Since 2008, two years after NZFS introduced a campylobacter formal risk management regime for food processors, it said cases have reduced by 50 per cent.
Within this achievement had been a 59 per cent drop in the cases of contamination of chicken meat.
In 2015 NZFS, part of the Ministry for Primary Industries, set a new target to reduce cases by another 10 per cent by 2020. This was nearly met in 2017 with a 9 per cent decrease in cases.
But the rate of case notifications had since plateaued.
An agency spokeswoman said it was important to have confidence New Zealand limits would reduce foodborne cases but also meet consumer demand for fresh, chilled and affordable chickens.
"An outcome of the limit review is that there may be scope for further improvements at poultry processors which will prompt further actions by the industry to reduce the levels of campylobacter and achieve nil detections...in a much more significant number of the total chickens processed in New Zealand."
In 2006 New Zealand had one of the highest reported rates of campylobacteriosis in the world with 379 cases per 100,000 people, said NZTS.
The management strategy had helped cut the number to 125 per 100,000 people.
Food sources are contaminated raw meats (poultry and red meat), and raw milk, fruit and vegetables. Takeaways and contaminated water are also culprits.
Previous very high rates of the bug in New Zealand were attributed to broiler chickens, NZFS said.
The bug can be fatal for very young children, elderly people and the immunity-suppressed.
Poultry association executive director Michael Brooks said the observation that human cases had plateaued had to be taken in context against the big growth in meat chicken production. The poultry industry was now worth more than $1 billion.
The testing standards for New Zealand chicken processors were the highest in the world, he said.
While the testing limits under review involved the processing side of the industry, the growth of the free range market meant a focus also on how chickens in an outside environment contracted campylobacter.
The intestines of chickens are an agreeable habitat for the bug, which doesn't make the bird itself sick.
The association worked consistently with NZ Food Safety on standards and had just committed to contribute $150,000 to a joint science project on genome sequencing, Brooks said.
The genome sequencing project was unique, world-leading science and it was hoped it could find how chickens got infected.
New Zealand had one of the highest incidences of campylobacter in the world, perhaps because of its warm moist climate, he said. But salmonella, another nasty gastro bug generally considered a poultry problem, had never been found inside an egg here.
In processing factories, the campylobacter risk was addressed by close attention to the gutting and washing process. Testing for campylobacter was done in plants every week and the results sent to the ministry and to the rest of the industry in a continuous benchmarking process, Brooks said.
At home, campylobacter is spread in the kitchen by cross-contamination from raw chicken meat and livers, including meat juices, to other food, utensils, bench surfaces and hands and clothing. It is recommended that frozen chicken should be thoroughly defrosted before cooking.
A separate cutting board and utensils should be used for preparing raw chicken and livers, which should be thoroughly cooked. Chicken destined for the barbeque should be pre-cooked.
