Robert A. Cook, V.M.D., M.P.A.
Adjunct Professor of Environmental Affairs
School of International & Public Affairs
July 17, 2003
Mr. Chairman, members of the committee, thank you for the opportunity to testify concerning the critical issues surrounding the importation of exotic species and its impact on public health and safety. Before I begin, I would like to request that this written testimony be entered in the hearing record.
My name is Dr. Robert Cook, I am the Chief Veterinarian and Vice President of Wildlife Health Sciences for the Wildlife Conservation Society and an Adjunct Professor of Environmental Affairs at Columbia University in the School of International and Public Affairs. In addition I am chair of the Animal Health Committee of the American Zoo and Aquarium Association as well as Chair of the Captive Wildlife and Alternative Livestock Committee of the United States Animal Health Association. The Wildlife Conservation Society is a science based membership organization, founded in 1895 to conserve wildlife and wild lands throughout the world and manage the Bronx Zoo and other living institutions in New York City. Our Health Sciences Division provides critical veterinary support to the care of 23,000 wild animals in our New York zoos and aquarium as well to over 300 international field conservation projects in 53 nations. In 1989 we began the first Field Veterinary Program of any conservation organization and are deeply involved in health surveillance programs in key wildlife habitats. At Columbia University I work with students in the Masters in Public Administration program in Environmental Science and Policy examining national and global health and conservation issues.
I have been specifically asked to speak on the health threats posed by the global movement of exotic animals and their products, including the bush meat trade, in three specific areas:
· Exotic animals that are carriers of disease
· The types of diseases
· The risks to human health
I regret to inform you that while these are the areas of greatest concern, they are also the areas that we know the least about. If we hope to generate solutions to these disease issues we must start to think about the health of people, domestic animals and wildlife in a more holistic way. A way that addresses the reality that the environment, human activities, movements of animals out of their native habitats and human health are obviously interrelated. As we better understand the complexity of these interrelationships we can--and must--devise solutions that are proactive and not reactive: solutions that address the realities of ONE HEALTH for our planet’s people, domestic animals and wildlife.
A wide range of domestic and non-domestic animals carry diseases that can threaten the health of people. Pet dogs can contract rabies if not vaccinated. They can also become infected and spread other zoonotic diseases (those transmissible between animals and people) such as tularemia, leptospirosis, visceral larva migrans, trichinosis, plague, scabies and salmonellosis. But if domestic dogs are properly managed with sound veterinary care, they are safe and wonderful additions to the American household.
Dr. Mark Woolhouse and his colleagues at University of Edinburgh noted in the journal SCIENCE that “humanity is currently plagued by 1709 known pathogens (from viruses and bacteria to fungi, protozoa and worms)”. They concluded that 49% of those are zoonotic and further it was noted that zoonoses are three times more likely to be emerging diseases than non-zoonotic diseases.1
While what we know about emerging diseases is instructive- it is what we don’t know that may threaten us the most. For example, rodents carry a plethora of diseases that move between people and animals. Leptospirosis, listeriosis, plague, streptobacillosis, lymphocytic choriomeningitis, hanta virus, ringworm, tapeworm, lassa fever and pneumocystis carinii to name a few. These are the major diseases that professionals routinely look for, but even though it was possible for Monkey Pox to be spread by rodents, until the crisis of a few weeks ago no one was looking for that one. It is only once the threat has realized itself by causing disease close to home that we institute control measures. We need to act sooner and more effectively on a global scale. But even at that, diseases such as Monkey Pox or West Nile Virus have been described elsewhere in the world before entering our country, we must also be prepared to handle diseases that make the jump to infect new species, including humans. The coronavirus which causes SARS appears to have moved from animals in the wildlife markets to people….and the prion disease, bovine spongiform encephalopathy (BSE) or “Mad Cow” made the jump from cattle to people. Both have had a devastating impact on human lives and the economy of nations. The World Health Organization listed the cumulative number of probable SARS cases in people as of 11 July 2003 at 8,437 with 813 deaths.2 The World Organisation for Animal Health (OIE) lists over 182,745 cases of BSE in United Kingdom cattle alone between 1988 and 2002.3 The University of Edinburgh reports 132 human deaths attributed to definite or probable vCJD, Creutzfeldt Jacob disease, the human prion variant linked to BSE.4
We must not limit ourselves strictly to those zoonotic diseases that can spread between animals and people. We must also look at emerging diseases that threaten domestic livestock and wildlife as well- for here too humanity is threatened, either through the loss of wild species or agricultural losses, such as those experienced in the 2001 Foot and Mouth disease outbreak in Great Britain or most recently the Enzootic Newcastle Disease (END) outbreak in the Southwest U.S. On July 2, 2003 Dr. Thomas Walton of the United States Department of Agriculture reported in the ProMed Digest that 3,928,281 domestic birds had been depopulated due to the END disease concerns.5
And we must consider both the legal and illegal exotic pet trade. According to most estimates, the illegal global trade in exotic pets is worth tens of billions of dollars a year. More must be done to halt this movement, not only for the sake of the wildlife taken from their natural environments but for the health of people, domestic animals and native wildlife- all threatened by the introduction of novel pathogens to a naïve population.
While I started with the illegal trade, it must be noted that there is a multi-billion dollar legal trade as well which needs to be addressed. Stricter regulations governing the movement of wild caught animals destined for the United States pet trade would not only bolster efforts to maintain intact landscapes but also would lessen the threat these animals pose to our health. For example, millions of reptiles and amphibians are transported around the globe as both pets and bushmeat. Few controls exist to stem this flow. We know that these animals can carry diseases such as salmonellosis, camplyobacteriosis, mycobacteriosis, Q fever and pentastosomiasis. At the Annual Meeting of the United States Animal Health Association in 1995, Dr. Stephanie Ostrowski of the Centers for Disease Control and Prevention reported on the work of Clark and Doten who studied ticks on imported reptiles coming into Miami International Airport. Between November 1994 and January 1995, United States Department of Agriculture’s Animal Plant Health Inspection Service personnel inspected 349 reptile import shipments with a total of 117,690 animals originating from 22 countries. Ticks were removed from one or more animals in each of 97 shipments. Infested shipments included 54,376 animals in total.6 Ticks are a disease vector species that can potentially carry a number of pathogens present in the United States as well as many other diseases from around the globe that threaten animal agriculture and human health within our borders.
Lastly we must also consider the broader scope of injurious invasive species of flora and fauna that have and will enter our air, land and waterways by chance or by purpose. More must be done to regulate conveyances and movement if we are to control these threats to our native environment and our health.
So what can be done now? We must be more proactive. And to be proactive we must be looking for those things we know little about- not only within our borders but in range countries around the world. We must do it in a way that respects the role that animals and people play in the perpetuation of a healthy ecosystem and not with an eye to eliminate one or another species that is believed to carry a particular disease. Such piece meal approaches will trap us in a never-ending cycle of reaction. To be proactive we must:
· Maintain high-quality quarantine protocols: Quarantine protocols such as those used by the 212 accredited institutions of the American Zoo and Aquarium Association. These procedures require that any animal entering their collections be examined and maintained in a secure facility for the quarantine period to ensure that disease threats can be controlled. Protocols are in place to quarantine all new arrivals under veterinary supervision, whether they come from across the country or across the world. These procedures include veterinary exams, diagnostic testing as well as pathology examinations in the event of an animal death.
· Expand range-country and homeland surveillance systems: Right now Ebola virus is ravaging the great ape and human populations of central Africa. Field veterinarians of the Wildlife Conservation Society are on the ground, working with a multi-disciplinary team of scientists and local peoples to collect samples from wild animals to not only determine the vectors of disease but to work towards understanding how to contain the disease within the forest. It was through these collaborative international efforts that we discovered gorillas also die of the disease and it is through the samples collected by trained field staff that eventually the vector will be identified- an important missing link that will allow the scientific community to begin to formulate sound control measures.
The West Nile virus entered the United States in the late summer of 1999. The first connections made between this deadly disease of birds and the illnesses in people came from the Wildlife Conservation Society’s Veterinary Pathology Department. The then head pathologist, Dr. Tracey McNamara, was performing standard surveillance protocols looking at wild crows that had died and whose disease could affect the health of the animals in the zoos collections. By expecting the unexpected, one of the hallmarks of a thorough surveillance system, the lesions were described and the alarm was sounded. While today we know that the isolate is identical to that found in a goose during the 1998 outbreak in the Middle East, we may never know how it breached our borders. However it arrived, the results are clear and ominous. Dr. Roy Campbell of The Centers for Disease Control and Prevention reported in February 2003 that the results from 2002 included 4,161 human cases with 277 fatalities. Thousands of horses were affected as well.
· Restrict the trade (legal or illegal) in exotic wildlife that is taken from the wild for the pet or bushmeat trade: In today’s global marketplace, wildlife is just another commodity. Wildlife destined for food markets and the pet trade is often transported over enormous distances. For example, animals found in the markets in Guangshou, Guangdong Province, China include soft-shelled turtles captured in Sumatra, pangolins from Vietnam and Thailand, pythons from Myanmar and red-eared sliders from Florida. The result is a dangerous concatenation of circumstances, with animals and would be consumers from different ecosystems coming into contact. The lack of resistance to new pathogens makes humans and animals alike, fertile, uncontrolled laboratories for these organisms to adapt and rapidly mutate. The staggering numbers of animals and people coming into contact with each other change the one-in-a-million odds of disease spillover into almost a daily possibility. Even under the most hygienic conditions, this pool of viruses, bacteria, and other pathogens creates an optimal breeding ground for diseases to multiply rapidly and jump between species enabling them to exploit new hosts.
What we know right now is that many different species of animals have the ability to carry infectious agents that can threaten human and animal health. These vectors of disease tell us not only what threatens us today but are especially instructive in showing us what is at stake when the balance of nature is tampered with. The Nipah virus emerged in Malaysia in 1999 and killed 105 people. One theory is that fruit bats were carrying the pathogen that infected domestic pigs that then became the “amplifying” hosts for the human outbreak.1 The bat “fear factor” amongst people prompted calls to annihilate the species- a major pollinator of the forests in that region. If this eradication had been successful the implications to the future of healthy forests, the food supply and ultimately human health would have been dramatic. It will not be enough to isolate specific species after an outbreak occurs or worse, to attempt to eradicate each implicated species when an emerging disease is diagnosed. If we limit ourselves to this view we will miss the big picture- that proactive measures including long term surveillance, effective quarantine protocols and limits on the global trade of exotic animals will best protect the public health, help ensure the quality of our food supply and improve the prospects for the conservation of wildlife worldwide.
Mr. Chairman, as you formulate legislation to address the issue of importation of exotic species and the impact on public health and safety, I strongly encourage you and your staff to call upon the informational resources and expertise of the Wildlife Conservation Society and the American Zoo and Aquarium Association. These resources can assist the Committee in developing effective, common sense measures that can help protect wildlife and human resources both here and abroad. I would be happy to answer any questions that you may have.
2. World Health Organization Communicable Disease Surveillance & Response: Cumulative Number of Reported Probable Cases of SARS. www.who.int/csr/sars/country/2003_07_11/en/
3. World Organisation for Animal Health (OIE): Number of cases of BSE reported in the United Kingdom. www.oie.int/eng/info/en_esbru.htm
4. University of Edinburgh, The UK Creutzfeldt-Jakob Disease Surveillance Unit. CJD Statistics. www.cjd.ed.ac.uk/figures.htm
5. ProMed-Ahead Digest V2003#12: Emergency Management Warning #105:Exotic Newcastles Disease in the United States www.promed.org
6. United States Animal Health Association. Proceedings of the Ninety-Ninth Annual Meeting, October 28-November 3, 1995. Report of the Committee on Public Health and Environmental Quality. Pages 471-480.