Shredded iceberg lettuce sold at some Taco Bell restaurants has been linked to an outbreak of cyclosporiasis in five US states, the US Centers for Disease Control and Prevention and the US Food and Drug Administration say.Taylor Fresh Foods, which supplied the lettuce, said Friday (US time) that it's removing all of its iceberg lettuce from central Mexico from the US market."Do not eat shredded iceberg lettuce served at Taco Bell locations in Indiana, Kentucky, Michigan, Ohio, and West Virginia," the CDC said in its investigation update late Thursday.Taco Bell said Friday that it has removed Taylor Farms lettuce from its restaurants and its nationwide supply chain.Cases of the intestinal illness caused by a microscopic parasite are surging across the US, with nearly 7000 cases confirmed or under investigation since 1 May, according to data published Tuesday by the CDC.States have reported at least 180 hospitalisations.The outbreak linked to the lettuce, however, is considered to be a regional one, centred in the Midwest. The CDC has identified at least 1,644 cases associated with the outbreak across the five affected states.The FDA said additional states may be added as the investigation continues."While the FDA traceback is indicating a specific independent farm, which represents less than one percent of the US's iceberg lettuce supply, as the potential source of the outbreak, we have removed all iceberg lettuce from the region indefinitely," Taylor Fresh Foods said in a statement.The CDC has identified at least 1,644 cases associated with the outbreak across the five affected US states.RNZ/Carol Stiles"No other Taylor Fresh Foods products across the country are impacted. No Taylor Farms-branded salad kits contain iceberg lettuce."The Michigan state health department has reported more than 5,000 cases of cyclosporiasis during the investigation of the outbreak.The state health department stated that it "cannot say with certainty that every illness is linked to the same source of exposure," but noted that the concentrated, sharp increase in cases "strongly suggests that the vast majority of these illnesses are associated with the same outbreak."This would make it the largest cyclospora outbreak in the US on record.Cyclosporiasis is not usually spread directly from person to person. Instead, people can become infected by consuming contaminated food or water. Previous outbreaks have been linked to fresh produce, the CDC said.People with cyclosporiasis may have symptoms that include watery diarrhea, cramping and bloating for weeks.Federal health officials said there are multiple investigations underway, some tied to the large outbreak in the Midwest, some involving single states and some involving cases not yet tied to any cluster.Taylor Farms' produce has also been linked with previous illness outbreaks, including E. coli cases tied to slivered onions in 2024 and cyclospora cases linked with lettuce in 2013.CNN's Katherine Dillinger contributed to this report.- CNN