Around 40 people have been struck down with food poisoning that is suspected of being linked to a bakery in Sydney’s south, health authorities say.

NSW Health confirmed 40 people had presented at St George and Sutherland hospitals since Saturday with symptoms of food poisoning, while 13 of those people were admitted to hospital for treatment.

It is understood a chicken or pork roll from the Box Village Bakery on Box Road in Sylvania is responsible for the outbreak. Patients ranged from young children to the elderly and prelinary tests showed the patients were suffering from salmonella poisoning.

“People presented with diarreah, vomiting, abdominal cramps, fever, aches,” Professor Mark Ferson, Director of Public Health for South Eastern Sydney, told The Daily Telegraph.

“Some of them we have results for which show they have salmonella.”

Professor Ferson said investigations into the actual food that may have caused the food poisoning were ongoing but confirmed the NSW Food Authority had visited the bakery yesterday and shut it down.

“We don’t have information on everyone yet but about 12 people had eaten at a common food premises in the Shire,” he said.

“Salmonella infection can be mild, but can be very nasty. People can get dehydrated and quite sick with it.”

Salmonella is mainly spread to humans when they eat under-cooked food made from infected animals. Symptoms often start 6-72 hours after infection and usually last for 4-7 days, although they sometimes last longer.

One woman, Katrina, said her two sons, aged 17 and 18, both fell extremely ill on Friday after eating chicken rolls from the bakery, however she did not take them to hospital because of the severity of their symptoms.

“The only reason we didn’t take ours [her sons] to hospital was because they couldn’t get out of the bathroom long enough to travel anywhere,” Katrina told radio station 2UE.

“We took them to the medical centre. I sent my husband up to see how long the line was so they didn’t have to wait there. They were very, very sick.”

According to ABC, another woman who spoke to Macquarie Radio in Sydney said her two sons, aged 19 and 17, fell sick after eating chicken rolls from a bakery, which has since been closed.

“The only reason we didn’t take [them] to hospital was because they couldn’t get out of the bathroom long enough to travel anywhere,” she said.

“They were very, very sick.”