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5.5.4 What is the difference between surveillance and monitoring of ORV?

Rabies surveillance (including enhanced rabies surveillance) is an essential and integral part of ORV programmes. A risk-based sampling scheme should be implemented, focusing on so-called indicator animals (see sections 5.2.1; 5.2.2). Testing animals taken as part of the fur harvest, nuisance control or the hunting bag is of limited value in terms of rabies surveillance, because these animals are up to 16 times less likely than indicator animals to be rabies positive (see case study here).

As a general rule, rabies surveillance needs to be conducted not only in the actual vaccination areas but also in bordering non-vaccinated areas, in particular in rabies-free areas, to detect a possible re-infection as early as possible.

In contrast, monitoring is considered an ongoing ORV programme component, aimed at detecting changes in prevalence of the disease in a given population and its environment. In terms of ORV, monitoring should provide information on the vaccination rate in the target fox population. This can be done both by determining (i) bait-uptake and (ii) seroconversion (herd immunity) in foxes from vaccination areas (see here for more details). In contrast to rabies surveillance, monitoring aims to target the ‘non-infected’ subpopulation, e.g. animals that are protected against the disease by vaccination, or remain unprotected (still susceptible).

For these investigations, sampling should focus on animals from the hunting bag (see also section 5.5.10). Monitoring should start at least three weeks after the vaccination campaign is completed in order to allow the development of an adequate immune response in foxes. In any case, the age structure of the animals tested should be taken into account in the final analysis of the results.


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Version 1 - Last updated November 2012