Public health units in Wollongong and Tamworth were the only two to report higher than average notifications of a type of gastroenteritis (cryptosporidiosis) in NSW Health's OzFoodNet report for 2014, with 28 and 29 cases respectively.

Meanwhile an outbreak of listeria in an Illawarra restaurant in May last year, which affected three customers, was included in the list of 44 foodborne disease outbreaks involving more than 500 people.

Chocolate milk, Vietnamese rolls and Spanish mackerel were some of the main offenders causing illness across the state, with oysters and pork liver pate also believed to be culprits.

In one incident, 13 guests at a North Sydney residence suffered salmonella poisoning after eating tiramisu made with raw egg; in another, 33 customers at a south-east Sydney bakery fell prey to the same illness thanks to raw egg mayo.

The annual NSW Health report tracks notifiable foodborne diseases such as cryptosporidiosis, listeriosis, rotavirus and salmonellosis.

In 2014 there were 8794 such notifications across the state - a 17 per cent increase on the previous five-year average.

The age distribution of cases in 2014 was very similar to that of previous years with 28 per cent of cases among those aged 20 to 39 years and 21 per cent of cases aged up to four years.

Salmonellosis was the most frequently reported foodborne disease last year with 4317 notifications - a 32 per cent increase on the previous five years.

Illawarra Shoalhaven Local Health District public health director Curtis Gregory said foodborne illness often resulted from a failure to store, handle or cook food correctly.

"When you're handling food, make sure you have washed your hands, and don't prepare food if you are sick," he said.

"It's also important to store food at the right temperature so that cross-contamination doesn't occur between high-risk foods."

Mr Gregory said that foodborne disease like salmonella often increased in the summer months when people failed to refrigerate or transport their food properly.

"When you're taking food to barbecues or other events, make sure you transport it properly so it maintains the correct temperature," he said.

Mr Gregory said cases of cryptosporidiosis also tended to increase in the summer months.

"We see cryptosporidiosis where there's untreated water supply, so when people go camping they might drink from a tap that doesn't have treated water," he said.

"Or they may have gone swimming and not washed their hands properly before eating."

The salmonella outbreak at aged care facilities throughout the Illawarra in early 2015 - which affected 32 residents, two of whom died - is not within the scope of this study.

The NSW Food Authority tracked the source of the outbreak to a Unanderra bakery which has since shut down. The authority is still investigating whether action should be taken.