School children may have consumed frozen berries linked to hepatitis A cases which have now spread to Western Australia.
Thirteen people in Victoria, NSW, Queensland and WA have now tested positive to hepatitis A after eating the Nanna's brand of imported frozen mixed berries, the health department says.
Children at nine South Australian primary schools and child care centres may have been served frozen berries from the recalled batches.
Department of Education and Child Development chief education officer Jayne Johnston said while SA Health advice suggests the infection risk is low, the facilities are taking a cautious approach.
"Parents will be understandably concerned to receive the letter, but I would like to emphasise that SA Health advises that the risk is considered to be quite low and the product recall was being undertaken as a precaution," she said in a statement on Wednesday.
Some students at a Victorian high school also consumed the berries after using them to make smoothies during a cooking class.
The Ballarat Secondary College year seven students used the berries in a food technology class last week, before the product was recalled, principal Rick Gervasoni said. None have tested positive for the virus, which can take between 15 to 50 days to develop.
WA communicable disease control director Dr Paul Armstrong said the state had recorded its first case linked to the recalled Nanna's and Creative Gourmet brands.
"There is no need for people who have eaten these products and remain well to see their doctor for testing or vaccination, as the risk to any individual should be low," he said.
Three Wests Tigers rugby league players are due to be tested for hepatitis A after eating the berries, News Corp Australia reported.
"As soon as the club were aware of it and the players put their hands up and said `we believe we've eaten these berries' the club doctor issued referrals for the boys to get tested," Wests Tigers chief executive Grant Mayer said.
Prime Minister Tony Abbott says the government is considering toughening up import screening procedures following the food contamination scare. He says companies also have to lift their game.
"The bottom line is that companies shouldn't be poisoning their customers," Mr Abbott told ABC radio. Farmers want an overhaul of labelling to help people identify Australian grown and packaged food.
Mr Abbott said more red tape and regulation of the private sector could lead to soaring food costs.
"We want safe products but we want safe products at a fair price. Some price is worth paying, but it's got to be a careful balancing act."
Federal Health Minister Sussan Ley said any areas such as biosecurity, quarantine and import-export policy that needed to be reviewed would be. Federal Agriculture Minister Barnaby Joyce urged consumers to buy Australian produce.
"I want to make sure I do everything in my power to say to people your safest food is your domestic food. That is why you pay a premium for Australian product. It is clean, green and healthy," he told the Nine Network.
