Provincial and government health agencies continue to investigate an outbreak of illnesses caused by e coli that has been linked to cheese made by Gort’s Gouda in Salmon Arm. Today (September 19th, 2013), the Interior Health Authority has positively confirmed that the death suspected to be linked to the e Coli infection is now POSITIVELY linked.
The cheeses in question were raw milk cheeses. In simple terms, a raw milk cheese is made from milk that hasn’t been pasteurized. In pasteurization, milk is heated to a temperature that is intended to reduce the number of dangerous pathogens that may be contained in the milk. It doesn’t sterilize the milk, but the likelihood of there being enough pathogens in the milk to make you sick is greatly reduced. In raw milk cheeses, you still heat the milk as part of the cheese making process, but not to the point where it kills off as many pathogens. However, when you age a cheese, and in Canada the rule is that a raw milk cheese has to be aged at least 60 days before consumption, the cheese itself becomes more acidic from a pH standpoint, and a more acidic composition kills off many pathogens and discourages them from growing to a dangerous number.
So what could have gone wrong with the cheese that has caused this outbreak? Could be lots of things, and obviously we don’t want to speculate as to the exact cause of the contamination, but in talking to some local cheese makers and reviewing some of the literature out there it probably comes down to some sort of human mistake. Milk is sterile as it is produced in the udder but can have some bacteria in it before it leaves, but not enough bacteria to make us sick. However, if the milk isn’t kept at the right temperature, if there is contamination from somewhere along the handling line, that could mean trouble. One example given to me was of a clean bucket of milk being placed on the floor. If there was some manure on the floor, the bottom of the bucket could pick it up and as you pour the otherwise uncontaminated milk into a larger container something could drop in. That’s just one scenario and we don’t know if that’s what has happened in this case.
One cheese maker consultant I met a few years ago, Peter Dixon, has talked about having coliforms turn up in the plastic matting and racks used in aging cheese, so that could be another situation to look at. The food microbiologist I heard on BC Almanac yesterday, though, Kevin Allan from UBC, is quite sure that the e coli originated in the cheese making kettle containing the raw milk.
When you pasteurize milk it does change the fat molecules and some people feel that it has an adverse effect on the flavour of the cheese. Back in the late 1990’s the federal government was going to pass a law making pasteurization mandatory for cheese making in Canada and was also going to ban any raw milk cheeses from being imported. So many people got up in arms over that the legislation was scrapped, so the 60-day rule remains intact, although Professor Allan says that 60 days does NOT guarantee that harmful bacteria is killed off enough to make a raw milk cheese safe for everyone to eat.
I talked with Clarke Gourlay of Little Qualicum Cheeseworks this morning and he told me that their raw milk cheeses, that’s the Rathtrevor, Raclette and Bleu Claire, are all aged at least 6 months before being consumed and that they do extensive testing and so does the CFIA to make sure the cheeses are safe. Their cheeses are clearly labeled as being made with raw milk. In their case he considers it as a selling point, since they have customers who prefer raw milk cheese over pasteurized milk cheese. They are going to continue with business as usual, although he says any time you get an outbreak like this you are going to look at your own operation to make sure you are still doing everything right. He also points out that it is not just raw milk cheeses that can become contaminated; cheese makers have to be careful with all of their cheeses, as there are other organisms that can creep into the cheeses even if the milk has been pasteurized.
Are raw milk cheeses safe? When they are coming from trusted sources, yes. Whether or not Gort’s Gouda will be able to regain the trust of people depending on the results of the investigation remains to be seen. One of the cheese makers I asked about this said he would like to see more inspectors and more spot-checks and general involvement from our regulators. He believes budget cutbacks have contributed to a lessening of the necessary oversight and people in the food industry need more education about food safety. He says, “Once you are approved, you get going and often forget some of the early basic lessons. We get into a habit of doing things as we always have – often passing on bad habits. Then one day a new person cuts a corner or isn’t quite as hygienic as they purport to be and you have a problem.”