KEY POINTS:
It was the food fad that ran and ran, transforming a nation of red meat lovers into white meat eaters. High in protein, low in fat _ and comparatively cheap until grain prices skyrocketed _ chicken sales outstripped beef and lamb from the mid-1980s to become our biggest
source of meat protein. This despite carping from red-blooded males and scares (largely overseas-sourced) about animal welfare, hormone use and antibiotic residues.
But when a group of public health academics, alarmed at soaring campylobacter illness rates, branded chicken the cheap and dirty food of New Zealand, consumers began to vote with their feet. Chicken sales and production fell in 2006 and have failed to regather momentum amid lingering concern about leakage and cross-contamination from fresh cuts packed in supermarkets. (The industry maintains health concerns have had little lasting impact on sales).
Now it appears chicken can resume its lofty perch on the household menu _ as long as cooks religiously follow the four Cs.
Among food-borne illnesses notified to the Institute of Environmental Science and Research, campylobacter is the standout, causing thousands of lost working days with its debilitating effects including vomiting, diarrhoea, fever, headaches and muscle pain. Although thorough cooking kills the bug, contaminated chicken is thought to be responsible for half to two-thirds of cases _ other sources being untreated water, contact with animals, overseas travel and faecal contact.
From the early 1990s, New Zealand's rates of illness kept pace with rising chicken consumption, to be dramatically higher than comparable Western economies such as Australia, Britain and the United States _ although the industry disputes the validity of the comparisons.
Two years ago, public health expert Dr Michael Baker and colleagues at the Otago University School of Medicine were so alarmed about campylobacter rates that they called for fresh chicken cuts to be withdrawn from sale until the industry got its act together. (Commercial freezing generally destroys the bacteria, although the industry claims thawing can revive the bug). The Otago study, published in the NZ Medical Journal, claimed our illness rates were more than three times higher than Australia's and 30 times higher than in the United States.
The industry fiercely resisted a ban on fresh cuts, which fetch more than frozen product. The Food Safety Authority _ which has been criticised as too close to food processors _ opted to work with the industry to tackle campylobacter rates and developed a risk management strategy.
Since countermeasures began a year ago, monthly notifications of campylobacter infection have plunged to their lowest level in a decade. The 10,591 cases notified in the year to March 30 represents a 35 per cent drop on the previous year, while figures for the first four months of 2008 are less than half those for the corresponding months last year.
Since April last year, processing plants have had to record levels of the bacteria and report results tothe national microbial database.
New codes of practice have been developed for farms and processing sheds, bringing hygiene improvements and standardised practices.
Last September, the FSA warned producers that from April this year, plants with unacceptably high readings risked having all produce frozen or plant closure. That was accompanied by the introduction of performance targets which processors have to reach or risk punishment including having product frozen or plant closure.
Judi Lee, the authority's principal risk management adviser, says the target selected should deliver a 90 per cent reduction in campylobacter levels in pre-packed raw meat.
The measures boil down to minimising the spread of the bug _ which resides in the gut of chickens _ both on farms and in processing plants _ where potential to contaminate raw meat is rife during defeathering, gutting and water-chilling.
Michael Brooks, executive director of the Poultry Industry Association, says rival processors have co-operated to an unprecedented extent to beat the bug and are sharing their practices. Advice from Australia prompted changes in the spin chiller phase of processing, when carcases are chilled in a water bath before further processing. Ensuring crates are dried as well as cleaned before transport has helped break the cycle of contamination between farm and processing plant.
Brooks maintains the industry was never as bad as international comparisons suggested, saying campylobacter is not a notifiable disease in New South Wales, while US rates are based on reporting in only 10 states.
He says data suggests contamination levels on raw meat leaving New Zealand processing sheds are now lower, on average, than Australia's.
Baker applauds the progress, though he notes that the drop in reported campylobacter illnesses confirms chicken's dominant role in the epidemic. "The industry has obviously been highly motivated and incentivised to get its act together. All the publicity has had an effect."
All parties are cautious about declaring the problem under control. Baker says campylobacteria illness rates are cyclical and the decline needs to be sustained for a couple of years to confirm a trend. Even the current 12-month rate of 227 cases per 100,000 (down from 382 a year ago) is twice Australia's rate. But if the industry continues to clean up its act, New Zealand may soon be in line with its neighbour.
"It's important that there's a baseline to compare ourselves with, such as Australia or even the US where the rate is still about a twentieth of ours."
Brooks predicts further gains from steps yet to come, including a possible switch from supermarket packing to packing at the processing plant.
"From data, we know we weren't bad by world standards but there was always room for improvement.
We clearly were a contributor to [high illness levels] but we've looked at it as an industry and the results have had a truly dramatic impact."
None of this means cooks _ home or restaurant _ can become complacent. The bug survives for longer in a fridge than at room temperature and during food preparation is easily spread from meat to hands, utensils and kitchen surfaces.
Judi Lee says the FSA plans further research into consumer behaviour. Campylobacter remains the authority's major foodborne disease focus, with reported illness rates still considerably higher than from salmonella or listeria.
Of course, reported rates are just the tip of the iceberg. Most people with vomiting and diarrhoea don't go to the doctor, and the causes of gastrointestinal illnesses are often not identified.
KITCHEN DOS AND DON'TS
With chicken, the 4Cs _ clean, cook, cover and chill _ cannot be overstated.
* Treat all fresh chicken as potentially contaminated
* Keep it separated from other foods
* Wash hands in soap and hot water and dry them after contact with raw meat and packaging
* Thoroughly wash surfaces and utensils which come in contact with raw meat and packaging
* Keep raw meat covered and refrigerated to avoid cross-contamination or spread of bacteria by insects
* Ensure frozen chicken is thoroughly defrosted so that it cooks properly
Cook chicken thoroughly until the juices run clear, not pink