With the wildlife trade being one of the possible sources of the current Ebola pandemic (please see previous ‘post’) it is worth noting that there is currently no international body comprehensively regulating the health risks of the international wildlife trade.
Unlike the international movement of farm animals, disease status is typically not a factor in inter-country wildlife trade regulation. However, movement of animals and plants beyond their natural habitat, and the associated inter-species interactions, including novel ones, create prime opportunities for “pathogen pollution” (pathogen spill-over from one species to other(s)), allowing for potential transmission and spread of disease. The yearly direct and indirect connectivity between species posed by the wildlife trade has been estimated as over one billion contacts.
There have been several examples of diseases spread through the trade. For example, the amphibian pathogens chytrid fungus (Batrachochytrium dendrobatidis) and Ranavirus, which have been responsible for large-scale amphibian die-offs, are thought to have been largely spread through the live amphibian trade.
Zoonotic diseases have been introduced through legal trade, as seen with cases in the United States of monkey-pox transmitted from imported Gambian cane-rats to humans via pet prairie dogs in 2003.
In addition to documented cases of zoonotic, inter-wildlife, and agricultural disease transmission from wildlife, recent studies of confiscated wildlife or wildlife products imported or destined for international trade have detected potentially zoonotic pathogens, including Highly Pathogenic Avian Influenza H5N1 and the retrovirus simian foamy virus.
While the World Organisation for Animal Health (OIE) strictly regulates international trade of animals based on scientific methodology, the focus has historically been on agricultural species given their importance for food security, with the majority of OIE Code chapters excluding wild species. In recognition of possible health risks of the international wildlife trade, the OIE has initiated voluntary reporting of non OIE-listed diseases that warrant more consideration in the context of trade.
Improved scientific understanding of the ecological and health risks should be incorporated into decision-making processes in a systemic way. Criteria for species listings vary among CITES, national threatened species lists and other frameworks setting legal boundaries on species import, export, commercialization and keeping, and IUCN assessments, resulting in different categorization; for example, a comparison of IUCN species on the Red List (classified as Vulnerable, Endangered, or Critically Endangered) with the United States Endangered Species Act listings found a high level of variation.
Furthermore, the different wildlife trade laws in place and their respective prohibited or permitted species listings and enforcement breadth make it challenging for customs and law enforcement officials, traders, and the public alike to navigate trade regulations (for example, some laws apply only to importation and exportation, but do not apply once an animal or wildlife product is imported).