Surveillance needed to prevent disease spread from wildlife trade

Smith KM. PLoS One. 2012;doi:10.1371/journal.pone.0029505.

Results from a pilot study suggest that illegal importation of “bushmeat” into the United States could likely foster the spread of zoonotic pathogens.

Kristine M. Smith, MD, of EcoHealth Alliance, an international non-profit focused on the intersection of human, animal and ecosystem health, and colleagues recommend the implementation of a disease surveillance system to aid in the prevention of disease emergence in wildlife trade.

A multitude of zoonotic viruses exist in nonhuman primates, rodents and their bushmeat, according to Smith.

“This study has shown bushmeat from species that host these viruses are entering the United States and are often uncooked and harbor viral DNA, posing a potential risk to US public health,” she told Infectious Disease News. “In addition to humans exposed to live nonhuman primates, there is potential risk for foamyvirus and similar zoonotic pathogen infections from bushmeat handling and consumption in West and Central African communities in the United States.”

Seized shipments

For the study, Smith and colleagues gathered data from eight shipments confiscated by the CDC at John F. Kennedy International Airport in New York from October 2008 to September 2010.

Further data from 20 passenger-carried packages were seized from the Philadelphia, Washington Dulles, George Bush Intercontinental-Houston and Atlanta Hartsfield-Jackson international airports from June to September 2010.

For each seizure, the researchers recorded the place of origin/destination, flight information, the date of arrival and date of sample collection. The genus and species of items were identified via gross examination or via barcoding techniques.

Additional data from bushmeat items confiscated by the US Fish and Wildlife Service at John F. Kennedy International Airport in 2006 were also assessed for the study.

Identification of specimens

The types of specimens gathered included items that were fresh, raw and transported in a cooler, smoked or dried. Four simian foamy virus strains and two types of herpes viruses were identified from nonhuman primate bushmeat specimens.

“Our finding of simian foamy virus DNA in smuggled nonhuman primate specimens comprising of four species — baboon, chimp, mangabey and African green monkeys — is significant because simian foamy virus is a known zoonotic infection of humans exposed to nonhuman primates,” the researchers wrote. “However, the mode of transmission to humans is poorly understood, and while most infected people reported sustaining a nonhuman primate exposure (mostly bites), others did not, suggesting a less invasive mode of infection is possible.”

The researchers also identified two herpes viruses in nonhuman primate specimens — cytomegaloviruses and lymphocryptoviruses.

Multiple viruses were also detected: cytomegaloviruses, lymphocryptoviruses and simian foamy virus were found in baboon; and lymphocryptoviruses and simian foamy virus were found in the bone marrow of African green monkey and the muscle of mangabey, according to the study.

“We are interested in conducting future research that will involve broadening zoonotic disease surveillance to wildlife products from other species of origin entering the United States via ports across the country,” Smith said. “This would broaden the range of zoonotic diseases that stem from wildlife investigated. The United States is the top importer of live wildlife and wildlife products — both legal and illegal — in the world, and there is a need for increased health regulation of these items/animals entering our borders.

“Seventy-five percent of emerging infectious diseases are zoonotic, most of which stem from wildlife. It is therefore important for the ID specialist to keep in mind exposures to wildlife and wildlife products when considering the medical history of patients with undiagnosed illness.” – by Jennifer Henry

Disclosure: The researchers report no relevant financial disclosures.

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