Evaluation of the economic impact of classical and African swine fever epidemics using OutCosT, a new spreadsheet-based tool.

African swine fever (ASF) and classical swine fever (CSF) are two major transboundary animal diseases of swine with important socioeconomic consequences at farm, subnational and national level. The objective of this study was to evaluate the direct cost of outbreaks and their control at country/regional level in four countries: namely CSF in Colombia in 2015-2016, the retrospective cost of ASF in the Philippines in 2019 and in a province of Vietnam in 2020 and a hypothetical ASF scenario in one region in North Macedonia, using the newly developed Outbreak Costing Tool (OutCosT). The tool calculates the costs of 106 different items, broken down by up to four types of farms, and by who assumes the cost (whether veterinary services, farmers or other stakeholders). The total cost of CSF in Colombia was US$ 3.8 million, of which 88% represented the cost of the vaccination campaign. For ASF, there were wide differences between countries: US$ 8,26,911 in Lao Cai (Vietnam), US$ 33,19,666 in North Macedonia and over US$ 58 million in the Philippines. While in the Philippines and Vietnam, 96-98% of the cost occurred in the affected farms, the highest expenditure in North Macedonia scenario was the movement control of the neighbouring and at-risk farms (77%). These important differences between countries depend on the spread of the disease, but also on the production systems affected and the measures applied. Apart from the financial cost, these diseases have other negative impacts, especially in the livelihoods of smallholder farms. The OutCosT tool also allows users to evaluate qualitatively other important aspects related to the epidemics, such as the impact on human health, the environment, animal welfare, socioeconomic vulnerability, trading and political response. OutCosT, which is a FAO corporate tool (available online at: https://www.fao.org/fileadmin/user_upload/faoweb/animal-health/OutCosT_PIG.xlsx), can be an important tool to support country authorities to rapidly respond to a swine disease outbreak by estimating the associated costs and for advocacy purposes to mobilize resources at national or international levels.

Optimizing the early detection of low pathogenic avian influenza H7N9 virus in live bird markets.

In Southeast Asia, surveillance at live bird markets (LBMs) has been identified as crucial for detecting avian influenza viruses (AIV) and reducing the risk of human infections. However, the design of effective surveillance systems in LBMs remains complex given the rapid turn-over of poultry. We developed a deterministic transmission model to provide guidance for optimizing AIV surveillance efforts. The model was calibrated to fit one of the largest LBMs in northern Vietnam at high risk of low pathogenic H7N9 virus introduction from China to identify the surveillance strategy that optimizes H7N9 detection. Results show that (i) using a portable diagnostic device would slightly reduce the number of infected birds leaving the LBM before the first detection, as compared to a laboratory-based diagnostic strategy, (ii) H7N9 detection could become more timely by sampling birds staying overnight, just before new susceptible birds are introduced at the beginning of a working day, and (iii) banning birds staying overnight would represent an effective intervention to reduce the risk of H7N9 spread but would decrease the likelihood of virus detection if introduced. These strategies should receive high priority in Vietnam and other Asian countries at risk of H7N9 introduction.

Infectious Diseases and Meat Production.

Most infectious diseases in humans originate from animals. In this paper, we explore the role of animal farming and meat consumption in the emergence and amplification of infectious diseases. First, we discuss how meat production increases epidemic risks, either directly through increased contact with wild and farmed animals or indirectly through its impact on the environment (e.g., biodiversity loss, water use, climate change). Traditional food systems such as bushmeat and backyard farming increase the risks of disease transmission from wild animals, while intensive farming amplifies the impact of the disease due to the high density, genetic proximity, increased immunodeficiency, and live transport of farmed animals. Second, we describe the various direct and indirect costs of animal-based infectious diseases, and in particular, how these diseases can negatively impact the economy and the environment. Last, we discuss policies to reduce the social costs of infectious diseases. While existing regulatory frameworks such as the "One Health" approach focus on increasing farms' biosecurity and emergency preparedness, we emphasize the need to better align stakeholders' incentives and to reduce meat consumption. We discuss in particular the implementation of a "zoonotic" Pigouvian tax, and innovations such as insect-based food or cultured meat.

A Stakeholder Survey on Live Bird Market Closures Policy for Controlling Highly Pathogenic Avian Influenza in Vietnam.

Extensive research in Vietnam and elsewhere has shown that live bird markets (LBMs) play a significant role in the ecology and zoonotic transmission of avian influenzas (AIs) including H5N1 and H7N9. Vietnam has a large number of LBMs reflecting the consumer preferences for live poultry. Under pressure to mitigate risks for H7N9 and other zoonotic AIs, Vietnam is considering, among other mitigation measures, temporary closures of LBMs as a policy to reduce risk of AI outbreaks. However, the efficacy of market closure is debated, particularly because little is known about how poultry traders may react, and whether trading may emerge outside formal marketplaces. Combining efforts of anthropologists, economists, sociologists, and veterinarians can be useful to elucidate the drivers behind poultry traders' reactions and better understanding the barriers to implementing risk mitigation measures. In this paper, we present results from a stakeholder survey of LBM stakeholders in Vietnam. Our qualitative data show that trading outside formal markets is very likely to occur in the event of a temporary LBM market closure. Our data show that the poultry value chain in Vietnam remains highly flexible, with traders willing and able to trade poultry in many possible locations. Our results indicate that simplification of the poultry value chain along with strict enforcement, engagement of stakeholders, and adequate communication would be a necessary prerequisite before market closure could be an effective policy.

VacciCost - A tool to estimate the resource requirements for implementing livestock vaccination campaigns. Application to peste des petits ruminants (PPR) vaccination in Senegal.

Vaccination is one of the main tools currently available to control animal diseases. In eradication campaigns, vaccination plays a crucial role by reducing the number of susceptible hosts with the ultimate goal of interrupting disease transmission. Nevertheless, mass vaccination campaigns may be very expensive and in some cases unprofitable. VacciCost is a tool designed to help decision-makers in the estimation of the resources required to implement mass livestock vaccination campaigns against regulated diseases. The tool focuses on the operational or running costs of the campaign, so acquisition of new equipment or vehicles is not considered. It takes into account different types of production systems to differentiate the vaccination productivity (number of animals vaccinated per day) in systems where animals are concentrated and easy to reach, from those characterized by small herds that are scattered and less accessible. The resource requirements are classified in eight categories: vaccines, injection supplies, personnel, transport, maintenance and overhead, training, social mobilization, and surveillance and monitoring. This categorization allows identifying the most expensive components of a vaccination campaign, which is crucial to design cost-reduction strategies. The use of the tool is illustrated using data collected in collaboration with Senegalese Veterinary Services regarding vaccination against peste des petits ruminants. The average daily number of animals vaccinated per vaccination team was found to be crucial for the costs of the campaign so significant savings can be obtained by implementing training to improve the performance of vaccination teams.

Economic Game Theory to Model the Attenuation of Virulence of an Obligate Intracellular Bacterium.

Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host's defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g., with Ehrlichia ruminantium), there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria.

The Impact of Farmers' Strategic Behavior on the Spread of Animal Infectious Diseases.

One of the main strategies to control the spread of infectious animal diseases is the implementation of movement restrictions. This paper shows a loss in efficiency of the movement restriction policy (MRP) when behavioral responses of farmers are taken into account. Incorporating the strategic behavior of farmers in an epidemiologic model reveals that the MRP can trigger premature animal sales by farms at high risk of becoming infected that significantly reduce the efficacy of the policy. The results are validated in a parameterized network via Monte Carlo simulations and measures to mitigate the loss of efficiency of the MRP are discussed. Financial aid to farmers can be justified by public health concerns, not only for equity. This paper contributes to developing an interdisciplinary analytical framework regarding the expansion of infectious diseases combining economic and epidemiologic dimensions.

Cost assessment of the movement restriction policy in France during the 2006 bluetongue virus episode (BTV-8).

This study aims at evaluating the costs of the movement restriction policy (MRP) during the 2006 BTV-8 epidemic in France for the producers of 6-9 month old Charolais beef weaned calves (BWC), an important sector that was severely affected by the restrictions imposed. This study estimates the change in the number of BWC sold that was due to the movement restrictions, and evaluates the economic effect of the MRP. The change in BWC sold by producers located inside the restriction zone (RZ) was analyzed for 2006 by using a multivariate matching approach to control for any internal validity threat. The economic evaluation of the MRP was based on several scenarios that describe farms' capacity constraints, feeding prices, and the animal's selling price. Results show that the average farmer experienced a 21% decrease in animals sold due to the MRP. The economic evaluation of the MRP shows a potential gain during the movement standstill period in the case of no capacity constraint faced by the farm and food self-sufficiency. This gain remains limited and close to zero in case of a low selling price and when animals are held until they no longer fit the BWC market so that they cannot be sold as an intermediate product. Capacity constraints represent a tremendous challenge to farmers facing movement restrictions and the fattening profit becomes negative under such conditions. The timing and length of the movement standstill period significantly affect the profitability of the strategy employed by the farmer: for a 5.5 month-long standstill period with 3.5 months of cold weather, farmers with capacity constraints have stronger incentives to leave their animals outside during the whole period and face higher mortality and morbidity rates than paying for a boarding facility for the cold months. This is not necessarily true for a shorter standstill period. Strategies are also sensitive to the feed costs and to the food self-sufficiency of the farm. Altogether, the present work shows the farmer's vulnerability to animal movement restrictions and quantifies the costs of the standstill. These results should assist decision-makers who seek to calculate adequate subsidies/aid or to efficiently allocate resources to prevent future outbreaks.

Pesticides and health: a review of evidence on health effects, valuation of risks, and benefit-cost analysis.

DESIGN/METHODOLOGY/APPROACH: This study presents literature reviews for the period 2000-2013 on (i) the health effects of pesticides and on (ii) preference valuation of health risks related to pesticides, as well as a discussion of the role of benefit-cost analysis applied to pesticide regulatory measures. FINDINGS: This study indicates that the health literature has focused on individuals with direct exposure to pesticides, i.e. farmers, while the literature on preference valuation has focused on those with indirect exposure, i.e. consumers. The discussion highlights the need to clarify the rationale for regulating pesticides, the role of risk perceptions in benefit-cost analysis, and the importance of inter-disciplinary research in this area. ORIGINALITY/VALUE: This study relates findings of different disciplines (health, economics, public policy) regarding pesticides, and identifies gaps for future research.