One Cheese, Three Years: The Listeria Outbreak Nobody Connected

At a glance

• As of the CDC's June 9 update, 9 people in 3 states are sick, 8 of them hospitalized, and one person in Maryland has died.
• The first illness began on March 6, 2023. The latest reported so far began on May 10, 2026.
• Clover Hill Dairy of Mechanicsville, Maryland recalled its requesón and soft ricotta on June 3. Nelson & Isa Lacteos recalled 1-pound clamshells of requesón sold in New York on June 5.
• Listeria symptoms can begin up to 70 days after eating contaminated food.

The issue

Listeria is slow. Symptoms can begin up to 70 days after eating contaminated food, which makes it the hardest pathogen to trace back to a product. The requesón outbreak linked to Clover Hill Dairy of Mechanicsville, Maryland is the clearest example this year: the illnesses tied to the same outbreak strain began more than three years apart.

How big it is so far

As of the CDC's June 9 update, 9 people in 3 states have been infected with the outbreak strain, 8 of them hospitalized, and one person in Maryland has died. Illness onsets range from March 6, 2023 to May 10, 2026. Clover Hill Dairy recalled its requesón and soft ricotta on June 3. On June 5, Nelson & Isa Lacteos recalled 1-pound clamshell packages of requesón sold to retail locations in New York from May 15 to May 28. Requesón is a fresh, soft cheese, the kind of food that is bought, used up, and forgotten long before a recall arrives.

What it means for you

When an outbreak runs this long, the people who got sick first bought their cheese years ago, and the people getting sick now may have bought it a few weeks ago and already thrown the container away. A recall that names a dairy and a product type is hard to match against a tub bought at a corner store, and harder still if you no longer have it.

How EatSure closes the gap

EatSure keeps the items on your scanned receipts on watch, for a month on the free plan and up to 12 months on Pro, and matches every new recall against them. When one matches, the alert explains the organism in plain terms, including who is at highest risk. For Listeria that means pregnant women, newborns, older adults, and people with weakened immune systems, and the alert says so. If you want to check by hand, here is how to know if something you already bought was recalled.

What to do if you have it

• Check your refrigerator for requesón or soft ricotta from Clover Hill Dairy, and for 1-pound clamshells of requesón from Nelson & Isa Lacteos.
• Do not eat it. Throw it away or return it to the store, and clean the shelf and anything the container touched.
• If you are pregnant or have a weakened immune system and ate a recalled product, call your doctor even if you feel fine. Otherwise, watch for fever, muscle aches, and tiredness over the next two months.