Public health researcher at the University of Otago, Wellington, Associate Professor Michael Baker is not only a respected specialist in his field, but also a researcher with a way with words which galvanises interest in his findings.

In 2006 he described chicken as "the cheap and dirty food of New Zealand" and, in a paper published in the NZ Medical Journal with Dr Nick Wilson and others, called for regulation of Campylobacter contamination levels in fresh poultry. The issue exploded across the media, rocking the chicken processing industry and the New Zealand Food Safety Authority (NZFSA) back on the ropes.

The figures were indisputable. Baker pointed out that this country had a huge and escalating public health problem with around 16,000 notified Campylobacter cases a year, about 1,000 hospitalisations and an estimated 100,000 more cases in the community. These infection rates were more than three times those of Australia's and 30 times higher than the US. The illness causes diarrhoea, stomach cramps, vomiting, fever and, in some severe cases, paralysis and death. The epidemic was also costing the country at least $75 million a year in lost production and health care.

"Notified Campylobacter cases began to drop sharply in the second half of last year and, in the first six months of 2008, the rate fell by 60 per cent compared to the same six months the previous year ..."

Because at least 90 per cent of chicken was contaminated with Campylobacter, this widespread bacterial poisoning of the population was increasing with the growing popularity of fresh chicken. And, although this bacteria is killed by proper cooking, the high levels in fresh chicken provided many opportunities for cross contamination to other foods, and to surfaces in restaurants and homes across the country.

"Something had to be done about Campylobacter in fresh chicken," Baker says. "This food has become the most consumed meat in New Zealand, with the average person eating 34kgs a year. Unfortunately, because fresh chicken was so highly contaminated, this situation created a food-safety crisis that harmed tens of thousands of people annually."

Baker's research findings lifted the lid on this issue. His results became the focus of intense media interest and strengthened the hand of the NZFSA to take stronger measures to force the industry to clean up its act and cut Campylobacter contamination in processing plants. Since 2007 a range of improvements has been introduced to processing and distribution. All plants are now required to report contamination rates to the NZFSA and there have been warnings of plant closures if these are breached.

"The results have been dramatic and have clearly shown the need for stronger agency intervention by the NZFSA," says Baker. "Notified Campylobacter cases began to drop sharply in the second half of last year and, in the first six months of 2008, the rate fell by 60 per cent compared to the same six months the previous year - a phenomenal drop."

However, Baker and the NZFSA are still cautious. Baker says that Campylobacter illness rates do have a degree of variability from year to year so the decline needs to be sustained for at least a couple of years to confirm definitively the current trend.

"We still have a long way to go before we see the end of this preventable epidemic."