Bringing home souvenirs from a long-awaited vacation abroad is one way to savor memories of a special trip.

Yet, travelers need to be mindful that those items in their suitcases are legal and healthy.

As African swine fever (ASF) spreads across parts of the world, U.S. officials have been monitoring movement and increasing surveillance to keep the disease out of the country. The disease, contagious in pigs and wild boars, has been spreading across the Caucasus region, Europe and Asia since 2007. Since the 2018 outbreak in China, the country has slaughtered an estimated 1,170,000 animals.

Due to dramatic changes in ASF global epidemiology, officials are concerned that the disease may continue to spread into disease-free regions such as the U.S. A team of researchers from around the world, including some from the University of Minnesota College of Veterinary Medicine, decided to measure the risk of ASF entering the U.S. through the smuggling of pork products in air passenger luggage. Their findings were recently published in the journal, Scientific Reports.

The researchers found:

“If ASF were to enter the United States, its spread would cause immense economic damage to the pork industry and food production more broadly, leading to the loss of billions of dollars for swine producers,” says Andres Perez, study co-author and director of the University of Minnesota Center for Animal Health and Food Safety, College of Veterinary Medicine. “Our study’s findings can help support decision-making for disease surveillance strategies in the U.S. swine industry and transportation hubs.”

Researchers noted in their report that data from USDA’s Animal and Plant Health Inspection Service indicate that airport screening activities conducted between 2010 and 2015 resulted in the confiscation of an average of 8,000 pork products per year. Nearly half (45%) of those prohibited pork products were intercepted at international airports inside air passengers’ personal luggage.

Researchers acknowledged, too, that it is unclear to what extent prohibited pork in luggage poses a risk of bringing in ASFV to the U.S. since seized product is not routinely diagnosed.

Much of the concern related to ASF entering the U.S. via travelers’ luggage is linked to the possibility if contaminated products are disposed of outside the airport where they may infect feral pigs. The feral pig population has been steadily increasing in the U.S. more than six million feral swine currently reside in at least 35 states.

Perez says U-M’s Center for Animal Health and Food Safety will continue working closely with state and U.S. swine veterinarians and producers to increase preparedness and awareness to prevent or mitigate the impact of a hypothetical ASF epidemic.

Specifically, Minnesota pork producers can continue to help educate the traveling public about the disease. Perez encourages producers to talk with neighbors and employees, anyone who could potentially reach the farm and animals, directly or indirectly. Those are the contacts with the highest risk, he adds.

Regarding on-farm biosecurity practices, Perez says they should be as strict as possible.

“If they are strict enough, then the challenge is compliance,” he says. “It is challenging to remain alert and comply with protocols at all times. We do not know when [ASF] is going to happen. If there is an unusual sign of disease, call the veterinarian and report your suspect immediately.”

Animal health experts say that ASF is one of the most feared food animal diseases in the U.S. ASF has traditionally been endemic to sub-Saharan Africa and the Italian island of Sardinia, with sporadic epidemics affecting a number of countries through the 20th century. However, in 2007, the ASF virus spread into Georgia, Armenia and Azerbaijan, and subsequently into the Russian Federation, Ukraine and Belarus. In 2014, four European Union countries became infected: Lithuania, Poland, Latvia and Estonia. Despite prevention and control measures, ASF continued to spread between 2014 and 2019 in eight more European countries: Moldova, Czech Republic, Romania, Hungary, Bulgaria, Belgium, Serbia and Slovakia.

In 2018, China officially reported its first case of ASF on a domestic pig farm. By summer 2019, 32 Chinese provinces were affected by the disease and more than 1,170,000 animals slaughtered. ASF has also been reported in Mongolia, Vietnam, Cambodia, North Korea, Laos and Myanmar.

Other countries have strengthened air passenger luggage control at points of entry. As a result of those efforts, ASF-contaminated pork products, such as sausages or dried pork, have been detected several times at ports and airports in Taiwan, South Korea, Japan, Thailand, Australia, Philippines and United Kingdom in 2018-2019. Most of the products confiscated at these airports originated from China.

In their study, researchers noted that summer months, particularly July, accounted for a higher risk of contaminated product possibly entering the U.S. They suggested targeting surveillance in the summer, particularly at the five high-risk airports.