Three of them have been hospitalized and two have developed kidney failure.
The other states affected include Connecticut, Missouri, Ohio, Pennsylvania and Washington, for a total of 17 cases.
On Friday the Centers for Disease Control said that it had determined that 35 people in eleven states were included in the outbreak.
The CDC says the current investigation "is still ongoing and a specific food item, grocery store, or restaurant chain has not been identified as the source of infections".
For more information on the outbreak visit the CDC page.
Blizzard conditions cause road, school, business closures
As North Platte and the surrounding area awaits predicted blizzard conditions, the weather is already starting to deteriorate. Total snow accumulations of 5 to 10 inches are expected, with winds gusting as high as 65 miles per hour .
Ages of those in outbreak range from 12 to 84 years of age; and 69 percent are female. Most recover from the infection within a week, though serious cases can be life-threatening, the Department of Health and Welfare said.
Restaurants and retailers should not serve or sell any chopped romaine lettuce, including salads and salad mixes containing chopped romaine lettuce, from the Yuma, Arizona growing region. "At this time, this advisory only applies to chopped, bagged romaine, not other forms of romaine such as whole heads or hearts", the groups said. All eight report eating romaine lettuce in the 10 days prior to becoming ill.
In addition, consumers are warned to not purchase or consume any romaine lettuce of unknown origins; if the origins are known, avoid romaine lettuce originating from Yuma, Arizona.
People are advised to contact their health care provider if they have diarrhea that lasts for more than three days or is accompanied by high fever, blood in the stool, or so much vomiting that they can not keep liquids down and they pass very little urine.
Now, CDC and public health investigators are working to identify any additional illnesses that may be a part of this outbreak.