As of 1 p.m. EDT Wednesday, 146 people, infected with the outbreak strain of E. coli, had been reported from 23 states. Among the sick, 76 were hospitalized, 23 developed a type of kidney failure called hemolytic-uremic syndrome (HUS), and one adult died.

    Arizona and Colorado have just been added to the list of states with confirmed cases. Wisconsin has 40, the largest number of reported cases. It also has the only fatality so far. The next largest number of cases is reported in Utah, with 16, followed by Ohio with 15.

    In the meantime, New Mexico's public health laboratory announced it had pinned the E. coli O157 bacteria to an opened package of spinach. The package came from the refrigerator of a patient who ate some of the vegetable before falling ill.

    The New Mexico laboratory completed "DNA fingerprinting" tests on Tuesday night, concluding that the "DNA fingerprint" matched 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 on Wednesday night.

    He said the source was Natural Selection Foods, the California food producer that has been the focus of the investigation.

    It is the first solid evidence amid 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 sick people.

    Dr Acheson also reported that health officials might have narrowed down the search for suspect plants. The search is centered on the greater Salinas valley in California, where almost 75 percent of the country's spinach crop is planted.

    The regions that interest investigators are Monterey, San Benito and Santa Clara counties.

    The CDC currently advises consumers not to eat any fresh spinach or salad blends containing fresh spinach that are consumed raw.

    E. coli O157:H7 in spinach can be killed by cooking at 160 Fahrenheit (about 71 centigrade) for 15 seconds. If spinach is cooked in a frying pan, and not all parts reach the temperature, bacteria may still exist.

    E. coli O157:H7 causes diarrhea, often with bloody stools. Although most healthy adults can recover completely within a week, some people can develop a form of kidney failure called HUS. HUS is most likely to occur in young children and the elderly, which can lead to serious kidney damage and even death. Enditem