Nanogirl: The fowl truth

Cook chicken thoroughly to keep campylobacter infections at bay. Picture / 123RF

Campylobacter has managed to get some bad press recently. An article by Consumer New Zealand found that 26 out of 40 raw chickens bought from supermarkets were infected with the bacteria.

Sensationalist, click-bait headlines saw social media feeds filled with "Bad Chicken On Sale", and "Most Store-Bought Chicken Tests Positive for Campylobacter", sparking countless comments from people worried about the risks of chicken consumption.

The truth is complex. There are simple steps that need to be taken at home to minimise infection risk day to day; there is also a need for ongoing research and intervention to minimise the risk of infected food and water reaching the consumer in the first place.

Finding bacteria in supermarket chicken sounds alarming, but in fact Campylobacter can easily make its way into the poultry food supply. Most of our food originates in fields and farms, and chickens are constantly exposed to a wide range of micro-organisms naturally present in the environment. Campylobacter is one of these.

A curve-shaped bacteria, Campylobacter is usually transmitted in contaminated food or water. It causes no ill-effects in chickens - in humans though, it can infect the gastrointestinal tract causing diarrhoea, fever, and cramps.

Campylobacter infection - Campylobacteriosis - is generally mild, and in most cases symptoms pass within a few days without treatment.

It can become a serious issue, however, and is potentially fatal among very young children, as well as elderly and immunosuppressed individuals.

Campylobacter is the leading cause of food-borne illness in New Zealand, though infection rates have dropped over the past decade. Hovering around 7000 reported cases per year, it is the most commonly notified disease in New Zealand, making up 35 per cent of all notifiable diseases reported to our Public Health Service.

Actual infection rates are thought to be significantly higher than those reported due to the relatively mild symptoms, as many people don't report their case to their doctor.

Minimising the risk of infection in the home is relatively straightforward, at least where meat is concerned. Campylobacter's biggest weakness is temperature - it is rapidly inactivated by heating to 55C and above.

Thorough cooking of chicken meat all the way through - especially important to watch during the summer barbecue season - will go a long way to avoiding campylobacter infection.

Reducing the spread of bacteria in the kitchen is also important, ensuring that all surfaces that have been exposed to raw meat are washed down thoroughly to prevent spread of bacteria.

While minimising risks around the home is relatively straightforward, there are issues of significant and increasing public health concern surrounding Campylobacter worldwide.

One of these, the increasing presence of antibiotic-resistant Campylobacter strains, has been called a 'global health crisis' by the World Health Organisation.

This is already evident close to home - a new strain detected in about 33 per cent of Campylobacter cases in Auckland is resistant to two antibiotics: fluoroquinolone and tetracycline. For now, there are still other antibiotics available, but as the bacteria continue to mutate other treatment will be needed.

Within the food chain, the complex ecology and biology of Campylobacter means that the development of effective risk reduction strategies is a major challenge for governments, livestock producers, processors and retailers.

Around the world, research across bioscientists, mathematical modellers, vets and social scientists along with relevant policy and industrial representatives is needed to keep infections under control.

There is no single clear intervention that will provide a solution; instead a multidisciplinary approach which intervenes at a variety of points in the food chain, as well as developing new ways to combat infection, will be required to help protect New Zealanders from further outbreaks.