Sysco, the nation’s largest food distributor, will stop buying iceberg lettuce from Mexico as federal health officials investigate a multistate cyclosporiasis outbreak linked to the product, the company’s CEO said Tuesday.

The announcement from Sysco CEO Kevin Hourican comes as the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) investigate the outbreak, which has been connected to two deaths this week in Michigan.

The outbreak has been linked to iceberg lettuce sourced from central Mexico through Taylor Farms de Mexico.

Taylor Farms’ U.S. business voluntarily recalled certain iceberg lettuce products sold under the Taylor Fresh Foods and Marketside brands. The company has maintained that the FDA has not identified a confirmed positive test result for Cyclospora after what it described as a false positive reported by the agency.

Cyclosporiasis is an intestinal illness caused by the parasite Cyclospora cayetanensis. According to the CDC, the infection commonly causes watery, often “explosive” diarrhea that can last for weeks or even months if left untreated. Other symptoms include severe abdominal cramping, bloating, nausea, fatigue and significant weight loss.

“We’re not buying iceberg lettuce from them, and we’re not buying it from Mexico,” Hourican said in an interview with Reuters. “To the degree that we can further diversify our procurement, that is something we’re actively working on.”

Hourican said Sysco stopped selling and distributing the affected lettuce last month and voluntarily recalled impacted products before Taylor Farms announced its own recall.

“It’s a high quality, high integrity shop, but we’ve had to take actions,” Hourican said. “We’ve moved source of product away from them to the degree that we can. Because they’re really big, you can’t just turn it off overnight.”

The report comes after the Michigan Department of Health and Human Services said two people in the state have died in connection with the sprawling cyclosporiasis outbreak, which has sickened at least 11,234 people statewide.

State health officials said evidence points to lettuce or salad greens as a possible source of the outbreak, but investigators cautioned that other food items have not been ruled out and no specific type of produce, grower or supplier has been identified.

Sysco said it is now buying iceberg lettuce grown in the U.S. and has been able to meet its supply needs despite the outbreak.

“Taylor Farms is the largest producer — they’re the biggest — and if we’re not able to buy from them, we can easily go elsewhere,” Hourican said. “Replacing the amount we buy elsewhere is the challenge, and it’s something that we’re working on.”

Health officials emphasized that cyclosporiasis is generally not considered a life-threatening illness and deaths tied to the infection are rare in the United States. According to Michigan health officials, medical records showed both people who died had significant underlying health conditions that may have been worsened by cyclosporiasis and dehydration.

FOX Business has reached out to Sysco and Taylor Farms for comment.

FOX Business’ Stephen Sorace, Eric Revell and Reuters contributed to this report.