One Health policies still leave wildlife surveillance as a major global blind spot

A global review of One Health policies finds that surveillance systems remain heavily concentrated on livestock, common pets and a limited number of economically important diseases, while wildlife health monitoring is fragmented or absent in much of the world. Despite the proliferation of international One Health initiatives since Covid-19, the authors identify a persistent gap between policy ambitions and the data needed to anticipate zoonotic spillover.

The study compares national and international regulations covering livestock, companion animals, wildlife, animal trade and plant health, while also examining pathogen databases and wildlife surveillance programmes. The authors start from a familiar but important figure: around 75% of human pathogens are estimated to have zoonotic origins, including approximately 80% of viruses and 50% of bacteria affecting humans.

Regulation is strongest for livestock and common pets

International biosecurity systems are most developed for commercially important livestock and commonly traded companion animals. High-income countries frequently require veterinary certification, quarantine or specific disease testing, and the EU Animal Health Law provides a harmonised framework covering 63 listed animal diseases. But surveillance becomes much less systematic outside those sectors. Exotic pets, traded wildlife and many non-commercial species may face limited or highly variable health requirements. Even strict import systems generally test only for recognised priority pathogens rather than unknown or emerging agents.

Wildlife surveillance remains sparse

The largest gap identified by the review concerns wildlife. Global systems such as WOAH's WAHIS, WHO platforms, GLEWS+, the International Pathogen Surveillance Network and specialised national programmes provide important infrastructure, but sustained national wildlife-health surveillance exists in relatively few countries. Examples include Wildlife Health Australia, the USGS National Wildlife Health Center, the Canadian Wildlife Health Cooperative, France's SAGIR network and the UK's HAIRS system.

In many lower-income regions, wildlife programmes instead depend on externally funded projects. This creates problems of continuity once funding ends. The authors conclude that very few countries maintain nationally funded systems capable of routinely monitoring broad wildlife-health risks.

A large surveillance problem is also a data problem

Even when wildlife pathogens are detected, the information collected is often insufficient for understanding spillover. Many databases record the pathogen and host species but omit variables such as exact sampling location, date, habitat, sex, reproductive status, body condition or environmental stressors. These missing data make it difficult to determine why infection occurred in one place or season and not another. The review notes that VERENA currently links more than 3,767 vertebrate hosts with over 9,000 viruses, but such databases remain exceptions in their attempt to integrate ecology with pathogen information.

Wildlife trade receives attention, but little systematic monitoring

Interest in wildlife trade and spillover surged during the Covid-19 pandemic but declined rapidly afterward. Research using the term “pathogens wildlife trade” increased from around 15 papers in 2019 to roughly 50 in 2020, remained elevated until 2023 and then fell back toward 20 publications annually. Of 427 papers identified, 35% came from US institutions. A broader search for “wildlife spillover” identified 1,286 publications, with around 40% authored in the United States.

Yet the policy response remains much weaker than this research activity would suggest. Few countries systematically screen wildlife in trade for pathogens, and many systems do not even provide comprehensive information on which species are being traded.

From One Health frameworks to operational surveillance

The study does not argue that One Health institutions are missing. On the contrary, the global architecture has expanded considerably through the Quadripartite collaboration, OHHLEP, the One Health Joint Plan of Action, GLEWS+ and numerous regional initiatives. The weakness lies in translating these frameworks into standardised, interoperable field surveillance. The authors call for wildlife-health data to include ecological and demographic information alongside laboratory results, and for national systems to use shared standards that allow data to be compared across countries and sectors.

Global systems are increasingly capable of recording an outbreak once it becomes visible, but remain much less capable of measuring the wildlife, environmental and trade conditions that precede spillover. Without those data, One Health surveillance remains largely reactive rather than predictive.