As China moves to contain an outbreak of African swine fever, the US Department of Agriculture has taken steps to keep the disease from entering the country and devastating the American pork industry.

African swine fever (ASF) is a hemorrhagic disease and causes high mortality in pigs, Dr Montserrat Torremorell, a veterinary professor at the University of Minnesota, said in an email.

“There is no vaccine. The virus is highly resistant in the environment, it is found in the blood and tissues of pigs and pork products and can be transmitted easily by contact from infected to susceptible pigs (including contact with wild pigs) and also orally after ingestion of contaminated pork products.

“The virus can also be transmitted by soft ticks,” said Torremorell.

China has reported more than 40 outbreaks of the highly contagious disease in 11 provinces and municipalities, culling an estimated 200,000 pigs.

ASF only infects pigs, according to Dr Dave Pyburn, senior vice-president of science and technology at the National Pork Board in Des Moines, Iowa. “(ASF) does not infect cattle, sheep, goats or humans so it is not a public health threat,” Pyburn said in an interview.

ASF has not been detected in the US, according to spokeswoman Joelle R. Hayden of the US Department of Agriculture (USDA).

To prevent ASF from entering the country, the USDA has in place a series of safeguards.

They include collaborating with states, companies and producers to ensure everyone follows on-farm biosecurity best practices; restricting the import of pork and pork products from affected countries (last week the USDA suspended imports of pork from Poland over an outbreak of African swine fever in that country) and working with customs staff at ports of entry to train their inspection dogs, while increasing screening vigilance to pay particular attention to passengers and products.

China also supplies much of the vitamins and minerals that are used in feed that is fed to pigs in the US, noted Pyburn.

“We are concerned with the possibility of accidentally bringing in the virus through these components,” he said.

In Minnesota, hog farmer Randy Spronk said he asked feed brokers and manufacturers such as Royal DSM, about the origin of the swine vitamins and feed additives he buys.

If the products come from China, he wants them kept in storage because the virus is thought to die out when held in dry conditions, Reuters reported.

Chris Hoffman, who raises 1,400 hogs yearly in McAlisterville, Pennsylvania, is a vice-president with the Pennsylvania Farm Bureau. He said in an interview that while he hasn’t implemented special practices for ASF, “we are always working to keep biosecurity at the highest possible level every day”.

China is the world’s largest pork market, so industry participants like Hoffman will be monitoring the situation there closely.

“It has the potential to affect (the hog market in the US) depending on how bad it gets,” he said.

China has imposed tariffs on US hog exports in response to American tariffs on Chinese goods. Hoffman said it’s too early to know if China may be forced to adjust its US tariff policy because of AFS in the country.

“China is buying pork from other countries because of the tariffs. It depends on if there is a total crash in Chinese production that seriously affects their production before we will know if (AFS) will force them to turn to the US for additional supplies,” Hoffman said.

If AFS “puts a serious dent in the total number of pigs available for slaughter in China, there could be some changes for the global pork market,” said Pyburn.