Patties Foods says its testing has found no link between its Nanna's brand frozen mixed berries and a national hepatitis A outbreak. The health department continues to investigate how 34 people in six states contracted the hepatitis A virus, all of whom consumed the same brand of frozen mixed berries. Patties Foods said no hepatitis A virus or E.coli were detected in any sample of its recalled and non-recalled Nanna's Mixed Berries 1kg product during its own testing. Managing director and CEO Steven Chaur said the company's microbiological and viral testing does not confirm any link between Nanna's Mixed Berries and the virus and shows no systemic failure of its quality assurance programs. Scroll down for video . Four adults, three in Victoria and one in NSW, have contracted potentially deadly Hepatitis A after condsuming the 1kg packets of Nanna's Frozen Mixed Berries . The product contains strawberries, raspberries and blackberries from China and blueberries from Chile . But he said Patties Foods remains guided by the health department's epidemiology, with the 1kg product remaining off supermarket shelves until further notice while the company evaluates alternative supply sources. 'If our Nanna's product was the source, the lack of laboratory findings from the testing conducted by Patties Foods for the presence of E.coli, Coliforms or HAV indicates there has been no systemic failure,' he said in a statement on Wednesday. 'Regardless, Patties Foods has significantly increased protection measures to ensure that any risk is further minimised in future.' No evidence of HAV or E.coli was found in re-tests of all batches of frozen berries that were not subject to the recall. Hepatitis A (pictured) is spread when traces of faecal matter containing the virus comes in contact with hands, water or food, and then enters a person's mouth. The company said one of two opened sample packs from consumers who contracted hepatitis A did test positive for HAV in health department testing but it may have been open to contamination. A trace amount of HAV was detected in one of eight random sample packs from supermarkets but the department noted that only demonstrated the virus was present, not whether it was alive and could cause infection, the company statement said. A health department spokeswoman said its investigation is ongoing with the source of the hepatitis A virus still unconfirmed and the same brand of frozen mixed berries the only common exposure for all cases. Patties Foods is again supplying its non-recalled Nanna's and Creative Gourmet berries varieties onto supermarket shelves but only after each batch tested negative for HAV and E.coli, Mr Chaur said. He said Patties Foods was keen for a locally sourced berry range but it could take some time to develop the required infrastructure and crop volumes. Several Victorian hospitals have been told to dispose of chocolate mousse, which has been found to contain listeria .
Patties Food insists testing hasn't found link between their berries & Hep A .
There was a national Hepatitis A outbreak in January which resulted in 34 people in six states contracting the virus .
All 34 people who contacted Hep A had consumed the China-grown berries .
The 1kg product remains off supermarket shelves until further notice.
The company says there was no systemic error but confirm they are considering alternative supply sources .