Incidence Of Foot-and-mouth Disease Research Articles

Socioeconomic and environmental determinants of foot and mouth disease incidence: an ecological, cross-sectional study across Iran using spatial modeling

Foot-and-mouth disease (FMD) is a highly contagious animal disease caused by a ribonucleic acid (RNA) virus, with significant economic costs and uneven distribution across Asia, Africa, and South America. While spatial analysis and modeling of FMD are still in their early stages, this research aimed to identify socio-environmental determinants of FMD incidence in Iran at the provincial level by studying 135 outbreaks reported between March 21, 2017, and March 21, 2018. We obtained 46 potential socio-environmental determinants and selected four variables, including percentage of population, precipitation in January, percentage of sheep, and percentage of goats, to be used in spatial regression models to estimate variation in spatial heterogeneity. In our analysis, we employed global models, namely ordinary least squares (OLS), spatial error model (SEM), and spatial lag model (SLM), as well as local models, including geographically weighted regression (GWR) and multiscale geographically weighted regression (MGWR). The MGWR model yielded the highest adjusted {R}^{2} of 90%, outperforming the other local and global models. Using local models to map the effects of environmental determinants (such as the percentage of sheep and precipitation) on the spatial variability of FMD incidence provides decision-makers with helpful information for targeted interventions. Our findings advocate for multiscale and multidisciplinary policies to reduce FMD incidence.

Foot and Mouth Disease (FMD) incidence in cattle and buffaloes and its associated farm-level economic costs in endemic India

The study investigated the important epidemiological parameters and farm-level economic costs of FMD incidence in cattle and buffaloes during 2013−14 to 2015−16 in various states of India. Multistage random sampling procedure was adopted for the primary survey and data was collected through face-to-face personal interview from 18,609 cattle and buffalo rearing farm households from 123 districts across twelve states and one Union Territory. Besides epidemiological parameters, different farm-level direct and indirect loss associated with FMD was assessed at disaggregated level (states) by employing deterministic mathematical models. Highest number of affected villages and disease incidence was observed in non- FMD control programme (FMD-CP) implemented Madhya Pradesh and Assam states, respectively whereas negligible incidence was in FMD-CP implemented Punjab state. The disease incidence was high during 2013−14 and declined during 2014−15 and 2015−16, respectively implied severe incidence scenario (2013−14) succeeded by moderate (2014−15) and mild (2015−16) scenarios. The crossbred and high productive animals were severely affected than local breeds whereas on sexwise and agewise comparison revealed higher incidence in females and adult animals. During severe incidence scenario, milk loss/animal ranged from USD 6.87–47.44, 18.42–125.88, 16.33–91.43, and 27.17–123.62; mortality loss/animal ranged from USD 32.61–804.27, 30.76–577.7, 65.36–502.2, and 188.04–413.7; distress sale loss/animal ranged from USD 3.22–188.63, 64.34–519.3, 214.47–341.8, and 209.11–450.3; and opportunity cost of labour/animal from USD 5.49–54.29, 5.49–67.78; 7.95–31.37 and 9.83–72.38 in indigenous cattle, crossbred cattle, local and improved buffalo, respectively. The estimated draught power loss/animal varied from USD 39.46–142.94 with least being in Madhya Pradesh and highest in Assam states whereas the median treatment cost/animal was USD 9.18 and USD 27.07 in indigenous cattle and upgraded buffaloes, respectively. The total farm-level economic loss projected due to FMD in cattle and buffaloes in India was USD 3159 million (INR 221,110 million), USD 270 million (INR 18,910 million) and USD 152 million (INR 10,610 million), respectively during the severe, moderate and mild incidence scenarios at 2015−16 constant prices. The loss varied across the states, and in severe incidence scenario, the country might lose USD 3.2 billion/year and hence, the bi-annual vaccination schedule need to be strictly implemented in all the states. Besides timely vaccination coverage, managing unabated animal movement, educating and motivating the farmers to vaccinate their animals might reduce the incidence and consequential losses to various stakeholders in endemic states like India.

Economic Analysis of Increasing Foot-and-Mouth Disease Vaccination Frequency: The Case of the Biannual Mass Vaccination Strategy.

Biannual mass vaccination is a routinely applied foot-and-mouth disease (FMD) control strategy in Turkey. However, because biannual mass vaccination may leave significant immunity gaps, this strategy may cause economic losses because of possible FMD infections. In high-risk areas—such as border cities, it was suggested by the government to increase the vaccination intervals in order to decrease the FMD infection risk. This study analyses and compares the economic effects of a biannual mass vaccination regime and vaccination every 4 months as an alternative strategy in border cities by using partial budgeting approach. Biannual mass vaccination was used as a baseline scenario. Data on the impact of FMD on animal health and production parameters for 2018 were obtained from the OIE-WAHIS system and complemented by literature data and expert opinion. In the partial budgeting model, weight loss was considered as a major loss of income because majority of the farming systems are based on cattle fattening in the border cities of Turkey. Results revealed that the net economic impact, which is the benefit that exceeds the losses and costs of increasing the frequency of vaccination, is 76.4 TL ($15.9) per cattle. The sensitivity analysis showed that average body weight and weight losses when infected had more effect on net impact changes than market prices. The lower and upper FMD incidence variability resulted in 19.2 TL ($4) and 190.8 TL ($39.6) of net impact per cattle, respectively. The new FMD control strategy would make a total net economic impact of 5,274,836 TL ($1,094,250) for a population of 800,970 fattening cattle in border cities. The results of this study indicated that intense FMD control strategies may be more cost effective than the current control strategies, especially in high-risk areas. Future studies with more comprehensive epidemiological and economic data must be conducted to analyze and compare alternative FMD control strategies in Turkey.

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.

Assessment of the efficacy of routine vaccination on the magnitude of Foot and Mouth Disease outbreak in Kafrelsheikh governorate, Delta Region, Egypt

Foot and mouth disease (FMD) is a highly contagious viral disease causes a serious economic impact on livestock production and trading. FMD is an endemic disease in Egypt and a national control program that depends on routine obligatory vaccination of all ruminant species is being followed for disease control. A nation-wide epidemic of FMD was commenced in early 2015 and typical clinical signs of the disease were observed even in vaccinated animals. The morbidity and case fatality rates were high enough to be investigated. In the current study, non-vaccinated and vaccinated animals of different sex and ages were examined to evaluate the efficacy of FMD different vaccines used in Egypt. Clinical, post-mortem and serological examinations were used to confirm the infection, while the molecular investigation was applied to identify the serotype responsible for this epidemic. The incidence rate and the attributable proportion (fraction) of FMD cases which could be avoided by vaccination and vaccine efficacy were calculated. The obtained results confirmed the infection with FMD virus (FMDV) serotype O in both non-vaccinated and vaccinated animals. The incidence of FMD was 86.67% among non-vaccinated animals, while it was ranged from 15% to 31.8% among vaccinated animals according to the type of vaccine used. The attributable fraction was 73.9% and the efficacy of the three used vaccines was 63.3%, 76.92% and 82.25% for Tri-Aphthovac, VSVRI and Meriel vaccines, respectively. In conclusion, vaccination in Egypt is able to minimize the magnitude of outbreaks caused by the same serotype found in the vaccine but was not able to prevent the infection and eliminate the disease. The highest vaccination efficacy was found in Mid-aged animals and male cattle.

Spatio-temporal patterns of foot-and-mouth disease transmission in cattle between 2007 and 2015 and quantitative assessment of the economic impact of the disease in Niger.

Foot-and-mouth disease (FMD) is endemic in Niger, with outbreaks occurring every year. Recently, there was an increasing interest from veterinary authorities to implement preventive and control measures against FMD. However, for an efficient control, improving the current knowledge on the disease dynamics and factors related to FMD occurrence is a prerequisite. The objective of this study was therefore to obtain insights into the incidence and the spatio-temporal patterns of transmission of FMD outbreaks in Niger based on the retrospective analysis of 9-year outbreak data. A regression tree analysis model was used to identify statistically significant predictors associated with FMD incidence, including the period (year and month), the location (region), the animal-contact density and the animal-contact frequency. This study provided also a first report on economic losses associated with FMD. From 2007 to 2015, 791 clinical FMD outbreaks were reported from the eight regions of Niger, with the number of outbreaks per region ranging from 5 to 309. The statistical analysis revealed that three regions (Dosso, Tillabery and Zinder), the months (September, corresponding to the end of rainy season, to December and January, i.e., during the dry and cold season), the years (2007 and 2015) and the density of contact were the main predictors of FMD occurrence. The quantitative assessment of the economic impacts showed that the average total cost of FMD at outbreak level was 499euros, while the average price for FMD vaccination of one outbreak was estimated to be more than 314euros. Despite some limitations of the clinical data used, this study will guide further research into the epidemiology of FMD in Niger and will promote a better understanding of the disease as well as an efficient control and prevention of FMD.

The long term effect of age and maternally derived antibodies against foot and mouth disease on the serological response following vaccination in young dairy calves

In Israel, occurrence of foot and mouth disease (FMD) in dairy farms is rare. However, when FMD outbreaks occur, dairy calves are the most affected, despite routine vaccination. Contradictory findings exist regarding the effect of age and maternally derived antibodies (MDA) on the serological response following vaccinations against FMD in dairy calves. Furthermore, the long term effect of FMD vaccination regimen during early life was rarely assessed. This study was conducted in order to assess both the short and long term effects. In total 44 non-vaccinated calves were divided into four groups of different age. Calves were vaccinated up to four times and 484 serum samples were collected on 11 time points in a period of 70weeks. Virus neutralizing tests were performed in order to determine the neutralizing antibody titers (NAT) against the vaccine strains (homologous serotypes): O-4625, O-Manisa, ASIA-1-Shamir and the heterologous serotype A-Turkey-20/2006. A similar NAT pattern was observed to all serotypes and therefore statistical analysis was restricted to O-4625 serotype. The MDA titer was negatively associated with the age of the calves and the MDA half-life was 22days. We demonstrated that early vaccination of calves (younger than three months) resulted in low NAT, even after four repeated vaccinations, compared with vaccination of calves older than three months. The percentage of time in which these calves had a NAT above 2.0 (log10) between the age of six months and 1.5years was significantly lower compared to older calves (older than three months). Additionally, we found that by increasing the frequency of vaccination in calves older than three months, it is possible to reach high NAT by the age of one year. Adoption of such a vaccination regimen in Israel as well as other FMD endemic countries may allow better protection against FMD in dairy calves and reduction in FMD incidence.

Foot-and-Mouth Disease Impact on Smallholders - What Do We Know, What Don't We Know and How Can We Find Out More?

SummaryFoot‐and‐mouth disease (FMD) endemic regions contain three‐quarters of the world's FMD susceptible livestock and most of the world's poor livestock keepers. Yet FMD impact on smallholders in these regions is poorly understood. Diseases of low mortality can exert a large impact if incidence is high. Modelling and field studies commonly find high FMD incidence in endemic countries. Sero‐surveys typically find a third of young cattle are sero‐positive, however, the proportion of sero‐positive animals that developed disease, and resulting impact, are unknown. The few smallholder FMD impact studies that have been performed assessed different aspects of impact, using different approaches. They find that FMD impact can be high (>10% of annual household income). However, impact is highly variable, being a function of FMD incidence and dependency on activities affected by FMD. FMD restricts investment in productive but less FMD‐resilient farming methods, however, other barriers to efficient production may exist, reducing the benefits of FMD control. Applying control measures is costly and can have wide‐reaching negative impacts; veterinary‐cordon‐fences may damage wildlife populations, and livestock movement restrictions and trade bans damage farmer profits and the wider economy. When control measures are ineffective, farmers, society and wildlife may experience the burden of control without reducing disease burden. Foot‐and‐mouth disease control has benefitted smallholders in South America and elsewhere. Success takes decades of regional cooperation with effective veterinary services and widespread farmer participation. However, both the likelihood of success and the full cost of control measures must be considered. Controlling FMD in smallholder systems is challenging, particularly when movement restrictions are hard to enforce. In parts of Africa this is compounded by endemically infected wildlife and limited vaccine performance. This paper reviews FMD impact on smallholders in endemic countries. Significant evidence gaps exist and guidance on the design of FMD impact studies is provided.

Evidence of foot-and-mouth disease virus infection in yaks reared in a farm of Arunachal Pradesh

Foot-and-mouth disease (FMD) is an economically devastating disease of cloven-hoofed animals including wildlife and semidomesticated species of mithun and yak. A serological survey was conducted during the months of June-July 2014 to gather evidence of FMD virus (FMDV) activity in yaks maintained in a farm located at Nyukmadung village of West Kameng district in Arunachal Pradesh. Serum samples were collected from 70 yaks and 3AB nonstructural protein (NSP) ELISA was performed to assess FMDV NSPantibodies (NSP-Abs). There appeared a positive serological response from 21 (30%) animals providing retrospective evidence of their previous exposure to FMDV, which correlated with the collected epidemiological information. Not a single animal borne post reported outbreak in October 2009 was found positive in NSP ELISA thereby ruling out any incidence of FMD in the farm after 2009. Also, persistence of 3AB NSP-Ab through 5 years post-outbreak was evident in the infected yaks.

Farm Community Impacts of Foot-and-Mouth Disease Outbreaks in Cattle and Buffaloes in Karnataka State, India

This study was conducted to assess the impact of Foot-and-mouth Disease (FMD) outbreak in cattle and buffaloes on farming community in Kolar district, Karnataka state, India. Primary data were collected using pre-tested schedule from 178 sample farms using multistage random cluster sample technique. The results revealed that 78% of surveyed villages were affected with FMD. The FMD incidence risk was high across the herd sizes, whereas the mortality risk was high in small herds. In indigenous cattle, the highest loss due to FMD was distress sale (208 USD) followed by other losses, whereas, in Crossbred cattle, the highest loss was mortality loss (515 USD) followed by distress sale (490 USD), milk yield loss (327 USD), treatment cost (38 USD) and extra labour engagement expenses for nursing of FMD-affected bovines (30 USD). In local and upgraded buffaloes, the mean total loss per affected animal was 440 USD and 513 USD, respectively. A very high variability in the loss per animal was observed across the type of losses in the Crossbred cattle, and it may be due to differences in age of the FMD-infected animal, value of the animal, milking stage, lactation levels, herd sizes and labour engagement levels, etc. In local and upgraded buffaloes, the mean total loss per animal was 639 USD and 1008 USD, respectively. The sensitivity analysis for 5% change in price revealed that the mean total loss per animal was positively correlated with price. Further, the social impact elicitation revealed that majority of the livestock owners perceived FMD had caused permanent asset loss, which in turn increased psychological stress of the family. The estimated losses and social impact due to FMD signify the importance of the intervention to control the disease and thus socio-economic gain to the farmer and society at large.

Epidemiology of foot and mouth disease in Karnataka state, India: a retrospective study.

A retrospective study on the epidemiology of foot and- mouth disease (FMD) in Karnataka, India between the years 1977 and 2012-13 based on the data collected through passive and active surveillance was undertaken. A total of 11,159 outbreaks with 0.271 million cases of FMD were recorded from 30 different revenue districts of Karnataka. There was a significant difference between the years for the annual incidence of FMD (P=<0.001, F=19.10) and also between the months (P=<0.001, F=4.22). Cattle and buffaloes were the predominant species affected being involved in all of the outbreaks reported. A significant correlation was observed between livestock density and the number of outbreaks reported (r=0.70, p<0.02), and number of cases (r=0.76, p<0.01) for all the agro-climatic zones. The Central dry zone (n=2257, 19.89%) reported the highest number of outbreaks followed by the Northern dry zone (n=1881, 16.58%) and the Southern transition zone (n=1761, 15.52%), and attack rates were concentrated in the North/Northeastern/Central dry and transition zones. A large majority of the outbreaks were caused by serotype O (64.04%), followed by Asia 1 (19.87%) and A (12.27%). Serotype C was not reported since 1993 in the state. In recent years, serotype O has dominated (82.59%), with the rest of the outbreaks being almost equally caused by A (9.01%) and Asia 1 (8.40%). The study highlights the significance of the O serotype and cattle as the main indicator species in the epidemiology of FMD in Karnataka, India. The findings from this study can be used as baseline epidemiological data for further research to identify endemic and epidemic areas for the development of a sustainable programme for the progressive control of FMD in the state of Karnataka as well as other endemic settings.

Development of a tetra-primer ARMS PCR-based assay for detection of a novel single-nucleotide polymorphism in the 5' untranslated region of the bovine ITGB6 receptor gene associated with foot-and-mouth disease susceptibility in cattle.

ITGB6 is known to be one of the major receptor components involved in host tropism of foot-and-mouth disease (FMD) virus in cattle. A competitive PCR technique called ARMS PCR was adapted to identify a single-nucleotide polymorphism (SNP), G29A, db SNP Id: rs109075046, in the 5' untranslated region (5'UTR) of the bovine ITGB6 gene. Genotype profiling identified three kinds of genetic variation within the targeted SNP among Frieswal crossbred cattle. The occurrence of FMD in the three genotypes was further evaluated, revealing a clear role in the incidence of FMD in the studied population.

Participatory epidemiology and associated risk factors of foot-and-mouth disease in cattle in South Omo zone, South-Western Ethiopia

Participatory appraisal was applied to determine the major cattle diseases and investigate the epidemiology of foot-and-mouth disease (FMD) in South Omo pastoral and agro-pastoral livestock production system. Furthermore, assessment of associated risk factors in particular concern to local production system was conducted by participatory appraisal. The participatory methods used were clinical observation, matrix ranking and scoring, proportional piling and seasonal calendar. The result of matrix ranking and scoring showed that hemorrhagic septicemia, contagious bovine pleuro pneumonia (CBPP), trypanosomosis, FMD, black leg and anthrax were the major diseases of cattle in South Omo zone. The finding of seasonal calendar indicated that incidence of FMD was found to be high during the dry season than cold dry season. The lowest incidence was reported during the rainy season. Similarly, contact of herds with wild animals increased during dry season than rainy season. Based on this finding participatory epidemiology was found to be an important approach in veterinary investigations and it can also be used besides to conventional approaches. Key words: Foot-and-mouth disease (FMD), participatory appraisal, South Omo zone, cattle, risk factors.

Evaluating the efficiency of participatory epidemiology to estimate the incidence and impacts of foot-and-mouth disease among livestock owners in Cambodia

The economic and social impacts of foot-and-mouth disease (FMD) for livestock owners of developed countries have been extensively documented over the past few years. In developing countries such as Cambodia, this evaluation is often lacking due to the scarcity of accurate data. In the present study, we used a range of participatory tools to infer farmers’ knowledge and perception, and the relative incidence of FMD from January 2009 to June 2010 in fifty-one villages of Svay Rieng province, Cambodia. In addition, the detection of non-structural protein at village level was used to cross-validate the results from the participatory epidemiology (PE) study. A quantitative assessment using Bayesian modeling was carried out to assess the ability of PE to retrospectively determine the FMD-infected status of a village in Cambodia. Our study shows that even if FMD is ranked second in the list of priority diseases, livestock owners did not see any benefit in reporting it since the disease entailed low direct losses. The average clinical incidence rates at individual level for cattle-buffaloes and pigs in infected villages were assessed by proportional piling at 18% and 11%, respectively for the year 2009. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PE study were estimated at 87%, 30%, 51% and 74%, respectively. This approach seems to largely overestimate the presence of the disease but proves useful in evaluating the impact of FMD at household level and in understanding the reasons for not reporting it. This information may be important in establishing well-adapted disease prevention and control strategies in Cambodia.

Mitigation Strategies for Foot and Mouth Disease

Prediction of epidemics such as Foot and Mouth Disease (FMD) is a global necessity in addressing economic, political and ethical issues faced by the affected countries. In the absence of precise and accurate spatial information regarding disease dynamics, learning- based predictive models can be used to mimic latent spatial parameters so as to predict the spread of epidemics in time. This paper analyzes temporal predictions from four such learning-based models, namely: neural network, autoregressive, Bayesian network, and Monte-Carlo simulation models. The prediction qualities of these models have been validated using FMD incidence reports in Turkey. Additionally, the authors perform simulations of mitigation strategies based on the predictive models to curb the impact of the epidemic. This paper also analyzes the cost-effectiveness of these mitigation strategies to conclude that vaccinations and movement ban strategies are more cost-effective than premise culls before the onset of an epidemic outbreak; however, in the event of existing epidemic outbreaks, premise culling is more effective at controlling FMD.

Risk factors for foot-and-mouth disease in sedentary livestock herds in selected villages in four regions of Bhutan

AIMS: To identify livestock husbandry practices important for transmission of foot-and-mouth disease (FMD) in the herds and villages of four regions in Bhutan. To consider using this information to enhance the current prevention and control programme, a consideration arising from the failure to control FMD in spite of a control programme in place. METHODS: Between March and May 2009, 383 livestock farmers originating from 80 villages in four districts of Bhutan were interviewed, using a structured questionnaire, about the livestock management practices and incidence of FMD in their herds. Multivariable logistic regression was used to quantify the risk factors that predicted the outcome variable ‘farmer-diagnosed FMD in Bhutan’. RESULTS: Sixty-two percent (49/79) of the villages and 87/355 (24%) of herds surveyed had at least one outbreak of FMD within the 5 years preceding the survey. The odds of having FMD in a herd increased substantially (OR=39.2; p<0.0001) when cattle mixed with herds from other nearby villages compared with those where mixing did not occur. Those cattle herds mixing with six or more other herds within the same village were 5.3 times (p<0.0001) more likely to have had FMD than those mixed with fewer than six herds. Farmers who fed kitchen waste to cattle were 14.1 times (p<0.0001), and those who sent their animals for grazing in the forest were 3.1 times (p=0.014), more likely to report FMD in their herds than those who did not. Farmers who kept their cattle always housed in a shed during the day (OR=0.033) or at night (OR=0.29) were less likely to report FMD than those who did not (p<0.04). CONCLUSIONS: Mixing of cattle at grazing areas was identified as a risk factor for FMD. This indicates that spread from infected herds and villages, through close contact, could be an important source of disease for non-infected herds in Bhutan. Therefore, quarantining of early cases in affected herds or villages could reduce the spread of disease within and between villages. This study also highlights the potential role of feeding kitchen waste to cattle as a risk factor for FMD. The findings from this study could be considered for strengthening of the FMD control programme in Bhutan.

A retrospective study on the epidemiology of foot-and-mouth disease in Bhutan

A retrospective study on the outbreaks of foot-and-mouth disease (FMD) in Bhutan, between the years 1996 and 2008, based on the data collected through passive surveillance, was undertaken. A total of 230 outbreaks of FMD at sub-district level were recorded in 299 villages located in 19 out of the 20 districts in the country. There were no significant differences between the years (P = 0.998) or months (P = 0.989) on the incidence of FMD. The sub-districts in the north (altitude >1,000 m above mean sea level) had significantly (P = 0.008) higher incidences of outbreaks in winter than in summer. The sub-districts that shared border with India had significantly more outbreaks than those that didn't (P = 0.001). Cattle were the most predominant species affected being involved in all of the outbreaks reported. Serotype O, which constituted 70.6% of the outbreaks typed was the most predominant serotype prevalent in Bhutan followed by A (16.7%), Asia 1 (8.8%), and C (3.9%). Cattle density was significantly positively correlated (P = 0.023) with the incidence of disease. Three waves of outbreaks of epidemic proportions were reported in 1997/1998, 2002/2003, and 2007/2008 due to the PanAsia strain of the O serotype. The study highlights the incursion of the PanAsia strain of the O serotype into the country, possibly, through the transboundary movement of animals and the need for active surveillance of FMD, especially at the border areas. The study also highlights the significance of the O serotype and cattle as the main indicator species in the epidemiology of FMD in Bhutan. The findings from this study can be used as baseline epidemiological data for further research to understand the epidemiology of FMD in Bhutan.

Simulative modeling to control the Foot and Mouth Disease epidemic

Abstract Reoccurring instances of Foot and Mouth Disease (FMD) in countries with underdeveloped infection surveillance have been taking a heavy toll on the lives of millions of livestock and causing annual financial losses worth billions of US dollars every year. FMD has been widely analyzed as a highly infectious disease that spreads rapidly with the movement of infected or contaminated animals of multiple species, and movement of people as well. Here, a metapopulation based stochastic model is implemented to assess the FMD infection dynamics and to curb the economic losses in such countries. This model predicts the spatio-temporal evolution of FMD over a weighted contact network where the weights are characterized by the effect of wind and movement of animals and humans. FMD Incidence data from Turkey is used to calibrate and validate the model, and the predictive performance of our model is compared with baseline models as well. Finally, cost effective mitigation strategies are simulated using the theoretical concept of network fragmentation. Based on the theoretical reduction in the total number of infected animals, several practical mitigation strategies are proposed and their cost effectivenesses are also analyzed.

Epidemiological Patterns of Foot-and-Mouth Disease Worldwide

Foot-and-Mouth Disease (FMD) is a clinical syndrome in animals due to FMD virus that exists in seven serotypes, whereby recovery from one sero-type does not confer immunity against the other six. So when considering intervention strategies in endemic settings, it is important to take account of the characteristics of the different serotypes in different ecological systems. FMD serotypes are not uniformly distributed in the regions of the world where the disease still occurs. For example, the cumulative incidence of FMD serotypes show that six of the seven serotypes of FMD (O, A, C, SAT-1, SAT-2, SAT-3) have occurred in Africa, while Asia contends with four sero-types (O, A, C, Asia-1), and South America with only three (O, A, C). Periodically there have been incursions of Types SAT-1 and SAT-2 from Africa into the Middle East. This paper describes the global dynamics for the seven sero-types and attempts to define FMD epidemiological clusters in the different regions of the world. These have been described on a continent by continent basis. The review has reaffirmed that the movement of infected animals is the most important factor in the spread of FMD within the endemically infected regions. It also shows that the eco-system based approach for defining the epidemiological patterns of FMD in endemic, which was originally described in South America, can apply readily to other parts of the world. It is proposed that any coordinated regional or global strategy for FMD control should be based on a sound epidemiological assessment of the incidence and distribution of FMD, identifying risk sources as either primary or secondary endemic eco-systems.

Temporal and Spatial Distributions of Foot-and-Mouth Disease Under Three Different Strategies of Control and Eradication in Colombia (1982–2003)

Outbreaks of foot-and-mouth disease (FMD) from January 1982 through December 2003 were used to examine variations in serotype- and species-specific risk for three control programmes in Colombia: (1982-1983) vaccination, using an aluminium hydroxide, saponin adjuvant, required but not enforced; (1984-1996) vaccination, using an oil double-emulsion adjuvant, required but not enforced; and (1997-2003) enforced vaccination, using an oil double-emulsion adjuvant, restricted animal movement enforced, and slaughter of infected animals. Hypotheses were tested for trend, cyclicity and seasonality in FMD occurrence, and for species- and serotype-specific differences in morbidity and case-fatality. The spatial density of outbreaks was estimated by kernel smoothing. The frequency of outbreaks decreased most between 1984 and 1996 (p < 0.01) for serotype A and between 1997 and 2003 (p < 0.01) for serotype O. Outbreaks occurred in cycles of 3-4 years for both serotypes (p < 0.05). Morbidity was not significantly different in pigs from that in cattle for serotype A-associated outbreaks (p = 0.314), but was higher in pigs than in cattle (p = 0.019) for serotype O-associated outbreaks. For both serotypes, case-fatality was higher for pigs than for cattle (p < 0.009). Temporal variation in FMD incidence provided insight into the expected evolution of FMD control for countries with similar conditions and where FMD is endemic.