Leisa Ross, from Dubbo, is one of 14 Australians in four states who caught the virus after eating Nanna's and Creative Gourmet-branded contaminated frozen berries, largely sourced from China.

She drank the berry-infused water for three weeks. She then began feeling sick.

"I had a day in hospital when they ran tests and discovered it was hepatitis A. [The doctors] couldn't figure out why my liver was failing," the mother of four said.

"I can't believe there is no testing before they go on the shelf. I had no idea that the fruit came from China," she said, intensifying existing pressure on the federal government to overhaul testing regimes and country-of-origin labelling.

On Thursday, Prime Minister Tony Abbott said the government had "moved to 100 per cent screening of these sorts of imports" until the public health crisis was resolved.

A spokeswoman later clarified Mr Abbott was only referring to Patties Foods' frozen berry products.

But federal Agriculture Minister Barnaby Joyce confused matters by saying it was Patties withholding the frozen fruit and conducting screening.

The Agriculture Department has formally requested a review of the risk status of frozen berries from Food Standards and sought assurances from the Chinese government about the safety of further shipments of frozen berries.

Parents of about 40 children at SDN childcare centre in Pyrmont are watching out for symptoms such as fever and jaundice after being told Nanna's frozen mixed berries had been served since September on Wednesdays.

"We innocently purchased the goods, as well as the community. We haven't had any parents contact us, but we will keep monitoring the situation, of course," said Ginie Udy, chief executive officer of SDN Children's Service, which operates 25 centres across the state.

While not life-threatening, hepatitis A may cause severe illness in young children, older people and immunosuppressed people, the federal Health Department says.

Brian and Bootz Whyte, parents of two-year-old Harper, who goes to the SDN centre in Pyrmont, said they were lucky the recalled berries were served only every Wednesday, and not Friday when Harper attends.

Mrs Whyte conceded it was now hard to avoid consuming Chinese-made products. "It's the convenience of it. China is one of the biggest producers in the world, and it's a price-driven thing, too."

Symptoms may not appear for seven weeks because of the lengthy incubation period of the virus.

Nesha O'Neil, president of Child Care New South Wales, the peak body for privately-owned centres, said no members had raised any berry-related issues with the organisation.

In Queensland, where five cases have been confirmed, Trinity Beach State School in Cairns released a newsletter saying the school's canteen used Nanna's mixed berries to make smoothies.

In Victoria, 48 government schools have advised the Education Department newsletter that some of their students had consumed the berries. The NSW Education Department would not provide figures.

The four recalled products – one-kilogram packs of Nanna's raspberries and frozen mixed berries, as well as 300-gram and 500-gram packs of Creative Gourmet mixed berries – were sourced and packed mainly in China.

Hans Hendrischke, professor of Chinese business at Sydney University, who has travelled to China every year since 1979, expects Chinese authorities to make Australia's berry concerns a top priority.

"Having worked in an embassy, these are points where the Chinese government is going to be very proactive because this is going to hurt their export prospects if nothing decisive is done and no answer found," he said.

Mr Hendrischke, familiar with the farming practices of Shandong province where some of the recalled berries are from, believes the outbreak was caused by a protocol, rather than systemic, failure.

"The water used to wash a batch could have been polluted, or the handlers of the fruits didn't observe hygiene regulations. Maybe they didn't have the right toilet facilities," he said.

Patties Foods managing director Steven Chaur said on Thursday that it tested for diseases such as hepatitis A, norovirus and listeria at Chinese facilities. Raspberries appear to be the common link, and may be the culprit.

"There's been a lot of talk about faecal matter over the last couple of days in the media and all of our tests through the supply chain into Australia have come up negative on these products," he said.

Chris Baggoley, Australia's chief medical officer, said it was important to keep perspective, estimating that one in 100 people who eat the suspect berries was likely to get the virus.