ANIMAS – The Portuguese tool for wildlife surveillance

The Role of Wild Animals in Disease Epidemiology

It is well recognized that conducting disease surveillance of wild animal populations is crucial to understand the epizootiology of specific infectious diseases and zoonotic infections within territorial borders, and protects wildlife, domestic animals and human populations.

The importance of the role of wild animals in epidemiology of diseases has been considered since the early 1900th, when outbreaks of rinderpest occurred in Belgium due to wild ungulates. Currently, wildlife health surveillance is a subject of growing importance.

Globally, all countries are encouraged to develop and maintain surveillance programs for wildlife disease to complement and support a national animal disease program. Soon, these wildlife monitoring programs will become part of proving freedom/status of significant diseases in territory. Efficient disease monitoring programs in free-living population may represent the initial alert that helps for early detection of exotic and ‘emerging’ diseases.

Most of the disease monitoring programs are usually proactive programs that aim at protecting domestic animal and public health, and supporting international trade in animals and animal products.

Besides its public health and economic implications, overt disease outbreaks and mass mortality in wildlife might be efficient indicator for introduction of new animal species, local pollution, ecological disturbance, climatic or habitat change.

We are going to focus on the progress achieved in Portugal for wildlife surveillance, particularly, following the expansion of African Swine Fever in Europe. Portugal has adopted several procedures to prevent the disease, including strengthening surveillance and early detection in dead wild boars. The national authorities for animal health and hunting resources have developed and implemented the Application for Immediate Notification of Mortality in Wild Animals (ANIMAS), as well as specific procedures concerning wild boars found dead including the systematic testing for African Swine Fever. ANIMAS identify the need to collect samples from animals found dead and take subsequent measures.

ANIMAS[1] is a citizen science, easy-to-use and easy-to-access tool (online or via mobile phone). It is essential to foster communication, and intended to be used by all those who are frequently in contact with wildlife. It aims for reporting dead mammals, birds, reptiles, amphibians, and fish, and was implemented in September 2021. Through this application, users can follow all notifications made in Portugal on a map, in real time, and details of information depend on the type of profile assigned.

Although ANIMAS was initially intended for African Swine Fever surveillance through notification of dead wild boars, it quickly became clear that there was a need to cover all other wild species for surveillance of other diseases or relevant situations.

The recorded information by ANIMAS consists of geographical coordinates, species, sex, age group, conservation state of the carcass, presence of other dead animals of the same species, and one or more photographs of the animal(s) [Figure 1]. Then during the processing of collected data, the official veterinary services identify whether samples were taken in that mortality event. At the central level, the notifications’ data are processed and analyzed, and regular summary reports of wildlife mortality are made available on the General Directorate for Food and Veterinary website[2].

Some priorities for diseases to be monitored/assessed have been defined and so far, specific internal procedures have been developed for wild boars, cervids and target species of wild birds. The priorities and/or diseases are updated whenever necessary.

In case of dead wild boars, following the notification, the regional veterinary services investigate the suspicion to confirm or exclude the presence of African Swine Fever, by taking samples for virological tests [Figure 2]. Whenever possible, the dead wild boars are also tested for Classical Swine Fever.

ANIMAS application has also contributed to the surveillance of Chronic Wasting Disease in cervids [Figure 3] and Highly Pathogenic Avian Influenza in wild birds.

During 2024, it is foreseen to use ANIMAS notifications to implement a surveillance plan in wild carnivores, and the application will also be used as a tool to enhance the passive surveillance of wild rabbits, within the scope of the LIFE Iberconejo project. In addition, new developments are currently being made to the application that will soon allow the notification of live wild animals with clinical signs.

During the first year of its use, there are valuable achievements which are prospected to be improved significantly in the upcoming years. Till 31st December 2023, these achievements are represented by 1103 active users in ANIMAS, majority (77%) are classified as “public”, and 544 wildlife mortality cases were registered on the application in Portugal’s mainland [Figure 4], mostly referred to mammals [Figure 5]. In this group (n=409), mustelids, foxes and wild boars represented 25%, 23% and 19%, respectively, of dead mammals notified.

Regarding birds, the most reported species were gulls [Figure 6], corresponding to 19% of the events in this group, followed by white storks and mallards, each corresponding to 9% of the notifications concerning birds.

Snakes (46%) and wall lizards (23%) were the most frequent species in the reptiles’ group, while salamanders and toads were the only species of amphibians notified.

Most of mortality events were recorded by the public (54%), followed by personnel of the central administration (21%) [Figure 7]. For a large part of death cases (n=245), it was not possible to assume a probable cause of death; while for the remaining events, road traffic accident has been the most frequent probable cause of death, in particular for mammals (56%) and reptiles (77%) [Figure 8], and infectious disease seems to be the probable cause in 26% of the mortality events in birds [Table 1]. Almost all deaths in mammals (97%) were represented by single dead animal; while 28% of deaths in birds were represented by several dead birds of the same species [Table 2].

Regarding wild boars, 79 mortality events were reported including 90 dead animals, of which 49 were tested for African Swine Fever and 26 for Classical Swine Fever, always with negative results [Figure 9].

With the use of the application along with the procedures implemented, it has been possible to reduce the time between notification of dead wild boars and sample collection. The average time to sample collection decreased from 0.8 days [0-7] in 2022 to 0.3 days [0-2] in 2023.

In conclusion, use of ANIMAS contributed to improving surveillance and early detection in different wildlife animal species. However, it is still necessary to improve dissemination and awareness campaigns to motivate, engage and increase citizens participation.

ANIMAS, combined with African Swine Fever awareness campaigns, has strongly increased the number of reported dead wild boars, and consequently the number of tested animals for African Swine Fever has increased. ANIMAS enhanced surveillance of Highly Pathogenic Avian Influenza through reported unusual mortality events in target-species of wild birds. Finally, reported dead cervids by ANIMAS allowed surveillance against Chronic Wasting Disease.

In the near future, ANIMAS will communicate by webservice with a broader information system, which encompasses all the management of wildlife surveillance (passive and active) and emergency and contingency situations.

Table 1 – Probable causes of mortality

 MammalsBirdsReptilesAmphibiansFishTotal
Road traffic accident23151730256
Suspected infectious disease02700027
Electrocution050005
Suspected poisoning310004
Predation300003
Poaching200002
Starvation/dehydration100001
Drowning010001
N.d.16965551245
Total4091042281544

Table 2 – Events with a single dead animal vs. events with several dead animals

 MammalsBirdsReptilesAmphibiansFishTotal
Single dead animal396752271501
Several dead animals132901043
Total4091042281544

Figure 1 – ANIMAS’s mortality event reporting form

Figure 2 – Mortality event with several dead wild boars and sampling in the Alentejo Region

Figure 3 – Mortality events in cervids

Figure 4 – Spatial distribution of wildlife mortality events in ANIMAS

Figure 5 – Events of wildlife mortality registered in ANIMAS (n=544)

Figure 6 – Mortality event in birds with several dead gulls in the Tagus Estuary

Figure 7 – Wildlife mortality events notifications by user type

Figure 8 – Road kills: j Wild boar (Sus scrofa), k European polecat (Mustela putorius), l Red fox (Vulpes vulpes), m Western Montpellier snake (Malpolon monspessulanus), n Beech marten (martes foina), o Eurasian otter (Lutra lutra), p Egyptian mongoose (Herpestes ichneumon)

Figure 9 – Wild boars mortality events and surveillance

[1] https://animas.icnf.pt

[2] https://sway.cloud.microsoft/8Ftt1Ut2jWcSHDML?ref=Link

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