Surveillance strategies for Classical Swine Fever in wild boar \u2013 a comprehensive evaluation study to ensure powerful surveillance

Katja Schulz,Barbara Häsler,Franz J Conraths,Marisa Peyre,Christoph Staubach,Birgit Schauer,Jana Schulz,Clémentine Calba

doi:10.1038/srep43871

Abstract

Surveillance of Classical Swine Fever (CSF) should not only focus on livestock, but must also include wild boar. To prevent disease transmission into commercial pig herds, it is therefore vital to have knowledge about the disease status in wild boar. In the present study, we performed a comprehensive evaluation of alternative surveillance strategies for Classical Swine Fever (CSF) in wild boar and compared them with the currently implemented conventional approach. The evaluation protocol was designed using the EVA tool, a decision support tool to help in the development of an economic and epidemiological evaluation protocol for surveillance. To evaluate the effectiveness of the surveillance strategies, we investigated their sensitivity and timeliness. Acceptability was analysed and finally, the cost-effectiveness of the surveillance strategies was determined. We developed 69 surveillance strategies for comparative evaluation between the existing approach and the novel proposed strategies. Sampling only within sub-adults resulted in a better acceptability and timeliness than the currently implemented strategy. Strategies that were completely based on passive surveillance performance did not achieve the desired detection probability of 95%. In conclusion, the results of the study suggest that risk-based approaches can be an option to design more effective CSF surveillance strategies in wild boar.

Highlights

The continuous surveillance of animal diseases is an important element of animal health management and helps to minimize the risk of infectious diseases spreading through the international movement of animals and their products
Data on wild boar and Classical Swine Fever (CSF) surveillance were used from three federal states of Germany, namely Rhineland-Palatinate (RP), Mecklenburg-Western Pomerania (MV) and Lower Saxony (LS)
Population density, season and samples originating from passive surveillance were through the literature search identified as risk factors for an infection of wild boar with CSF virus or for detecting the virus in wild boar samples

Summary

Introduction

The continuous surveillance of animal diseases is an important element of animal health management and helps to minimize the risk of infectious diseases spreading through the international movement of animals and their products. Despite the obvious need to perform appropriate surveillance in animals, the funds available are limited[2,3,4]. In view of these constraints, surveillance should be as cost-effective as possible. With regard to the surveillance objective of demonstrating disease freedom, Drewe et al.[9] recommended analysing the evaluation attributes sensitivity and timeliness. In this context, the sensitivity of a surveillance strategy is defined as the probability of detecting an outbreak of the disease under surveillance[10,11]. Acceptability is defined as the willingness of a person or institution to contribute to the implementation of a strategy or system[13]

Objectives

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Results

Conclusion