A massive cyclosporiasis outbreak linked to shredded iceberg lettuce has expanded to an additional six states, according to a source familiar with the matter. The Centers for Disease Control and Prevention’s update marks a significant expansion in the outbreak of cyclosporiasis, a foodborne illness that often leads to watery, sometimes explosive, diarrhea. The additional states, however, do not necessarily mean the outbreak is continuing to spread, said Dr. Stephen Ostroff, a former acting FDA commissioner. On Monday, health officials in Michigan — which has the most cyclosporiasis cases — confirmed the first deaths linked to this outbreak in the United States. Ostroff said the key question about the newly added states is when their patients became sick.