The economic impact of foot and mouth disease control and eradication in the Philippines

Evaluation of foot and mouth disease control measures: Simulating two endemic areas of Thailand

Foot and mouth disease (FMD) is an important livestock disease in Thailand, with outbreaks occurring every year. However, the effects of FMD control measures in Thailand have received little research attention. Epidemiological models have been widely used to evaluate FMD outbreak control, but such a model has never been developed for Thailand. We constructed a stochastic between-farm transmission model to evaluate FMD control measures. The epidemiological unit of the model was the farm, which could be in different states: susceptible, latent, undetected infectious, detected infectious and recovered. The between-farm transmission was calculated by the sum of distance-dependent transmission and trade network transmission using parameters derived from FMD outbreaks in 2016-2017. We used this model to simulate the outbreaks with and without the implementation of the following control measures: culling all animals on infected farms, ring vaccination, animal movement restrictions and isolation of infected farms. The control measures were evaluated by estimating the number of secondarily infected farms and the outbreak duration for each scenario. The model was simulated in two study areas located in the Lamphaya Klang subdistrict (high farm density) and the Bo Phloi district (low farm density). The effects of control measures differed between the two study areas. When farm density was high, rigid control measures were required to prevent a major outbreak. Among all options, culling the animals on infected farms resulted in the lowest number of infected farms and the shortest outbreak duration. In contrast, for an area with a low farm density, less stringent control measures were sufficient to control the usually minor outbreaks. The results indicate that different areas require a different approach to control an outbreak of FMD.

Approaches for disease prioritization and decision-making in animal health, 2000-2021: a structured scoping review

This scoping review identifies and describes the methods used to prioritize diseases for resource allocation across disease control, surveillance, and research and the methods used generally in decision-making on animal health policy. Three electronic databases (Medline/PubMed, Embase, and CAB Abstracts) were searched for articles from 2000 to 2021. Searches identified 6, 395 articles after de-duplication, with an additional 64 articles added manually. A total of 6, 460 articles were imported to online document review management software (sysrev.com) for screening. Based on inclusion and exclusion criteria, 532 articles passed the first screening, and after a second round of screening, 336 articles were recommended for full review. A total of 40 articles were removed after data extraction. Another 11 articles were added, having been obtained from cross-citations of already identified articles, providing a total of 307 articles to be considered in the scoping review. The results show that the main methods used for disease prioritization were based on economic analysis, multi-criteria evaluation, risk assessment, simple ranking, spatial risk mapping, and simulation modeling. Disease prioritization was performed to aid in decision-making related to various categories: (1) disease control, prevention, or eradication strategies, (2) general organizational strategy, (3) identification of high-risk areas or populations, (4) assessment of risk of disease introduction or occurrence, (5) disease surveillance, and (6) research priority setting. Of the articles included in data extraction, 50.5% had a national focus, 12.3% were local, 11.9% were regional, 6.5% were sub-national, and 3.9% were global. In 15.2% of the articles, the geographic focus was not specified. The scoping review revealed the lack of comprehensive, integrated, and mutually compatible approaches to disease prioritization and decision support tools for animal health. We recommend that future studies should focus on creating comprehensive and harmonized frameworks describing methods for disease prioritization and decision-making tools in animal health.

Temporal analysis of the bovine lymph node transcriptome during cattle tick (Rhipicephalus microplus) infestation

Livestock production is a fundamental source of revenue and nutrition, wherein cattle-farming constitutes one of the major agricultural industries. Vectors and vector-borne diseases constitute one of the major factors that decrease the livelihood of all farming communities, more so in resource-poor communities and developing countries. Understanding the immunological responses during tick infestation in cattle is instrumental in the development of novel and improved tick control strategies, such as vaccines. In this study, gene expression patterns were compared within the lymph nodes of three cattle breeds at different life stages of the cattle tick, Rhipicephalus microplus. For Bonsmara (5/8Bos taurus indicus × 3/8B. t. taurus) cattle specifically, some 183 genes were found to be differentially expressed within the lymph nodes during larval and adult tick feeding, relative to uninfested cattle. Overall, the data provides evidence for a transcriptional regulatory network that is activated during immature tick infestation, but is down-regulated towards basal transcriptional levels when adult ticks are feeding. Specific processes in the lymph nodes of Bonsmara cattle were found to be differentially regulated on a transcriptional level. These include: (1) Leukocyte recruitment to the lymph node via chemokines and chemotaxis, (2) Trans-endothelial and intranodal movement on the reticular network, (3) Active regulation of cellular transcription and translation in the lymph node (including leukocyte associated cellular regulatory networks) and (4) Chemokine receptors regulating the movement of cells out of the lymph node. This work provides a first transcriptome analysis of bovine lymph node responses in tick-infested cattle. Findings show a dynamic immune response to tick infestation for the Bonsmara cattle breed, and that suppression of the maturation of the cattle hosts' immunity is especially evident during the larval feeding stages.

A history of FMD research and control programmes in Southeast Asia: lessons from the past informing the future

Foot and mouth disease (FMD) is a major animal health problem within Southeast Asia (SEA). Although Indonesia and more recently the Philippines have achieved freedom from FMD, the disease remains endemic on continental SEA. Control of FMD within SEA would increase access to markets in more developed economies and reduce lost productivity in smallholder and emerging commercial farmer settings. However, despite many years of vaccination by individual countries, numerous factors have prevented the successful control of FMD within the region, including unregulated ‘informal’ transboundary movement of livestock and their products, difficulties implementing vaccination programmes, emergence of new virus topotypes and lineages, low-level technical capacity and biosecurity at national levels, limited farmer knowledge on FMD disease recognition, failure of timely outbreak reporting and response, and limitations in national and international FMD control programmes. This paper examines the published research of FMD in the SEA region, reviewing the history, virology, epidemiology and control programmes and identifies future opportunities for FMD research aimed at the eventual eradication of FMD from the region.

Timeliness of vesicular disease notification system in Brazilian foot-and-mouth disease surveillance programme

Animal health surveillance programmes should be reliable and informative to ensure their effective implementation. As such, the regular assessment of those aiming to demonstrate the absence of disease, as well as the ability to detect outbreaks on time, is of vital importance. Several criteria make it possible to assess the performance of surveillance systems, including timeliness, which represents the speed between steps in a surveillance system. Therefore, the objective of this study was to evaluate the variability in the timeliness, within and between states, of the surveillance programme of the Brazilian Veterinary Services (BVS) for foot-and-mouth disease (FMD), for the notification of vesicular disease. A total of 14 years (2004-2017) of data relating to vesicular syndromes from the Brazilian Continental Information and Surveillance System (SivCont) were included. A categorical variable was created with four classes to group the notified vesicular processes in the SivCont, according to two criteria, the similarity of the symptoms of the diseases reported with FMD and aetiology (viral, bacterial, fungal and non-infectious). The three timeliness values (TL-1, TL-2 and TL-3) related to different portions of the FMD surveillance system were analysed as a response in a generalized linear model in which the states of Brazil were the explanatory variables. The analyses were performed separately for each notification class (FMD, vesicular stomatitis, similar symptoms and similar non-infectious symptoms) and included comparisons within and between states. The study results provide an understanding and evaluation of the timeliness of the Brazilian FMD surveillance system, thereby providing a base of knowledge from which involved agents and decision-makers can evaluate BVS and reinforce surveillance measures in the states with poorer timeliness than permitted.

Phylodynamic reconstruction of O CATHAY topotype foot-and-mouth disease virus epidemics in the Philippines

Reconstructing the evolutionary history, demographic signal and dispersal processes from viral genome sequences contributes to our understanding of the epidemiological dynamics underlying epizootic events. In this study, a Bayesian phylogenetic framework was used to explore the phylodynamics and spatio-temporal dispersion of the O CATHAY topotype of foot-and-mouth disease virus (FMDV) that caused epidemics in the Philippines between 1994 and 2005. Sequences of the FMDV genome encoding the VP1 showed that the O CATHAY FMD epizootic in the Philippines resulted from a single introduction and was characterised by three main transmission hubs in Rizal, Bulacan and Manila Provinces. From a wider regional perspective, phylogenetic reconstruction of all available O CATHAY VP1 nucleotide sequences identified three distinct sub-lineages associated with country-based clusters originating in Hong Kong Special Administrative Region (SAR), the Philippines and Taiwan. The root of this phylogenetic tree was located in Hong Kong SAR, representing the most likely source for the introduction of this lineage into the Philippines and Taiwan. The reconstructed O CATHAY phylodynamics revealed three chronologically distinct evolutionary phases, culminating in a reduction in viral diversity over the final 10 years. The analysis suggests that viruses from the O CATHAY topotype have been continually maintained within swine industries close to Hong Kong SAR, following the extinction of virus lineages from the Philippines and the reduced number of FMD cases in Taiwan.

Impact of foot-and-mouth disease on pork and chicken prices in Central Luzon, Philippines

Central Luzon is the number one pig-producing region in the Philippines and was affected by Foot-and-Mouth disease (FMD) in 1995. In this paper, the impact of FMD on the Central Luzon meat market from 1995 to 1999 was examined. Employing the error correction model (ECM) and historical decomposition, the impact of FMD on the Central Luzon pork and chicken meat market was quantified. The following findings were observed: (a) pig farm and pork wholesale prices dropped 11.8% and 15.7%, respectively, after the initial FMD outbreaks in January, 1995; (b) in February, 1995, chicken farm and wholesale prices declined by 21.1% and 14.2%, respectively (while chicken retail prices also went down by 10.5%); (c) the margins of pig and chicken traders were also adversely affected at some point; and (d) FMD caused changes of dynamic interdependence among prices by meat type at different levels of the meat supply chain. This study makes several contributions to the literature on the impact of FMD outbreaks. This study is the first that simultaneously investigates the impact of FMD outbreaks on meat prices, price margins along the supply chain, and price interdependence in the meat system in Central Luzon, Philippines. Also, the Philippine pork industry is dominated by backyard farmers rather than the predominantly large commercial pig farmers existing in developed countries. Secondly, it yielded the novel finding of price decline in both pig and chicken prices as a result of the FMD outbreaks. And lastly, the study showed that the profit margins of the pig traders, pork traders, chicken traders and chicken meat traders were also negatively affected by the FMD outbreaks in January 1995. However, over the long term, the price margins of pork traders were more severely affected in contrast to that of the other traders' profits.

The economic impacts of foot and mouth disease - what are they, how big are they and where do they occur?

Although a disease of low mortality, the global impact of foot and mouth disease (FMD) is colossal due to the huge numbers of animals affected. This impact can be separated into two components: (1) direct losses due to reduced production and changes in herd structure; and (2) indirect losses caused by costs of FMD control, poor access to markets and limited use of improved production technologies. This paper estimates that annual impact of FMD in terms of visible production losses and vaccination in endemic regions alone amount to between US$6.5 and 21 billion. In addition, outbreaks in FMD free countries and zones cause losses of >US$1.5 billion a year. FMD impacts are not the same throughout the world: FMD is highly contagious and the actions of one farmer affect the risk of FMD occurring on other holdings; thus sizeable externalities are generated. Control therefore requires coordination within and between countries. These externalities imply that FMD control produces a significant amount of public goods, justifying the need for national and international public investment. Equipping poor countries with the tools needed to control FMD will involve the long term development of state veterinary services that in turn will deliver wider benefits to a nation including the control of other livestock diseases.

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.

The economic and poverty impacts of animal diseases in developing countries: new roles, new demands for economics and epidemiology

Animal disease outbreaks pose significant threats to livestock sectors throughout the world, both from the standpoint of the economic impacts of the disease itself and the measures taken to mitigate the risk of disease introduction. These impacts are multidimensional and not always well understood, complicating effective policy response. In the developing world, livestock diseases have broader, more nuanced effects on markets, poverty, and livelihoods, given the diversity of uses of livestock and complexity of livestock value chains. In both settings, disease control strategies, particularly those informed by ex ante modeling platforms, often fail to recognize the constraints inherent among farmers, veterinary services, and other value chain actors. In short, context matters. Correspondingly, an important gap in the animal health economics literature is the explicit incorporation of behavior and incentives in impact analyses that highlight the interactions of disease with its socio-economic and institutional setting. In this paper, we examine new approaches and frameworks for the analysis of economic and poverty impacts of animal diseases. We propose greater utilization of "bottom-up" analyses, highlighting the strengths and weaknesses of value chain and information economics approaches in impact analyses and stressing the importance of improved integration between the epidemiology of disease and its relationships with economic behavior.

The role of land use patterns in limiting the spread of equine influenza in Queensland during the 2007 epidemic

In 2007, an epizootic of equine influenza (EI) occurred in Australia, involving parts of the states of Queensland and New South Wales. Following an extensive control program, the disease was eradicated within 4 months, after infecting more than 75,000 horses on over 10,000 properties. In Queensland, examination of land use patterns revealed that the majority of infected premises (89.5%) were located in one of three land use classes viz. rural residential, residential-unspecified or grazing natural vegetation. All nine clusters of infection in Queensland were surrounded to some degree by parcels of land whose designated use precluded the presence of horses. In four clusters, these horse-free areas completely enclosed the cluster and spread was limited to a relatively small area whereas the remaining five clusters were not completely surrounded by horse-free buffers and spread was much more extensive. The cumulative incidence of infection with EI dropped from 41% of properties in rural-residential areas to 4% of properties located further than 5 km from rural-residential areas. This decrease was associated with a 10-fold increase in the median size of properties and a 5-fold decrease in the density of horses on those premises. There was a strong negative correlation between the cumulative incidence of infection and the median property size (R = -0.91, P < 0.05) and a positive correlation with the horse density on those properties (R = 0.93, P < 0.01).

Planning for the progressive control of foot-and-mouth disease worldwide

In the wake of on-going successful programmes for global eradication of rinderpest and the current effort to contain the spread of avian influenza, the progressive world-wide control of FMD must be regarded as a major contribution to the international public good. FMD is the single most animal disease constraint to international trade in animal products. Its control is relevant, on the one hand, to protecting the livestock industries of industrialised countries and, on the other, to the livelihoods and income generation of developing countries, where, as a general rule, FMD continues to be endemic. The strategy that is advocated in this paper is one that is based on progressive risk reduction of FMD in the context of progressive market access of livestock commodities from developing countries. It is suggested that FMD control should be linked to improvement in livelihoods of livestock dependent communities in the FMD endemic settings. It is expected that this in turn will lead to increasing demand for effective national veterinary services and disease surveillance. This strategy has also taken lessons from the global rinderpest eradication programme and regional FMD control programmes in Europe and South America. The strategy that is advocated for the progressive control of FMD in the endemic settings is based on a seven stage process within a horizon of about 30 years, namely: (1) Assessing and defining national FMD status; (2) instituting vaccination and movement control; (3) suppressing virus transmission to achieve absence of clinical disease; (4) achieving freedom from FMD with vaccination in accordance with the OIE standards; (5) achieving freedom from FMD without vaccination in accordance with the OIE standards; (6) extending FMD free zones; and (7) maintaining FMD Freedom. Concomitant with progressive FMD control, there needs be the encouragement of such risk reduction measures as in-country commodity processing in order to encourage regulated trade in livestock commodities without unduly increasing the risk of disease spread. Finally, the progressive control of FMD should also be seen as part of reducing the overall, world-wide threat of infectious diseases to human health and economic development.

The epidemiological transition: the current status of infectious diseases in the developed world versus the developing world

Wealthy, industrialized countries of the developed world successfully underwent the "epidemiologic transition" from infectious diseases to degenerative diseases, but developing countries have not yet achieved that transition. This article reviews the current status of Omran's Theory of Epidemiologic Transition, comparing the burden of infectious diseases in the developed world versus the developing world. The advent of modern sanitation and hygiene practices, effective vaccines, and antibiotics have significantly diminished the burden in the developed world, but infectious diseases remain the most common cause of death worldwide. The persistence of this disease burden has been due to a failure to employee effective strategies and to unforeseen developments, such as the emergence of HIV and the re-emergence of malaria and tuberculosis driven by newly developed drug resistance. The challenge in accurately assessing infectious disease burden and developing effective interventions is reviewed along with the most common diseases and current intervention strategies.

Human and animal vaccination delivery to remote nomadic families, Chad

Vaccinating nomadic pastoralists and their livestock at the same time reduces delivery costs.

Vaccination services for people and livestock often fail to achieve sufficient coverages in Africa’s remote rural settings because of financial, logistic, and service delivery constraints. In Chad from 2000 through 2005, we demonstrated the feasibility of combining vaccination programs for nomadic pastoralists and their livestock. Sharing of transport logistics and equipment between physicians and veterinarians reduced total costs. Joint delivery of human and animal health services is adapted to and highly valued by hard-to-reach pastoralists. In intervention zones, for the first time ≈10% of nomadic children (>1–11 months of age) were fully immunized annually and more children and women were vaccinated per day during joint vaccination rounds than during vaccination of persons only and not their livestock (130 vs. 100, p<0.001). By optimizing use of limited logistical and human resources, public health and veterinary services both become more effective, especially at the district level.