WEDNESDAY, Sept. 20, 2006 (HealthDay News) -- The number of victims and hospitalizations in the nationwide E. coli outbreak rose starkly Wednesday as U.S. health officials presented the first evidence confirming that fresh spinach was indeed the cause.
As of Wednesday, 146 people in 23 states had been infected with the strain of E. coli O157:H7; 76 have been hospitalized, and 23 have developed a type of kidney failure called hemolytic-uremia, according to the U.S. Centers for Disease Control and Prevention.
Meanwhile, a public health laboratory in New Mexico has isolated E. coli from an opened spinach package found in the refrigerator of a patient who ate some before becoming ill, a top health official announced.
The New Mexico laboratory then completed "DNA fingerprinting" tests Tuesday night, and health officials have determined the "DNA fingerprint" matches that of the outbreak strain.
"We now have a confirmed positive sample that was obtained from one of the patients in New Mexico," Dr. David Acheson, chief medical officer of the U.S. Food and Drug Administration's Center for Food Safety and Applied Nutrition, said during a news conference Wednesday night.
"The bag was Dole baby spinach, 'best if used by Aug. 30,'" he added, noting the source was Natural Selection Foods, the California food producer that has been the focus of the investigation.
It is the first solid evidence to emerge after almost a week of public health warnings not to eat any fresh spinach products, massive recalls by major California spinach producers, and state-by-state reports of growing numbers of sickened people.
Among those reporting the illness, 93 percent were sickened between Aug. 19 and Sept. 5. The earliest onset of illness known to be linked to spinach consumption was on Aug. 19. All told, 103 of the victims were females, and eight were children under 5.
On Wednesday, Arizona and Colorado became the latest states to report their first confirmed cases of E. coli.
They joined California, Connecticut, Idaho, Illinois, Indiana, Kentucky, Maine, Michigan, Minnesota, Nevada, Nebraska, New Mexico, New York, Ohio, Oregon, Pennsylvania, Utah, Virginia, Washington, Wisconsin and Wyoming.
Wisconsin has the largest number of reported cases, 40; it has also had the only fatality so far. The next largest number of cases are in Utah, which has 16, followed by Ohio with 15.
Meanwhile, Acheson also reported that health officials may have narrowed down the search for suspect plants.
The search is centered in the greater Salinas valley in California, where almost 75 percent of the country's spinach crop is found. The regions that interest investigators are Monterey, San Benito and Santa Clara counties, Acheson said.
"All the affected spinach appears to come from that area. We are getting a better handle on where it's grown," he added.
Acheson said that in November 2005 there had been a small outbreak of E. coli in spinach from the Silanas valley. "More should have been done," he added. "We are learning from this outbreak."
In 18 other outbreaks of E. coli since 1995, the FDA has not been able to trace the outbreak to a specific farm, Acheson said.
"In this case, the likelihood that we will get it back to a specific farm is good because of the number of cases and because of the UPC codes on the packages," he noted. However, trying to identify a specific cause on that farm is unlikely, he added.
Natural Selection Foods, in San Juan Batista, began recalling all of its prepackaged spinach and its salad mix products that contain spinach on Saturday.
River Ranch Fresh Foods, which operates in Salinas and El Centro, recalled its brands of mixed salads containing spinach Sunday, after FDA inspectors found that the company had bought spinach from Natural Selection.
And on Tuesday, an East Coast company said it was voluntarily recalling salad mixes that may contain spinach supplied by Natural Selection. RLB Food Distributors, based in West Caldwell, N.J., said the recall included various salad mixes sold under the Balducci's and FreshPro brands and distributed on the East Coast.
The FDA on Monday also dismissed a claim by Natural Selection Foods that its organic spinach products had been cleared of suspicion, the Associated Press reported. The company, one of the largest in the business, produces both organic and conventionally grown spinach in separate areas at its plant.
"The FDA has not cleared any products from the list and continues to recommend consumers avoid eating fresh spinach products," spokeswoman Susan Bro said.
Consumers should throw away any fresh packaged spinach they may have bought in the past few weeks and not buy more until the warning is lifted, the FDA said. It also said that washing the spinach won't help because the bacteria is too tightly attached.
The affected products were also distributed to Canada and Mexico, the FDA said.
The FDA said the first cases of infection apparently surfaced on Aug. 23. But it wasn't until Sept. 13 that the agency was able to identify bagged spinach as the possible cause.
According to the CDC, E. coli lives in the intestines of cattle and other animals and is linked to contamination by fecal material. It can be found in undercooked meats and other foods, such as spinach, sprouts, lettuce, unpasteurized milk and juice.
The primary symptom of E. coli contamination in humans is diarrhea, often with bloody stools. There are an estimated 73,000 cases of infection, including 61 deaths, each year in the United States, according to CDC statistics.
Here are the FDA's latest E. coli outbreak updates.