- Feature: When food goes wrong
The number of Australians struck down by food poisoning has leapt almost 80 per cent in a decade and the number of outbreaks linked to restaurants has more than doubled, according to the latest government statistics.
In the decade to 2011, the number of Australians affected by food-borne gastroenteritis increased 79 per cent, according to figures from OzFoodNet, the national food-borne disease monitoring network. In 2011, 150 outbreaks affected 2241 people compared with 86 affecting 1768 people in 2001. The rate of hospitalisation has trebled since 2001.
The figures capture only a fraction of infections since most victims don't go to a doctor, experts say. A 2002 estimate of people affected by food poisoning put the number at 5.4 million cases of gastro and 120 deaths a year at a cost of $1.25 billion.
Changing eating habits are believed to be a leading cause. People cook less and eat out more, say public health experts, which may partly explain why the food service industry was responsible for more than three-quarters of food poisoning outbreaks in 2011.
''Traditionally food is prepared and eaten immediately but now food might be prepared and left longer before eating,'' says CSIRO food microbiologist Cathy Moir.
''Because we're making these foods more available, the exposure to the population is greater, whereas if someone made it in their home and fed it to their family, the organism is only being exposed to five people rather than 500.''
The rate of salmonella poisoning has jumped 60 per cent in the past decade, figures show. The rise is largely attributed to a shift in preference towards chicken, with contamination by raw or undercooked chicken a major cause. But Martyn Kirk, a senior lecturer in epidemiology at the Australian National University and former OzFoodNet senior epidemiologist, warns that any foods prepared without the bacterial ''kill step'' of cooking increase the risk of bacteria spreading.
''It's definitely not always the chicken … We've had outbreaks of salmonella linked to rockmelon, papaya, cucumbers - and we know that's just the tip of the iceberg,'' he says.
Raw or minimally cooked eggs are the single largest cause of food-borne illness in Australia. But fresh produce has been increasingly implicated in outbreaks as health-conscious consumers favour salads, raw vegetables and minimally processed foods with lower salt and fat contents.
Food-borne illness is a growing problem worldwide, with new pathogens emerging and some existing strains becoming harder to control. Australia's comparatively tough regulations risk being undermined by what has become a global food production system, public health experts say.
For example, a 2002 gastroenteritis outbreak linked to a kebab shop in NSW was traced back to a tahini supplier in Egypt.
An ageing population is also ''a huge challenge'', says food industry consultant and former CSIRO food quality and safety director Patricia Desmarchelier.
Older people were particularly susceptible to illness and reduced mobility could mean that elderly people shopped less often, stored food for longer and ate more pre-prepared food, which could put them at risk.