The U.S. FDA and the CDC are widening their investigation into a cyclosporiasis outbreak linked to shredded iceberg lettuce from central Mexico after identifying cases in four additional states.

This outbreak now includes cases from nine states: Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania, and West Virginia, the FDA said on Friday.

A total of 1,947 people infected with the cyclospora parasite, with exposure to Taco Bell, have been reported by the nine states, the FDA said, citing epidemiological data collected by CDC.

There have been at least 98 hospitalizations, and no reported deaths from the infection, the regulator said.

Oklahoma’s health department said it is working with the FDA to determine whether additional cases are tied to the outbreak.

Cases of cyclosporiasis have been reported in at least 41 states this year, though investigators are still working to determine how many cases are linked to the outbreak tied to shredded iceberg lettuce supplied by Taylor Farms and served at Taco Bell restaurants.

State health departments in Nebraska, Rhode Island, New Mexico and Maryland told Reuters they have not found evidence linking cyclosporiasis cases reported in those states this year to the recent multistate outbreak.

New Hampshire health officials confirmed nine cyclosporiasis cases linked to recalled Taylor Farms lettuce served at Cheshire Medical Center’s cafeteria and are investigating additional potentially related illnesses.

North Carolina health officials said the state’s rise in cyclosporiasis cases does not appear linked to the multistate Taco Bell outbreak, with parsley, cilantro and lettuce the most commonly reported exposures among patients.

Michigan, the hardest-hit state, reported 8,176 probable cases of the intestinal infection on Friday, up 532 from a day earlier.

On July 17, Taylor Farms recalled iceberg lettuce sourced from central Mexico. The recall includes lettuce sold in retail stores, served in restaurants and distributed to food service customers.

The FDA urged the public to continue to avoid all products listed in Taylor Farms’ recall.

Taylor Farms has temporarily shut down the Central Mexico processing facility that U.S. health officials have linked to the outbreak, an industry source familiar with the matter said on Thursday.

(Reporting by Siddhi Mahatole, Mariam Sunny and Bipasha Dey in Bengaluru; additional reporting by Christy Santhosh; Editing by Maju Samuel, Shinjini Ganguli and Shailesh Kuber)