Two Minnesota women have died in a national E. coli outbreak that has been linked to romaine lettuce grown in the southwestern United States.

A third Minnesota victim remains hospitalized with serious complications from the illness.

While the tainted lettuce has either been removed from stores or discarded in homes because it is now beyond its 21-day expiration date, the outbreak’s toll is growing. The two Minnesota adults were infected in April and died in May, but their deaths were first reported Friday by the U.S. Centers for Disease Control and Prevention.

“It’s unlikely we’re going to have additional cases. We haven’t had any for a few weeks now,” said Amy Saupe, a food-borne disease epidemiologist for the Minnesota Department of Health. “Obviously we don’t want to say never.”

While specific fields or suppliers haven’t been identified, investigators have traced the outbreak to lettuce grown in the Yuma, Ariz., region. The CDC on Friday reported 197 infections in 35 states, resulting in 89 hospitalizations and five deaths.

One Minnesota fatality involved hemolytic-uremic syndrome (HUS), which occurs when infection results in the depletion of red blood cells and clogging of kidneys. The other was a woman with health problems that were complicated by her infection. Both were from the Twin Cities area, Saupe said.

The state Health Department didn’t identify the Minnesotan who remains hospitalized, but a family lawyer, Bill Marler, identified her as Linda Miller, 68. Miller is in a coma at Abbott Northwestern Hospital in Minneapolis.

Miller became ill a month ago and during her hospitalization went from being talkative, to communicating with facial gestures, to being unconscious and needing a feeding tube and other supports to stay alive. She has had severe seizures and, due to her kidney failure, needed multiple procedures to filter her blood.

“My sister may die from this,” said her brother, Marty Asleson of Circle Pines. “We’re all really sad for my sister and angry that this happened. It shouldn’t have happened. It’s not just my sister. It’s a lot of people.”

For every severe case that reaches the attention of public health authorities, an estimated 26 more don’t get diagnosed and reported. Most cases result in diarrhea, stomach cramps and vomiting.

E. coli bacteria must be ingested to cause infection. The O157 strain in this outbreak can cause illness, even in lower amounts, by producing a Shiga toxin that attacks the body.

Most people were infected by eating romaine, but some had only been in close contact with others who ate the tainted lettuce. In general, people can transmit E. coli if they touch infected animals or fecal matter and then don’t wash their hands before touching other people or preparing food.

Saupe said the last known infection-related illness in Minnesota emerged May 2. That person didn’t eat romaine but had been around someone who did.

The Health Department also warned Friday of salmonella in four people in Minnesota and Wisconsin linked to frozen breaded chicken products sold at Ruby’s Pantry stores.