Wednesday, October 31, 2007

Hand washing not allowed

I hope that all of us in the food industry know just how important hand washing is. If done properly, using hot water and soap, working on all the fingers and paying attention to nails, then rinsing and drying thoroughly, it can significantly reduce the amount of bacterial contamination on the hands. Indeed, there is evidence that clean hand contact with food is far less hazardous than contact from a gloved hand if the operator is not careful about glove use.

Rotavirus infections are highly contagious and commonly affect young children. The main symptoms are watery diarrhoea and vomiting, carrying the risk of dehydration. The outbreaks are often seen in kindergartens and schools. As with all gastrointestinal infections, the main route of infection is directly from improperly washed hands or through contact with contaminated surfaces and toys. The virus is resistant to the environment and to disinfection and will survive on surfaces for a long time, so toilet facilities used by children with watery diarrhoea are obvious transfer points. The time between infection and appearance of symptoms varies from 1 to 3 days.

OK – so what set me off on this lecture? My daughter in law has just had a new baby and we are obviously very aware of the potential for infection during her first few weeks of life. My son, (he’s an engineer but grew up being indoctrinated about food safety) informed me that there is an outbreak of diarrhoea at his children’s school. He has provided the girls with an alcohol hand wash to use at lunchtime, because apparently the children ARE NOT ALLOWED TO WASH BEFORE LUNCH. What kind of education for life is that?

Wednesday, October 17, 2007

Guaranteed safe (?) At what cost?

You may have read of the shocking toll taken by Escherichia coli O157:H7 in the U.S. and the apparent increasing incidence of the disease. E. coli O157:H7 infection often causes severe bloody diarrhoea and abdominal cramps that may last for 5 to 10 days. In some people, particularly young children and the elderly, the infection can also cause haemolytic uremic syndrome (HUS), in which the red blood cells are destroyed and the debris causes kidneys failure. About 8% of patients may develop HUS. Sometimes the patients recover after a long illness, but a significant number of children have required kidney transplants.

Topps Meat Company, a US company specializing in manufacture of frozen ground beef, initially recalled 330,000 pounds of beef hamburger patties because of E. coli contamination. There had been a number of cases of O157:H7 infection tied to its products. On the 29th September, the company extended the recall to 21.7 million pounds of ground beef, bringing the total recalls in the U.S from April this year to over 30 million pounds of red meat, mostly hamburger. A week later, the company announced that it was going out of business, citing inability “to overcome the reality of a recall this large”.

Clearly, 21.7 million pounds is more than a single day’s production, so there is some sort of systemic failure in the plant. An inability to identify unique batches of product probably contributed to the size of the recall. The USDA also cited the company for “inadequate process controls in the non-ground meat production line”.

The recall highlights the problem of regulations based on product testing. In the US, E. coli O157:H7 is regarded as an adulterant; there is zero tolerance for its presence, so if it is found, the whole product lot must be withdrawn. However, it is extremely difficult to demonstrate total absence of a micro-organism from a product – even with large numbers of samples, it is highly likely that a low-level non-homogeneous contamination would be missed. I am told that the product in question had actually passed two levels of testing and that the recall began only when consumers became ill.

The problem is compounded by the predilection of Americans for consumption of hamburgers cooked rare. Doug Powell at Kansas State University has said many times (and again today) that colour is a poor indicator of sufficient cooking and that consumers should use a meat thermometer. Nobody should be made ill by the food they consume and no company has a right to claim that their small size should exempt them from running properly controlled safe production processes, but consumers must take some responsibility for their own safety. At least one of the consumers who contracted the O157:H7 infection admitted that she had cooked the burgers until they were pink inside.

Raw ground meat is inherently hazardous – it is manufactured from animals that may carry bacteria capable of causing human disease. It is almost impossible to guarantee that some of these bacteria will not be found on the carcase. When the meat is ground, the exterior surfaces and interior tissues are all mixed together, spreading the contamination throughout the meat. (That’s why you can cook a steak rare and produce a beautiful, safe meal, but cooking ground meat rare can leave the pathogens in the centre undamaged and capable of causing illness).

The whole thing is getting out of hand in the US. Companies are recalling huge amounts of food, the authorities are closing processing plants, lawyers are suing for massive damages and consumer advocates are calling for guarantees that food is safe. The result can be only a loss of confidence in the food supply and an increase in costs to the consumer. I see some parallels developing in the case of Campylobacter in poultry in New Zealand

From the industry point of view, the answer lies in greater process control based on a thorough risk analysis, not on discredited end product testing.