The experience of becoming sickened with salmonella from contaminated beef bought at Hannaford stores in 2011 turned two Maine residents into food-safety advocates. And their stories appear to have made a difference.

Danielle Wadsworth of Lewiston and Kenneth Koehler of Old Orchard Beach have both traveled to Washington, D.C., and spoken to members of Congress with the hope they could help prevent food-borne illnesses in the future.

In a proposed rule published in the Federal Register last week, the U.S. Department of Agriculture cited the outbreak that sickened Wadsworth, Koehler and at least 18 other people in seven states as evidence of the need for new rules to require retail stores to keep better records of the beef they grind.

While pleased to see at least some of the changes they pushed for, neither Wadsworth nor Koehler is yet satisfied or reassured. More than two years after enduring the illness, both try to avoid eating beef. And, while Koehler and many of the sickened customers have settled claims against Hannaford for undisclosed amounts of money, Wadsworth says she may still sue the grocery chain.

Investigators were able to link the cases of illness back to Hannaford ground beef. But the USDA was unable to trace the contamination source in Hannaford’s beef beyond the Scarborough-based grocery chain because store employees didn’t record all the sources of meat each time they put it into their grinders. They also didn’t clean equipment between every grind, creating opportunities for cross-contamination.

Although the USDA blamed the stores’ incomplete records for impeding its search for a cause – the source never was found – Hannaford was complying with all federal requirements in place at the time. In fact, there is still no rule that retailers keep track of the meat sources. That gap in the nation’s food-safety system was highlighted by the Portland Press Herald/Maine Sunday Telegram in a special report published in March 2012.

The company could not entirely escape the blame for sickening customers and became responsible for compensating them, however. At least eight people who ate the contaminated beef have said they reached settlements with Hannaford in the injury claims. Neither Hannaford nor the claimants would reveal the terms or how much money was awarded to those who became ill.

Right after the recall, Hannaford opted to change its record-keeping and equipment-cleaning practices. It has since cleaned equipment more often and kept track of beef sources used in its ground meat.

Now, the USDA wants to require other grocers to do the same.

USDA officials have said a rule requiring retailers to keep better records of grinding beef was in the works before the salmonella outbreak in December 2011. But that outbreak of salmonella led Hannaford to pull 17,000 pounds of ground beef off the shelves and created a new sense of urgency for getting those requirements in place, they said.

Soon after the incident that sickened Wadsworth and Koehler, the federal agency said it planned to send a detailed proposal to the White House’s Office of Management and Budget by the summer of 2012. The proposal wasn’t actually sent until last April, a USDA spokeswoman said last week.

Last Tuesday, when the proposed rule was published in the Federal Register, marked the start of a two-month public comment period before a final draft is written and reviewed. The USDA would not predict when the requirements could take effect.

Both Wadsworth and Koehler said the proposed rule marks a step in the right direction. But nothing could make them feel comfortable eating ground beef again, they said.

“I’m in fear every time I get cramps in my stomach,” said Wadsworth, 34.

Koehler, 55, said he’ll never buy another package of hamburger from the grocery store.

“They’ve lost my trust, let’s put it that way,” he said. “The USDA has lost my trust.”

Koehler will only eat farm-raised, non-grocery store ground beef and Wadsworth said she’ll eat it at a cookout if there’s no other option.

Koehler filed a lawsuit against Hannaford in January 2013 and settled in June of the same year. Although the settlement agreement precludes him from disclosing what compensation he received, he said he was far from satisfied.

Wadsworth has yet to accept an offer from Hannaford and is planning to file a lawsuit, she said.

She’s been advised by other people sickened by food-borne illnesses not to settle for less than six figures.

Brian DiGeorgio of Watervliet, New York, who was hospitalized for two weeks and lapsed into a coma because of the illness, sued Hannaford a week after the recall. He settled in March 2013, according to court documents. His attorney, Benjamin Hill of Albany-based Dreyer Boyajian, said the firm has settled four cases resulting from the outbreak, but wouldn’t comment on the terms.

Three members of the Dugan family from Manchester, New Hampshire, who were sickened with salmonella, resolved their cases a couple of years ago, their attorney has said.

Even though Koehler’s case has been settled, he still has an interest in seeing improvements to the nation’s food-safety system. He said he wants to make sure others don’t have to learn about its shortcomings the hard way, like he did.

“When we go into the store and we pick up a package of ground beef, we’re assuming that everything is being done right,” he said. “We can cook it and eat it and not have to worry, that our federal government is looking over everything, and that’s not the case.”

Koehler said he still experiences discomfort as a result of his bout with salmonella, though he declined to get specific about his symptoms.

He said he’s disappointed with how long it took to move the record-keeping rule forward. He also would like to see more measures that don’t just help identify the source of contamination but stop it before it happens, he said.

“Everything from how the animals are treated to what you put on your dinner plate is a very scary process,” he said.

For Wadsworth, the inspiration to get involved was the thought of having children and what could happen to them just from eating a hamburger.

“You shouldn’t have to be worried about that,” she said.