FMD Outbreak Research Articles

Assessment of Financial Impact of Foot and Mouth Disease on Smallholder Cattle Farmers in Southern Cambodia

The financial impact of an outbreak of FMD in 2010 on 62 smallholder cattle farmers in four villages in southern Cambodia was investigated by a financial impact survey questionnaire. Financial losses associated with FMD infection were severe with variation depending on whether the animal survived or died or was used for draft. The average post-FMD loss varied from USD 216.32, a 54% reduction from the pre-FMD value because of weight loss and treatment costs, to USD 370.54, a 92% reduction from pre-FMD values if the animal was treated, died and a rental draft replacement was required. Partial budget analysis identified a strongly positive incentive for cattle to be vaccinated biannually for FMD, providing USD 31.48 per animal for each animal owned. However low vaccination rates suggest that farmers are mostly unaware of the need or averse to the practice of vaccinating their cattle for FMD. This may be due to poor understanding of preventative disease strategies such as vaccination, unavailable disposable income for purchase of vaccines, and failure to recognize the full costs that are incurred when the disease occurs. Enhancing smallholder cattle productivity through the introduction of forage growing systems has been suggested as a pathway for alleviating rural poverty in the Mekong region. As our financial analysis identified a net benefit of vaccination for smallholder farmer enterprises in an endemic FMD area in Cambodia, it is considered important that farmer education strategies aimed at improving cattle productivity, also include both access to vaccine and training in preventative disease risk management and biosecurity practices in Cambodia.

No long-term influence of movement restriction regulations on the contact-structure between and within cattle holding types in the Netherlands

BackgroundMore and more countries hold databases on cattle movements. The primary purpose of the registration of cattle movements is to provide data for quick tracing of contagious animals in case of disease outbreaks and food safety scares. Nevertheless, these data can also be used for analytical studies to get insight into the nature of the contact structure between and within cattle holding types. This paper focuses on the effect post-2001 FMD movement regulations have had on the number of cattle movements between different and within the same cattle holding types. Important characteristics and dynamics of cattle movement patterns of Dutch cattle holding types were identified using data on cattle movements after the 2001 FMD outbreak.ResultsThe results showed that in 2001, just after the FMD outbreak when strict movement restriction regulations were in force, a reduced number of cattle movements was seen compared to before the FMD outbreak. However, the number of cattle movements off-farm for live trade and the number of imported cattle increased in the period 2002–2004 to higher levels than expected, i.e. to levels almost as high as before the FMD outbreak, despite operative movement restriction regulations. As the number of cattle movements to and from traders strongly decreased just after the FMD outbreak in 2001, traders regained their central role again in the network in the years 2002–2004.ConclusionsQuantifying the Dutch cattle contact structure between and within holding types up to 3.5 years after the FMD outbreak gave evidence that the post-FMD movement restriction regulations were not able to reduce the number of cattle movements in the longer term. With that the risk of a large epidemic increased. Quantifying contact structures based on animal movement data between different and within the same cattle holding types is important for targeting disease control and for assessing compliance with legislation.

台湾の口蹄疫

台湾の口蹄疫

家畜伝染病予防法の改正について

After the FMD outbreak in Miyazaki prefecture in 2010, government of Japan amended the Animal Infectious Diseases Control Low in April 2011. In this amendment, compulsory notification of the suspected animal, regulations for animal keepers about preventive measures in farms, penalties for delayed notification were reinforced.

Epidemic and Economic Impacts of Delayed Detection of Foot-And-Mouth Disease: A Case Study of a Simulated Outbreak in California

The epidemic and economic impacts of Foot-and-mouth disease virus (FMDV) spread and control were examined by using epidemic simulation and economic (epinomic) optimization models. The simulated index herd was a ≥2,000 cow dairy located in California. Simulated disease spread was limited to California; however, economic impact was assessed throughout the United States and included international trade effects. Five index case detection delays were examined, which ranged from 7 to 22 days. The simulated median number of infected premises (IP) ranged from approximately 15 to 745, increasing as the detection delay increased from 7 to 22 days. Similarly, the median number of herds under quarantine increased from approximately 680 to 6,200, whereas animals slaughtered went from approximately 8,700 to 260,400 for detection delays of 7-22 days, respectively. The median economic impact of an FMD outbreak in California was estimated to result in national agriculture welfare losses of $2.3-$69.0 billion as detection delay increased from 7 to 22 days, respectively. If assuming a detection delay of 21 days, it was estimated that, for every additional hr of delay, the impact would be an additional approximately 2,000 animals slaughtered and an additional economic loss of $565 million. These findings underline the critical importance that the United States has an effective early detection system in place before an introduction of FMDV if it hopes to avoid dramatic losses to both livestock and the economy.

Inhibitors of foot and mouth disease virus targeting a novel pocket of the RNA-dependent RNA polymerase.

BackgroundFoot-and-Mouth Disease Virus (FMDV) is a picornavirus that infects cloven-hoofed animals and leads to severe losses in livestock production. In the case of an FMD outbreak, emergency vaccination requires at least 7 days to trigger an effective immune response. There are currently no approved inhibitors for the treatment or prevention of FMDV infections.Methodology/Principal FindingsUsing a luciferase-based assay we screened a library of compounds and identified seven novel inhibitors of 3Dpol, the RNA-dependent RNA polymerase of FMDV. The compounds inhibited specifically 3Dpol (IC50s from 2-17 µM) and not other viral or bacterial polymerases. Enzyme kinetic studies on the inhibition mechanism by compounds 5D9 and 7F8 showed that they are non-competitive inhibitors with respect to NTP and nucleic acid substrates. Molecular modeling and docking studies into the 3Dpol structure revealed an inhibitor binding pocket proximal to, but distinct from the 3Dpol catalytic site. Residues surrounding this pocket are conserved among all 60 FMDV subtypes. Site directed mutagenesis of two residues located at either side of the pocket caused distinct resistance to the compounds, demonstrating that they indeed bind at this site. Several compounds inhibited viral replication with 5D9 suppressing virus production in FMDV-infected cells with EC50 = 12 µM and EC90 = 20 µM).SignificanceWe identified several non-competitive inhibitors of FMDV 3Dpol that target a novel binding pocket, which can be used for future structure-based drug design studies. Such studies can lead to the discovery of even more potent antivirals that could provide alternative or supplementary options to contain future outbreaks of FMD.

Coping without farm location data during a foot-and-mouth outbreak

Since the 2001 outbreak of FMD in the United Kingdom (4, 5), the epidemiology of future similar outbreaks has become a popular example for the application of mathematical models of infectious disease (6–8). In particular, spatially explicit simulation models (9) have helped to quantify the relationship between farm density in the United Kingdom and transmissibility (10). Although similar approaches have been used to describe likely patterns of transmission in the United States (11), Australia (12), Korea (13), New Zealand (14), and the Netherlands (15), analysis of the 2001 United Kingdom outbreak benefits from an unusually rich dataset. Precise locations are available for both affected and unaffected farms; furthermore, the number of infected premises during 2001 was sufficient to permit accurate estimation of key transmission parameters. Together, the rich data from the 2001 United Kingdom outbreak and the development of simulation models have greatly facilitated the investigation of spatially heterogeneous intervention policies. For example, it has been shown that if a well-matched vaccine were …

Airborne spread of foot-and-mouth disease – Model intercomparison

Foot-and-mouth disease virus (FMDV) spreads by direct contact between animals, by animal products (milk, meat and semen), by mechanical transfer on people or fomites and by the airborne route, with the relative importance of each mechanism depending on the particular outbreak characteristics. Atmospheric dispersion models have been developed to assess airborne spread of FMDV in a number of countries, including the UK, Denmark, Australia, New Zealand, USA and Canada. These models were compared at a Workshop hosted by the Institute for Animal Health/Met Office in 2008. Each modeller was provided with data relating to the 1967 outbreak of FMD in Hampshire, UK, and asked to predict the spread of FMDV by the airborne route. A number of key issues emerged from the Workshop and subsequent modelling work: (1) in general all models predicted similar directions for livestock at risk, with much of the remaining differences strongly related to differences in the meteorological data used; (2) determination of an accurate sequence of events on the infected premises is highly important, especially if the meteorological conditions vary substantially during the virus emission period; (3) differences in assumptions made about virus release, environmental fate and susceptibility to airborne infection can substantially modify the size and location of the downwind risk area. All of the atmospheric dispersion models compared at the Workshop can be used to assess windborne spread of FMDV and provide scientific advice to those responsible for making control and eradication decisions in the event of an outbreak of disease.

Analytic approximation of spatial epidemic models of foot and mouth disease

The effect of spatial heterogeneity in epidemic models has improved with computational advances, yet far less progress has been made in developing analytical tools for understanding such systems. Here, we develop two classes of second-order moment closure methods for approximating the dynamics of a stochastic spatial model of the spread of foot and mouth disease. We consider the performance of such ‘pseudo-spatial’ models as a function of R 0 , the locality in disease transmission, farm distribution and geographically-targeted control when an arbitrary number of spatial kernels are incorporated. One advantage of mapping complex spatial models onto simpler deterministic approximations lies in the ability to potentially obtain a better analytical understanding of disease dynamics and the effects of control. We exploit this tractability by deriving analytical results in the invasion stages of an FMD outbreak, highlighting key principles underlying epidemic spread on contact networks and the effect of spatial correlations.

Market implications of FMD epidemics in the Finnish pig sector: Does market structure matter?

This paper examines the role of market coordination and market distortions caused by a hypothetical FMD outbreak in the Finnish pig sector. By using stochastic dynamic programming, it simulates the consequences of two outbreak scenarios (large vs. small) under two distinct market regimes (competitive market vs. monopoly in the domestic supply). Simulated losses depend on the magnitude of outbreak and expected duration of possible turndown of meat exports, whereas market regime has a limited impact.

Short-term economic impact of Foot and Mouth disease outbreak in a large Diary Farm in Kiambu District, Kenya

The short term farm level economic impact of foot and mouth disease outbreak in a large scale diary farm was assessed during quarantine period (35 days) and 60 days after lifting the quarantine. Direct and indirect areas that contribute to financial losses were identified for the period of observation (95 days) the greatest direct financial impact due to milk losses (42.0%) followed by purchase of additional feeds (13.6%) and culling of milk cows that developed chronic mastitis (12.5%). the other direct costs were extra labor inputs (8.9%), veterinary fees (3.3%), transport (3.0%) deaths(3.0%) drugs(2.9%) abortions (1.4%) and chemicals (0.5). the indirect costs associated with the effects of the quarantine period on other farm enterprises. During quarantine period on other farm enterprises. During the quarantine period there were no sales of pigs and hay and the retained pigs in addition to not fetching premium prices required additional feeds. The overall short-term farm level direct and indirect costs associated with outbreak amounted to Ksh 1,201,950 equivalent to US $ 16,026 (1 US $= 75Ksh.). This colossal economic loss within such a short period of time indicates that the control of FMD is of paramount importance in the diary farming sector in Kenya. The factors that would determine the magnitude of the financial losses due to an outbreak of FMD are discussed. The Kenya Veterinarian Vol. 22 2001: pp. 76-78

Immune responses to foot-and-mouth disease virus in pig farms after the 1997 outbreak in Taiwan

This paper reports on a retrospective study of the antibody responses to structural and non-structural proteins of FMD virus O Taiwan 97 in six pig herds in Taiwan in the year after the 1997 Taiwanese FMD outbreak. All herds were vaccinated against FMD after the outbreak as part of the countrywide control program. Three of the herds had confirmed FMD infections (herds N, O and P) and three herds remained non-infected (herds K, L and M). The serum neutralizing antibody titers and the non-structural protein ELISA (NSP) antibody responses in sows and 1-month-old pigs in the infected herds were higher than in the non-infected herds, but over time a number of positive NSP reactors were detected. From the serological studies and the herd monitoring and investigations it was considered that the FMD NSP positive reactors may not have constituted a true reservoir of FMD virus infection especially in herds where susceptible pigs were no longer present post-exposure or post-vaccination. Pigs vaccinated with an unpurified FMD type O vaccines being used at that time also showed false positive responses for NSP antibodies.

Spatiotemporal patterns and risks of herd breakdowns in pigs with postweaning multisystemic wasting syndrome

A retrospective cohort study of 116 British pig farms was undertaken to investigate the epidemiological risk factors associated with herd breakdowns with postweaning multisystemic wasting syndrome (pmws). Farmers reported the...

The potential role of wild and feral animals as reservoirs of foot-and-mouth disease

We investigated the potential role of feral pigs and wild deer as FMD reservoirs with a susceptible–latent–infected–recovered geographic-automata model, using spatially referenced data from southern Texas, USA. An uncontrolled FMD outbreak initiated in feral pigs and in wild deer might infect up to 698 (90% prediction interval 181, 1387) and 1557 (823, 2118) cattle and affect an area of 166 km 2 (53, 306) and 455 km 2 (301, 588), respectively. The predicted spread of FMD virus infection was influenced by assumptions we made regarding the number of incursion sites and the number of neighborhood interactions between herds. Our approach explicitly incorporates the spatial relationships between domesticated and non-domesticated animal populations, providing a new framework to explore the impacts, costs, and strategies for the control of foreign animal diseases with a potential wildlife reservoir.

Value of animal traceability systems in managing a foot-and-mouth disease outbreak in southwest Kansas (2007)

Concerns regarding management of animal disease and related perceptions about food safety have escalated substantially in recent years. Terrorist attacks of September 2001, discovery of bovine spongiform encephalopathy (BSE) in a dairy cow in December 2003 in Washington, subsequent discoveries of BSEinfected animals in Texas in 2005 and Alabama in 2006, and recent worldwide outbreaks of highly contagious animal diseases (i.e., foot-and-mouth disease [FMD] and Avian influenza) have made apparent the need for animal traceability in U.S. livestock production and marketing. In addition, animal identification systems are rapidly developing throughout the world, effectively increasing international trading standards. One way to combat and more quickly arrest spread of contagious diseases is through animal ID. Capability to rapidly identify locations where an animal has been affects the ability to isolate, trace, and arrest spread of a disease. Animal ID systems are rapidly developing throughout the world and the U.S. is behind many other countries in this development. Efforts to develop animal ID systems in the U.S. were launched prior to the initial BSE discovery, but they gained considerable momentum afterwards. The National Animal Identification System is intended to identify specific animals in the U.S. and record their movement over their lifetime. The goal is to enable a 48-hour trace-back of the movements of any diseased or exposed animal. This will limit spread of animal diseases by enabling faster trace-back of infected animals; limit production losses due to disease presence; reduce the costs of government control, intervention, and eradication; and minimize potential international trade losses3. The purpose of this research is to determine the economic implications of increased improvements in animal ID systems in the event of an FMD outbreak in southwest Kansas. Specifically, a disease spread model is used to determine the probable spread of a hypothetical FMD outbreak. Results from the disease-spread model are integrated into an economic framework to determine economic impacts.

Space–time interaction as an indicator of local spread during the 2001 FMD outbreak in the UK

During the 2001 FMD outbreak in the UK, decisions on the level of implementation of control measures were supported by predictive models. Models were mainly used as macro-level tools to predict the behaviour of the disease in the whole country rather than at the local level. Here we explore the use of the magnitude and characteristics of the space–time interaction as an indicator of local spread and, indirectly, of the effectiveness of control measures aimed at reducing short-range transmission during the course of a major livestock disease epidemic. The spatiotemporal evolution patterns are described in the four main clusters that were observed during the outbreak by means of the hazard rate and space–time K-function ( K( s, t)). For each local outbreak, the relative measure D 0( s, t), derived from K( s, t), which represents the excess risk attributable to the space–time interaction was calculated for consecutive 20-day temporal windows to represent the dynamics of the space–time interaction. The dynamics of the spatiotemporal interaction were very different among the four local clusters, suggesting that the intensity of local spread, and therefore the effectiveness of control measures, markedly differed between local outbreaks. The large heterogeneity observed in the relative impact of being close in time and space to an infected premises suggests that the decision making in relation to control of the outbreak would have benefited from indicators of local spread which could be used to complement global predictive modelling results. Despite its limitations, our results suggest that the real-time analysis of the space–time interaction can be a valuable decision support tool during the course of a livestock disease epidemic.

Comparison of sensitivity and specificity in three commercial foot-and-mouth disease virus non-structural protein ELISA kits with swine sera in Taiwan

Three commercialized ELISA kits for the detection of antibodies to the non-structural proteins (NSPs) of FMD virus were compared, using sera from uninfected, vaccinated, challenged and naturally infected pigs. The kinetics of the antibody response to NSPs was compared on sequential serum samples in swine from challenge studies and outbreaks. The results showed that ELISA A (UBI) and ELISA B (CEDI) had better sensitivity than that of the 3ABC recombinant protein-based ELISA C (Chekit). The peak for detection of antibodies to NSPs in ELISA C was significantly delayed in sera from natural infection and challenged swine as compared to the ELISA A and B. The sensitivity of the three ELISAs gradually declined during the 6-month post-infection as antibodies to NSP decline. ELISA kits A and B detected NSP antibody in 50% of challenged pigs by the 9–10th-day and 7–8th-day post-challenge, respectively. ELISA B and C had better specificity than ELISA A on sequential serum samples obtained from swine immunized with a type O FMD vaccine commercially available in Taiwan. Antibody to NSPs before vaccination was not detected in swine not exposed to FMD virus, however, antibody to NSPs was found in sera of some pigs after vaccination. All assays had significantly lower specificity when testing sera from repeatedly vaccinated sows and finishers in 1997 that were tested after the 1997 FMD outbreak. However, when testing sera from repeatedly vaccinated sows or finishers in 2003–2004, the specificity for ELISAs A, B and C were significantly better than those in 1997. This effect was less marked for ELISA A. The ELISA B was the best test in terms of the highest sensitivity and specificity and the lowest reactivity with residual NSP in vaccinates.

Did Foot-and-Mouth Disease-Control Operations Affect Rodenticide Exposure in Raptors?

The source outbreak of the 2001 foot-and-mouth (FMD) epidemic in Britain was on a farm in northeast England (Northumberland) in February. The disease then spread rapidly throughout England, Wales, and the Scottish borders. This was due to transportation of infected animals and associated airborne transmission of the disease before the outbreak was recognized and control measures implemented (Scudamore 2002). There were just over 2,000 confirmed FMD cases, most of which occurred between March and October (DEFRA 2002). Part of the strategy for containing the disease was the slaughter of all livestock on infected premises, on neighboring holdings, and on other holdings considered to have close contact with infected animals. Thus, the total number of premises on which animals were slaughtered exceeded the number of confirmed FMD cases. Animals were killed on the farm premises, and the scale of the cull (peak slaughter rates of half a million animals per week) meant that there could be a delay of some days between slaughter and carcass disposal. Scavengers, particularly the brown rat (Rattus norvegicus), which might feed on the abundant carcasses, were considered a potential route of FMD transmission and a general hygiene problem. Rat control was carried out on all affected premises by teams, which included private contractors, led by the Ministry of Agriculture, Fisheries and Food (now, the Department for Environment, Food and Rural Affairs [DEFRA]). Ministry teams baited solely with the second-generation anticoagulant (SGAR), difenacoum, whereas contractors used difenacoum and another SGAR, bromadiolone (P. Butt, DEFRA, personal communication). We are not aware of any published records for the amount of bait used during the epidemic, but it was estimated that typically no more than 20 kg bait was used on each premises, although more than 100 kg, and occasionally more than 300 kg, was required on a small proportion (,10%) of farms with very high rat populations (P. Butt, DEFRA, personal communication). The average amount of difenacoum used per farm growing grassland and fodder crops in Britain is estimated to be approximately 14 kg per year (Garthwaite et al. 1999). Thus, the amount of difenacoum used over a few days on each treated premises during FMD clean-up operations could typically be up to 40% more than the amount normally used over a whole year, and in some cases, it exceeded normal annual usage more than 20-fold. Routine use of difenacoum and other SGARs for pest control in Britain is known to be associated with unintentional widespread exposure of a range of nontarget species, particularly avian and mammalian predators and scavengers (McDonald et al. 1998; Newton et al. 1999b; Shore et al. 2001; Burn et al. 2002; Shore et al. 2003a,b). Most of this exposure is thought to be secondary, caused by predators feeding on contaminated rodents, and exposure can result in mortality (Joermann 1998, Luttik et al. 1999, Carter and Burn 2000), although relatively few deaths have been diagnosed either in exposure studies (Newton et al. 1999b) or during investigations of mortality incidents (Barnett et al. 2000a,b; Barnett et al. 2002a,b, 2003). However, it has been argued that the levels of exposure and mortality in predators could increase if there was greater SGAR use (and associated increased numbers of rodents with SGAR residues), or if there were dietary shifts by predators toward eating more poisoned rodents (Shore et al. 2003a). The concern during the FMD outbreak was that the largescale use of SGARs during the epidemic could pose an increased risk to nontarget species by increasing the number of contaminated rodents available to predators on and around treated premises. Our aim was to determine whether the high use of SGARs, especially difenacoum, on FMD-infected premises was associated with increased SGAR exposure in 2 bird of prey species that are relatively common in Britain, the barn owl (Tyto alba) and the buzzard (Buteo buteo). We examined barn owls because their exposure to SGARs was already well characterized (Newton et al. 1990, Newton et al. 1999b, Shore et al. 2005), and we believed this would aid us in the interpretation of our data. There were no such previous studies of rodenticide residues in buzzards from England and Wales, but it was anticipated that this species might be at high risk of exposure during the FMD epidemic. This is because buzzards largely feed by scavenging (Newton 1979), and 1 E-mail: rfs@ceh.ac.uk

Cultural consequences of the FMD outbreak

Veterinary RecordVolume 158, Issue 7 p. 215-215 News & Report Cultural consequences of the FMD outbreak First published: 18 February 2006 https://doi.org/10.1136/vr.158.7.215Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume158, Issue7February 2006Pages 215-215 RelatedInformation

Stochastic models of foot and mouth disease in feral pigs in the Australian semi‐arid rangelands

SummaryFoot and mouth disease (FMD) is one of the world's most important livestock diseases and pigsSus scrofaare highly susceptible. In countries with significant feral pig populations, such as Australia, the possibility that FMD may become established in these populations is a cause of considerable concern.Current models of FMD in feral pigs in Australia are based on deterministic population and behavioural parameters. However, the population dynamics of feral pigs in the semi‐arid regions of Australia vary stochastically, in concert with the biomass of rainfall‐driven pasture.This study explored how stochastic variation in the population dynamics of feral pigs in semi‐arid rangelands affected the probability of persistence of an FMD epizootic, and its impact on the density of feral pigs. A stochastic model of feral pig population dynamics, with death rate linked to vegetation and rainfall, was linked to a deterministic model of FMD in feral pigs.Unlike the fully deterministic model, the stochastic model predicted inevitable extinction of the disease. When the transmission coefficient for FMD (β) was set at the mean value of 9 km2pig−1 day−1, the mean persistence time of the epizootic (in 1000 simulations) was 3338 days, with a maximum persistence time of 8439 days.On average the FMD epizootic reduced the population density of feral pigs, compared with the density of uninfected pig populations, by between 54% and 43% for transmission coefficients (β) equal to the estimated likely mean and minimum values (9·0 km2pig−1 day−1and 2·5 km2pig−1 day−1), respectively. This compares with a suppression of 27% in density for the equivalent deterministic model.Further stochasticity was introduced to the linked population and disease model by making the transmission coefficient β stochastic with values based on radio‐telemetry of a population of feral pigs in the semi‐arid rangelands over an 18‐month period.The addition of a stochastically varying β lowered the mean persistence time of the simulated epizootic to 1037 days in 1000 simulations and reduced the maximum persistence time to 3907 days. Pig density was reduced by 45% compared with uninfected populations.Synthesis and applications.These simulations suggest that any control programme to suppress a FMD outbreak in feral pigs in the semi‐arid rangelands of Australia should take account of prevailing environmental conditions when aiming to reduce feral pig populations beneath a threshold density (NT) below which the disease cannot persist. As theNTis higher than for the equivalent deterministic model, the disease may be easier to control than such models suggest.