The value of information: Current challenges in surveillance implementation.

Animal health surveillance is a complex activity that involves multiple stakeholders and provides decision support across sectors. Despite progress in the design of surveillance systems, some technical challenges remain, specifically for emerging hazards. Surveillance can also be impacted by political interests and costly consequences of case reporting, particularly in relation to international trade. Constraints on surveillance can therefore be of technical, economic and political nature. From an economic perspective, both surveillance and intervention are resource-using activities that are part of a mitigation strategy. Surveillance provides information for intervention decisions and thereby helps to offset negative effects of animal disease and to reduce the decision uncertainty associated with choices on disease control. It thus creates monetary and non-monetary benefits, both of which may be challenging to quantify. The technical relationships between surveillance, intervention and loss avoidance have not been established for most hazards despite being important consideration for investment decisions. Therefore, surveillance cannot just be maximised to minimise intervention costs. Economic appraisals of surveillance need to be done on a case by case basis for any hazard considering both surveillance and intervention performance, the losses avoided and the values attached to them. This can be achieved by using an evaluation approach which provides a systematic investigation of the worth or merit of surveillance activities. Evaluation is driven by a specific evaluation question which for surveillance systems commonly considers effectiveness, efficiency, implementation and/or compliance issues. More work is needed to provide guidance on the appropriate selection of evaluation attributes and general good practice in surveillance evaluation. Due to technical challenges, economic constraints and variable levels of capacity, the implementation of surveillance systems remains variable. Political and legal issues are also influential. A particular challenge exists during outbreaks when surveillance needs to be conducted under emergency conditions. Decision support systems can help make epidemiologically and economically sound choices amongst surveillance options. However, contingency planning is advisable so that pre-defined options allow for rapid decision making.