Two South Dakota men who live and work together also shared an infection of hantavirus, bringing the total number of cases in the United States to 131.

The federal Centers for Disease Control and Prevention reported on Thursday that sporadic outbreaks of the virus, first identified in 1993, continued in 24 states through March 21.

Both men, who worked and lived at a cattle feedlot, survived. The CDC said they could have picked up the bug from rodents, the primary source of infection.

The CDC said 49.6 percent of the people who contracted hantavirus died. New Mexico has had the most cases - 28 - followed by 21 in Arizona and 13 in California.

Most people who have contracted the virus, which causes severe cardiopulmonary illness, work outdoors and around animals.