Foot-and-mouth disease: evaluation of control strategies against a potential outbreak

In a simulation study conducted by Vetmeduni Vienna in cooperation with the Austrian Agency for Health and Food Safety and the Federal Ministry of Social Affairs, Health, Care and Consumer Protection, researchers evaluated the efficiency of different emergency measures and control strategies in response to foot-and-mouth disease.

All member states of the European Union are currently free of foot-and-mouth disease (FMD). However, outbreaks of the disease in regions close to Europe’s borders, for example in Turkey, the Middle East or North Africa, represent a constant risk of introduction of the virus into the EU. The largest epidemic of foot-and-mouth disease in decades broke out in the UK in 2001 and later spread to France, the Netherlands and Ireland. Millions of animals had to be slaughtered, resulting in economic losses of several billion euros.

Simulation study evaluates control strategies

Because an outbreak of animal disease can occur suddenly and unexpectedly, it is crucial to be prepared to handle such a crisis with a specific and appropriate response. This includes, among other things, evaluating different control strategies and emergency measures as well as assessing the necessary resources that would be required.

With this in mind, researchers from the Unit of Veterinary Public Health and Epidemiology at Vetmeduni Vienna, in collaboration with experts from the Austrian Agency for Health and Food Safety (AGES) and the Federal Ministry of Social Affairs, Health, Care and Consumer Protection (BMSGPK), carried out a simulation study to evaluate different strategies to control a potential FMD outbreak in Austria.

“The aim of the study was to evaluate the effectiveness of various control measures on the spread of the disease und the number of animals to be culled and to analyse the costs associated with an outbreak,” says first author Tatiana Marschik from the Institute of Food Safety, Food Technology and Veterinary Public Health at Vetmeduni Vienna.

The results of the study are to be used to assist the decision-making process of the national crisis management with the aim of rapid and efficient containment in the event of an FMD outbreak in Austria.

Epidemiological modelling

Simulation models represent an approximation of real scenarios. With regard to FMD, these models are of enormous value especially for those countries that have not had an outbreak of FMD for decades. In the current study, the experts simulated such an outbreak using the European Foot-and-Mouth Disease Spread Model (EuFMDiS), a European adaptation of the Australian Animal Disease Spread Model (AADIS).

“The model simulates an FMD outbreak under realistic conditions, including the transmission of the disease inside and outside susceptible farms, taking into account all plausible routes of transmission,” explains Marschik.

The control measures are implemented by the model in accordance with the European legal framework. The deployment of human and logistical resources in activities such as surveillance, culling or decontamination is modelled based on resource availability.

Simulation of an FMD outbreak in Austria

The researchers compared outbreaks in two different regions of Austria. These regions – “West” (Tyrol/Vorarlberg) and “North” (Lower Austria/Upper Austria) – differ significantly with regard to livestock density and herd size. The livestock density in region “West” is low (more than half of all susceptible farms comprise less than 14 animals) in contrast to region “North”.

The outbreak in both regions was initiated at a dairy farm and simulated to remain undetected for three weeks. For the control phase (from initial detection to the end of the outbreak), five different control scenarios were implemented for both regions based on variations of the culling and vaccination policy and the pre-emptive depopulation programme.

“The results of the study show that an outbreak of FMD in Austria would cause total costs between € 270 million and € 580 million. The extent of this damage depends heavily on the region affected, the control measures chosen and the availability of human resources,” says Tatiana Marschik.

Implementation of additional control measures, such as vaccination or pre-emptive depopulation, which is allowed in exceptional cases under EU legislation, would only be necessary if the epidemic started in an area with high livestock density. For example, pre-emptive depopulation would be the most cost-effective strategy to control the outbreak in region “North”, whereas the standard control strategy (culling of infected farms) would be enough to efficiently control the outbreak in region “West”.

The study also showed that an increase in human resources in Austria could significantly reduce the size of the epidemic.

Sustainable strategy

Strategies to control rapidly spreading animal diseases are often accompanied by negative consequences for the environment, nature and the population of the affected regions. The global strategy for the progressive control and eradication of FMD is supported in the European region by the close partnership between the European Commission, the World Organisation for Animal Health (OIE) and the Food and Agriculture Organization of the United Nations (FAO).

The goal of this strategy includes increasing the readiness of European countries to implement lasting control programmes with European neighbours and to support the progressive control of FMD in all regions. The present study demonstrates not only the importance of rapid and efficient control, but also the need to provide human resources to reduce the negative impact of an FMD outbreak in Austria if needed.