ST. PAUL — University of Minnesota experts are working to prevent the further spread of a swine virus that was first confirmed in the United States last month.

Dr. Montserrat Torremorell said it’s not clear how the porcine epidemic diarrhea virus was introduced to the U.S. She said more than 60 cases have been confirmed in Minnesota, Colorado, Indiana, Iowa and Illinois combined.

While it can be fatal to newborn piglets, she said older pigs generally recover after a few days.