More than 111 cases of smoked salmon sold at Costco have been recalled over fears they could be contaminated with listeria.

The FDA announced the recall, stating that it is classified as a Class I recall, which is the most severe risk level. This classification indicates that there is a ‘reasonable probability’ that consuming the salmon could lead to death or serious health issues.

It was sold in twin 12-oz packs at branches of Costo based in south-eastern Florida, and branded as ‘Kirkland Signature’.

Although the salmon had a sell-by date of November 13, suggesting that it may no longer be in stores, there are concerns that some consumers could still have the product stored in their freezers.

People who have the product at home have been urged to throw it away or return it to stores for a full refund.

While there have been no reported illnesses or fatalities associated with the recalled salmon so far, officials are advising individuals who believe they may have fallen ill due to consuming the salmon to report their symptoms for further investigation.

Listeria can cause a serious bacterial infection, which can lead to someone suffering from sepsis — a life-threatening condition.

The bacteria is particularly dangerous for newborns, elderly adults and pregnant women, who all have weaker immune systems.

The above shows the front of the twin bags of Kirkland Signature salmon that were recalled

And this shows the back. The salmon was sold in Costco as a twin product

The FDA first announced the recall in late October, but this week the agency updated its risk level classification to a Class I.

It is not clear how the contamination was detected, but this was likely via routine testing of the product.

Recalled salmon has the lot number 8512801270, and the UPC number — which can be found below the barcode — of 0 96619 25697 6.

It was manufactured by Acme Smoked Fish Corporation, based in Brooklyn, New York.

The company also faced a recall in 2021, after officials found that some of its salmon was contaminated with salmonella.

It is also not clear how the salmon became contaminated with listeria, but this may have been via contaminated machinery.

Salmon can pick up listeria while they are in farms, as the bacteria can live in water, which is then transferred to machinery during processing. The machinery then spreads the bacteria to other salmon.

Salmon is smoked cold, which does not kill listeria, and is also refrigerated — which also does not eradicate the bacteria.

Listeria can contaminate everything from raw vegetables, unpasteurized dairy and deli meats, and is behind about 47 recalls every year.

It causes the disease listeriosis, and while healthy people may only have a short-term illness, pregnant women, newborns and elderly people are at risk of serious infections.

Symptoms healthy people may experience include high fever, severe headache, stiffness, nausea, abdominal pain and diarrhea. 

In more serious cases, it can cause confusion, loss of balance and convulsions if it spreads to the nervous system.

About 1,600 people are infected with listeria every year.

Listeria contamination was behind several major recalls last year, including a recall of 10million pounds of beef and poultry used in ready-to-eat meals.