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FDA Investigates presence of Listeria in some Hispanic-style Cheeses

Posted February 2, 2016

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Update February 1, 2016

On Friday, January 22, 2016, the Department of Justice filed criminal information in the U.S. District Court for the District of Delaware against Roos Foods Inc., charging the company with the distribution of adulterated cheese in interstate commerce. The company has signed a plea agreement in which it has agreed to plead guilty to a misdemeanor violation of the federal Food, Drug and Cosmetic Act (FDCA). In addition to the company’s agreement to plead guilty, Roos, and its principals, Ana A. Roos and Virginia Mejia, have agreed to a proposed consent decree of permanent injunction.

What was the Problem and What was Done?

The FDA, CDC and state and local officials investigated a multi-state outbreak of listeriosis linked to Hispanic-style cheese products made and distributed by Roos Foods of Kenton, Delaware. 

On April 18, 2014, the CDC reported that the outbreak appeared to be over.  There were 8 cases of illness reported with the outbreak strain of Listeria monocytogenes in two states; California and Maryland.

Among persons for whom information is available, dates that illness was diagnosed range from August 1, 2013 to November 27, 2013. Seven of the eight ill persons were hospitalized. Five of the illnesses were related to a pregnancy; two of these were diagnosed in two mother–newborn pairs, and one in only the newborn. The three other illnesses occurred among adults.  One death was reported in California.  All ill persons were reported to be of Hispanic ethnicity. 

Whole-genome sequencing (WGS) of Listeria monocytogenes strains isolated from Roos Foods cheese products has been performed by the FDA and Virginia’s Division of Consolidated Laboratory Services. These strains were found to be highly related by WGS to the Listeria strains isolated from patients in this outbreak, adding further confidence that cheese products produced by Roos Foods were a likely source of the outbreak.  WGS provides genetic information that allows investigators to rapidly identify differences among isolates. Compared with pulsed-field gel electrophoresis (PFGE), WGS provides clearer distinction between cases and foods that are likely part of a given outbreak and those that are not.

Roos Foods has voluntarily recalled all lots, sizes and types of cheese distributed under the Amigo, Anita, Mexicana, and Santa Rose de Lima brands.  Roos Foods also recalled all product sizes and containers of Santa Rosa de Lima Crema Salvadorena Cultured Sour Cream, Santa Rosa de Lima Mantequilla de Bolsa Tradicion Centroamericana, Crema Pura Mexicana Cultured Sour Cream, La Chapina Crema Guatemalteca Guatemalan Style Cream, and Amigo Brand Crema Centroamericana Cultured Sour Cream.  

The recalled products were distributed through retail stores in Delaware, Maryland, New Jersey, New York, Virginia and the District of Columbia.

On February 21, the Virginia Department of Agriculture and Consumer Services (VDACS) reported that Listeria monocytogenes had been found in cheese products manufactured by Roos Foods of Kenton, Delaware. This followed an earlier warning VDACS issued on February 15 that the pathogen Listeria monocytogenes was isolated from a sample of Cuajada en Terron (Fresh Cheese Curd) manufactured by Roos Foods and collected by VDACS food safety inspectors at Mega Mart, a retail store in Manassas, Virginia. Listeria monocytogenes is a bacterium linked to a rare and serious illness, listeriosis.  The strain of Listeria monocytogenes identified was the same strain of the bacteria that has caused 8 cases of listeriosis in two states.

On February 19, the Maryland Department of Health and Mental Hygiene (MDHMH) warned consumers that Listeria had likely been found in cheese products manufactured by Roos Foods, of Kenton, Delaware.  The MDHMH reported that Roos Foods manufactures cheeses under the Santa Rosa de Lima, Amigo, Mexicana, Suyapa, La Chapina, and La Purísima Crema Nica brand, and advised consumers not to eat any cheese products made by Roos Foods, or foods that have been made with these cheeses. MDHMH confirmed Listeria monocytogenes of the outbreak strain.  The District of Columbia issued a similar warning to consumers on February 20.

The FDA suspended the food facility registration of Roos Foods Inc. of Kenton Delaware on March 11, 2014 after the FDA determined there was a reasonable probability of food manufactured, processed, packed, or held by Roos Foods causing serious adverse health consequences or death to humans.

The FDA ordered the suspension after an investigation by the FDA, Centers for Disease Control and Prevention, and state and local partners linked a multi-state outbreak of listeriosis to cheeses found to be contaminated with Listeria monocytogenes and manufactured by the company. Food facility registration is required for any facility engaged in manufacturing, processing, packing, or holding food for consumption in the United States, and if the registration of a facility is suspended, no person shall introduce food from such facility into interstate or intrastate commerce in the United States. The FDA inspected the company’s facility from February 18 – March 4, 2014. During the inspection, FDA investigators found insanitary conditions including:

  • the roof leaking so badly that water was raining down into the cheese processing room, including onto the cheese processing equipment and storage tanks;
  • standing water on the floor throughout the cheese curd processing room in proximity to the cheese vats and in the storage rooms;
  • metal roof/ceiling and metal supports exhibiting a rusted appearance with metal flaking precluding effective cleaning and sanitizing;
  • food residues found on equipment after cleaning had been performed;
  • openings to milk storage tanks and transfer piping were not capped to prevent contaminants from entering or contaminating food contact surfaces; and
  • floors, wall, and equipment that were deteriorated and in bad repair, including processing equipment and storage vats with rust holes and floors with rough concrete deterioration.

Additionally, the FDA collected environmental samples from different areas of the facility, including the cheese processing room and various pieces of equipment.  FDA's testing identified 12 swabs that tested positive for Listeria monocytogenes, and pulsed-field gel electrophoresis (PFGE) analysis showed that 11 of those swabs had the same  Listeria monocytogenes "DNA-fingerprint" as the outbreak strain.

In response to evidence collected during the investigation by the FDA, CDC, and state officials, the state of Delaware’s Division of Public Health issued a Cease and Desist Production and Distribution order to the firm on February 28, 2014.

The FDA will vacate the suspension order and reinstate Roos Foods’ facility registration when the FDA determines that food manufactured, processed, packed, or held at the facility no longer has a reasonable probability of causing serious adverse health consequences or death to humans.

What are the Symptoms of Listeriosis?

Listeriosis is a rare and serious illness caused by eating food contaminated with the bacteria called Listeria monocytogenes. Persons in a higher-risk category, including pregnant women, people with weakened immune systems, and the elderly, who experience fever after eating any of the Roos Foods cheeses listed above should seek medical care and tell the health care provider about eating the potentially contaminated cheese.

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Who is at Risk?

Listeriosis can be fatal, especially in certain high-risk groups. These groups include the elderly, and people with weakened immune systems and certain chronic medical conditions (such as cancer). In pregnant women, listeriosis can cause miscarriage, stillbirth, premature labor, and serious illness or death in newborn babies, though the mother herself rarely becomes seriously ill. 

What Specific Products were Recalled?

On March 1, 2014, Roos Foods expanded and clarified the description of products in its recall, which was initiated on February 23 and expanded on February 25.  The recall includes all lots and all product sizes and containers of Santa Rosa de Lima Queso Duro Blando (hard cheese), and Mexicana Queso Cojito Molido. The recall also includes all lots and all sizes and containers of the Amigo, Anita, Mexicana, and Santa Rose de Lima brands of: Cuajada En Terron, Cuajada/Cuajadita Cacer, Cuajada Fresca, Queso Fresco Round, and Queso Duro Viejo (hard cheeses), Requeson, Queso de Huerta and Quesco Fresco. These cheeses were packaged in various sized clear plastic wrapped Styrofoam trays, clear plastic wrapped, clear plastic vacuum package, and clear rigid plastic containers.

Roos Foods also recalled all product sizes and containers of Santa Rosa de Lima Crema Salvadorena Cultured Sour Cream, Santa Rosa de Lima Mantequilla de Bolsa Tradicion Centroamericana, Crema Pura Mexicana Cultured Sour Cream, La Chapina Crema Guatemalteca Guatemalan Style Cream, and Amigo Brand Crema Centroamericana Cultured Sour Cream. These sour creams were packaged in various sized white plastic tubs, clear plastic bags, clear plastic pouches, and clear plastic jars.

The recalled products were distributed through retail stores in Delaware, Maryland, New Jersey, New York, Virginia and the District of Columbia.

What Do Consumers Need To Do?

Consumers should not eat any of the recalled products and should check their homes for these dairy products, and discard them. 

Recommendations for preventing listeriosis are available at the CDC Listeria website:

Listeria monocytogenes can grow at refrigerator temperatures, about 40 degrees Fahrenheit (4 degrees Celsius). The longer ready-to-eat refrigerated foods are stored in the refrigerator, the more opportunity Listeria has to grow. 

It is very important that consumers thoroughly clean their refrigerators and other food preparation surfaces and cheese cutting utensils that may have come in contact with the potentially contaminated cheese. Consumers should follow these simple steps:

  • Wash hands with warm water and soap for at least 20 seconds before and after handling food.
  • Wash the inside walls and shelves of the refrigerator, cutting boards and countertops; then sanitize them with a solution of one tablespoon of chlorine bleach to one gallon of hot water; dry with a clean cloth or paper towel that has not been previously used.
  • Wipe up spills in the refrigerator immediately and clean the refrigerator regularly.
  • Always wash hands with warm water and soap following the cleaning and sanitization process.    

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What Do Retailers and Restaurants Need To Do?

Do not sell or serve the products identified above.  If you do not know the source of your dairy products, check with your supplier.

  • Dispose of the dairy products listed above.
  • Wash and sanitize display cases and refrigerators where potentially contaminated dairy products were stored.
  • Wash and sanitize cutting boards, surfaces, and utensils used to cut, serve, or store potentially contaminated dairy products.
  • Wash hands with warm water and soap following the cleaning and sanitation process.

Retailers, restaurants, and other food service operators who have processed and packaged any potentially contaminated dairy products need to be concerned about cross contamination of cutting surfaces and utensils through contact with the potentially contaminated products.

Regular frequent cleaning and sanitizing of cutting boards and utensils used in processing may help to minimize the likelihood of cross-contamination.

Listeria monocytogenes can grow in food at room and refrigerator temperatures. Listeria can also spread to other food cut and served on the same cutting board or stored in the same area. For that reason, retailers, restaurants, and other food service operators may wish to consider whether other foods available for sale could have been cross-contaminated from the potentially contaminated dairy products, and should be discarded.

Because Listeria can grow at refrigeration temperatures in foods like dairy products the FDA recommends and many state codes require that cheeses be discarded within 7 days of the date that they are opened in a retail establishment.

See the FDA Bulletin, Advice to Food Establishments that Sell or Repackage Cheese Products, for additional information.

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Who Should be Contacted?  

Customers with questions may contact Virginia Mejia at 302-653-0600, Monday thru Friday from 9:00 a.m. to 3:00 p.m. Eastern time.

The FDA also encourages consumers with questions about food safety to call 1-888-SAFEFOOD Monday through Friday between 10 a.m. and 4 p.m. Eastern time, or to consult the website:

The information in this release reflects the FDA’s best efforts to communicate what it has learned from the manufacturer and the state and local public health agencies involved in the investigation. The agency will update this page as more information becomes available.
For more information:


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