The effect of Widespread Animal Diseases on Wildlife Populations

The World Organisation for Animal Health (WOAH) has released exceptionally a Wildlife Situation Report for 2024, providing a comprehensive overview of the current state of wildlife health worldwide. This report underlines the critical role of wildlife health in preserving biodiversity and ensuring a sustainable future.

Between January and June 2024, 55 countries and territories reported to WOAH, through the World Animal Health Information System (WAHIS), a total of 3,800 wildlife outbreaks. The outbreaks involved over 11,500 cases of eight diseases, across 151 wildlife species.

Alarmingly, the International Union for Conservation of Nature (IUCN) classifies 15 of the affected species (10%) as at risk of extinction. African Swine Fever (ASF) and High Pathogenicity Avian Influenza (HPAI), diseases with severe implications for domestic animal populations, were identified as the primary drivers of these outbreaks, accounting for 2,863 and 659, respectively.

A significant 78% of the affected species are classified as "Least Concern" by conservation standards. However, seven species (4%) are classified as "Vulnerable," four (3%) as "Near Threatened”, three (2%) as “Endangered” and one (1%) species as "Critically Endangered." This data emphasizes the widespread impact of diseases across species with varying conservation statuses.

The report identifies that 20% of the reported outbreaks involve diseases with zoonotic potential, highlighting the interdependence of wildlife health and human health.

African swine fever was the most frequently reported disease in wildlife during the reporting period, outstanding all others in outbreak numbers. It was also identified as the second-most detrimental disease to species at risk of extinction, affecting one of the 15 species, at risk of extinction, highlighted in the report. ASF’s widespread impact emphasizes the urgent need for improved surveillance, biosecurity measures, and coordinated international efforts to mitigate its effects on both domestic and wild animal populations.

High Pathogenicity Avian Influenza has led to the death and mass culling of over 557 million poultry globally between 2005 and 2023. In 2024, its geographic range expanded alarmingly, reaching the Antarctic region for the first time. The report highlights that HPAI affected 13 of the 15 at-risk species documented. For instance, in Chinese Taipei, five black-faced spoonbills (estimated global population: 2,200 adults) died. Similarly, a saker falcon was infected in Hungary (population estimated between 12,200 and 29,800). Moreover, 12 endangered jackass penguins, endemic to southern Africa with a population of approximately 41,700, were also affected.

Although HPAI primarily affects avian species, its detection in various wild mammalian species raises significant concerns about its expanding interspecies transmission capability and zoonotic potential. To date, HPAI has only occasionally affected humans: mostly people working or living in close contact with animals, with limited capacity of human-to-human transmission.

A total of 3,688 wildlife disease outbreaks were reported, with the majority occurring in Europe (78%), followed by Asia (12%), Africa (4%), the Americas (3%), and Oceania (2%). Notably, no outbreaks were reported in Antarctica.

The report underscores the intricate interdependence of ecosystems, emphasizing that the health of wildlife is deeply entwined to the health of domestic animals, the environment, and humans. By systematically reporting and monitoring diseases across the animal health spectrum, we can protect livestock, ensure food safety, preserve biodiversity, and safeguard human health. These efforts represent a fundamental investment in fostering a healthier and more sustainable future for all.

The report in numbers:

Total number of outbreaks: 3,688

Total number of cases: 11,500

Number of diseases: 8

Geographic distribution of outbreaks:

• Europe: 3,317
• Asia: 371
• Africa: 10
• Americas, Oceania, and Antarctica: 0

Conservation status of affected species:

• Least Concern (LC): 78%
• Endangered (EN): 12%
• Vulnerable (VU): 4%
• Near Threatened (NT): 3%
• Critically Endangered (CR): 1%
• Data Unavailable: 2%
• Zoonotic Potential: 20% of the reported outbreaks involve diseases with zoonotic potential.

Source: World Organisation for Animal Health (WOAH)