Field Notes: Predicting how the pet trade spreads infectious disease

Mongabay's Elizabeth Devitt recently profiled the research of SESYNC Postdoctoral Fellow, Elizabeth Daut.

•The exotic animal trade is a multi-billion dollar industry, and the US is the world’s leading importer. While the US government is on the alert for well known animal-transmitted diseases, there is no mandatory health surveillance for most animals coming though US ports for commercial distribution.

•Live animal imports could bring new diseases into the US and infect endemic wildlife, with devastating consequences as, for example, was seen with the worldwide exposure of amphibians to Chytrid fungus which resulted in the decline of more than 200 species.

•Elizabeth Daut is drawing on her training as a veterinarian and her extensive experience with wildlife to create a computer model that evaluates the risk of importing infectious diseases to the US via the exotic animal trade.

•Predictions produced by her model could help prioritize which species and exporting countries might warrant extra attention at ports of entry. With a better understanding of disease risks, government agencies could improve surveillance and develop better infectious disease prevention plans.

The legal commercial exotic animal trade is a booming enterprise that ships ornamental fish, mammals, birds, reptiles and amphibians around the world. These pets, livestock and other animals can carry unexpected infectious diseases from their homelands. If these non-native species escape or are released to the wild, they can create epidemics among susceptible endemic wildlife.

Four US agencies oversee live animal imports, but there is currently no systematic screening for disease in most live animal imports. The majority of animals processed through American ports for the pet industry fall under the aegis of the US Fish and Wildlife Service, which has no authority to conduct health inspections. Livestock imports are regulated by the US Animal and Plant Health Inspection Service (APHIS), with oversight by the Department of Homeland Security’s Customs and Border Protection. Species known to carry certain diseases (rabies in dogs, or tuberculosis in monkeys, for example) are monitored by the Centers for Disease Control and Prevention.

According to a 2010 report from the US Government Accountability Office, a lack of interagency collaboration creates gaps in health surveillance that could leave native wildlife and people exposed to disease. These risks could potentially be enormous. A single fungal disease, Chytrid, for example, devastated more than 200 amphibian species worldwide.

A related pathogen, Batrachochytrium salamandrivorans, originating with the Asian salamander trade, wreaked similar havoc on native populations in the Netherlands and Belgium. If this fungus gains a foothold in the US — a salamander biodiversity hotspot — experts fear entire species could be wiped out.

“There’s been a lot of attention focused on the human health risks from wildlife disease,” says veterinarian Elizabeth Daut. “While that’s obviously important, nobody is really talking about the risks these exotic imports pose for wildlife.”

Daut is delving into the dynamics and consequences of the spread of infectious diseases by the exotic pet trade, through a post-doctoral project with the National Socio-Environmental Synthesis Center at the University of Maryland.

She is using US Department of Agriculture methodology as part of the basis for her model — the agency routinely inspects plants from other countries and also helps improve plant nursery practices in nations at risk for exporting pathogens. Daut is developing a computer algorithm to predict which countries are at the highest risk of exporting infectious diseases through birds, fish, amphibians, reptiles and mammals.

Read the full interview at Mongabay.

For more on the topic:

Daut EF, Lahodny G Jr, Peterson MJ, Ivanek R. (2016) Interacting Effects of Newcastle Disease Transmission and Illegal Trade on a Wild Population of White-Winged Parakeets in Peru: A Modeling Approach. PLoS ONE, Vol. 11.

GAO. LIVE ANIMAL IMPORTS, Agencies Need Better Collaboration to Reduce the Risk of Animal-Related Diseases. GAO-11-9 (Washington, D.C.: Nov. 8, 2010).

Kolby JE. (2014) Presence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in native amphibians exported from Madagascar. PLoS ONE. Vol. 9.