The nationwide food poisoning outbreak from E. coli-tainted romaine lettuce has spread to 29 states and sickened 149 people, the Centers for Disease Control and Prevention said Wednesday.

That is an increase of 28 people and four states – Florida, Minnesota, North Dakota and Texas – since the most recent CDC update May 2. The number of people sickened in this outbreak has climbed steadily since federal authorities began investigating a month ago, making it the worst since the 2006 baby spinach E. coli outbreak in which 205 people became ill and five of them died.

This strain of E. coli produces a toxin that causes vomiting and diarrhea and potentially other severe symptoms, including in some cases kidney failure. Of 129 people, 64, or 50 percent, have been hospitalized, including 17 people who developed severe kidney failure. One death from California has been reported. The ill people range in age from 1 to 88 years old. About 65 percent of those sickened are women. The most recent illness started April 25. But there is a time lag in reporting and confirming these cases. People who have gotten sick in the last two or three weeks may not yet be reported.

California leads the nation with 30 cases, followed by Pennsylvania with 20, and Idaho with 11.

The CDC continues to urge consumers to avoid eating or buying any kind of romaine lettuce from the Yuma region. The Yuma region grows the overwhelming majority of the lettuce and other leafy greens consumed in the United States in the winter months through early April, before shifting to California’s Central Valley and Salinas Valley. Lettuce from California is not implicated in the outbreak.