A pilot study reported online this week in the journal PLoS ONE reveals how scientists found evidence of potentially dangerous viruses, including retroviruses and herpesviruses, in bushmeat and other wildlife products smuggled into the US. The report authors say the study shows the importance of establishing proper surveillance and testing of imported wildlife products in order to assess the potential risks they pose to public health.

The products had been confiscated at several US international airports, including John F. Kennedy International Airport, George Bush Intercontinental-Houston and Atlanta Hartsfield-Jackson International.

The US Centers for Disease Control and Prevention (CDC) led the pilot study, with the collaboration of the American Museum of Natural History, Columbia University, EcoHealth Alliance, the USGS National Wildlife Health Center, and the Wildlife Conservation Society.

The authors note in their introduction that although we know that the global trade in wildlife has contributed to the emergence and spread of many infectious diseases, and the US is the world’s largest importer of wildlife and wildlife products, it has “minimal pathogen surveillance”, which makes it virtually impossible to assess the risks to public health posed by this practice.

Research estimates that 75% of emerging infectious diseases in humans originate from contact with wildlife, and these diseases are transmitted through human-animal interactions inherent in the global wildlife trade.

So the pilot study was set up in order to establish a level of monitoring and testing so the authorities can begin to assess what risks wildlife products that find their way into the US illegally might pose to public health.

Among the items confiscated were raw to semi-cooked parts of baboon, chimpanzee, other non-human primates such as mangabey, guenon and green monkey, and various rodent species, including cane rat and rat.

The animal parts were identified by the American Museum of Natural History’s Sackler Institute for Comparative Genomics, Columbia University, and the Wildlife Conservation Society using advanced DNA barcoding technology.

The CDC and Columbia University’s Center for Infection and Immunity then tested the animal parts to look for pathogens: agents like viruses and bacteria that cause disease in humans.

They found retroviruses (such as the simian foamy virus SFV, a close relative of the human immunodeficiency virus, HIV), and herpesviruses (cytomegalovirus and lymphocryptovirus).

The authors conclude:

“These results are the first demonstration that illegal bushmeat importation into the United States could act as a conduit for pathogen spread, and suggest that implementation of disease surveillance of the wildlife trade will help facilitate prevention of disease emergence.”

The lead author of the study was Dr. Kristine Smith, the Associate Director for Health and Policy at EcoHealth Alliance. She said in a statement that although their findings are only those of a small pilot program, 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.”

Dr Denise McAloose, chief pathologist for the Global Health Program of the Wildlife Conservation Society (WCS), said:

“The increase in international travel and trade brings with it an increased risk of unmonitored pathogens via the illegal wildlife trade.”

W. Ian Lipkin of Columbia University’s Mailman School of Public Health, said the study highlights the importance of surveillance at points of entry into the country such as ports, but there is also a need to reduce demand for products that drive the trade in wildlife.

A previous study by EcoHealth Alliance found that in the six years from 2000 to 2006, approximately 1.5 billion live wild animals were legally imported into the US, 90% of them for the pet trade.

Written by Catharine Paddock PhD