Experts say the virus can't be transmitted nor is not harmful to humans.
The virus is expected to reduce the number of pork in markets causing an increase in prices.
"Those pigs would be hitting the market in 5 to 6 months from the date they were born. We're going to start seeing diminished supplies of pork in the market place due to the fact that there's 5 million that are on feed right now," said Bob Kelly, farming specialist.
In some cases the virus has wiped out entire nurseries in Missouri.
Researchers are working to develop a vaccine to prevent it from spreading.