More than 5.4 million Australians are affected by food poisoning each year.
The most common source of potentially fatal food poisoning is bacteria, or the toxins they produce, but it can also be caused by some viruses or fungi.
High risk foods include cooked rice and pasta, meat, seafood, poultry , dairy products, and smallgoods such as salami and hams.
NSW Health’s director of communicable diseases, Dr Jeremy McAnulty, said the illness can last from a few hours to days.
“It can be hard to pinpoint particular foods as a cause, but if it’s piping hot not much will survive in it,” he said.
Symptoms include a sudden onset of nausea, vomiting, stomach cramps and diarrhoea, which can lead to severe dehydration.
Although many people blame the food they ate immediately before they got ill, experience indicates that its onset is often more than 24 hours later.