The illnesses have been tied to eggs purchased from an unnamed Brisbane fresh food wholesaler which were used by Piccalilli Catering in fresh mayonnaise.
The firm provided catering services to clients at venues around Brisbane on Melbourne Cup Day, which is Australia's best known horse racing event.
A possible factor
Doctor Susan Vlack, director of Metro North Public Health Unit, said Salmonella was possibly a contributing factor to the 77 year old woman's death and investigations are continuing.
The unit is investigating the series of outbreaks across up to 40 different Melbourne Cup functions.
"We have written to all companies and private function coordinators who used this caterer, advising them of the situation, and providing information for all attendees about the importance of careful personal hygiene to limit spread,” said Vlack.
"It has been stressed that they need to report to us if they experience sickness, particularly if they are health workers or work in handling food.”
Salmonella can spread to humans via contaminated food, such as meat, poultry, eggs and their by-products.
It may cause severe illness in young children, older people and in the immuno-suppressed.
University of Adelaide resources are currently investigating the sources of Salmonella on egg farms and in the supply chain to prevent the pathogen spreading.
Piccalilli Catering: We were let down
Piccalilli Catering co-owner Helen Grace said it is undertaking an investigation of supply chain arrangements, to ensure it is “not let down by suppliers in this manner again”.
“We are deeply upset and distressed by this outcome. We always pride ourselves on sourcing the freshest Australian ingredients for our kitchens,” she said in a statement.
“We feel very disappointed and let down that the normally reliable fresh food supply chain has failed us – and our clients – on this occasion.
“Having sourced those eggs from a normally reputable fresh food market, we had no reason to believe they were not up to the very high standards we demand of our suppliers.
“Suffice to say we will not source produce from this supplier in the future. We will leave it to our insurers and lawyers to determine what other action should be taken.”