VIC LEIPZIG AND LOU MURRAY:Vegetables not the culprits in spinach contamination

Spinach is a wonderful vegetable. We enjoy it in salads with almond slivers and sliced strawberries or mandarin oranges, served with raspberry dressing. We like it with sliced mushrooms and Chinese chicken salad dressing, topped with crispy chow mein noodles or toasted pine nuts.

But for now, we’re not eating spinach.

Bags of fresh spinach have been recalled because of contamination with fecal bacteria. By press time, eating raw spinach had sickened 183 people in 26 states, and two deaths had been reported. Other possibly related deaths are being investigated.

Like millions of Americans, we’ve thrown out our spinach, but we’ll buy it again as soon as the ban is lifted.

Scientists at the Centers for Disease Control and Prevention have made a positive link between raw spinach and this latest outbreak of illness.

Bags of spinach found in New Mexico and Utah have tested positive for E. coli O157:H7, a bacterial strain found in cattle. Contamination of spinach and other low-growing leafy vegetables is possible if a farmer uses unsterilized manure to fertilize crops, or if the irrigation water is contaminated with runoff from feedlots or fields where cattle grazed.

E. coli O157:H7 is infected with a virus that produces a nasty substance called Shiga toxin. Cattle lack receptors for Shiga toxin, and thus are not bothered by it. However, humans become seriously ill if they ingest as few as five to 10 of these bacteria.

When most people eat something contaminated with this germ, they might have either no symptoms or mild diarrhea. However, other people experience severe diarrhea, bloody stools, intense abdominal cramping and even kidney damage.

These toxins are particularly attracted to receptors in human kidneys, but in severe cases can also affect the pancreas, liver, heart and lungs, and cause swelling of the brain.

People can die from the infection. Shiga toxins cause more severe illness in children and the elderly, who have weaker immune systems.

Most people recover in about five to 10 days without treatment. Doctors recommend that certain antibiotics not be used to treat the infection because the antibiotics can actually increase the risk of complications. The good news is that a monoclonal antibody treatment is in development.

The first human case of this disease was identified in 1975. When a widespread outbreak of severe diarrhea occurred in 1982, the culprit was identified as E. coli O157:H7, found in McDonald’s hamburgers.

Other outbreaks occurred in 1993, 1997 and 2000 from contaminated hamburgers at Jack in the Box, Burger King and Wendy’s, respectively. The last major outbreak due to contaminated ground beef was in 2002 at processing plants that supplied grocery stores. Outbreaks have also been linked to petting zoos, parsley, lettuce, alfalfa sprouts and unpasteurized apple juice.

The reason why we’re seeing more epidemics from eating contaminated hamburger is because of changes in the food industry. Most of our food isn’t locally produced. Hamburger mixes are now mass-produced from ground meat combined from hundreds of cattle. The presence of meat from one infected cow can contaminate the entire lot, which is then distributed nationwide.

Similar changes in food processing have now spilled over from the ground beef industry to packaged salad greens. If you buy a bunch of loose spinach, it came from a single field. But packaged, pre-washed spinach and salad greens are more convenient for cooks than bunch spinach.

These bagged greens are batch mixed. If spinach from one field has been contaminated with infected manure or runoff, then everything that has been mixed with that batch is also contaminated.

The branch of science that tracks the origins of such outbreaks is called epidemiology — the study of epidemics. The governmental agency in charge of tracking down the culprit germ is the Centers for Disease Control and Prevention.

Epidemiologists there report that there is now an average of 73,000 cases per year of this illness, with 63 deaths annually.

Epidemiologists recommend cooking hamburger thoroughly. Because this strain of bacteria lives in healthy cows and can get onto udders and contaminate milk, people should avoid drinking raw milk, which is milk that hasn’t been pasteurized.

We want to emphasize that vegetables aren’t the culprits in this story. Harmful bacteria don’t grow on vegetables. They grow in cows. The bacteria get to vegetables via contaminated water.

Vic and I aren’t vegetarians, but we eat more vegetarian meals than many people. One reason we do so is that the beef, pork and mutton industries are hard on the environment.

Cattle and pigs produce fecal waste that contaminates waterways. Sheep badly overgraze the public lands on which they’re raised. Another reason is that an acre of land can support more vegetarians than meat-eaters. Eating grains that have been converted into meat is a lot less efficient than eating the grains ourselves.

The reality of the future is that more people will be eating a more vegetarian diet. There isn’t enough suitable land to feed sufficient cattle, pigs and sheep for the ever-burgeoning human population.

One way to be kind to the environment is to cut down on your meat consumption. Once the spinach recall has ended, have a nice salad.