Importance of Tracking Diseases Associated with Illegal Wildlife

"The increase in international travel and trade brings with it an increased risk of unmonitored pathogens via the illegal wildlife trade," said Dr. Denise McAloose, chief pathologist for the Global Health Program of the Wildlife Conservation Society (WCS). She was referring to wildlife products being imported into the United States.

The global trade of wildlife has largely contributed to the emergence of new diseases in livestock, native wildlife and humans worldwide. Current research shows that 75 percent of emerging infectious diseases affecting people originate from contact with wildlife. These wildlife-borne diseases can be transmitted through human-animal interactions inherent in the global wildlife trade.

An article published in a January 2012 issue of PLoS ONE entitled, Zoonotic Viruses Associated with Illegally Imported Wildlife Products, from a collaborative study led by the U.S. Centers for Disease Control and Prevention (CDC), identified evidence of retroviruses and herpes viruses in illegally imported wildlife products confiscated at several U.S. international airports, including John F. Kennedy International Airport, George Bush Intercontinental-Houston and Atlanta Hartsfield-Jackson International.

The pilot program was initiated to establish surveillance and testing methods to uncover the potential public health risks from illegally imported wildlife products coming into the United States. The preliminary results of the program clearly demonstrate the potential human health risk from the illegal wildlife trade at major international travel hubs as a pathway to disease emergence in animals and humans.

Lead author and Associate Director for Health and Policy at EcoHealth Alliance, Dr. Kristine Smith, stated "although the findings to date are from a small pilot study, they remind us of the potential public health risk posed by illegal importation of wildlife products - a risk we hope to better characterize through expanded surveillance at ports of entry around the country."

Items confiscated as part of the study included raw to semi-cooked animal parts, identified by American Museum of Natural History's Sackler Institute for Comparative Genomics, Columbia University, and WCS as nonhuman primates, including baboon and chimpanzee, and various rodent species using advanced genetic bar-coding technologies. Pathogen analysis was conducted at the CDC National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention and Columbia University's Center for Infection and Immunity. Among the pathogens identified in the products were a zoonotic retrovirus, simian foamy viruses, and several nonhuman primate herpes viruses. These results are the first to confirm evidence of pathogens in illegally imported bushmeat that may act as a conduit for pathogen spread, and suggest that implementation of disease surveillance of the illegal wildlife trade will help facilitate prevention of disease emergence.

"Exotic wildlife pets and bushmeat are Trojan horses that threaten humankind at sites where they are collected in the developing world as well as the U.S. Our study underscores the importance of surveillance at ports, but we must also encourage efforts to reduce demand for products that drive the wildlife trade," said W. Ian Lipkin of Columbia University's Mailman School of Public Health. In fact, the U.S. is one of the largest consumers of imported wildlife products and wildlife. A previous study by EcoHealth Alliance showed that over a six-year period (2000-2006) approximately 1.5 billion live wild animals were legally imported into the U.S. - with 90 percent slated for the pet trade.

There is also a risk of disease introduction to native wildlife and agricultural species, proliferation of non-native wildlife causing damage to US ecosystems, as well as the protection of threatened and endangered species identified by the International Union for Conservation of Nature. "These important research results highlight the value of using new DNA bar-coding identification technologies to accurately monitor the wildlife trade, important for both disease surveillance and the conservation of endangered species," stated Dr. George Amato from the Sackler Institute of Comparative Genomics at American Museum of Natural History.

Kruger National Park - South African Safari