E. coli forum: Experts discuss illness and how to avoid it

About 170 people attended a public forum Friday, spilling into an overflow room, to hear about foodborne E. coli illness, the food-safety practices in place in the Yuma fresh vegetable industry and what the public can do to prevent its spread.

Hosted by the University of Arizona Cooperative Extension at Arizona Western College, experts gave a rundown of the steps taken routinely in hopes of preventing the spread of E. coli and other dangerous organisms through the food supply.

Vicki Scott of Amigo Farms, a member of the Yuma Safe Produce Council, said farmers need to guard against three broad categories of contamination: trash/foreign objects, chemicals such as improperly used pesticides, and organic, biological agents.

"These bacteria are not visible to the human eye, they're microscopic, they don't have any odor, you can't taste them, so they're definitely a danger to us," she said.

Romaine lettuce grown in Yuma has been identified as the source of a multistate E. coli outbreak, which has caused 121 illnesses in 25 states, including one death, according to the U.S. Centers for Disease Control's most recent update Wednesday.

Federal investigators from the Food and Drug Administration have not determined how the dangerous strain of E. coli came into contact with the lettuce. All but eight of the confirmed illnesses have been traced to chopped romaine in bags or salad mixes.

Eight prisoners in Alaska got sick after eating lettuce purchased as whole heads of romaine, rather than pre-cut. A field grown by one local company, Harrison Farms, has been named as the origin of that lettuce only, but the contamination could have been introduced later in the process.

Because E. coli bacteria, most of which is harmless, is generally found in the digestive tracts of humans and other warm-blooded animals, growers are constantly trying to guard against animal intrusions into their fields by either wild or domestic animals.

The 2006 E. coli spinach outbreak, which led to three deaths and more than 200 illnesses, was traced by the FDA to a field in San Benito County, Calif. Investigators found that it was located downstream from a farm where cattle had access to the same body of water and wild pigs roamed the area.

Tests found the same strain of E.coli 0151:H7 in the pigs, cattle feces and the water, but the precise cause was never pinpointed.

The incident led to new government and industry efforts to protect vegetable products from contamination, including formation of the Arizona and California Leafy Greens Marketing Agreements.

These industry-led groups, administered by the state department of agriculture, implemented new practices among shipping and growing companies, many of which are included in the federal Food Safety Modernization Act being implemented this year.

"On our farm we do a minimum of a weekly inspection by our food safety professional, but we have eyes on the farm almost every day. and those workers are trained to look for those types of hazards, and hopefully they take care of it themselves.

"If they feel they understand what it is, they'll handle it at the lowest possible point, or if they're not sure what it is they're looking at, they're trained to contact the food safety professional on staff for an evaluation of that," she said.

Food-safety measures begin before a field is planted, with an affidavit about the field's history, a preseason assessment of conditions, survey of the water distribution system, letters of guarantee for fertilizers, seeds and soil amendments.

Once the crop is in the ground growers must guard against animals, clean equipment as it switches between uses and fields and ensure portable toilets for field workers are accessible while also a safe distance from the crop.

Laborers and other employees are trained on food safety at the beginning of the season and given refresher courses throughout the season.

Some practices vary based on the requirements of the contracted buyer for the crop, said Paula Rivadeneira, a food safety specialist and assistant professor at the UA's Yuma Ag Center. When some animal feces are discovered in the field, all participating growers have agreed not to harvest all plants within a 5-foot buffer zone, regardless of whether the poop has been tested for E.coli or other pathogens.

"In some cases that buffer zone is going to be bigger because the company that's buying it from you, they want more protection. So they'll say, I want you to buffer 50 feet out from the furthest piece of poop, or even 100 feet out from the furthest piece of poop.

"Now you're talking about acres, of losing crops. But it's better to lose those crops than to risk contamination," she said.

Food-safety audits lasting up to a week are done during the season, and the crops themselves are tested as harvest approaches, with up to 60 samples taken per acre in the last three to seven days. If anything tests positive for pathogens like E. coli or salmonella, the crops surrounding them are also buffered.

"It's a very serious process, just waiting for the tests to come in as harvest approaches," she said

Processors, shippers and other facilities have additional food-safety measures, which were not covered during the meeting.

Scott said fields may or may not be fenced, depending on whether the grower or customer thinks it's needed.

"A lot of times on those busy thoroughfares, we will use fending to keep out trash, that's one of our physical contaminants that can contaminate a crop and possibly even be a biological hazard. As well as animals, we have a lot of different types of fencing we use depending on the need, but do we put fending up no matter what? Some do and some don't," she said.

Other Yuma residents have their own role to play in not spreading E. coli and other pathogens as well, by staying out of fields, keeping their pets out and getting word out to others that they need to do the same.

In the stores and at home, people can take additional measures such as washing their reusable shipping bags, not placing raw chicken in the bags, avoiding cross-contamination through surfaces such as cutting boards and not relying on tap water when washing vegetables in the sink, which Rivadenaira said "just moves pathogens around."

"You do need bacteria in your life, you don't want to be washing every bacterium of off everything you ever use," she said. "But if you're suspicious, that your produce may not be great, you want to not just wash it in water. You want to use a vinegar rinse, there's vegetable washes, things like that.

"And I can't say it's going to work 100 percent of the time, either, but It's all about minimizing the risk; that's what we do with everything," she said.