Hello Fresh fish causes food poisoning in New Zealand

 At least three people have been treated in hospital for scombroid poisoning after eating Trevally from a meal kit supplied by Hello Fresh.

Histidine in the fish tissue can be converted to histamine by histidine decarboxylase, found in Escherichia coli, Morganella morganii, Proteus, Pseudomonas and Klebsiella species, which may occur naturally in the gills, skin and gut.  If the fish is not properly handled after being caught and during transport and distribution, allowing the temperature to rise for an extended period, these bacteria can grow and produce sufficient histamine to cause an allergic reaction in the consumer.  

Scombroid poisoning was originally named because Scombridae fish naturally contain higher levels of histidine.  The range of symptoms varies, but includes nausea, headaches, vomiting and diarrhoea and possibly itching and a burning sensation in the lips.

Unfortunately, the fish may not appear to be spoiled and the enzyme remains active even after the bacteria have been killed,  continuing to produce histamine under cold storage.  Activity can  resume when frozen fish is thawed.  Histamine cannot be destroyed by cooking, so control of storage temperature is essential throughout the food chain.

Downside of reusable shopping bags?

Supermarkets in New Zealand are discontinuing the use of single-use plastic bags as a contribution to reducing plastic pollution.  (My personal view is that this is just scratching the surface of the problem - produce is still wrapped in plastic and just about everything we buy in the line of detergents, shampoos, hand creams, water etc. is packed in plastic).

Some supermarkets are offering free or very inexpensive fabric bags to carry home the purchases.

A New Zealand politician has jumped on this, quoting a discredited overseas study that suggests that the use of reusable fabric bags will result in some deaths from food poisoning.

The general opinion among experts, myself included, is that this is silly scaremongering.  If meat and poultry is carried in these bags and blood or drip escapes the packaging, then the bag will be contaminated.  If unwrapped salads, cured meats, cakes, pastries and bread are carried in the same bag, cross contamination may occur.

Just as in the kitchen, it is sensible to separate raw meats, which will be cooked, from foods that will be consumed without further cooking.  Different chopping boards should be used for raw and cooked foods, and fabric bags used for raw meats should be washed regularly.  This not rocket science.

Others have jumped on the bandwaggon, once again putting forward the suggestion that sale of raw chicken, which often contains Campylobacter, should be banned in favour of frozen products.  Certainly, freezing reduces the numbers of Campylobacter, but does not eliminate it.

It seems to me that a slight change in mindset is required, together with a greater understanding of food hygiene.

MPI provides an interactive tool to determine your responsibilities under The Food Act 2014

The New Zealand Food Act 2014 comes into force on 1st March, 2016.  This will not be news to major food manufacturers, but does affect everyone working in the food industry; their responsibility is to produce safe food.

The new Act focusses on the processes of food production, rather than the premises where these activities are carried out. i.e. the old "floors, walls and ceilings" approach is long gone.  The other major difference from earlier legislation is that it takes account of the risk associated with any particular business (and that includes the activities of clubs and societies that raise funds via sales of food, such as pizzas).  The new Act brings in Food Control Plans for high risk food production and supply (in fact, many businesses have been operating under FCPs for some time), and introduces National Programmes for activities with lower risk.  Thus manufacture of ice cream is treated rather differently from the sale of coffee from a mobile operation at shows and open days.

One of the problems currently faced by smaller operations, such as corner dairies, saussage sizzles and community shared meals like club gatherings for members and guests, where food may be sold, but not as the primary purpose of the gathering, is knowing exactly what is required in terms of the regulations.  The New Zealand Ministry of Primary Industries (Te Manatu Ahu Matua) has provided an easy-to-use interactive tool to help all organisations involved in producing, selling and providing food to determine their responsibilities under the new Act.  The tool is called Where do I fit? and poses a series of questions you can answer by clicking responses.  The tool will then tell you your responsibilities and the requirements of the Act, together with links to further information.

I have not tested the tool extensively, but it is very easy to use and provides lots of helpful information.  I specifically tested it from the perspective of my gliding club's putting on a fundraiser and found the output very helpful.

Happy and safe Christmas to you all

For us in New Zealand, Christmas Day is only 12 hours away.  It is summer and we will be having BBQs and parties outside.

Don't forget - if you are cooking outside on a fire or a BBQ, steak requires only to be cooked on the outside, as the inside of meat from a healthy animal is essentially sterile.  If the steaks are thick, make sure that the edges are also cooked.  However, meat patties have been made by blending together minced meat and possibly egg as a binder.  The inside of the patty is not sterile and so the patties must be cooked through properly.  Use a meat thermometer to be sure that the inside has reached at least 75C.  You can't judge whether the meat is cooked just by its colour.

I prefer not to cook chicken on the BBQ because it is difficult to ensure even heating.  However, if the BBQ has a hood, it is essentially the same as an indoor oven.  Ensure that the chook is cooked properly, again using a meat thermometer.  I also prefer not to put stuffing into the body cavity - it slows down the cooking process and it's difficult to determine when it's done.  Cook the seasoning separately.

Round our place, there are very rarely any leftovers.  However, make sure that food doesn't stay in the sun any longer than necessary.  Ham that has been handled may well be contaminated with Staphylococcus.  If eaten straight away, this is no problem, but if left at room temperature, the bacteria may grow, since all their competitors have been killed in the preparation process, leaving them free to grow in the salty favourable conditions.

Remember that several food borne pathogens can grow, albeit slowly, in the refrigerator, so use leftovers within a day or so.

Recent changes in legislation in New Zealand mean that driving after more than one alcoholic drink risks being charged with driving under the influence of alcohol.  Better to have a designated driver, or stay off the turps!

To all my readers, I wish a happy Christmas and an enjoyable New Year.

TV chefs fail at basic hand hygiene

I have just watched famous TV chefs preparing demonstration dishes.  One worked in his kitchen, others in an outside setting.

In both cases, the chefs were handling raw meat with their bare hands and preparing salads and sauces.  At no point did the chefs wash their hands and of course, they were moving between raw meats, fresh vegetables and spices. 

Of most concern to me was the use of a towel.  Chefs often have a towel at their waist; they use it for wiping spills from plates prior to service.  On this occasion, the chef handled the raw meat and repeatedly wiped his hands on the towel.  The sauce was blended from fresh vegetables and was not cooked.  There were no hand washing facilities in the shot and the sauce vegetables were also handled with bare hands.  The potential for food poisoning is significant.

Now, perhaps the chefs really did wash their hands between handling raw meats and salads.  However, these are demonstrations for ordinary viewers.  They should be setting a better example and emphasising the necessity of hand washing.

Fancy a snot pie?

The thought of this is totally gross.  Why would I contemplate writing under such a heading?

Unfortunately, it's quite possible that some customers have in fact been sold pies contaminated by the profuse nasal secretions of a baby held in the arms of the cook filling the pies.  Talia Shadwell wrote a piece in the Manawatu Standard at the end of December 2012 about a family-owned Rangitikei food premises forced to close because of a very unfavourable food safety inspection report.  In addition to the highly probable contamination of the pies by the infant, the milkshake blender was encrusted with rotten milk.  It is likely that there were other violations of good catering practice and the Food Hygiene Regulations.

Legislation is changing in New Zealand, but it is safe to say that the intent of the regulations will not change.  District councils are responsible for registering food premises and it is illegal to sell food not produced in registered premises.

"No persons shall be issued with a Certificate of Registration for food premises (except a vehicle used solely for the carriage or delivery of food for sale) unless -

• That person has been issued with a Council recognised Certificate in Food Hygiene or another qualification approved by Council; or
• There is, working on the food premises, a Manager or a staff member with specific responsibility for staff training in food hygiene, who has been issued with a Certificate in Food Hygiene, a Certificate in Basic Food Hygiene or other qualification approved by Council."

 It is perhaps surprising that the inspection report noted that the family had 'very limited' knowledge of food hygiene and food safety practices.

Unfortunately, this state of affairs is probably more common than we would like to think - many food premises are run by immigrants who provide the rich diversity of foods available in New Zealand, but who may have very limited knowledge of the language and regulations. This is no excuse for poor hygiene and food production practices.

Consumers have a right to expect their food to be safe to consume and to be produced under aesthetically acceptable conditions.

You can lead a horse to water, but you can't make her drink

Another saying from my childhood, translated from the original Yorkshire dialect into English!


What triggered this?  Well, HACCP (Hazard Analysis and Critical Control Points) has been around since 1959, when NASA attempted to ensure that food fed to astronauts would not make them ill, or cause injury.  The possibility of early astronauts, trapped in orbit and vomiting into their helmets, could not be contemplated.  Originally developed as a microbiological safety programme by the US Natick laboratory and later by The Pillsbury Company, the Modes of Failure programme eventually covered all aspects of astronaut food, not just microbiological hazards.  By 1971, the HACCP system was published and documented in the USA and by 1985, the National Academy of Science recommended the use of the system. Incidentally, I began teaching HACCP to food technology undergraduates in New Zealand in 1978.

Recently, Roy Costa posted an article on Food Safety and Environmental Health Blog:

http://www.safefoodsblog.com/2011/03/articles/outbreaks-1/schools-skip-out-on-haccp/

in which he pointed out that retailers demand food safety management systems from suppliers.  The end of the supply chain - institutions and food service organisations - are also required to have HACCP-based food safety plans in place, but schools seem to have dropped beneath the regulatory radar: few have implemented the requirements and they are not being pursued by the local health departments.  Costa suggests that this is because the schools and health departments are both part of the counties, which claim that this is an unfunded Federal Government mandate. 

Politics aside, this problem of lack of implementation of HACCP-based food safety plans is not restricted to schools and food service outlets.

Some years ago, I wrote an HACCP-based food safety programme for a local food manufacturer.  This is not something I will do again; as a consultant, I was an outsider and though I had a close familiarity with the factory, I don't think that the production manager wanted to do more than "tick the box" that they had a programme.

About a year after I wrote the programme, one of my students got a job at the factory.  "What do you think of the HACCP programme?" I asked.  "What programme?" he replied, "I never saw it".  The next time I visited the factory, I mentioned this to the manager.  He said "Oh, I'm sure it's around somewhere, probably on the shelf in my office".

So, after that roundabout story, we come back to the title of this posting.  The factory complied with the regulations - it had an HACCP-based food safety programme, so any auditor could be shown the document.  But just having a nicely bound document on the shelf is only the beginning.  The plan must actually be implemented in the factory and reviewed on a regular basis.  This manager wasn't even sure where it was, his staff didn't know of its existence and there is no doubt in my mind that he never reviewed it.

Microbial tongue twisters

Today Bill Marler published a link to a clip of Larry King making an ass of himself while introducing a segment on Escherichia coli.

http://www.youtube.com/watch?v=omaF9kA94Io&NR=1

Perhaps it's a good thing he used the abbreviation E. coli

That set me thinking.  Does the general public find the names of bacteria so difficult to pronounce that they put all thoughts of them to the back of their minds?  Or do they regard all bacteria as "germs"?

The difficulty is that there are literally thousands of different bacteria, so microbiologists have to give them names that mean something and so that they can be grouped for study.  Sometimes the genus is named after its discoverer, or in honour of a famous microbiologist.  Salmonella was named after D.E. Salmon, an American bacteriologist; Bacillus is named from the Latin noun meaning "a small rod", while Acetobacter is so named because it oxydises ethanol to acetic acid (vinegar).

When microbiology students start out, they often have difficulty in remembering, or even pronouncing, names like Vibrio parahaemolyticus and Pediococcus pentosaceus.  Small wonder that the rest of the population has problems.

In fact, in terms of food poisoning, Joe Sixpack doesn't need to know these names.  Basically, if you mistreat food by contaminating it, or by holding it at temperatures that permit growth, there is a possibility that numbers of pathogenic bacteria will increase to what is termed an "infecting dose" or that toxins will be secreted into the food.  The latter cause food poisoning when ingested.  So what is our favourite bloke going to do to keep himself and his family safe?

Easy - clean, cook, cover and chill.  This little mnemonic includes it all: Clean-handle all foods with clean hands and utensils; Cook frozen foods after proper defrosting and use a thermometer to ensure that poultry or meat patties are properly heated through.  If foods are to be reheated, ensure that the temperature reaches at least 75C right through to the centre; Cover cooked foods during cooling and place in the refrigerator within 30 minutes; Chill foods to 4C and hold at that temperature until served (remember that some bacteria grow readily at refrigerator temperatures, so even chilled food will not remain safe forever) or hold above 60C.  You can find more extensive guidelines for these important concepts on the MAF website in New Zealand, or the FDA sites in America.

In the Southern Hemisphere, we are at the start of the barbecuing season.  It's important to be really careful - never put cooked meat on the same plate as raw meat and pre-cook chicken legs etc. making sure that patties are heated right through.

I was once at a company barbecue, standing in line to collect my meal.  I heard someone behind me whisper "See what he takes, he's a microbiologist".  I didn't need to name the bacteria that might have survived on my meats, choosing only steak and thoroughly cooked burger patties.

Where's my PhD student?

I had a scheduled meeting with my PhD student this morning, but she didn't turn up.  I got a somewhat graphic text message, saying that she had food poisoning.  It seems that she, her partner and two friends went out for dinner in a restaurant in Auckland on Saturday.  They all appear to have food poisoning.

Of course, this doesn't prove that the restaurant was responsible.  Indeed, her description of the symptoms and time of onset make me wonder if another common source was involved.

However, a TVNZ One News investigation shows that on average, one Auckland food establishment per week has been shut down this year because of safety or cleanliness violations.

http://tvnz.co.nz/health-news/shocking-food-hygiene-figures-auckland-3800902

An Auckland City Council Environmental Health spokesperson said that the increase in closures was a result of tougher action by health inspectors in response to unsatisfactory performance and suggested that this was partly because of the economic recession - companies were selling food that would previously have been thrown out.

A disturbing statistic given in the TVNZ report is that over 100 restaurants and cafes are still operating, despite poor hygiene ratings, though to be fair, businesses are given the opportunity to clean up their act before being closed down if they don't improve.

This report begs the question "If inspectors had previously found unsatisfactory conditions in food outlets, why didn't they close them down at the time?  What has changed in the requirements to serve wholesome, safe food in clean premises?"

Old lessons not learned - Re-post

I have just returned from a meeting of food experts in Wageningen, Holland. One evening, we were taken to the Zoo in Arnhem. This fantastic place has a number of indoor environments, such as a jungle, ocean, desert and a restaurant.

After the visit, we had a meal in the somewhat inappropriately named Burgers Zoo Restaurant. A feature of this is the do-it-yourself barbeque. This ingenious device is like the continuous toasters you see in some hotel dining rooms – the food is placed on a continuous belt grill and passes over heated briquettes. Diners select their meats and salads from the large range set out on side tables.

Not having completely switched out of professional mode, I watched my fellow foodies to see how they would cope. I guess I should not have been surprised to see several of them take their raw meats and salads onto a single plate. They cooked the meats and then put them back onto the same plate! Nobody took fresh tongs or heated the ones used to put the meat on the grill.

Clearly, not all the participants were experts in food safety, but I had hoped that they would know about basic food safety rules – cooked food should NEVER be put on a plate that has held uncooked meat and cross contamination of salads from raw meats must be avoided. When I pointed out their mistake to a couple of my colleagues, they understood, but still didn’t know what to do about it.

At the other end of the scale, one young lady expressed concern as to whether she had cooked her steak sufficiently and was she at risk of food poisoning? In my opinion, her meat was over-cooked, but it would certainly have been safe to eat. Raw steaks from a healthy animal are essentially sterile on the inside, so they can be made safe by cooking the outside properly. (Minced or ground meat has had the outside mixed into the inside, so cannot safely be eaten rare). She expressed the view that barbequing was a bloke’s job, but I wonder if it should be left to food microbiologists?

“The Law is an Ass” – with apologies to Mr. Dickens.

In the last week, the Far North District Council in New Zealand has enforced the law and required community members to desist from cooking pickles and jams and selling them through a Hospice Shop. Over the years, these wonderful people have raised around $5000 for the hospice funds each year.

It appears that the District Council received a complaint that the goods were being produced in private kitchens. Under the Food Hygiene Regulations, the council was then obliged to investigate. The regulations specify that production of foods for public consumption may be conducted in unregistered premises only on special occasions.

This situation crops up more than you might expect. About 25 years ago, when my children were small, our country school raised significant amounts of money by pizza drives. About three times a year, the Parents Association purchased commercially made pizza bases and assembled pizzas for sale. The council received a complaint from a commercial pizza parlour that this was unfair competition, since the school did not have a registered premises and therefore had lower costs. We were able to comply with the regulations by specifying the number of times a year our Occasional Food Premises would be used and by registering a relatively simple Food Safety Programme.

To give credit where it is due, the Far North DC and the New Zealand Food Safety Authority (NZFSA) are looking at ways the volunteer cooks can continue to produce their foods. Their home kitchens are not registered premises and it is not practical for the volunteers to set up a separate kitchen. I’m looking forward to seeing how the Authority gets around its own antiquated regulations.

However, what is the real risk? The products are essentially heated, acid foods – jams are made from acidic fruit and have a low water activity*, so the most likely microbial spoilage – if there were to be any – would be mould growth, which would be apparent to the consumer. Pickles are acidified foods and the low pH has the same effect, preventing the growth of pathogens. So the microbiological risk to consumers is low. Fruit cakes and similar baked goods are not hazardous either. Obviously, good hygiene in production and handling of all these foods is essential and potential contamination with cleaning chemicals etc. must be prevented.

What are the most hazardous foods on sale today? According to the Centre for Science in the Public Interest, these are leafy greens, with 363 outbreaks (13,568 reported cases of illness); eggs (11,163), tuna (2341), oysters (3409), potatoes (3659), cheese (2761), ice cream (2594), tomatoes (3292), sprouts (2022) and berries (3397). These are listed in order of outbreaks. Notice that jams, pickles and cakes don’t figure in the statistics.

Back in the Far North, everyone is looking to see this resolved soon, so that the volunteers can resume their work for the hospice. The Food Hygiene Regulations are due for replacement with a new Food Act that will shift the emphasis to risk assessment of food processing operations.

As the Assistant Director of NZFSA apparently said, “The law isn't based on common sense and we're looking to improve things."


* See the end of "Free Choice or Safety of the Population" for an explanation of water activity.

It’s happened before, it’s happened again and it won’t be the last.

The Queenstown District Court (South Island, New Zealand) was told an all too familiar tale a couple of days ago. Two women had been poisoned and subsequently hospitalized after consuming a contaminated drink. On this occasion, the drink was mulled wine; the contaminant was sodium hydroxide – industrial dishwashing liquid.

At first sight, this would seem to be an impossible occurrence. Closer inspection shows a familiar pattern. I expected that the mulled wine would have been made on the premises from wine, sugar, cinnamon stick etc. However, the drink was apparently dispensed from a bulk container of pre-prepared “mulled wine”. Unfortunately, the container appears to have been used to deliver the cleaning chemical. Presumably, the label was not changed and the person serving the product didn’t detect the substituted liquid. It is not clear to me why the industrial chemical looked to all involved like mulled wine.

This is utterly poor practice of the worst sort. I have been teaching HACCP for the last 30 years and during the whole of that time, the use of food containers for other materials has been proscribed as part of the food safety plan. Proper labelling of containers is also critical. There have been so many cases where this practice has resulted in injury or even death that I have lost count. Some examples include preservative being mistaken for sugar; fire retardant powder being mistaken for cattle feed; cleaning agents being used in food preparation instead of the expected food ingredient. In one admittedly non-commercial case, a person died after drinking from a spirit bottle containing paraquat - a herbicide.

No food container should ever be used to store non-food chemicals; chemicals should not be stored with food ingredients and all containers should be clearly labelled with the identity of the contents.

The news just keeps on getting worse!

After so many years of living with a food microbiologist, my wife has become a valuable food retail spy. Today she told me two more horror stories:

In our local supermarket there is a display stand for unwrapped bakery goods that extends from about chest height down to the floor. The store manager has supplied tongs for customers to use and there are signs asking customers to use the tongs.

Today she arrived at the bakery counter in time to see a mother wrestling the tongs from her toddler. If this were not bad enough, the mother then said to the toddler “I thought you said you were going to eat that”. Grabbing a bun from the child’s other hand, she stuck it back in the cabinet. Now both of them had handled the bun.

Now, I realise that bread buns are not a particularly good growth medium for food poisoning bacteria, but this is unacceptable. Some food borne pathogens have a very low infecting dose. The display cabinet should be arranged so that products and tongs are inaccessible to toddlers. Owners of self-service food displays need to be aware that simply providing tongs does not guarantee the safety of the food they sell. Needless to say, we will not purchase unwrapped goods from that store again.

The second incident was observed on TVNZ’s Good Morning show. Unfortunately, I didn’t see it and have not been able to locate a replay on their website. It appears that The Mad Butcher was on the show and demonstrating the preparation of chicken. After handling the raw chicken, he put his fingers into some spices and tasted a pinch. The bowl of spices was thus contaminated with whatever bacteria were on the raw chicken. A short while later, he put a cooked chicken onto the same chopping board, contaminating it with raw poultry juices.

OK – the Mad Butcher is not a professional chef and neither is Steve Grey, the host for that segment. The poultry industry in New Zealand has had a bad press recently over Campylobacter food poisoning, allegedly transmitted largely via chicken (though in fact we have seen a significant and sustained reduction over the last year in the incidence of the disease in the human population). This sort of example on daytime television, which is probably watched by many young mothers, is perhaps one of the reasons that we see such a high incidence of campylobacteriosis in New Zealand. Young adults are not getting the food safety message and we need to have good kitchen habits shown on our national television channels. We can’t rely on the food suppliers to take total responsibility for control of food poisoning.

This type of poor kitchen practice is not confined to New Zealand; Doug Powell at Kansas State University, who runs the Food Safety Net and writes the Barfblog has castigated some TV chefs in the USA for similar indiscretions (see for example: http://barfblog.foodsafety.ksu.edu/tags/tv/).

Norovirus spreads fast

We have all read of the mystery illnesses that strike down students in schools and universities and perhaps thought that these outbreaks were caused by overcrowding or poor cleaning in these establishments.

The importance of properly educating food handlers has been emphasized once again. Workers at a Michigan restaurant displayed an almost unbelievable ignorance of simple food handling rules in January last year. (Warning: those with a weak stomach should receive guidance from a food microbiologist before reading further).

Three staff reported for work at the restaurant even though they were suffering intestinal illness. The US Centre for Disease Control and Prevention reports this in a summary of findings of an investigation released two weeks ago. One of the workers vomited into a waste bin before continuing their kitchen duties. They may have believed that using the waste bin was OK, but obviously didn’t think about aerosol generation, transfer of infective particles by their hands and contamination of surfaces in the kitchen and washrooms (or even plain old aesthetics).

The infection turned out to be a Norovirus. These viruses are highly contagious and have an infecting dose as low as 10 particles. The efficiency of infection may be as high as 93% of those people exposed. That’s why we see these outbreaks spread like wildfire through student hostels. The normal transmission pathway is the faecal-oral route, but the particles can survive on surfaces for up to four weeks, so washrooms used by sufferers become very hazardous. The particles can be killed by chlorine (bleach) solutions, but the quaternary ammonium compound used on cleaning cloths in the restaurant was thought to be ineffective.

The CDC recommended that after a vomiting event like this, all exposed food, paper serviettes, takeaway containers and straws should be discarded. All surfaces within an 8-metre radius and all washrooms should be disinfected with a chlorine solution. I would also rewash all crockery and cutlery. It was suggested that restaurant owners should consider briefly closing down for complete cleaning after someone has vomited in the facility. Staff training is critical. Part of the training should be an injunction to stay away from work for at least three days after gastrointestinal illness (and not to handle utensils or ready-to-eat foods for a further three days). Rigorous hand washing and segregation of raw and cooked foods is another obvious precaution.

You can find more information on Norovirus at:
http://www.nzfsa.govt.nz/consumers/food-safety-topics/foodborne-illnesses/
norovirus/factsheetnorovirusv2.htm