide the higher level of protection against the circulating FMDV, the present study recommended the thorough investigation of the immunogenic interaction between the vaccine strains and the field strains. Further investigations should also be conducted with larger sample size and across diverse geographical regions to gain a more comprehensive understanding of herd immunity.

Comparação de sete differentes RT-qPCR para detecção do virus da febre aftosa

Abstract The prompt and accurate diagnosis of foot-and-mouth disease outbreaks is crucial to curb the swift transmission of its causative agent, the foot-and-mouth disease virus (FMDV), which poses a substantial threat to the nation’s livestock. This study aimed to perform a comparative analysis of various RT-qPCR methods for the detection of FMDV. The methods evaluated for the 3D region demonstrated similar sensitivity and specificity. Nevertheless, noticeable distinctions emerged in samples with low RNA concentration. While these methods can be interchangeably utilized with consistent outcomes when handling a large number of samples sent to the laboratory to pinpoint an outbreak, minor variations may assume significance when working with a limited quantity of samples containing low FMDV RNA copies.

Investigation of the association between foot-and-mouth disease clinical signs and abattoir serological data in large ruminants in northern Lao People's Democratic Republic.

Foot-and-mouth disease (FMD) is a highly infectious and endemic disease in Lao PDR. However, surveillance is weak, and outbreaks are not routinely reported. To address this, serum samples were routinely collected from cattle and buffalo from provincial abattoirs between November 2021 and December 2022. A total of 2,663 serum samples were collected from large ruminants (n = 1,625 cattle; n = 1,038 buffalo) from 17 provinces. Samples were tested for specific antibodies directed against FMD non-structural protein (NSP) to determine the proportion of animals exposed to FMD virus. In addition to sampling from abattoirs, further independent data was collected to report clinical signs and outcomes from 94 districts in 12 northern provinces. These incident reports were recorded by district staff using a Google Form and summarised monthly in the National Animal Disease Reporting System. Information was collected on species, incident date, herd size, location and which clinical signs the animals presented. Overall, 46% of the tested animals returned a positive result using ID Screen® FMD NSP Competition ELISA. Results from serological testing were then compared with reported clinical signs from the same district. In districts reporting 'mouth problems' (regardless of other clinical signs) the median FMD seroprevalence was 49.7%, compared to 31.6% in districts not reporting mouth problems (p = 0.021). This finding suggests that reporting clinical cases of 'mouth problems' could be a potential predictor of FMD infection at a district level in cattle and buffalo in Lao PDR. Furthermore, in districts reporting 'fever', 'mouth problems', and 'nose/mouth secretions' together, the median FMD seroprevalence was 46.2%, compared to 24.4% in districts not reporting these signs (p = 0.033). In districts reporting 'mouth problems' and 'nose/mouth secretions' the median FMD seroprevalence was 49.4%, compared to 25.5% in districts not reporting these signs (p = 0.037). In districts reporting both 'fever' and 'mouth problems,' the median FMD seroprevalence was 46.4% compared to 25% in districts not reporting these signs (p = 0.017). Based on serological data generated by abattoir surveillance, this study identified clinical signs most predictive of FMD seroprevalence. These novel findings can be used to guide passive surveillance efforts in the future specifically in northern Laos and help support improved FMD surveillance more broadly in FMD endemic countries in Southeast Asia.

A STUDY ON HOMOLOGY AND HETEROLOGY BETWEEN PANASIA-II & PAK-98 LINEAGES OF FOOT AND MOUTH DISEASE VIRUS SEROTYPE-O

To understand the dynamics of epidemics, it is crucial to evaluate prior exposure to infectious diseases as a possible defense against newly developing strains. The cross-protection prediction is unresolved matter that holds great importance, particularly in the field of Foot-and-Mouth Disease Virus (FMDV). The new methods for controlling FMD involve the implementation of vaccine, limited movement, containment and elimination of cattle that are either affected or vulnerable to the disease. Therefore, it is necessary to use a serological analysis strategy that applies association coefficients (r1-values) to identify effective vaccines. The primary objective of this study was aimed to explain the genetic homologous and heterologous association among two ancestries of FMDV serotype O found in Pakistan (Pk) and to find a suitable strain from field for selection of vaccinated seed that provide cross-protection against both ancestries. Virus neutralization tests (VNTs) were used to evaluate an antigenic association among the two groups of viruses, indicates a significant degree of antigenic similarity between stains within a particular cluster. Conversely, r1 values ranging from 0.07-0.2 were obtained from cross-combinations among clusters, suggesting antigenic variation amongst virus strains. These results were further supported by in vitro tests, which showed that heterologous combinations of PanAsia-II and PAK-98 isolates showed antigenic variation, except for 25-06-PK-19, SDG-43-FSD-PK, and TANWL-34PK, which showed a 0.3 (r1 value). In contrast, when considering homologous combination of strains from both lineages showed antigenic similarity. Furthermore, it was projected that these combinations would provide protective titers during in-vivo. As a conclusion, it is recommended that all strains, except 25-06-PK-19, SDG-43-FSD-PK, and TANWL-34PK considered as potential vaccine candidates for effectively managing outbreaks of FMDV serotype-O, due to their ability to confer broad-spectrum immunity.

Foot and Mouth Disease (FMD): Etiology, Pathogenesis, Prevention and Control in Even or Split Hoofed Livestock

Foot and Mouth Disease (FMD) was first reported in 1987 in Malang, East Java, caused by imported dairy cattle from the Netherlands. After 36 years of FMD freedom, the disease was re-introduced on 5 May 2022 in East Java. The disease is caused by a virus of the genus Aphthovirus of the Picornaviridae family, which affects even-toed or split-hoofed livestock, both wild and domesticated. Transmission of FMD virus from sick animals to other susceptible animals can occur directly and indirectly. FMD virus can be transmitted rapidly, entering the animal's body directly through the mouth or nose and replicating in epithelial cells in the nasopharyngeal area, then entering the blood (viremia), then multiplying in lymphoglandular glands and epithelial cells in the mouth and footpads resulting in vesicle lesions and blisters. Animals or livestock infected with FMD will show clinical symptoms such as fever up to 41oC, the formation of vesicles or blisters on the mouth, gums, tongue, nipples, and skin around the hooves, hypersalivation, weight loss, and livestock production. Handling and controlling FMD in livestock or animals can be done by isolating and quarantining sick animals, vaccination programs, biosecurity measures in animal husbandry, monitoring livestock traffic, and conducting surveillance.