CDC closed its investigation of a multistate Listeria monocytogenes outbreak linked to requesón cheese made by Clover Hill Dairy, LLC of Mechanicsville, Maryland on August 26, 2026, with a final count of 15 people sick in four states — Illinois, Maryland, New York and Virginia — 14 hospitalized and one dead in Maryland. Illnesses began on dates ranging from March 6, 2023 through July 8, 2026, a span of three years and four months. Of the 14 sick people whose hospitalization status was known, every single one was hospitalized.
Every person in this outbreak whose hospitalization status was known went to the hospital
Fourteen of fourteen. CDC’s closing page puts it at 100 percent of the 14 people with information available. Measured against all 15 cases, it is 93 percent.
That number tells you what this count is and what it is not. Listeria gets counted when someone is sick enough that a clinician draws blood or spinal fluid and a laboratory grows the organism. People who ate the same cheese and ran a fever for a few days were never cultured, never sequenced, and never entered PulseNet. Fifteen is not the number of people this cheese made sick. It is the number it made sick enough to put in a hospital bed and confirm by genome.
The outbreak ran three years and four months before anyone connected it
First illness onset was March 6, 2023. The last was July 8, 2026 — 1,220 days apart.
The outbreak strain sat in PulseNet that entire time. Whole genome sequencing showed that samples from sick people were closely related genetically, which is how CDC knew, in hindsight, that a 2023 case and a 2026 case belonged to the same event. The genetic link was there to be found. What was missing was anything tying it to a food. At one to a handful of confirmed cases a year, scattered across four states, a Listeria cluster this slow does not throw off the kind of signal that opens an investigation.
A retail cheese sample in Brentwood, New York broke a case that had been open since 2023
Here is how it actually ended, and it is worth laying out, because it says something about where the capability sits.
On May 13, 2026 the Suffolk County Health Department told the New York State Department of Agriculture and Markets about two related Listeria illnesses in a single family who had bought food from a retailer in Brentwood. The next day the New York State Department of Health confirmed both had eaten requesón from that store. NYS AGM investigators collected five cheese samples at the retailer. One requesón the store had repacked itself tested positive, and sequencing matched it to the strain in the two patients.
On May 27, NYS AGM inspected the retailer’s cheese distributor and identified Clover Hill Dairy, LLC as the manufacturer. A sample drawn from a sealed, unopened 18-pound bucket of Clover Hill requesón also came back positive. Maryland suspended the dairy’s operating license on May 30. Clover Hill recalled its requesón and soft ricotta on June 3.
A county health department, a state agriculture laboratory and a retail sampling program closed a three-year-old case in fifteen days. Not a national database — a tub of cheese on a shelf in Suffolk County.
Chronology of the Clover Hill Dairy requesón Listeria outbreak, built from published CDC and FDA updates, August 26, 2026. Panel A is the onset window; Panel B is the documented event sequence. This is a chronology, not an epidemic curve.
The cheese reached consumers under at least seven brand names that were not Clover Hill
This is the part that should trouble anybody who assumes a recall reaches the people holding the product.
Clover Hill sold requesón in its own 10-, 12- and 14-ounce clamshells, and it sold it in bulk — five-gallon and two-gallon buckets — to customers who repackaged it. FDA’s advisory lists the brands the bulk cheese was relabeled under: KESSO, QUESOS LA RICURA, IZALCO, DE MI PUEBLO and RIO LINDO — and says “including but not limited to.” Nelson & Isa Lacteos of Bay Shore, New York recalled one-pound repacked clamshells on June 5, with a list of retail locations added a week later. La Ceiba Foods Latin Market recalledRequesón Salvadoreño and Requesón Mexicano under the La Colonia and Selectos Latinos brands on June 26. The Brentwood retailer repacked it in-store.
FDA’s instruction to consumers was to look for Clover Hill Dairy’s plant number, 24-128, on the label. That number is printed on Clover Hill’s own clamshells. It is not on somebody else’s tub. For a family holding a container of Selectos Latinos requesón, the recall notice amounted to checking for a number that was never on the package.
Fresh soft cheese is on FDA’s Food Traceability List. The commodity — cheese made from pasteurized milk, fresh soft or soft unripened — expressly names ricotta, queso blanco and queso fresco, and FDA’s own risk ranking put it on that list because of Listeria monocytogenes. Records that follow the product through the repackers are precisely what FSMA 204 was written to require. Congress has directed FDA not to enforce that rule before July 20, 2028.
Twelve of the thirteen people with ethnicity reported were Hispanic
CDC reports ethnicity for 13 of the 15 sick people: 92 percent Hispanic, 8 percent non-Hispanic. Requesón is a staple. CDC published this notice in Spanish alongside the English version, which is right, and the relabeled brands — Salvadoreño, Mexicano, De Mi Pueblo — tell you exactly which shoppers were buying it.
This keeps happening with Hispanic-style fresh cheeses. It will keep happening as long as bulk soft cheese moves through repackers without records that travel with it.
The last illness began on July 8, five weeks after the first recall
Clover Hill recalled requesón on June 3 and expanded to all of its cheese on June 18. La Ceiba recalled on June 26. The final illness onset in this outbreak is July 8.
Two readings are available and neither one is comforting. Listeria symptoms can start as late as 10 weeks after exposure, so a July 8 onset is entirely consistent with cheese eaten well before any recall was announced. It is also consistent with recalled cheese still sitting in a refrigerator under a brand name that never appeared on a recall notice.
CDC’s closing page counts one environmental sample; its own June page counted two
A small thing, but the closeout is the document people will cite for years.
CDC’s August 26 investigation page reads that Listeria was detected in six product samples of requesón cheese and in one environmental sample. CDC’s own June 29 update, on the same page, said six product samples and two environmental samples. FDA’s June 29 advisory describes both of them: six product samples and one environmental sample as of June 15, then a second environmental sample collected by Maryland partners on June 24 that also matched the outbreak strain.
The figure carried into the closing document is the June 15 figure. The second positive from inside the plant did not make it in.
FDA’s advisory still says the investigation is ongoing and still counts twelve
As of today, FDA’s outbreak page for this investigation is marked “Content current as of: 06/29/2026.” Status: Ongoing. Total Illnesses: 12. Hospitalizations: 10.
CDC closed the same investigation today at 15 and 14. FDA’s page has not moved in two months, and it still tells a reader the investigation is live at a count three cases and four hospitalizations behind the final one.
No one is assigned to close out an FDA advisory when CDC closes the corresponding investigation. That is an architecture problem, not a knock on the people who worked this outbreak — and the people who worked this outbreak did good work.
The count as CDC reported it, update by update
| As CDC reported it | June 4, 2026 | June 9, 2026 | June 24, 2026 | Aug. 26, 2026 (final) |
| Cases | 8 | 9 | 12 | 15 |
| States | 3 | 3 | 4 | 4 |
| Hospitalized | 7 | 8 | 10 | 14 |
| Deaths | 1 | 1 | 1 | 1 |
| People interviewed | 7 | 8 | 10 | 13 |
| Reported eating any cheese | 5 | 6 | 9 | 11 |
| Reported eating Clover Hill requesón | 2 | 2 | 2 | 5 |
Source: CDC investigation updates for the June 2026 soft cheese Listeria outbreak dated June 4, June 9, June 24 and August 26, 2026; compiled August 26, 2026. Check: cases rose by seven across the investigation (8 to 15) and hospitalizations rose by exactly seven (7 to 14) — every case added after the first update was hospitalized. CDC reports hospitalization for 14 of 14 people with information available, one short of the 15 total cases.
One further arithmetic note. CDC’s final page states that of the 13 people interviewed, five (45 percent) reported eating Clover Hill requesón. Five of 13 is 38 percent. Five of the 11 who reported eating any cheese is 45 percent — so the percentage is calculated on the cheese eaters, not on everyone interviewed. Worth knowing before anyone quotes it.
Questions people are asking
Is Clover Hill Dairy cheese still on the market? No. CDC says the recalled foods are past their shelf life and no longer available for sale, and Maryland suspended the dairy’s operating license on May 30, 2026.
How would I know whether cheese in my refrigerator came from Clover Hill? On Clover Hill’s own packaging, look for plant number 24-128. On repacked product that number may not appear at all — the same cheese was sold as KESSO, QUESOS LA RICURA, IZALCO, DE MI PUEBLO, RIO LINDO, La Colonia and Selectos Latinos, among others. If it is loose or store-repacked requesón, the package will not tell you.
How long after eating contaminated cheese can Listeria make you sick? Usually within two weeks, but as early as the same day and as late as 10 weeks. If you are pregnant, 65 or older, or immunocompromised and you have a fever with muscle aches, call your doctor and mention the cheese.
Fifteen counted cases over forty months is a floor, not a total
I have been handling Listeria cases for a long time, and I represented the families of all 33 people who died in the 2011 Jensen Farms cantaloupe outbreak. What those files teach is that the counted cases are the floor, and that the people listeriosis kills are the very people we tell ourselves we are protecting. Here the median age was 55, and the range ran from 16 to 81.
Fifteen people, fourteen hospital admissions and one death over forty months, from a cheese that reached the people who ate it under seven other names. The recall worked about as well as a recall can work when nobody can tell you what is in the tub.
Earlier coverage of this outbreak: When Cheese Kills and the count at eleven on Marler Blog, and the expanded Clover Hill recall and La Ceiba cottage cheese recall here.
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