Foot-and-mouth Disease Risk Research Articles

Unveiling the spatial distribution and transboundary pathways of FMD serotype O in Western China and its bordering countries.

Foot-and-mouth disease (FMD) is a severe, highly contagious viral disease of livestock that has a significant economic impact on domestic animals and threatens wildlife survival in China and border countries. However, effective surveillance and prevention of this disease is often incomplete and unattainable due to the cost, the great diversity of wildlife hosts, the changing range and dynamics, and the diversity of FMDV. In this study, we used predictive models to reveal the spread and risk of FMD in anticipation of identifying key nodes to control its spread. For the first time, the spatial distribution of FMD serotype O was predicted in western China and border countries using a niche model, which is a combination of eco-geographic, human, topographic, and vegetation variables. The transboundary least-cost pathways (LCPs) model for ungulates in the study area were also calculated. Our study indicates that FMD serotype O survival is seasonal at low altitudes (March and June) and more sensitive to temperature differences at high altitudes. FMD serotype O risk was higher in Central Asian countries and both were highly correlated with the population variables. Ten LCPs were obtained representing Pakistan, Kazakhstan, Kyrgyzstan, and China.

Bovine Sero- surveillance of Foot- and – Mouth Disease in Four States in Nigeria

Animals with cloven hooves are susceptible to highly contagious foot and mouth disease (FMD). FMD epidemics have affected several underdeveloped countries, including Nigeria. The migration of pastoralist animals has been linked to FMD transmission in Nigeria, and surveillance is essential for assessing the threat and impact of FMD, as well as the emergence of PCP-FMD. Here, we report the sero-surveillance of FMD in cattle in four states in Nigeria in 2019. Sera collected from four states (Anambra, Enugu, Imo, and Katsina) were tested for antibodies against FMD non-structural protein (NSP), with an overall prevalence of 45%. Significantly higher seroprevalence was recorded in Imo (63%), followed by Kastina (56%), Anambra (29%), and Enugu (6%). An overall serotype-specific prevalence of 81%, 35 %, 50 %, and 35% was recorded for serotypes O, A, 50% for SAT 2, and SAT 1, respectively. Furthermore, circulating antibodies against four serotypes of FMDV were found in 16% of sera samples, 20% had antibodies against three circulating serotypes, 33% had antibodies against two serotypes, and 25% showed exposure to only one serotype, indicating exposure to multiple FMD serotypes. These findings demonstrate the presence of FMDV antibodies in cattle across all surveyed states, which may be related to the presence of multiple FMDV serotypes (O, A, SAT1and SAT2) and concurrent co-infection in these states. Therefore, there is a need for the continuous surveillance of FMD in Nigeria. This will help ascertain the burden of the disease and enable the implementation of necessary control measures to stop its potential transmission and further spread. This sero-surveillance data expands our understanding of the FMD situation in Nigeria and is crucial for determining the country’s FMD risk in order to advance the PCP-FMD.

Factors associated with foot-and-mouth disease seroprevalence in small ruminants and identification of hot-spot areas in northern Nigeria

Many small ruminants infected with foot-and-mouth disease (FMD) remain asymptomatic, with the capacity to promote silent viral spread within domestic and wildlife species. However, little is known about the epidemiological role played by small ruminants in FMD. In particular, there are few studies that examine FMD seroprevalence, spatial patterns and risk factors for exposure in small ruminants. A cross-sectional study was conducted in northern Nigeria (Bauchi, Kaduna, and Plateau States) to determine the true seroprevalence of FMD in backyard small ruminants, identify factors associated with FMD seroconversion at animal and household levels, and identify spatial patterns for FMD virus exposure. Data on animal (n = 1800) and household (n = 300) characteristics were collected using a standardised questionnaire. Sera samples from 1800 small ruminants were tested for antibodies against non-structural proteins of FMD virus. True seroprevalence was estimated stochastically to account for variability and uncertainty in the test sensitivity and specificity previously reported. Risk factors for FMD seropositivity were identified at animal and household levels and spatial patterns were determined. The overall true seroprevalence for FMD virus, in the small ruminant population tested, was estimated to be 10.2 % (95 % Credible Interval (CrI) 0.0–19.0), while State-level estimates were 17.3 % (95 % CrI 0.0–25.8) for Kaduna, 6.9 % (95% CrI 0.0–15.8) for Bauchi, and 3.6 % (95 % CrI 0.0–12.6) for Plateau. State and species were the main risk factors identified at animal level, with interaction detected between them. Compared to goats in Plateau, the odds of testing positive were higher for goats in Bauchi (Odds Ratio (OR)= 1.83, 95 % CI 1.13–2.97, p = 0.01) and Kaduna (OR=2.97, 95 % CI 1.89–4.67, p < 0.001), as well as for sheep in Plateau (OR=3.78, 95 % CI 2.08–6.87, p < 0.001), Bauchi (OR=1.61, 95 % CI 0.91–2.84, p = 0.10), and Kaduna (OR=3.11, 95 % CI 1.61–6.01, p = 0.001). Households located in Kaduna were more likely to have a higher number of seropositive SR compared to those in Plateau (Prevalence Ratio (PR)= 1.75, 95 % CI 1.30–2.36, p < 0.001), and households keeping sheep flocks were more likely to be seropositive (from 1 to 10 sheep: PR=1.39, 95 % CI 1.05–1.82, p = 0.02; more than 10 sheep: PR=1.55, 95 % CI 1.12–2.15, p = 0.008) compared to those that did not keep sheep. A hot-spot was detected in Kaduna, and a cold-spot in Plateau. These results reveal that small ruminants had been recently exposed to FMD virus with spatial heterogeneity across the study area.

A scoping review of foot-and-mouth disease risk, based on spatial and spatio-temporal analysis of outbreaks in endemic settings.

Foot-and-mouth disease (FMD) is one of the most important transboundary animal diseases affecting livestock and wildlife species worldwide. Sustained viral circulation, as evidenced by serological surveys and the recurrence of outbreaks, suggests endemic transmission cycles in some parts of Africa, Asia and the Middle East. This is the result of a complex process in which multiple serotypes, multi-host interactions and numerous socio-epidemiological factors converge to facilitate disease introduction, survival and spread. Spatial and spatio-temporal analyses have been increasingly used to explore the burden of the disease by identifying high-risk areas, analysing temporal trends and exploring the factors that contribute to the outbreaks. We systematically retrieved spatial and spatial-temporal studies on FMD outbreaks to summarize variations on their methodological approaches and identify the epidemiological factors associated with the outbreaks in endemic contexts. Fifty-one studies were included in the final review. A high proportion of papers described and visualized the outbreaks (72.5%) and 49.0% used one or more approaches to study their spatial, temporal and spatio-temporal aggregation. The epidemiological aspects commonly linked to FMD risk are broadly categorizable into themes such as (a) animal demographics and interactions, (b) spatial accessibility, (c) trade, (d) socio-economic and (e) environmental factors. The consistency of these themes across studies underlines the different pathways in which the virus is sustained in endemic areas, with the potential to exploit them to design tailored evidence based-control programmes for the local needs. There was limited data linking the socio-economics of communities and modelled FMD outbreaks, leaving a gap in the current knowledge. A thorough analysis of FMD outbreaks requires a systemic view as multiple epidemiological factors contribute to viral circulation and may improve the accuracy of disease mapping. Future studies should explore the links between socio-economic and epidemiological factors as a foundation for translating the identified opportunities into interventions to improve the outcomes of FMD surveillance and control initiatives in endemic contexts.

Spatio-temporal patterns and risk factors of foot-and-mouth disease in Malawi between 1957 and 2019

Foot-and-mouth disease (FMD) is an important livestock disease causing short-term and long-term production losses and hindering local and international trade. To gain access to lucrative foreign markets and also improve local trade, there is a need to employ effective preventive and control strategies. Although FMD has been present in Malawi for over 60 years, little knowledge is available concerning the dynamics and drivers of FMD in the country. A modelling study based on retrospective data was conducted to establish the spatio-temporal distribution and determine the risk factors associated with FMD in Malawi. A retrospective space-time analysis was performed and a matched case-control study was carried out to investigate risk factors. The number of reported FMD outbreaks has descriptively increased after 2000 and the disease has spread to previously unaffected areas. Two significant spatio-temporal clusters of FMD were identified; one in the southern region and the other in the northern region. An analysis of only index cases (first detected locations) also detected two clusters with one in the northern region and the other in the southern region. Higher beef cattle density (p = 0.023), higher pig density (p = 0.043) and increased distance to wildlife protected areas (p = 0.036) were positively associated with the risk of FMD while increased distances to international borders (p = 0.008) and roads (p = 0.034) were associated with reduced risk of FMD. High FMD risk areas were observed in the southern and northern regions but not in the central region during the early years (1957–1981). The more recent increase in FMD risk at the end of the study period (2019) in the central region might be attributed to increases in livestock density in this region. These findings provide insight into the pattern of FMD occurrence that will promote informed decisions for the progressive control of FMD in the region.

Impact of mass vaccination on the spatiotemporal dynamics of FMD outbreaks in India, 2008-2016.

Foot-and-mouth disease (FMD) is endemic in India, where circulation of serotypes O, A and Asia1 is frequent. Here, we provide an epidemiological assessment of the ongoing mass vaccination programs in regard to post-vaccination monitoring and outbreak occurrence. The objective of this study was assessing the contribution of mass vaccination campaigns in reducing the risk of FMD in India from 2008 to 2016 by evaluating sero-monitoring data and modelling the spatiotemporal dynamics of reported outbreaks. Through analyzing antibody titre data from>1 million animals sampled as part of pre- and post-vaccination monitoring, we show that the percent of animals with inferred immunological protection (based on ELISA) was highly variable across states but generally increased through time. In addition, the number of outbreaks in a state was negatively correlated with the percent of animals with inferred protection. We then analyzed the distribution of reported FMD outbreaks across states using a Bayesian space-time model. This approach provides better acuity to disentangle the effect of mass vaccination programs on outbreak occurrence, while accounting for other factors that contribute to spatiotemporal variability in outbreak counts, notably proximity to international borders and inherent spatiotemporal correlations in incidence. This model demonstrated a ∼50% reduction in the risk of outbreaks in states that were part of the vaccination program. In addition, after controlling for spatial autocorrelation in the data, states that had international borders experienced heightened risk of FMD outbreaks. These findings help inform risk-based control strategies for India as the country progresses towards reducing reported clinical disease.

What drives small-scale farmers to vaccinate their multiple livestock species animals against common infectious diseases in Myanmar?

Livestock rearing is an important income source for small-scale farmers in Myanmar, but Foot and Mouth Disease (FMD) and Newcastle disease (ND) are major constraints to livestock production. A study was conducted to identify perceptions of farmers about FMD and ND disease risks and perceptions about vaccination practices by using the modified health belief model. The majority of livestock farmers (>70%) reported that they were aware of the risk and impact of FMD and ND and were willing to vaccinate their livestock (>60%). Focusing on three main livestock farmer groups, about 17.0% of cattle, 15.4% of village chicken, but only 2.3% of small ruminant owners, indicated that the non-availability of vaccinations in the villages was the major constraint to vaccinations (p<0.001), while in contrast twice as many small ruminant farmers compared to cattle and village chicken farmers indicated they had no knowledge about vaccinations and no funds to conduct vaccinations. Limited accessibility to vaccines and vaccinators was related to size of villages (p = 0.001 for cattle; p = 0.027 for small ruminants; p = 0.005 for village chicken). Willingness to vaccinate small ruminants against FMD was associated with the perceived impact of the disease on sales and accessibility of information about vaccination. Accessibility to information about ND vaccination influenced the willingness of village chicken farmers to conduct vaccinations. In addition, beliefs in the effectiveness of vaccinations played a major role in the willingness to carry out vaccinations on both, cattle (β = 0.3, p = 0.018) and village chicken farms (β = 0.5, p<0.001). Our study highlights that policies that increase the accessibility of vaccines and the dissemination of information about disease prevention and vaccination practices in villages of all sizes, have the potential to increase FMD and ND vaccination rates and thereby reduce outbreak occurrence in Myanmar. On the other hand, indirect factors, such as village size strongly influenced the availability of vaccinations.

Self-Reporting of Risk Pathways and Parameter Values for Foot-and-Mouth Disease in Slaughter Cattle from Alternative Production Systems by Kenyan and Ugandan Veterinarians.

Countries in which foot-and-mouth disease (FMD) is endemic may face bans on the export of FMD-susceptible livestock and products because of the associated risk for transmission of FMD virus. Risk assessment is an essential tool for demonstrating the fitness of one’s goods for the international marketplace and for improving animal health. However, it is difficult to obtain the necessary data for such risk assessments in many countries where FMD is present. This study bridged the gaps of traditional participatory and expert elicitation approaches by partnering with veterinarians from the National Veterinary Services of Kenya (n = 13) and Uganda (n = 10) enrolled in an extended capacity-building program to systematically collect rich, local knowledge in a format appropriate for formal quantitative analysis. Participants mapped risk pathways and quantified variables that determine the risk of infection among cattle at slaughter originating from each of four beef production systems in each country. Findings highlighted that risk processes differ between management systems, that disease and sale are not always independent events, and that events on the risk pathway are influenced by the actions and motivations of value chain actors. The results provide necessary information for evaluating the risk of FMD among cattle pre-harvest in Kenya and Uganda and provide a framework for similar evaluation in other endemic settings.

Sero-epidemiology of foot-and-mouth disease in Darfur area, Western Sudan.

A total of 367 bovine sera positive to antibodies against non-structural proteins (NSPs) of foot-and-mouth disease (FMD) virus were screened for serotype O, A and SAT2 antibodies using the virus neutralization test (VNT). Sera had been collected in 2016 from North (228) and South (139) Darfur States in Western Sudan, where high and low circulation of FMD virus, respectively, prevailed. Tested sera represented the positive-NSPs portion in a random sample of 669 sera collected from both States. According to standard statistical methods, calculations for serial testing (NSPs ELISA and VNT) were applied to estimate prevalence rates of serotype-specific antibodies in the two States. In each State, approximately 20% of NSPs positive sera failed typing. Prevalence's detected were 49% ± 5% (O), 27% ± 5% (A) and 14% ± 4% (SAT2) in North Darfur State and 27% ± 5% (O), 17% ± 4% (A) and 8.0% ± 3% (SAT2) in South Darfur State. In both States, prevalence rates were significantly higher for serotype O, followed by A then SAT2; the same order that was known in most parts of Sudan. Consistently, estimated prevalence's were statistically significantly higher (P < 0.05) in North Darfur than in South Darfur State. Apart from serotype SAT2, detected prevalence rates were lower or similar to those inside the country in previous occasions. Frequency and pattern of distribution of serotype O prevalence were consistent with its suggested pattern of circulation from the Nile valley to other parts in Sudan and significant within the country's circulation. Alternatively, serotype SAT2 prevalence and distribution in Darfur area were suggestive of sporadic occurrence. However, slightly higher prevalence rates of SAT2 antibodies in Darfur than in neighbouring Kordofan areas in 2013 reflected the wide dissemination of SAT2 ( http://www.wrlfmd.org ) in Sudan in early 2014. Risk of FMD in Darfur seemed to be associated with the movement of animals to the North in the wet season as part of the pastoral system, and with movement related to trade into urban centers more than with pastoralism across the Western borders. Generally, the result presented little evidence to suggest presence of FMD primary endemic foci in Darfur area.

Assessing the impact of climate change on the spatio-temporal distribution of foot-and-mouth disease risk for elephants

Elephants are the largest extant terrestrial animals and are important for maintaining regional ecosystem balance and community diversity. However, poaching, population growth, habitat fragmentation, and viruses are major threats to global elephant populations. Foot-and-mouth disease (FMD) is one of the major threats to the health of elephants. Global warming has a serious impact on wildlife and accelerates the spread of viruses. In this study, the effects of climate change on the risk of disease in elephants were evaluated based on 1833 sites with reported FMD cases. Maximum entropy (MaxEnt) was used to model the current and future geographic distributions of FMD and to assess the risk of FMD in elephants under climate change. The results showed that the average annual temperature and annual precipitation were higher in elephant habitats than in the range of the FMD virus. The mean temperature in the driest quarter, temperature seasonality, annual mean temperature, and precipitation in the driest month had relatively large contributions to the risk of FMD, with a cumulative contribution rate of 82.8%. Both Asian elephants and African elephants had high overlap with the FMD virus with respect to altitude, annual mean temperature, and annual precipitation. An overall high risk of disease was detected at a certain band, mainly concentrated from 10°N to 50°N in the northern hemisphere and from 10°S to 35°S in the southern hemisphere. The risk of FMD was higher for the Asian elephant than the African elephant. The FMD risk increased gradually from the southeast to northwest in habitats of the Asian elephant, and presented a pattern of high north–south risk and low intermediate risk in the habitats of the African elephant. The area proportions of high risk, medium risk, and low risk in the distribution of both the Asian elephant and African elephant were all higher than the proportions of all risk types worldwide. Under global warming, the FMD risk was not expected to change significantly in most of the habitat areas of the Asian elephant or the African elephant in the 2050s and 2070s. Moreover, the areas and proportions of high risk, medium risk, and low risk were likely to change slightly. These results could benefit the conservation of elephants and provide relevant data for the prevention of FMD in high-risk areas under climate change.

Understanding the vulnerability of beef producers in Australia to an FMD outbreak using a Bayesian Network predictive model

Effective and adaptable biosecurity and surveillance systems are crucial for maintaining and increasing Australia’s competitive advantages in international markets, and for the production of high quality, safe animal products. These systems are continuously strengthened by ongoing government and industry investment. However, a better understanding of evolving disease risks and the country’s capacity to respond to these risks is needed. This study developed a vulnerability framework based on characteristics and behaviours of livestock producers that impact exposure and response capacity to an emergency animal disease (EAD) outbreak among beef producers in Australia, with a focus on foot and mouth disease (FMD). This framework articulated producer vulnerability typologies to better inform surveillance resource allocation and future research direction. A cross-sectional study of beef producers in Australia was conducted to gather information on producers’ demographics, husbandry characteristics, biosecurity and animal health management practices and beliefs, including those specific to FMD risk and response capacity. A Bayesian Network (BN) model was developed from the vulnerability framework, to investigate the complex interrelationships between variables and identify producer typologies. A total of 375 usable responses were obtained from the cross-sectional study. Regarding EAD exposure, producers implemented appropriate biosecurity practices for incoming stock, such as isolation (72.0 %), inspection for disease (88.7 %) and the use of vendor declarations (78.5 %); however, other biosecurity practices were limited, such as restriction of visitor access, visitor biosecurity requirements or feral animal control. In relation to response capacity, a moderate uptake of practices was observed. Whilst daily or weekly visual inspection of animals was reported by most producers (90.1 %), physical inspection was less frequent. Most producers would call a private veterinarian in response to unusual signs of disease in their cattle; however, over 40 % of producers did not cite calling a government veterinarian as a priority action. Most producers believe an FMD outbreak would have extremely serious consequences; however, their level of concern was moderate and their confidence in identifying FMD symptoms was low. The BN analysis identified six vulnerability typologies, with three levels of exposure (high, moderate, low) and two levels of response capacity (high, low), as described by producer demographics and practices. The model identified property size, number of cattle and exposure variables as the most influential to the overall producer vulnerability. Results from this study can inform how to best use current biosecurity and surveillance resources and identify where opportunities exist for improving Australia’s preparedness for future EAD incursions.

Risk factors of foot and mouth disease in an endemic area on low vaccination rate in Xayaboury province of Lao People's Democratic Republic (Lao PDR).

In Xayaboury province, located in the northern region of Lao PDR, the foot and mouth disease (FMD) vaccination campaign just began in 2009. Up until now, a small number of farms have been vaccinated. When FMD outbreaks occur, it is interesting to determine the risk factors of FMD, especially in the area where vaccination rates are low. The questionnaire survey, using a case-control design at the household level, was carried out. From 59 villages with a total number of 434 households, 181 households who experienced FMD were assigned as case households, 146 households without FMD occurrence inside the outbreak villages as inside control households, and 107 households without FMD occurrence outside the outbreak villages as outside control households. Household owners were interviewed. The logistic regression model was used to identify the relationship between FMD occurrence (dependent variable) and the collected data (independent variables), including the social status of livestock owners, FMD prevention strategies, and farm locations. A non-parametric test was performed to determine the association of FMD and network parameters of animal movements among villages. In general, results show that a limited number of holders did vaccinate animals before the outbreaks (13.8-17.8%). The results indicated that livestock owners who had known information about FMD before the outbreaks had been less severely affected by the FMD outbreak than the owners who had not known information about FMD (P < 0.01, OR 0.16, 95% CI 0.09-0.29). Before the outbreaks, higher FMD risk was observed in owners who sold the livestock through animal traders (P < 0.01, OR 4.76, 95% CI 1.68-13.50). Spatial data show that households in the community closer to the main roads had higher FMD risk (P < 0.01, OR 4.76, 95% CI 1.68-13.50). In addition, the network parameters including in-degree, out-degree, and betweenness indicated that the villages with high movements of livestock were at high risk of FMD (P < 0.05). The present study emphasized the importance of the government units to distribute the information about FMD to all livestock farmers in Xayaboury. Disease awareness and prevention strategy should be prioritized in areas close to high density communities and in the trading of livestock.

Foot-and-Mouth Disease Virus: Immunobiology, Advances in Vaccines and Vaccination Strategies Addressing Vaccine Failures-An Indian Perspective.

A mass vaccination campaign in India seeks to control and eventually eradicate foot-and-mouth disease (FMD). Biosanitary measures along with FMD monitoring are being conducted along with vaccination. The implementation of the FMD control program has drastically reduced the incidence of FMD. However, cases are still reported, even in regions where vaccination is carried out regularly. Control of FMD outbreaks is difficult when the virus remains in circulation in the vaccinated population. Various FMD risk factors have been identified that are responsible for FMD in vaccinated areas. The factors are discussed along with strategies to address these challenges. The current chemically inactivated trivalent vaccine formulation containing strains of serotype O, A, and Asia 1 has limitations including thermolability and induction of only short-term immunity. Advantages and disadvantages of several new-generation alternate vaccine formulations are discussed. It is unfeasible to study every incidence of FMD in vaccinated animals/areas in such a big country as India with its huge livestock population. However, at the same time, it is absolutely necessary to identify the precise reason for vaccination failure. Failure to vaccinate is one reason for the occurrence of FMD in vaccinated areas. FMD epidemiology, emerging and re-emerging virus strains, and serological status over the past 10 years are discussed to understand the impact of vaccination and incidences of vaccination failure in India. Other factors that are important in vaccination failure that we discuss include disrupted herd immunity, health status of animals, FMD carrier status, and FMD prevalence in other species. Recommendations to boost the search of alternate vaccine formulation, strengthen the veterinary infrastructure, bolster the real-time monitoring of FMD, as well as a detailed investigation and documentation of every case of vaccination failure are provided with the goal of refining the control program.

Review of epidemiological risk models for foot-and-mouth disease: Implications for prevention strategies with a focus on Africa.

Foot-and-mouth disease (FMD) is a highly infectious transboundary disease that affects domestic and wild cloven-hoofed animal species. The aim of this review was to identify and critically assess some modelling techniques for FMD that are well supported by scientific evidence from the literature with a focus on their use in African countries where the disease remains enzootic. In particular, this study attempted to provide a synopsis of the relative strengths and weaknesses of these models and their relevance to FMD prevention policies. A literature search was conducted to identify quantitative and qualitative risk assessments for FMD, including studies that describe FMD risk factor modelling and spatiotemporal analysis. A description of retrieved papers and a critical assessment of the modelling methods, main findings and their limitations were performed. Different types of models have been used depending on the purpose of the study and the nature of available data. The most frequently identified factors associated with the risk of FMD occurrence were the movement (especially uncontrolled animal movement) and the mixing of animals around water and grazing points. Based on the qualitative and quantitative risk assessment studies, the critical pathway analysis showed that the overall risk of FMDV entering a given country is low. However, in some cases, this risk can be elevated, especially when illegal importation of meat and the movement of terrestrial livestock are involved. Depending on the approach used, these studies highlight shortcomings associated with the application of models and the lack of reliable data from endemic settings. Therefore, the development and application of specific models for use in FMD endemic countries including Africa is encouraged.

Transmission of Foot-and-Mouth Disease from Persistently Infected Carrier Cattle to Naive Cattle via Transfer of Oropharyngeal Fluid.

Control and eradication of foot-and-mouth disease (FMD) are impeded by the existence of a persistent, subclinical phase of infection in ruminants; animals with this status are referred to as carriers. However, the epidemiological significance of these FMD virus (FMDV) carriers is uncertain. In the current investigation, the contagion associated with FMDV carrier cattle was investigated by exposure of susceptible cattle and pigs to oropharyngeal fluid (OPF) samples or tissues harvested from persistently infected cattle. Naive cattle were inoculated through intranasopharyngeal deposition of unprocessed OPF samples that had been collected from FMDV carriers at 30 days postinfection. These inoculated cattle developed clinical FMD, and the severity of disease they developed was similar to that of animals that had been infected with a high-titer inoculum. In contrast, pigs exposed via intraoropharyngeal inoculation of the same OPF samples or via ingestion of nasopharyngeal tissues harvested from the same cohort of persistently infected cattle did not develop FMD. These findings indicate that there is demonstrable contagion associated with FMDV carrier cattle despite the lack of evidence for transmission by direct contact. The findings presented herein provide novel information that should be considered for FMD risk mitigation strategies.IMPORTANCE Foot-and-mouth disease (FMD) is a viral disease of livestock with substantial impact on agricultural production and subsistence farming on a global scale. Control of FMD is impeded by the existence of a prolonged asymptomatic carrier phase during which infected cattle shed low quantities of infectious virus in oropharyngeal fluid (OPF) for months to years after infection. The epidemiological significance of FMD virus (FMDV) carriers is unresolved. However, the existence of the FMDV carrier state has substantial impact on international trade in animal products. The current investigation demonstrated that transfer of OPF from persistently infected FMDV carrier cattle to naive cattle led to fulminant clinical FMD. It was thus demonstrated that, although the risk for disease transmission under natural conditions is considered to be low, there is detectable contagion associated with FMDV carrier cattle. This finding is important for optimization of FMD risk mitigation strategies.

Foot and mouth disease: the risks of the international trade in live animals

The growth in world trade has generated significant benefits to humankind, but it has also generated costs. Among these is an increase in the dispersal of pests and pathogens across the globe. International trade has been implicated in outbreaks of several re-occurring livestock diseases. This paper is focused on the risk of foot and mouth disease (FMD) associated with the international trade in live animals. A model was used to estimate FMD risk as a function of the international trade in live animals, controlling for the biosecurity measures undertaken by importing and exporting countries, and for the presence of endemic FMD reservoirs. It was found that the indirect risks associated with exports may be as great as the direct risks associated with imports. For countries where livestock production occurs in disease-free zones (with or without vaccination), the trade risks vary with both species and trading partner. These findings may assist the targeting of disease risk mitigation activities.

Investigation of smallholder farmer biosecurity and implications for sustainable foot-and-mouth disease control in Cambodia.

In Cambodia, the majority of the population is rural and reliant on subsistence agriculture, with cattle raised by smallholder farmers using traditional practices, resulting in low productivity and vulnerability to foot-and-mouth disease (FMD). As FMD causes deleterious impacts on rural livelihoods, known FMD risk factors were reviewed, using knowledge, attitudes and practice (KAP) surveys of smallholders (n=240) from four regions. The study aimed to understand current biosecurity threats to smallholder livelihoods and investigate the hypothesis that smallholder farmers practising FMD risk management should be associated with higher incomes from cattle. Descriptive data were examined to demonstrate trends in KAP and a multivariable linear regression model developed to identify cattle income predictors. Results showed that baseline mean knowledge scores were low at 28.4% across all regions and basic biosecurity practices, including quarantine of new cattle, isolation of sick cattle and FMD vaccination, were lacking. As farmers purchase and sell cattle from and to various administration levels (including export), there is high risk of FMD transmission into and from smallholder communities. The final multivariable linear regression model identified significant explanatory parameters for annual cattle income, including region, number of calves born, forage plot size (ha), vaccination of cattle and the number of cattle purchased (F pr.<0.001, R2 =29.9). Individual biosecurity practices including FMD vaccination were not significant predictors of income. With the current focus of farmers on treatment of FMD with inappropriate antibiotics leading to potential anti-microbial residue issues, yet receptivity to payment for vaccine in most regions, there is an urgent need for a coordinated national biosecurity and FMD management public awareness campaign. Further, to enhance the association between improved cattle health and rural livelihoods, it is recommended that livestock development programmes implement a systems approach to enhance farmer KAP in biosecurity, nutrition, reproduction and marketing of cattle.

Epidemiological situation of foot-and-mouth disease in 2014–2015 and the beginning of 2016

This article presents key information about foot-and-mouth disease (FMD) outbreaks around the world, based on data from Office International des Epizooties (OIE), World Reference Laboratory for Foot-and-Mouth Disease (WRL FMD) and the European Laboratory for Foot and Mouth Disease (EURL) at the Pirbright Institute. In the years 2014–2015 and early 2016, FMD caused by immunologically diverse serotypes O, A, Asia 1, SAT 1, SAT 2, SAT 3 occurred in areas of Asia and Africa, but there were no new outbreaks of the disease in South America. Within this period of time the dominating serotype was serotype O. For many years there were no reports about outbreaks caused by serotype C, the last of them occurring in 2004 (Brazil, Kenya). Significant epidemiological events were related to spreading of the virus serotype O (ME-SA/Ind-2001) and A (ASIA/G-VII(G-18)) from the Indian subcontinent to new regions. Serotype O (ME-SA/Ind-2001) spread in the years 2013 – 2015 in the Middle East (United Arab Emirates, Saudi Arabia, Bahrain) and North Africa (Libya, Tunisia, Algeria, Morocco); it was also detected in 2015 in Southeast Asia (Laos). In turn, the serotype A (ASIA/G-VII(G-18)) was recorded in 2010 in Myanmar, and in 2015 appeared in the Middle East (Saudi Arabia, Iran, Armenia, Turkey). Those events constituted a threat to neighbouring countries and increased the risk of intrusion FMD to Europe. A reason for concern was also given by the numerous outbreaks of foot-and-mouth disease in South Korea, caused by serotype O (SEA/Mya-98). In European countries there have been no outbreaks since 2011 (Bulgaria). For the record, the last outbreak in Poland was identified 45 years ago, in 1971.

Space-Time Analysis of Foot-and-Mouth Disease from 2005 to 2014 among Cattle Populations in Benin: A Retrospective Study

Many cases of foot-and-mouth disease (FMD) are reported every year in Benin. In order to elucidate the epidemiology of this disease, a space-time analysis was carried out in all the 77 municipalities of the country aiming to identify high risk areas as well as risk factors such as season and transhumance on the period of 2005 to 2014. Data were collected retrospectively from the Directory of Animal Production of Benin. The method of Kulldorff was used with the software SaTScanTM for the space-time analysis while a script was designed in the software R to generate new sizes with three different models of transhumance. From 2005 to 2014, 434 foci were recorded. Many outbreaks occurred in August, September and October. This period corresponds to the small rainy season in the South and the rainy season of the North. The municipality of Parakou was regarded as the source FMD outbreaks in Benin because it hosts one of the largest livestock markets in the country and many rivers. It was the municipality at the highest risk. The other municipalities at risk were Nikki, Pèrèrè and Kalaléas well as Karimama (hosting the national parkW), Kouandé and Toucountouna located nearby Pendjari’s national park. This study revealed that the space-time configuration is real and the main factors of persistence and dissemination of FMD virus were national parks, classified forests and the livestock market of Parakou all located in the North. The variation of the number of cattle due to their transhumance from the North to the South did not influence the zones at risk. Therefore, Northern Benin is probably at high risk of FMD.

Wildlife-livestock interface, veterinary cordon fence damage, lack of protection zones, livestock theft and owner apathy: Complex socio-ecological dynamics in Foot and Mouth disease control in southern Africa

Current efforts to control and possibly eradicate the highly contagious and economically important Foot and Mouth disease (FMD) in Botswana are hampered by numerous inextricably linked constraints. These constraints were unveiled using a questionnaire-based approach among 94 communal area livestock owners in eastern Botswana’s Zone 6 (FMD-free zone without vaccination, straddling part of the Central and North East Districts, sharing a common border with Zimbabwe to the east). The area has a history of FMD, with the last outbreaks recorded in 2002 and 2003 prior to the study. Some of the most outstanding constraints in FMD control were (1) rampant cross-border livestock theft, (2) veterinary cordon fence damage attributed to illegal immigrants and an ever-increasing elephant population, (3) livestock interaction with FMD-susceptible wild ungulates on the same rangelands, and (4) an absence of a protection zone (formerly ‘buffer zone’) along the Botswana/Zimbabwean border as well as (5) general apathy towards daily livestock management demonstrated by some owners/herders. The paper further discusses these complex socio-ecological constraints as perceived by livestock owners and offers possible policy considerations including targeted FMD awareness campaigns, strengthening of FMD risk analysis capacity and synchronization of surveillance and control strategies among neighbouring countries as well as adoption of approaches such as compartmentalization and commodity-based trade to enable greater access of Botswana’s beef to high-value international markets.