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Food Focus August 2008

Track and trace

Authorities around the world have banded together to make sure people do not consume foods that are unfit for consumption. Every year New Zealand is involved in several recalls of products that have crossed country borders

In a world where food production and trade are becoming increasingly globalised, it is important that there is good international cooperation when one country discovers potentially serious contamination incidents in foods traded internationally. To help spread this information, an international notification system, the World Health Organization’s International Food Safety Authorities Network (INFOSAN), has been established to alert all potentially affected countries. Some regions have additional systems such as the European Commission’s Rapid Alert System for Food and Feed (RASFF).

NZFSA’s Event and Emergency Response Adviser Janice Attrill says NZFSA is only involved in a few international recall incidents each year, but being linked to a global network makes it significantly easier to spread the word about a problem that is detected in New Zealand. “If we have a recall of an imported product that has wider international ramifications, we immediately notify the exporting country and, where appropriate, supply the information to INFOSAN. For those incidents that involve a potential imminent health threat, as opposed to just a technical non-compliance, INFOSAN then sends out alerts to the appropriate authorities in the countries concerned.”

Border detections trigger local responses

When importing countries discover significant incidents of non-compliance (such as contaminated food), the country of origin is notified and an investigation is initiated to determine the source and extent of the problem. In some cases this work is far from straightforward. In March 2006 NZFSA received a RASFF notification from the EU that a carton of chilled beef from New Zealand, which was supposedly sampled at the Belgium border, was found to contain low levels of chloramphenicol (CAP).

While not an imminent health threat, CAP is not a registered veterinary medicine in New Zealand and should not be found in food. NZFSA started work to find the source of the contamination and the case file of the investigation began to read like a whodunnit.

The EU provided details of the carton that was supposedly sampled and the exporter quickly confirmed from their processing records that the identified carton may have contained product from animals from six South Island farms. NZFSA investigators visited each farm and the veterinary practices servicing those farms and didn’t find any evidence of possible use. Since CAP is an antibiotic used in human eye drops and only available by prescription, they also reviewed local pharmacy prescription records and the health records of the staff at the processing premises. Once again they failed to come up with any plausible link.

An EU reference laboratory confirmed the results of the first sample. It further confirmed that the CAP was evenly distributed throughout the sample and so was highly unlikely to be associated with any post-slaughter contamination. NZFSA requested a portion of the sample be sent back so we could conduct further tests.

To try and break the deadlock in its investigation, NZFSA then used some cutting-edge and novel scientific strategies and processes involving DNA profiling and isotope ‘fingerprinting’ to try and establish the origin of the suspect sample. This time the investigation came up trumps and unequivocally showed the sample supplied by the EU could not have come from an animal farmed in New Zealand.

As a consequence NZFSA put a successful case to the EU questioning the validity of the testing and the origin of the meat, arguing that the sample of meat could not have originated from New Zealand, but must have been mixed up with meat from somewhere else. It was never established where the infected meat came from.

Tracing in action

On another note, in April this year a Lower Hutt rest-home resident received a gift basket containing a jar of organic pumpkin seed butter sent from Britain, only to discover he would never get to eat it. The product was delivered to the recipient, but before it had even been opened NZFSA was notified through RASFF that the product (originally produced in Serbia even though exported from Britain) had tested positive for Salmonella in the company’s own checks. Salmonella is a pathogen that can cause salmonellosis, which inflicts nausea, vomiting, abdominal cramps, diarrhoea, fever and headache lasting from six hours to two days. NZFSA liaised with Hutt Valley District Health Board who contacted the elderly gentleman’s son to ensure the jar was disposed of.

Further testing found that the pathogen in the product was not in fact Salmonella, but rather Citrobacter. While Citrobacter is not as severe, it is still a pathogen that could cause a bout of diarrhoeal illness.

In another case in August 2006, NZFSA was alerted to a shipment of Dutch fruit bars destined for New Zealand consumers. The product was recalled because the bars were contaminated with fragments of metal wires. The shipment was retrieved and destroyed before it even left for the Antipodes.

Lack of traceability can be costly

Not having traceable products can have significant financial consequences. This was the case for a Manawatu organic juice maker, whose entire season of apple juice had to be seized after a routine inspection found the potential carcinogen patulin in some of his products.

Patulin is produced when fruit starts to rot. Apparently some decaying apples had made their way into production. However, the manufacturer had not used batch numbers or other identifying features to enable a trace-back to the specific bottles of juice that were affected by patulin.

“The only option available to the producer if he wanted to salvage his products would have been to turn them into cider as that process would have killed off the patulin, but even that would have been a very expensive exercise”, Janice says. “Being a smart manufacturer means incorporating sound production systems that allow for trace-backs when they are required.”