Listeria Outbreak in Arizona and Food Safety

March 26, 2024

Just last month, an outbreak of Listeria (also called Listeriosis) associated with queso fresco and cotija cheese was reported by the Centers for Disease Control and Prevention (CDC) in Arizona. Various dairy products sold in stores like Whole Foods Market, El Super, and Food City were affected, and the production facility linked to the outbreak recalled their food items shortly after the outbreak occurred. If you have purchased any of these contaminated food products, do not eat any of them. Throw the item away or return it to the store. Ensure that you thoroughly clean out the refrigerator, as the bacteria that causes Listeria can survive and spread to other foods as well. Click here for more information about the outbreak and affected products.   

What is Listeria?  

Listeria is a type of bacteria found in moist environments such as in soil and water. It can survive and even grow under standard food preservation methods, including refrigeration. It is transmitted when food products are harvested, processed, prepared, packed, transported, or stored in an area that is already contaminated. The soil, air, water, or equipment can harbor the bacteria. Both people and pets can become sick with Listeria should they consume contaminated food.  

Signs and Symptoms of Listeria  

The symptoms of listeria depend heavily on the severity of the illness. Symptoms can develop within a few hours to two or three days of exposure to a contaminated food item. The most severe cases can take anywhere from three days to three months to develop. Click here for more detailed information on symptoms of Listeria.  

  • Mild symptoms may include fever, muscle aches, nausea, vomiting and diarrhea.  

  • Severe symptoms may include headache, stiff neck, confusion, loss of balance, and convulsions.  

If you or someone you know may have had contact with the bacteria that causes Listeria, and has developed symptoms that resemble Listeria, contact your healthcare provider immediately.  

Who is at risk of Listeria? 

Those with weakened immune systems, including elderly individuals and those with chronic diseases are most at risk of severe illness. Pregnant women are also at increased risk of serious complications from Listeria infection, including miscarriage and stillbirth. Infants born with a Listeria infection are at risk of lifelong health complications and death. 

Incorporate these food safety tips to protect yourself and your family against food-borne illnesses:  
  • Maintain your refrigerator at 40º Fahrenheit (4º C) and your freezer at 0º Fahrenheit (–18º C) to slow or prevent the growth of pathogens like Listeria.  

  • Wash the inside walls and shelves of the refrigerator, cutting boards, countertops, and utensils, and sanitize them with a solution of 1 TBSP bleach to 1 gallon of hot water before drying them with a clean cloth or paper towel.  

  • Wash hands with soap and warm water for at least 20 seconds before and after handling food.  

  • People with pets should take special care to avoid cross-contamination when preparing pet food.  

  • Pregnant, elderly, or immunocompromised individuals should avoid unpasteurized or raw milks, cheeses made from unpasteurized milk, raw fish, raw sprouts, and other raw foods associated with Listeria. Click here to read more in our previous food safety article 

If you would like to report a potential food-borne illness, please contact your County’s Environmental Health Department. If you have questions, please call the Arizona Food Safety & Environmental Services Program at 602-364-3118 

Resources: