Analysis of a European general wildlife health surveillance program: Chances, challenges and recommendations

Abstract

In a One Health perspective general wildlife health surveillance (GWHS) gains importance worldwide, as pathogen transmission among wildlife, domestic animals and humans raises health, conservation and economic concerns. However, GWHS programs operate in the face of legal, geographical, financial, or administrative challenges. The present study uses a multi-tiered approach to understand the current characteristics, strengths and gaps of a European GWHS that operates in a fragmented legislative and multi-stakeholder environment. The aim is to support the implementation or improvement of other GWHS systems by managers, surveillance experts, and administrations. To assess the current state of wildlife health investigations and trends within the GWHS, we retrospectively analyzed 20 years of wildlife diagnostic data to explore alterations in annual case numbers, diagnosed diseases, and submitter types, conducted an online survey and phone interviews with official field partners (hunting administrators, game wardens and hunters) to assess their case submission criteria as well as their needs for post-mortem investigations, and performed in-house time estimations of post-mortem investigations to conduct a time-per-task analysis. Firstly, we found that infectious disease dynamics, the level of public awareness for specific diseases, research activities and increasing population sizes of in depth-monitored protected species, together with biogeographical and political boundaries all impacted case numbers and can present unexpected challenges to a GWHS. Secondly, we found that even a seemingly comprehensive GWHS can feature pronounced information gaps, with underrepresentation of common or easily recognizable diseases, blind spots in non-hunted species and only a fraction of discovered carcasses being submitted. Thirdly, we found that substantial amounts of wildlife health data may be available at local hunting administrations or disease specialist centers, but outside the reach of the GWHS and its processes. In conclusion, we recommend that fragmented and federalist GWHS programs like the one addressed require a central, consistent and accessible collection of wildlife health data. Also, considering the growing role of citizen observers in environmental research, we recommend using online reporting systems to harness decentrally available information and fill wildlife health information gaps.

Fig 1. Study setting Switzerland is a federative state comprising 26 states (“cantons”) which feature three distinct hunting regimes.

The diagnostic institute is located in the capital city Bern. Map data ©swisstopo.

Fig 2. Case submissions.

A) Total case numbers. Annual number of carcasses submitted for post-mortem investigation to the diagnostic institute during the study period (2002–2019). B) species-specific submissions. of birds, lagomorphs, rodents, carnivores, amphibians and reptiles (see Table 1 for species grouping) during the study period. C) Pathogen-specific trends. Most common diagnosed diseases in land birds and other taxa/species (lagomorphs, beaver, carnivores) during the study period.

Fig 3. Submission patterns.

A) Submitter roles. ~2/3^rd of all cases are submitted through hunting-associated stakeholders, while ~1/3^rd of cases came from other stakeholders in 2002, 2010, and 2019. The contributions of certain alternative sources are alternating through the years. B) Submitter location. Between 2002 and 2019, the geographic origin of the submissions expanded to previously uncovered regions and administrative units. Map data ©swisstopo.

Fig 4. Submission gaps.

A) Species gaps. Only ~3% of ungulates and carnivore carcasses were submitted to the GWHS for examination. For lagomorphs the numbers were much higher. B) Geographic gaps. Not all species groups were represented equally in all geographic areas. Data from 2002, 2010 and 2019 together illustrated that ungulates and carnivores (hunted and protected species) were submitted from all over the country, while small species (not hunted) were mostly submitted by areas north of the alps. Map data ©swisstopo.

Fig 5. Knowledge and data sources, collection points, gaps, and recommendations.

Wildlife health surveillance (WHS) knowledge and expertise is scattered across various levels of geographic areas and expertise. Citizens, local experts, general surveillance, targeted surveillance, research projects, and specialist centers each contribute different types of expertise (violet), and their knowledge is currently collected at different sites (teal). More holistic collection options would include a central database that is accessible for all contributors, and the inclusion of online reporting systems (ORS) in the data collection process (orange). Importantly, local veterinarians are presently not allowed to handle/treat wildlife except for euthanasia to end suffering, and official veterinarians are usually not trained to recognize or deal with wildlife disease.