The first victim of the outbreak was confirmed on Tuesday lunchtime by health authorities in Andalusia who said a 90-year woman had died after being admitted in Seviille's Virgen del Rocio hospital with the listeria infection.

The bacteria has so far hospitalized 56 of those infected including 15 pregnant women, at least two of whom suffered miscarriages, said the Junta de Andalusia. Five victims are still being treated in intensive care.

A case has also been confirmed in Extremadura, and others are being investigated in Madrid and Girona, Castilla-La Mancha and Tenerife, prompting Spain's health minister, María Luisa Carcedo, to issuee a health warning on a national level.

Authorities are investigating whether a pork product sold by Sevilla-based Magrudis could be the source of the outbreak after several of those afflicted were found to have eaten it.  

The product under investigation is a packet meatload called ‘Mecha’, of which a batch of 2,000 are thought to be the source of the contamination.

A spokesman for the company told Spanish news agency EFE that the protocol had been followed to the letter after the contamination was discovered and that recalls had been put in place and an investigation launched into the possible source.

The Spanish consumer organisation FACUA warned that the outbreak could continue to grow as many people don’t show symptoms until between one and four weeks after consuming contaminated produce.

Although the product has been taken off supermarket shelves and the source investigated, FACUA warned that smaller stores may not have heeded the recall or that contaminated products could already have been bought and are in households awaiting consumption.

Listeria infection is rare and usually causes a mild illness in healthy people,  but those at highest risk of serious illness include pregnant women, their unborn children and newborns, adults 65 and over, and people with weakened immune systems.

The infection is caused by the bacteria listeria monocytogenes, which can grow in foods, especially soft cheese, unpasteurised milk, and smoked fish, which is why pregnant women are advised to avoid these. It can also grow on other food products, including salads, and can continue to replicate even when food is refrigerated at cold temperatures.

Two of the pregnant woman who contracted listeria suffered miscarriages, reported Facua; one on August 2nd in her 18th week of gestation, and another in her third trimestre. 

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