Illustration of cage with paw prints

Future Pandemics Lurk in Unscreened Wildlife Imports

April 13, 2023
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Emily Murphy 

The following op-ed by Emily Murphy is one of five standout essays written as part of an assignment for the Columbia MPH Core and published online on the Columbia Mailman news page.

In Newark port, a ventilated container labeled “mammal” is the infectious disease edition of Schrodinger’s cat; the animal housed inside could be a harmlessly healthy hedgehog or an Ebola-incubating macaque. This mystery mammal is one of an estimated 225 million live animals imported annually into the United States, and although it could be carrying any one of a host of dangerous zoonoses, or diseases capable of jumping from animals to humans, it likely won’t be screened for infection risk at its port of entry.

Though COVID-19 has familiarized us with the potential human and economic toll of infectious disease, the US currently does not require most imported wildlife to be tested for pathogens, and no federal agency has clear responsibility over the health of incoming animals. To remedy this gap and prevent the scaled, furry, or feathered source of the next epidemic from being shipped in through Miami or Los Angeles, Congress must amend the Lacey Act. The Act, which currently restricts the importation of wildlife deemed invasive or injurious to the country’s horticultural interests or economic interests, should be updated to require screening of species at high risk of zoonotic diseases.

Destined for zoos, research labs, or life as pets, live animals entering the United States may be carrying any of several zoonoses, including anthrax, rabies, SARS, or Ebola, which cause millions of deaths annually. We’ve already seen examples of how disease can jump from imported wildlife to humans: macaques imported from the Philippines introduced Ebola into the U.S. in 1989, and in 2003 monkeypox spread to 37 people after it entered the country through Ghana-originating rodents.

 The current system for preventing zoonotic diseases from entering the country through live wildlife is piecemeal and reactive. Responsibility for screening and monitoring imported wildlife for disease doesn’t lay with a single agency, and regulations on wildlife imports are overly specific and often established only after outbreaks have already threatened American lives. For example, although the Centers for Disease Control and Prevention banned the importation of African rodents after the 2003 monkeypox outbreak, the agency doesn’t mandate proactive monitoring for the same disease in other species. Similarly, while the US Fish and Wildlife Service (USFWS) employs port wildlife inspectors charged with keeping records of live imports and enforcing regulations against species barred by the Lacey Act, those inspectors don’t typically test imported animals for disease.

Fixing the United States’ unnecessary risk-taking with wildlife imports starts with scientifically analyzing the relative risk of zoonoses among species entering the country. Those judged most likely to be carrying dangerous diseases should be added to the Injurious Species list so that they can’t be imported without a permit for specific scientific, educational, or medical purposes. Critically, even permitted high-risk species imports should be tested for a range of zoonotic diseases or held in quarantine until the contained animals are confirmed disease-free, similar to how Australia handles high-risk species arriving without veterinary proof of good health. USFWS port wildlife inspectors, acting on powers granted by the existing Lacey Act, would ensure that imported wildlife is tested as part of their inspection process and deny entry to shipments containing animals with suspected or confirmed zoonoses.

Of course, this risk analysis and expanded mandate wouldn’t be free. But, it wouldn’t be prohibitively expensive either; a 2015 estimate with Congressional input found that standing up a national risk assessment and screening program could be accomplished with just $2 million and six employees. This cost certainly pales in comparison to the disastrous health and economic losses from zoonotic epidemics, exemplified by COVID-19’s $24 trillion global price tag.

Faced with the risk of infectious diseases brought in by imported animals, some may suggest a ban on wildlife trading altogether. However, conservation programs often rely on imported wildlife, and well-regulated wildlife trade provides an economic incentive for the preservation of critical ecosystems. Completely banning the importation of wild animals into the United States, one of the largest markets, would be an overreaction with globally-felt economic consequences on a $220 billion industry.

Reducing the risk of zoonotic disease from wildlife trading must ultimately be a global effort. But, given the current absence of a coherent national strategy for preventing dangerous zoonoses, domestic legislation, particularly the long-standing Lacey Act, is a powerful place to start. Congress must pass legislation amending the Act to require USFWS port inspectors to screen high-risk incoming wildlife for potentially deadly and debilitating pathogens at the border. Otherwise, someone’s new canary or common iguana could carry in the next COVID-19.

Emily Murphy is a first-year MPH student in the Department of Epidemiology.