A number of recalled guacamole products have been given the highest risk classification by the U.S. Food and Drug Administration (FDA).

Five different dips were recalled earlier this month following routine testing by Metro Produce Distributors Inc., the company that produced them, as they may have been contaminated with Listeria monocytogenes -- which is capable of triggering fatal infections in vulnerable groups.

Each of the five products has now been given a Class I risk classification by the FDA, which is issued when there is a "reasonable probability" that the use of or exposure to a product could "cause serious adverse health consequences or death."

The fresh guacamole was sold at Lunds & Byerlys stores located throughout the Twin Cities area and St Cloud in Minnesota. They were also available in select locations of "Taco Mas" food bars from July 27-31.

The following products are subject to the recall:

All products have a use-by date of August 2, 2024. The products were packaged in clear plastic containers, bearing white labels with black lettering including the Lunds & Byerlys logo and a list of ingredients.

"Consumers who have purchased Lunds & Byerlys fresh guacamole products with a use-by date of August 2, 2024 are urged to destroy the products or return them to any Lunds & Byerlys stores for a full refund. Consumers with questions may contact Metro Produce at 612-436-3825," the recall statement said.

Newsweek has contacted the FDA and Metro Produce Distributors Inc. for comment outside of normal working hours.

While no confirmed illnesses related to the dips had been reported at the time of the recall, consuming food contaminated with Listeria monocytogenes can cause serious medical concerns, even for those who are otherwise healthy.

Listeriosis, an infection of Listeria monocytogenes, is experienced by an estimated 1,600 people in the U.S. each year, according to the Centers for Disease Control and Prevention (CDC). Around 260 of the cases are fatal.

Many infections are limited to the digestive system, with symptoms including diarrhea and vomiting developing within 24 hours of consuming contaminated food. However, a more invasive form of the illness develops in some within two weeks.

Symptoms of invasive listeriosis include fever, muscle aches, headache, stiff neck, confusion, loss of balance and seizures. About one in 20 people who contract the invasive form of the illness without being pregnant die as a result.

For those who are pregnant, symptoms are generally mild or nonexistent, but invasive illness "usually leads to miscarriage, stillbirth, premature delivery, or life-threatening infection of the newborn," according to the CDC.

Concerns about possible Listeria monocytogenes contamination is a relatively common reason to initiate a food recall. Other potentially dangerous pathogens like salmonella or norovirus, as well as concerns about undeclared allergens, also frequently elicit recalls.