Foot and Mouth Disease in North Africa: Epidemiology and Control Strategies

This study was aimed to determine the seroprevalence of foot and mouth disease (FMD) in cattle and identifying the potential risk factors associated with the disease among sedentary cattle in northern part of Plateau state, Nigeria. Two hundred and seventy cattle aged from 6 months to ?3 years old were randomly selected and identified and whole blood collected from the jugular vein using plain evacuated tubes. Whole blood was processed and separated and sera were screened for foot and mouth disease virus (FMDV) 3D non-structural proteins using blocking enzyme linked immunosorbent assay (ELISA). Overall, 55.9% (95%CI: 49.96-61.77) FMD seroprevalence was obtained from the study area. Seroprevalence was highest in Riyom (82.5%), followed by Barkin Ladi (66.2%), Jos South (55.5%) and Bassa (41.2%) (x2 = 17.21, P<0.05). Risk factors for age, management system and location were significant associated (P<0.05) with seroprevalence of FMD. However, there was no significant association with sex (P>0.05). The prevalence odd ratio of FMD was more in Riyom than in Jos South, Barkin Ladi and Bassa (P<0.05). Prevalence odd ratio of FMD was more in extensively managed system relative to intensively managed system, more in adult cattle aged >2 years old. This study has indicated that FMD is an important disease among sedentary cattle in Northern Plateau, however little is currently known about the economic impact of the disease on the local farmers and their livelihoods. As a control measure, efforts should be improved on animal movement during outbreaks while prophylactic control using vaccination should be considered as another option using vaccines containing virus representative of the region.Asian J. Med. Biol. Res. June 2015, 1(2): 169-174

Foot and mouth disease (FMD) is a major Transboundary Animal Disease (TAD) which causes major economics losses to the developing countries. In Pakistan the disease is considered endemic and outbreaks are still being reported. Rapid diagnosis of the disease and Isolation of FMD virus is important to confirm viral subtyping and allow for the development of effective vaccines against the specific subtypes. Carrier animals are the major source of current outbreaks of FMD in Pakistan. Current study was planned and conducted for isolation of FMD virus from persistently infected animals by using LFBK cell line and comparison of LFBK and LFBK αVβ6 for isolation of FMDV isolates from recent FMD outbreaks. A total of 120 serum samples were collected from persistently infected riverine buffaloes and examined for the presence of FMD virus Non-Structural Proteins by using NSP-ELISA. Of 120 sera samples 23 animals were found positive for NSP’s. The Oro-pharyngeal fluids (OP) were collected from NSP-ELISA positive animals. The OP fluids samples were treated with Tri-cholo-Tri-flouro-Ethane (TTE) and inoculated onto LFBK cell line. Out of 23 OP fluid samples 11 exhibited CPE’s. A total of six (06) FMD viruses were confirmed by rRT-PCR and characterized by Indirect Sandwich ELISA as type O, Asia-1and A. The FMD virus isolates were acquired from FAO-UN project on FMD in Pakistan. All isolates were inoculated on both of the cell lines and observed for the development of CPEs. We found that the newly modified LFBK αVβ6 cell line exhibited CPEs more rapidly after 18-20 hours, while LFBK cell line CPEs developed after 24 to 48 hours. TCID50 calculated on LFBK αVβ6 was higher for the all the serotypes tested than LFBK cell line. Percentage of CPEs in LFBK αVβ6 per plate resulted higher than over LFBK cell line.

Foot and mouth disease (FMD) is a highly contagious viral infection in cloven hoofed domestic and wild animals and endemic in many countries of the world including Bangladesh. Clinical investigation was carried out to identify natural cases of FMD and characteristics signs of FMD like salivation, ulceration in oral and pedal tissues and lameness was seen. The specific serotypes of FMD viruses involved in infected cattle were, therefore, identified using reverse transcriptase polymerase chain reaction (RT-PCR). Samples (N=97) from oral lesions was collected from infected cattle from seven divisions of Bangladesh during May to December, 2013. Viral RNA was extracted from the infected oral tissues and FMD virus specific uniplex RT-PCR was designed to detect FMD viruses. Multiplex RT-PCR was adapted to detect serotype specific amplicons. Out of 97 samples tested in uniplex and multiplex RT-PCR, 92 and 90 samples showed amplification reaction for FMD virus and viral serotypes respectively. Among the 90 FMD virus specific positive identification, single infectivity due to FMD viral Serotypes O, A and Asia 1 were seen in 56 (62.2%), 13 (14.4%) and 16 (17.8%) cases respectively. Three cattle (3.3%) were co-infected with FMD viral Serotypes O and Asia 1 and two (2.2%) with FMD viral Serotypes O and A. FMD viral serotype O was dominating all over the country followed by Asia1 and A. Cattle of Bangladesh were infected with FMD viral serotype O, A and Asia 1 alone or in combination. The RT-PCR protocols designed and adapted successfully detected FMD viruses and viral serotypes in a fraction of the time required for virus isolation and serological detection. These RT-PCR protocols can be used for rapid serotyping of FMD viruses from filed infectivity and selection of vaccine viruses.SAARC J. Agri., 15(1): 33-42 (2017)

Foot and mouth disease in human beings

Foot and mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals, including cattle, pigs, sheep, goats, and certain wildlife species. The disease can cause massive economic losses when introduced into countries that were free from the infection, generating negative effects due to reduced animal productivity and restrictions on international livestock trade. Following 15 years of FMD absence, Tunisia and Algeria experienced an incursion of the disease in 2014. The epidemiological situation and disease control measures in operation for FMD in the North African region are not homogeneous. The FMD virus detected in Tunisia and Algeria during the epidemic in 2014 showed 99% identity with a strain isolated in Libya in 2013. Morocco was not affected by the 2014 epidemic but it started a preventive vaccination campaign for cattle in August of that year. The relatively short distance between the North African continent and southern Europe may facilitate the introduction of pathogens, including FMD virus. The history of infectious diseases demonstrates that the Mediterranean Sea is not a sufficient barrier to viral infections. Considering the geography and the FMD situation in North African countries, strong and coordinated intervention strategies are required, including economic, political and disease control aspects, to prevent the spread of FMD to other countries in North Africa or to other regions, e.g. southern Europe. Regional platforms such as the Mediterranean Animal Health Network (REMESA) could play a crucial role in coordinating and managing animal health crises, such as the 2014 FMD epidemic.

Foot and mouth disease (FMD) virus remains enzootic in Lao People's Democratic Republic (Lao PDR) due to insufficient control measures, including low vaccination coverage. We assessed virus epidemiology and evaluated knowledge, attitude and practice of Lao farmers and animal health stakeholders towards FMD to support politics in devising evidence-based control measures. Sera were collected from 972 domestic ruminants in three provinces of Lao PDR: Vientiane Capital, Vientiane and Xiengkhouang provinces. Seroprevalence of antibodies directed against non-structural proteins of FMD virus was assessed using a commercial ELISA. Positive sera were further characterized by detecting antibodies directed against the structural proteins of FMD serotypes O, A and Asia 1. Information about farm management, biosecurity practices, livestock trade, and past FMD outbreaks was obtained. Overall 35% (340/972) of the ruminants had antibodies against FMD virus with a similar seroprevalence in each province. Seroprevalence depended significantly on the ruminant species (p<.001): 61% of buffaloes, but only 41% of cattle and 15% of goats were seropositive. While antibodies against FMD serotype Asia 1 were absent, 87% (297/340) of the seropositive animals had antibodies against FMD serotype O and 32% (110/340) against FMD serotype A. Many seropositive animals (31%) had antibodies against both serotypes O and A. The majority of the farmers could name the symptoms of FMD and the susceptible animal species. Although many had likely observed FMD outbreaks in their herd and were aware of FMD vaccines, only few vaccinated their animals. This study confirms that FMD remains enzootic in at least three provinces of Lao PDR where vaccination coverage is low. It also shows the relevance of nationwide active and passive disease surveillance, as well as of vaccination campaigns using bivalent FMD vaccines and targeting all susceptible animal species.

Review question / Objective: What is the epidemiology and effectiveness of control measures for foot and mouth disease in African countries?’ PICOS: Description of elements Population/ problem/Setting: Artiodactyla (cloven ungulates), domestic (cattle, sheep, goats, and pigs), camels and wildlife (buffaloes, deer, antelope, wild pigs, elephant, giraffe, and camelids) affected by Foot and Mouth Disease (FMD) or Hoof and Mouth Disease (HMD) caused by the Foot and Mouth Disease Virus (FMDV) in Africa. Intervention: Prevention measures: vaccination, ‘biosafety and biosecurity’, sensitization of the public. Control measures: quarantine, movement control, closure of markets and stock routes, mouth swabbing of animals with infected materials (old technique that is no long applicable), culling, mass slaughter, stamping out and any other interventions or control measures generally accepted by the ‘community of practice’ of animal health practitioners. Comparator: areas that did not have any control activities for FMD, in head-to-head comparisons in the same study. Outcome: epidemiological outcomes: incidence, prevalence, patterns or trends, clinical symptoms, and risk factors. Effectiveness outcomes: success, and usefulness of the interventions measured as averted deaths, illness and infections, and costs associated with the interventions (cost–effectiveness). Study design: epidemiological designs include cohort design for incidence, cross sectional for prevalence and case-control for clinical symptoms and risk factors. Interventional designs include randomized controlled trials, cluster randomized trials, quasi-experimental designs – controlled before and after, interrupted time series, [regression discontinuity design, difference-in-difference, and propensity score matching]. Timelines: 1900 – 2022.

Foot and mouth disease virus (FMDV) is the cause of foot and mouth disease (FMD) outbreaks in livestock worldwide, which affects domestic and international trade, resulting in significant economic losses and social consequences. For efficient monitoring and prevention of FMD outbreaks, the need for improved strategies to control FMDV and achieve FMD-free status with various control measures including vaccination can be established. In vaccinology, major advances and discoveries in vaccination variations including DNA and protein subunit vaccines proved to be more economical and sustainable. To develop a safe vaccine for animals, possible antigenic genes or antigens need to be identified and characterised. The FMDV is a single-stranded RNA virus consisting of a capsid precursor polypeptide, P1, which encodes for four structural proteins (VP4-1), leading to antigenic variation and VP1 potentially carrying the key epitope for vaccine development. This study aims to identify and characterise the capsid polypeptide, P1 and capsid protein, VP1 of the Malaysian FMDV serotype O and serotype A isolates. The nucleotide and protein sequences were identified based on the FMD outbreaks in Malaysia and the antigenicity of the P1 and VP1 was predicted by Kolaskar and Tongaonkar's semi-empirical method. Subsequently, the P1 and VP1 genes were inserted into pET-28a, respectively, and used for protein expression analysis. The P1 and VP1 were predicted to be antigenic via in silico analysis and successfully expressed and characterised through in vitro analysis. Hence, this study can be exploited as a tool to design a new novel vaccine for vaccine development against FMD in bovines.

Foot and mouth disease (FMD) is a severe, highly contagious viral disease of livestock that has a significant economic impact. A cross-sectional study was conducted from September 2019 to June 2020 in three selected districts of Sidama region, southern Ethiopia with the objectives of determining the sero-prevalence of cattle against foot and mouth disease virus (FMDV), identifying potential risk factors and assessing farmers' perception on vaccination against FMD. Purposive and systematic random sampling techniques were employed to select the districts and study animals, respectively. A total of 510 cattle were tested for FMDV antibodies using 3ABC-ELISA. The overall cattle and herd level sero-prevalence were 15.5% and 24.7%, respectively. Among the considered risk factors age, herd size, and season were significantly associated with the sero-positivity of FMDV (P&lt;0.05). Out of 120 farmers interviewed84.2% had never vaccinated their cattle against FMDV. Inaccessibility (83.7%) and unaffordable cost (72.1%) of the vaccine were mentioned as leading causes for the low vaccination practice in the current study areas. Majority of the respondents (68.3%) don’t perceive vaccinating cattle against FMDV as one of the preventive measures. In districts with lower perception of farmers on vaccinating their cattle against FMDV, higher sero-prevalence of the disease were recorded. The present serological and questionnaire survey indicated that the presence of FMD sero-positive animals in the current study area. Therefore, an integrated strategy for disease control has to be designed and implemented which could include enhancing farmers’ perception about the use of vaccination in preventing FMD and government provision of vaccines at an affordable cost to the farmers.

The carrier state in foot and mouth disease—an immunological review

Foot and mouth disease (FMD) is a highly contagious transboundary disease that affects all cloven hoofed animals. It is caused by a virus that belongs to the genus Aphthovirus of the family Picornaviridae. Foot and mouth disease virus (FMDV) occurs in seven standard serotypes: A, O, C, and South African Territories (SAT) 1, SAT 2, SAT 3, and Asia1. The disease has a high morbidity although mortality is rare in adult animals. The impact posed by the disease is enormous. It affects animal’s performance directly through reduction of milk yield. Death of young animals and fertility impairment due to increased abortion rate are also the grave consequences of the disease. FMD has a great potential for causing severe economic loss. Greatest losses can result from refusal of FMD free countries to import livestock and livestock products from infected region. The disease has been present in almost every part of the world where livestock are kept. More than 100 countries are still affected by FMD worldwide and distribution of the disease roughly reflects economic development. Despite considerable information being available about the virus, the disease and vaccines, FMD remains a major threat to the livestock industry worldwide. FMD is endemic disease in Ethiopia with multiple serotypes in circulation at varying prevalence levels. Estimation of economic losses by FMD can provide a better overall view of the impact of the disease on national economy and can contribute in estimating the extent of the losses to be avoided and also understanding its transmission dynamics can contribute for suggesting appropriate control intervention mechanism. In Ethiopia there is limited research done on this aspect. Many resources have been and still are devoted to surveillance and molecular characterization of FMD, therefore the aims of this seminar paper are to review the major risk factors for transmission of disease, review the economic impact of FMD and suggest prevention and control measures.

Foot and mouth disease (FMD) virus: Quantification of whole virus particles during the vaccine manufacturing process by size exclusion chromatography

The aim of this study was to assess the seroprevalence against serotype O FMD (foot and mouth disease) virus in vaccinated pigs and cattle in Ho Chi Minh City, as a basis to serve the prevention of FMD epidemics in these animals. A total of 535 pigs and 366cattle sera were tested by using the Elisa kit for the detection of serotype O FMD antibody (Pirbright, UK). Results of this study showed that most pig farms had the proportions of positive animals for antibodies against FMDV serotype O which met the requirements of Decision no. 07/2016/ Ministry of Agriculture and Rural Development, except Xuan Thoi Thuong, Thai My and Phu My Hung. All sows had high levels of antibodies against serotype O FMD virus. There were no significant differences in the ratios of positive pigs for antibodies against FMDV serotype O among types of pig and age groups. However, there were significant differences in the seroprevalence of vaccinated pigs across herd sizes and days post-vaccination. Meanwhile, the overall seroprevalence of vaccinated cattle against FMDV at individual-level was over 80.00%. No statistical differences were found in the seroprevalence of vaccinated cattle against type OFMDV among regions, types of cattle, herd sizes, age groups and days post-vaccination. In conclusion, pigs raised in farms of Xuan Thoi Thuong, Thai My and Phu My Hung communes should be revaccinated with FMD vaccine to prevent the risk of pigs being infected with FMD virus and reduce the amount of virus produced by an infected animal.

Interferon is an important cytokine that plays a critical role in the initial host defense against viral infection. Recombinant human adenoviruses expressing human interferon-α (Ad-HIFNα) or pig interferon-β fused with interleukin-18 (Ad-PIFNβ-IL18) were constructed and used to induce an early protective response against foot and mouth disease (FMD). To analyze the antiviral effect, bovine thyroid and porcine kidney IBRS-2 cells and ICR mice were treated with Ad-HIFNα, Ad-PIFNβ-IL18, and cocktail of Ad-HIFNα and Ad-PIFNβ-IL18. The survival rate of suckling mice was monitored after foot and mouth disease virus (FMDV) challenge following intra-peritoneal (IP) administration of appropriate adenovirus. Indirect antigen ELISA was performed to evaluate inhibition of FMDV replication following challenge with the FMDV O, A, or Asia 1 serotypes in vitro. These recombinant adenoviruses reduced the replication of FMDV in susceptible cells, thereby decreasing the fatality in mice, suggesting that they can be a useful control method for the early protection against FMD infection in livestock after field trial.

Antiviral activity of merimepodib against foot and mouth disease virus in vitro and in vivo