The introduction of HACCP (Hazard Analysis and Critical Control Point) systems in the manufacturing process help to reduce the potential for incidents of food poisoning.

However, despite strong hygiene regimes and the strictest food safety practices, incidents of food poisoning still occur.

And these incidents are not only a danger to consumers producing illness and sometimes death, they are also highly costly to the company or companies involved.

According the Centers for Disease Control (CDC), food-borne illnesses in the US cause about 300,000 cases where people have to be taken to hospital and 5,000 deaths every year in the United States.

Food recalls cost food companies dearly each year in loss of production and also loss of reputation. In some cases, the loss to the company can be so great that it is forced out of business.

Recalls Cost US $7 Billion

In the US, the economy haemorrhages about $7 billion every year due to these recalls and the foodborne illnesses.

The recall costs, which include getting food off shelves, handling lawsuits, revamping plants and repairing public relations, can be huge for companies.

On top of this, the company has to rebuild its reputation and rebuild sales.

In the last quarter of 2011, food recalls across the United States increased by 50 per cent and affected more than 80 per cent more companies and plants compared to the previous three-month period, according to the quarterly ExpertRecall index published by Stericycle ExpertRecall.

The most common pathogens that lead to food recalls around the world are Salmonella, Campylobacter, E. coli and Listeria.

In August last year, a Salmonella outbreak caused Cargill to voluntarily recall 36 million pounds of ground turkey. Cargill initiated the recall after learning that the US Centers for Disease Control had detected an outbreak of Salmonella-related illnesses.

Listeria: Particular Problem for Poultry Processors

Listeria has been discovered to be a particular problem in poultry processing and further processing plants.

The most disruptive recalls in the last decade have been at Maple Leaf Foods in Canada and at Pilgrims' Pride in the US although more recently, there have been serious foodborne illness outbreaks related to Listeria in other products including cantaloupe melons from a California farm and bean sprouts distributed in Germany.

The outbreak at Maple Leaf Foods' Bartor Road Plant led to the recall of 191 products in 2008. The outbreak led to severe illness and loss of life among those who had eaten the products.

Maple Leaf was forced to close the plant for a period and it forced the introduction of a completely new protocol for handling product.

The measures the company had to take includes taking more than 1,000 swabs for testing, disassembling and sanitising all the company's slicing machines and retraining staff in food safety.

Recent studies in the US have shown that poultry processing plants can be reservoirs for Listeria in particular.

Research by the USDA Agricultural Research Service at the Russell Research Center in Georgia looked at the potential sources of Listeria monocytogenes in a newly built chicken further processing plant.

To discover the colonisation of Listeria in the plant, the research team took samples from floor drains after a production shift and after wash down over 21 months.

By testing a brand-new commercial cooking facility before and after processing began, the research team was able to track sources of contamination.

The researchers, led by ARS microbiologist Mark Berrang of the Bacterial Epidemiology and Antimicrobial Resistance Research Unit at the agency's Richard B. Russell Research Center in Athens, Georgia, found that there was no Listeria contamination in the plant before production was started.

However, the team had pinpointed potential sources of L. monocytogenes to the plant including incoming raw meat, incoming fresh air and personnel. Nearby environment and community samples were also examined.

All L. monocytogenes detected were subjected to DNA sequence-based subtyping.

Raw Poultry Meat Source of Listeria in Processing Plants

Potential sources of L. monocytogenes were tested by taking samples of soil and water around and near the facility exterior, and by testing heavily travelled floor surfaces following personnel shift changes. Samples were also collected and tested from incoming air from air vent filters and from monthly swabs of incoming raw meat.

Floor drains in the facility were sampled approximately monthly to determine at what point the plant would become colonised with the bacteria. Within four months of operation, L. monocytogenes was detected in floor drains, indicating that the organism had been introduced from some outside source.

No L. monocytogenes was recovered from any floor samples in the plant entryways, locker room or cafeteria. Likewise, the organism was not detected on air vent filters during the survey. The only tested source found to be consistently positive for L. monocytogenes was incoming raw poultry meat.

Quality assurance in the test plant was exceptional and included an extensive proactive sampling plan to assure food safety. L. monocytogenes can become prevalent in food processing environments; sanitation, biosafety and product sampling protocols are in place in these facilities to prevent shipping contaminated product.

One subtype of L. monocytogenes was detected in a natural stream near the plant. However, this subtype was never detected inside the plant.

Eight subtypes of L. monocytogenes were detected in raw meat staged for further processing; one of the raw meat subtypes was indistinguishable from a persistent drain subtype recovered after cleaning on eight occasions in four different drains.

The research finding concluded that poultry further processing plants are likely to become colonised with L. monocytogenes and that the raw product is an important source of the organism to the plant.

May 2012