Health officials in New Mexico positively identified a deadly strain of E. coli in a bag of spinach yesterday, providing a crucial clue that investigators say can be used to trace the source of an outbreak that has sickened 146 people.

Until now, the evidence implicating spinach has been circumstantial.

The E. coli outbreak, which was reported a week ago, has led to the leafy vegetable’s banishment from restaurants and dinner tables across the country and is threatening the spinach industry with severe damage. Losses are estimated at up to $100 million if the crisis lasts just a month, and the industry has been hoping for a quick resolution in order to stem long-term damage. Nutritionists and food-policy experts said public fears about spinach could extend to other popular produce, such as bagged salads. Even though there have been 20 E. coli outbreaks from spinach or lettuce since 1995, this one has attracted the most attention because it has the most victims, with one death, another death suspected and the number of illnesses climbing by 15 yesterday. Two more states, Arizona and Colorado, reported cases yesterday.

The uncertainty has virtually shut down the fresh spinach industry reports the Washington Post.

Federal officials yesterday narrowed the source of the outbreak to three counties, Monterey, Santa Clara and San Benito, in and around the greater Salinas Valley. The germ was found in a bag of Dole baby spinach, marked best used by Aug. 30. Acheson said the spinach was processed by Natural Selection Foods LLC, saying the code on the bag fit with information provided by the company, which has previously been linked to the outbreak.

And officials reiterated that no one should consume fresh spinach until they lift their warning.

The Salinas Valley is a dominant area for spinach production in California, which produces roughly 74 percent of the country’s fresh spinach, thanks in large part to Natural Selection’s Earthbound Farm and its innovative bagged produce. California recorded $258 million in spinach sales last year. In Monterey County, sales of spinach reached $188.2 million last year, up from $56 million in 1995.

Spinach is grown in 80-inch beds and harvested mechanically, at a cost of about $33,500 an acre. Farmers with hundreds of acres, who may lose more than one crop before the end of the growing season in November, stand to suffer big losses, according to Richard F. Smith, a farm
adviser in the University of California Cooperative Extension program in Monterey County. Last year, 17,000 acres in the county were planted with spinach.

As a leafy green vegetable, which nutritionists would like Americans to eat more of, spinach is known as being a good source of fiber and vitamin A, as well as iron, vitamin C and folic acid. "It’s a pretty
power-packed vegetable compared with iceberg lettuce," said Reed Mangels, nutrition adviser for the Vegetarian Resource Group.

There are other sources of leafy vegetables that provide similar nutritional value: kale, collard greens, mustard greens, arugula. Some of those have already become a replacement for dishes containing spinach in restaurants. Also, frozen and canned spinach are not included in the warning.