Spain has issued an international alert over the country’s biggest ever listeria outbreak.

A 90-year-old woman has died from the infection and there are 150 confirmed cases in the country.

The Spanish Health Ministry said it was looking into another 523 suspected cases.

The majority of the confirmed cases on in the southern region of Andalusia – where a packaged pork plant linked to the outbreak is located.

However, there have also been cases in Catalonia – where 50 people remain in hospital.

Listeriosis is usually contracted from food containing the bacteria listeria.

The bacteria can be found in many foods, but is common in unpasteurised milk, soft cheeses and ready-to-eat food like chilled sandwiches.

It usually causes mild sickness but it can be dangerous to pregnant women and people with weakened immune systems.

Spain’s health ministry issued the alerts to EU authorities and the World Health Organization (WHO).

The plant linked to the outbreak has been closed with all of its products recalled.

The company has not responded to requests for comment.

Spain’s acting health minister Maria Luisa Carcedo said: "Obviously there was a failure to follow the established procedures.

"Now we need to carry out the inspections and investigations to figure out exactly where this failure took place."

A listeria outbreak in the UK claimed the lives of six people earlier this year.