When most people think of deadly zoonotic diseases, they assume they’re the cause of the illegal wildlife trade, but actually it’s legal trade that we need to worry about.
In 2019, $4.3 Billion of legal wildlife were imported to the US. That’s approximately 200 million live animals. Because the US doesn’t have any specific laws requiring wildlife entering the country to be screened for diseases, most aren’t and diseases often go unnoticed.
There isn’t even a federal agency responsible for screening wildlife imports for disease!
While the Fish and Wildlife Service enforces many laws and regulations surrounding illegal and unsustainable trade, they don’t need to check for animal health. Their only disease related responsibilities are making sure certain fish and salamander species don’t make it in. (They can spread devastating diseases to other animals of the same family.) The CDC is only responsible for checking wildlife and wildlife products that “present a significant public health concern,” mainly bats, African rodents, and non-human primates. The USDA only checks if there’s a risk to agriculturally important poultry or livestock.
These three organizations all do a small part of the job, but due to a lack of communication it can lead to a false sense of security if they assume someone else has the job covered. But the US isn’t the only one struggling. Most countries in the world don’t have a specialized entity to screen the health of wildlife imports.
The monkeypox outbreak in 2003 that affected dozens of people in 6 states was the result of a shipment of 800 rodents from Ghana for the pet trade. The rodents passed through customs without being properly screened and ended up being housed in the shed of an Illinois animal dealer along with a group of prairie dogs.
The prairie dogs were then sold to the public which was the start of the animal to human transmission. Luckily, although it would have been possible, there were no human to human transmissions. We may not be so lucky next time.
As a result of the outbreak, the CDC banned the import of all African rodents. But only 3 months after the infected shipment had arrived. In addition, although this ban allowed the Fish and Wildlife Service the ability to detain new shipments, the CDC stopped short of assessing the possibility that diseases might come from rodents from other countries too.
And it’s not just animal to human transmissions that we need to worry about. Animal to animal transmission of diseases can be so dangerous that they wipe out entire species populations.
One example of such a disease is amphibian chytrid fungus. It is the first known disease to infect hundreds of species at the same time and can spread to any amphibian. There are over 8,000 different species of amphibians. Chytrid has contributed to the decline of over 500, making it one of the most destructive invasive species in the world.
The main way chytrid makes its way around the globe so quickly is through the legal importation of infected species. In the US, the most imported amphibian is factory-farmed American Bullfrogs–almost 2.5 million every year. These introduce shockingly high numbers of infected animals that all have the possibility to further spread the pathogen.
Scientists already know that global trade is the reason why the chytrid pandemic is so bad, and they have known for a while, yet trade still continues. The Fish and Wildlife Service spends millions of dollars to stop the extinction of species due to chytrid, yet they aren’t doing anything to stop the infections from coming in. It’s like mopping up a pool of water instead of turning the faucet off.
It’s not that the government isn’t doing the best they can. Much of why there has been so little action taken is because of the lack of economic and staffing resources. One Fish and Wildlife inspector said, “In some states we have no officers watching out for trade; in other states we may have just one officer. I doubt that any officer would disagree with me when I say we do not have enough officers to take on the job.”
In addition, to control and prevent more zoonotic diseases from spreading around we need to better understand the diversity and volume of pathogens coming in. “We need more data through risk assessments and basic research before adding any new regulations,” CDC spokesperson Jasmine Reed says.
Unfortunately it’s a bit of a sticky situation. In order to systematically collect data from wildlife being brought in, one would need a government mandate and the government isn’t likely to issue one unless it already has pathogen data to guide its decision.
We don’t know when the next big pandemic will occur, but we need to be ready for when it happens. We need people in all areas of government, industry, and academia to put their minds together to have an action plan so we can stop these disasters before they happen.