Wildlife trade has been spreading diseases from animals to humans for decades, data now prove
The trade in wild animals has been one of the primary routes for new diseases jumping from animals to humans for at least forty years.
Zoonotic diseases — infections that cross from animals to humans — account for more than sixty percent of all emerging infectious diseases in people. Ebola, SARS, MERS, and almost certainly Covid-19 all have animal origins. But the specific routes through which those transfers happen are rarely systematically documented. Researchers publishing in Science have now analyzed forty years of data on pathogen transmission via the international wildlife trade.
The results are unambiguous: countries that import more wild animals — live or as products — show higher rates of novel zoonotic infections. The association holds after adjusting for population density, deforestation, and proximity to animals through other pathways. Particularly alarming is the pattern in the Amazon, detailed in a companion article in the same issue of Science: infrastructure development in the Amazon rainforest accelerates contact between wildlife and humans, raising the risk of new spillover events.
Why this matters for aging and longevity
At first glance this topic seems distant from longevity science. The connection is more direct than it appears. First, older people are disproportionately vulnerable to novel infectious diseases. An aging immune system offers weaker protection against pathogens for which no vaccine or immunological memory yet exists. Second, infection-induced chronic inflammation is one of the mechanisms that accelerates biological aging. Every new zoonotic outbreak exposes a large population of older adults to exactly that combination of acute infectious pressure and chronic inflammatory burden.
The researchers note that existing international regulation — CITES, the Convention on International Trade in Endangered Species — is poorly equipped to monitor or prevent pathogen transmission. The framework focuses on biodiversity protection, not biosecurity. These are overlapping but separately governed domains, with a coordination gap that becomes painfully visible with every new outbreak.
The political obstacles are at least as large as the scientific ones
The economic stakes in the international wildlife trade are substantial. From exotic pets to traditional medicine and food markets, the industry is global and partly underground. Stricter regulation meets resistance from countries economically dependent on the trade, cultural objections, and enforcement challenges in states with limited governmental capacity.
What this study adds to the debate is empirical weight. The quantitative link between wildlife trade and pathogen transmission was plausible before but difficult to demonstrate across long time periods and large geographic scales. Now that the link has been strengthened, the question is whether policymakers will act on it.