05/02/2016 12:52 PM AEDT | Updated 15/07/2016 12:51 PM AEST

How You Can Avoid Contracting Salmonella Through Lettuce

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A salmonella outbreak that has been linked to popular pre-packaged lettuce and salad mixes at Coles and Woolworths is believed to have spread wider than first thought.

On Thursday the supermarket giants issued an urgent recall for pre-packaged salads that had been linked to the outbreak.

Most often associated with meat and poultry rather than vegetables, contracting salmonella through foods such as lettuce is thought to be a relatively rare occurrence.

However, Dr Jian Zhao, senior lecturer in the Food Science and Technology Group from the University of New South Wales, believes that it is becoming increasingly common for people to become infected through vegetables.

“Salmonella is common -- it is one of, if not the most, commonly implicated pathogens involved in foodborne outbreaks,” Dr Zhao told The Huffington Post Australia.

“It is less common for people to be infected through salad but in recent years there has been a trend that it is increasing, mainly because we consume more pre-prepared foods.

“For consumers, the best advice is to wash their food, even if it is pre-packaged. However, the onus is still on the producers and retailers to ensure that the food that they supply is of the highest standard.”

Whilst salmonella infections from pre-packed lettuce and salads may be on the rise, Dr Zhao stressed that simple food safety practices can greatly reduce the risk of contamination.

“Fruit and vegetables need to be washed very thoroughly before consumption as they can be contaminated very easily,” he said.

“Warm water is better than cold water and can remove most of the bacterial contaminations and reduce the possibility of food poisoning.”

Lorraine Haase, spokesperson for Food Standards Australia and New Zealand, also highlighted that packaging makes little difference when it comes to contracting salmonella.

“It isn’t the packaging that makes the difference, it can occur regardless of whether it is packaged or just a lettuce head,” she told HuffPost Australia.

“What makes a difference is the food safety practices along the production chain.”

Food Standards Australia and New Zealand has provided a list on its website of the products affected by the salmonella recall, with consumers urged to dispose of them or return them for a full refund.