On Thursday, officials from the Centers for Disease Control and Prevention toured the Sioux Falls plant, an eight-story facility that churned 24 hours a day alongside the Big Sioux River, producing 5 percent of the nation’s pork. The agency is expected to release recommendations in the next few days on how to prevent another outbreak when the plant reopens. The company has not given a date.

Before the plant closed this past week, the company had provided employees with face shields and masks and installed plexiglass barriers in certain areas to separate employees. But in reality, it may be difficult for any meat plant to accommodate social distancing and remain as profitable. Jobs with titles like “gut snatcher” require people to work closely, slicing open pigs and pulling out entrails.

“It is not going to be easy to get workers six feet apart,” said Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University’s medical school. “If you space people out, you reduce productivity.”

Officials in the meat industry have also argued that South Dakota’s decision to not issue a stay-at-home order may be contributing to the outbreak, because it has left relatives and neighbors of plant employees free to mingle. South Dakota officials have said residents should exercise “personal responsibility” and practice social distancing.

“That’s a very, very high rate,” Dr. Schaffner said of the infections at the Smithfield plant. “But it’s difficult to know how much of the transmission occurred in the workplace or in the community.”

Some meat companies have expressed reluctance to test workers, saying such targeted testing creates the false impression that meat plants are the main culprits for the spread of the virus. The more aggressively employees are tested, the more cases emerge, putting pressure on plants to shut down.

“Everybody wants to test meatpacking employees, but nobody is testing the communities around them to show what’s the baseline,” said Steve Stouffer, the president of the fresh meats division at Tyson Foods. “And until we know the baselines, my question has always been: Are we the cause or are we just the victim of our surroundings?”