A dangerous intestinal infection known as Cyclosporiasis has spread across nine U.S. states, infecting more than 8,100 people, according to media reports.

Michigan remains the hardest-hit state, with the highest number of reported cases. Health officials say efforts to contain the outbreak have been hampered by staff shortages and reduced federal funding.

The U.S. Centers for Disease Control and Prevention (CDC) issued a public health warning after the number of infections continued to rise. The illness can cause severe diarrhea, abdominal pain, and other gastrointestinal complications.

Preliminary investigations have linked the outbreak to iceberg lettuce served at Taco Bell restaurants, prompting the company to stop using the affected supplier's products while the supplier initiated a recall.

However, Michigan health authorities say around 12% of patients had no known connection to the contaminated lettuce or any fast-food restaurant, indicating that additional sources of infection may still exist and remain under investigation.