Michigan has been the hardest hit state, with health officials there saying on Friday that the number infected has increased to more than 8,100. Residents stricken by the parasite told the BBC it was "the most painful thing I've ever been through in my life". In its update on Friday, the CDC warned people not to eat recalled iceberg lettuce from Taylor Farms that sourced from central Mexico. Taylor Farms, a major US food supplier, voluntarily recalled all of its iceberg lettuce sourced from central Mexico on 17 July. Health experts that spoke to the BBC said it is often difficult to track the origins of cyclospora, the parasite that when consumed causes the intestinal illness cyclosporiasis.