This is the VOA Special English Agriculture Report.

California produces about seventy-five percent of the spinach grown in the United States.  State officials estimated the full value of the California crop last year at almost two hundred sixty million dollars.  Now growers are concerned that the rest of this year’s crop may be lost because of an outbreak of E. coli oh-one-five-seven-H-seven.

Markets removed fresh spinach after warnings about E. coli O157:H7

Since last month, bacterial infections from fresh spinach have sickened more than one hundred seventy people in half of the fifty states.  One death was confirmed as related; two others were suspected.

On September fourteenth, federal officials warned Americans not to eat spinach sold in bags.  Later the warning expanded to all fresh spinach. 

The Food and Drug Administration says the spinach in the outbreak was grown in three California counties.  They are Monterey, San Benito and Santa Clara. 

Officials says the outbreak is not connected to other produce grown in these three counties in the Salinas Valley.  And they say spinach grown in other areas of the United States is safe to eat.  Frozen or canned spinach has not been linked to the outbreak either. 

Experts say E. coli in spinach can be killed by cooking at seventy-one degrees Celsius for fifteen seconds. 

E. coli oh-one-five-seven-H-seven has been found in the intestines of healthy cattle, deer, goats and sheep.  The organism produces a strong poison in humans.  It can result in kidney failure and death.  Officials say more of these infections in the United States have been caused by eating undercooked ground beef than by any other food. 

But last November the Food and Drug Administration restated concerns about continuing E. coli outbreaks in leafy greens.  The F.D.A. noted eighteen outbreaks involving fresh or fresh-cut lettuce and one involving fresh-cut spinach since nineteen ninety-five.  Those outbreaks resulted in more than four hundred reported cases of sickness and two deaths. 

Investigators found that at least eight of the outbreaks involved greens from the Salinas Valley. 

Officials say the current outbreak might have been caused by water polluted with waste from cattle.  Or it might have been caused by wildlife in the fields, or by infected workers.  Experience suggests that investigators might never find the exact cause.

Last week the Western Growers Association announced it is developing a new food-safety plan.  The plan will include measures such as improved water and soil testing.