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Foot-and-mouth disease (FMD) is a contagious viral disease that affects the livelihoods and productivity of livestock farmers in endemic regions. It can infect various domestic and wild animals with cloven hooves and is caused by a virus belonging to the genus Aphthovirus and family Picornaviridae , which has seven different serotypes: A, O, C, SAT1, SAT2, SAT3, and Asia-1. This paper aims to provide a comprehensive overview of the molecular epidemiology, economic impact, diagnosis, and control measures of FMD in Ethiopia in comparison with the global situation. The genetic and antigenic diversity of FMD viruses requires a thorough understanding for developing and applying effective control strategies in endemic areas. FMD has direct and indirect economic consequences on animal production. In Ethiopia, FMD outbreaks have led to millions of USD losses due to the restriction or rejection of livestock products in the international market. Therefore, in endemic areas, disease control depends on vaccinations to prevent animals from developing clinical disease. However, in Ethiopia, due to the presence of diverse antigenic serotypes of FMD viruses, regular and extensive molecular investigation of new field isolates is necessary to perform vaccine-matching studies to evaluate the protective potential of the vaccine strain in the country.

Foot-and-mouth disease (FMD) is a highly contagious viral disease of livestock that has a significant economic impact on the country. The inactivated vaccine is the most widely used type of FMD vaccine, with the inactivation procedure being one of the most crucial steps. This study aims to evaluate the inactivation kinetics and post-vaccination immune responses of FMD vaccine developed using three inactivation methods: binary ethyleneimine (BEI), formaldehyde, and a combined approach. A randomized controlled trial included 20 healthy, unvaccinated calves, allocating five calves to each of the three vaccinated groups and one control (unvaccinated) group. A monovalent inactivated FMDV vaccine (O-ETH/38/2005) was developed using the above three inactivation methods. Each prepared vaccine was then randomly administered to seronegative experimental calves. Blood samples were collected at 0, 7, 14, 21, 28, and 42 days post-vaccination and analyzed using solid-phase competitive enzyme-linked immunosorbent assay to assess the antibody response level. Regression analysis demonstrated that both the combined and BEI-inactivated vaccines exhibited linear kinetics, with higher and comparable virus titer reduction rates of 1.27 and 1.05 log 10 TCID 50 per hour, respectively. The formaldehyde-inactivated vaccine exhibited curvilinear kinetics with a slower rate of 0.34 log10 TCID 50 per hour. This demonstrated that methods for virus inactivation lead to significant variability in the antibody responses induced by the vaccine. Significantly higher antibody titer ( p  = 0.006) was found in a vaccine inactivated by combined methods compared to those inactivated using formaldehyde. Comparative analysis revealed no significant difference in antibody responses between combination-inactivated and BEI-inactivated vaccines ( p  = 0.696). This study revealed that the combined approach has faster inactivation and better immune induction. Thus, It is recommended to replace formalin with a combined inactivant following optimization and validation of strain-specific inactivation procedures to enhance FMD vaccine efficiency.

Background and Aim: Foot-and-mouth disease (FMD) is endemic in several developing countries and affects poor farmers through loss of production, death of diseased animals, and loss of animal byproducts. Forty-three samples were collected from 12 sites of five geographical located areas from suspected FMD virus (FMDV)-infected cattle during 2018. This study aimed to isolate and characterize the FMDVs using reverse transcription-polymerase chain reaction (RT-PCR) and gene sequencing. Materials and Methods: Forty-three FMDV-suspected clinical samples cultured on BHK-21 cell were examined, followed by virus serotype identification using RT-PCR and gene sequencing. Results: Twenty-nine (67.44%) samples were cultured on BHK-21 cell, of which 14 (32.56%) were not isolated; the 43 samples were analyzed using FMDV screening primers and serotype-specific primers. The contribution of the disease-causing serotype was serotype O of 8 (18.60%) samples, serotype A of 20 (46.51%) samples, and mixed infection (O and A) of 1 (2.33%) sample. Serotypes O and A were further characterized by phylogenetic analysis, which grouped them under East Africa 3 and Africa topotypes of genotype IV, respectively. Interestingly, serotype A was isolated for the 1st time from Keyet sub-woreda and Mulo woreda of Ethiopia, and mixed serotypes (O and A) were identified from the purchased animal. Conclusion: Molecular test result, sequencing, and phylogenetic tree reconstruction analysis revealed that the 2018 FMD outbreak in Ethiopia was caused by FMDV serotypes O and A. FMDV serotype A was the predominant strain circulating in most study areas of the country. Infections in one sample with mixed serotypes of O and A were also reported. The authors recommend a vaccine matching study of those field isolated viruses with the vaccine strain.

The aim of this study was to assess the vaccine-matching and antigenic properties of foot-and-mouth disease virus (FMDV) isolates collected from Ethiopia between 2011 and 2014. Samples (n = 51) were collected from cattle and pigs with clinical signs consistent with foot-and-mouth disease (FMD) on farms in Debre-Berhan, Debre-Zeit/Bishoftu, Sidamo, Mekelle, and Addis Ababa. Infectious FMDV was isolated using BHK-21 cell cultures from 38 of the 51 field samples (74.5%). All of these FMDV-positive samples were characterized as serotype O, belonging to two East Africa topotypes (EA-3 and EA-4), and their VP1-encoding sequences demonstrated amino acid sequence variability encompassing 27 positions in comparison to the vaccine strain (O/ETH/38/2005) currently provided by the National Veterinary Institute of Ethiopia. One-dimensional virus neutralization test (1 dm VNT) results showed that O/ETH/38/2005 was antigenically matched to 10 of the 16 serotype O viruses. These findings indicate that the O/ETH/38/2005 vaccine strain can provide protection against outbreaks caused by the O/EA-3 topotype, although poorer vaccine-matching results for the O/EA-4 topotype reinforce the importance of using a good-quality vaccine with high coverage in the susceptible herds with supporting post-vaccination serosurveillance to ensure that sufficient antibody titers are generated in the vaccinated animals.

Infectious bursal disease is a highly contagious disease of young chickens caused by the infectious bursal disease virus. This disease poses an important threat to the commercial poultry industry globally. This study was designed to develop an In-House Indirect Enzyme-Linked Immune Sorbent Assay Kit for the serological detection of antibodies against infectious bursal disease viruses. An infectious bursal disease virus antigen dilution (1:2), sample serum (1:500), and mouse anti-chicken immunoglobulin G (IgG) labeled with horseradish peroxidase (HRP) (1:2,000) were used in this assay. The calculated cutoff value was 0.24. This in-house indirect ELISA method was compared with a commercial ELISA kit for the detection of antibodies against infectious bursal disease virus in chickens. The performance of the newly developed and commercial ELISA kit was evaluated as described by Samad et al. (1994). The sensitivity and specificity of the current ELISA method were 98% (95% CI: 92.96–99.76) and 97% (95% CI: 91.48–99.38), respectively. The average intra-assay % CV of the triplet of 2 samples was 7.6, and interassay comparisons indicated a CV of 5.45%. As indicated by the results, we described a valuable and cost-effective, sensitive and specific in-house indirect ELISA kit for the serological diagnosis of infectious bursal disease in Ethiopia.