Thirteen more people have tested positive for a strain of salmonella linked to custard-filled cakes.

Health authorities will interview each of them to determine whether they had consumed any of the products linked to the current outbreak.

Vili’s custard berliners and St George Cakes & Gelati custard eclairs and cannolis were withdrawn from sale last Friday, after SA Health established they were the common denominator in 60 salmonella cases.

At least 29 of those cases had required hospital treatment.

The 13 new cases would have been sick before the public health warning was issued on Friday but test results were completed today.

SA Health also has confirmed that two custard-filled product samples from St George Cakes & Gelati, purchased at retail stores, have tested positive for Salmonella Typhimurium phage type 9, which is the strain found in the current outbreak.