After a salmonella link was discovered in 28 cases reported in Victoria, a national voluntary recall has been issued for prepackaged lettuce from Tripod Farmers company.

People have been hospitalised but no one has died from the outbreak.

“Normally we only see a handful of cases of this strain each year, but so far this year there have been 28 adult cases of salmonella anatum – mostly adults – notified to the department,” said Department of Health and Human Services senior medical adviser Dr Finn Romanes.

The doctor said it was still unclear exactly how many products were involved and “unfortunately there probably will be more cases that do come in as people present their symptoms and attend a doctor for a test.

“We have good systems in place in Victoria and in other states,” he reassured the ABC reporters.

Meanwhile, a recall notice on Food Standards Australia’s website listed outlets in all states and territories, excluding Tasmania and Western Australia.

“Tripod Farmers has recalled the following products from Coles, Bi-Lo (VIC, NSW, SA, NT & ACT), Woolworths (ACT, VIC & NSW) and trade outlets in NSW, QLD, VIC, SA, NT and ACT due to microbial (salmonella) contamination,” the notice said.

List of recalled products:

Woolworths brand: Spinach 100g, Rocket 100g, Salad mix 100g
Wash N Toss: Watercress 100g, Sorrell 50g, Baby Cos 100g, Spinach 100g, Salad Mix 100g, Rocket 100g, Kale 100g
Coles brand: Spinach 60g, Rocket 60g and 120g, Spinach and Rocket 120g, Spinach 120g, 4Leaf 120g and 200g
SupaSalad: SupaSalad 180g, Green Coral 180g, Supamix 1kg, Spinach 1kg, Rocket 1kg, Baby Cos 1kg, Spinach 180g

The recall was issued after Victoria’s Department of Health said there had been 28 salmonella cases so far this year, and the lettuce was the common source.

Tripod lettuce is sold at Coles and Woolworths in both supermarkets’ prepackaged salad mixes, including Coles 4 Leaf Mix, Woolworths salad mix, SupaSalad Supamix and Wash N Toss salad mix.

Dr Finn Romanes said people should either return products with best-before dates leading up to and including February 1 to the place of purchase, or throw them out.

The outbreak is said to have been caused by the fertiliser used to grow the lettuce linked back to chickens and eggs.”

“In any investigation it’s only possible to interview some of the cases, but 10 of the cases we’ve interviewed have identified consumption of bagged lettuce products and a number of those bagged lettuce products from the supermarkets that Tripod Farmers provide their lettuce to,” the doctor said.

The department of health said an inspection of Tripod Farmers had been carried out and a “thorough clean” had taken place.