The European Food Safety Authority (EFSA) has published surveillance strategies that will help countries affected by African swine fever (ASF), determining when the virus stopped circulating among their wild boar populations, and developing exit strategies from ASF for these countries.
The publication recommends that such an exit strategy comprises of two phases, these being a period of routine surveillance of wild boar (the screening phase) followed by a shorter period of intense surveillance (the confirmation phase).
Modelling has demonstrated that:
- the accuracy of the approach rises in line with the number of wild boar carcasses collected and tested
- lengthening the monitoring period increases the chances of verifying that the ASF virus is no longer circulating
- the use of active surveillance based on hunting has limited impact on the effectiveness of the exit strategy
The publication gives practical examples of how to apply the exit strategy to both large and small affected areas, and also recommends the minimum monitoring periods needed to make the strategy effective.
Source: EFSA. 3 March 2021