LISTERIA OUTBREAKS & THE CRITICAL ROLE OF DRAINAGE
(Posted on 5 April 2018)

The importance of optimising hygiene in South Africa’s food and beverage manufacturing facilities has been underlined following what has become the world’s largest outbreak of listeria. Food and beverage manufacturers are understandably looking to ensure the hygienic performance of their factories is optimised and that the risks of such an outbreak occurring again are reduced. Yet whether you’re an international brewer or a manufacturer of ready-meals for a major supermarket, you may be overlooking one of the most important areas when it comes to your factory’s hygienic performance: drainage. Here with talk to Marco Cassol, Managing Director of ACO Building Drainage in South Africa to learn more about the critical role drainage has to play.

1. Why does drainage have such a big impact on hygiene?

Although drainage is often overlooked by specifiers and factory operators, many independent studies show that a significant amount of bacteria can be present in drainage. In fact, 70 per cent of positive listeria screens are found in drainage so it’s critical that your drainage system is designed in a way that minimizes the risk of bacteria being harbored within it. Bacteria require water to grow so the residual amounts of water contained within drainage or on a factory floor present a potential food contamination risk. Bacteria can also travel through a drainage system and, as a result, contaminate different areas of a food processing facility. Therefor the specification of hygienically designed drainage should be a priority for any food and beverage manufacturer, particularly with regard to the prevention of listeria outbreaks.

2. Why is listeria so hard to fight?

Research conducted by the University of Southern Denmark’s Department of Biochemistry and Molecular Biology in 2015 identified the three factors that make listeria so hard to fight: Its ability to react instantly to its surroundings and environment, and deal with threats; its ability to hide from the body’s immune system by producing a special protein that makes it very hard to detect, and its ability to defend its own cells from attack by threats including antibiotics. The University’s research underlines why it’s so important to take every possible step to prevent an outbreak of listeria and why it’s so important to ensure your drainage is hygienically engineered to the highest possible standards.

3. How should food and beverage manufacturers specify drainage?

Drainage should be hygienically designed in accordance with best practice design principles and the latest research regarding product performance and specification. Importantly, food and beverage manufacturers should take an evidence-led approach to drainage specification. Ask yourself, how many claims made by potential suppliers are based on proven facts?

At ACO a commitment to evidence-led product development is a core part of our overall business strategy and the ‘Hygiene First’ approach we apply to hygiene-sensitive applications. It is important to us that our product designs and the advice we give to our clients is based on the findings of robust academic research that not only enables us to improve the drainage systems we provide but also gives our clients the additional knowledge they need to optimise food safety and operational costs.

For example, ACO’s range of hygienically designed drainage products embody the best practice design principles of EHEDG. EHEDG (The European Hygienic Engineering & Design Group) is a global not-for-profit organization whose remit is to improve hygienic engineering and design standards in all aspects of food manufacture. It comprises a group of equipment manufacturers, research institutes, academic bodies and food manufacturers which work collaboratively to improve hygienic engineering and design standards, and is a leading source of independent guidance on a range of topics.

In the last year alone, ACO has also commissioned two significant R&D projects to help our customers improve the hygienic performance of their drainage. The first study, commissioned with Fraunhofer IVV Dresden – part of the renowned Fraunhofer Institute, evaluated the impact of hygienic design on drainage performance and found that ACO’s hygienically design channel could be fully cleaned in less than 10 minutes whereas a standard drainage channel could not be cleaned even after more than three hours of cleaning. The second study, undertaken with flooring experts, SIKA, identified the best floor-drainage connections for hygiene-critical environments and provides clear evidence-led guidance regarding floor-drainage specification.

As a company, ACO is committed to taking an evidence led approach to product development, drainage system design and specification, and we would strongly advise food and beverage manufacturers to do the same.

4. What are the key design features drainage specifiers should look for?

When it comes to drainage design, there are a number of key product design features that EHEDG and our own research have identified as critical to hygiene.

For example, it’s important to ensure channels have a completely drainable dry sump with a one degree slope to prevent the build-up of stagnant water, smells, microbial growth and potential chemical hazards; a deep drawn body with smooth contours which eliminates crevices that can harbor bacteria; a completely smooth stainless steel surface; continuous welding of joints, and radiused corners with a minimum radius of 3mm.

For optimum hygienic performance, ACO’s slip-resistant grates have no mesh but are fully cast or welded, and every joint is curved to make removal and cleaning an easy and safe process without the need for inappropriate power washing.

ACO’s foul air trap (FAT) also incorporates a number of design features to further reduce bacteria harbourage potential - all edges of the new FAT are rounded, connections have been minimised and there are no overlapping joints.

Our team can provide more detailed guidance on the key design features to look for in different drainage products and we would also advise you to review EHEDG Document 44.

5. What else is important?

Working with a drainage supplier which has a track record in the design and manufacture of hygienically engineered drainage systems for the food and beverage sector is invaluable. Drainage companies which specialize in the development of hygienically engineered solutions for the food and beverage sector should have world-class manufacturing facilities which will produce consistent high quality drainage products.

Importantly, they should also have in-house technical design teams who can provide the required level of specification advice and guidance. Working with experts such as these is arguably one of the simplest ways to ensure that every aspect of your drainage system has been considered and the drainage system you end up with can meet current and future needs when its comes to hygiene, employee health and safety, and operational costs.

For more information about ACO’s range of hygienically designed products or to talk with a member of the ACO team about optimising the performance of your drainage, call 011 8243525

Listeria´s secret weapons

Listeria´s secret weapons: Awareness, adaptability & camouflage


"At ACO, we not only invest in research into the ‘cleanability’ of drainage products but we also keep a close eye on the very latest research being conducted by academic organisations throughout the world. Here, we highlight the key findings of a report which explains why listeria is so hard to fight."


Last summer in Denmark alone, no less than 28 people were infected with listeria and 13 of those died. The outbreak underlines how harmful and potentially deadly this bacterium can be and we were interested to learn about new research undertaken to establish why listeria is so resilient.

Conducted by Associate Professor Birgitte Kallipolitis PHD and her colleagues from the Department of Biochemistry and Molecular Biology at the University of Southern Denmark, the research tested how listeria reacts when exposed to a number of substances that can normally fight pathogenic bacteria.

This is what the Associate Professor and her team discovered...

1. Listeria is constantly aware of its surroundings and it reacts quickly

In fact, listeria reacts instantly to changes in its surroundings and environment, and it has a number of strategies for dealing with threats.

2. It’s an expert at “not attracting unwanted attention from the body’s immune system”

Listeria has to produce special proteins to successfully infect the cells in our body but it has become an expert at doing this without producing so many of these protein cells that our immune system can detect their presence. Researchers found that listeria produces ‘RNA molecules’ which enable it to adjust the amount of each protein it produces so it can infect someone and sneak past their immune system!

3. Listeria actively protects its own cell walls from infection

The RNA molecules produced by listeria protect its own cells from attack by detecting any threats including the presence of antibiotics. In fact, RNA molecule production is only triggered when listeria is exposed to a threat. This response mechanism enables listeria to adapt so effectively and, if it senses an attack, to quickly repair any cell damage. And this is a key factor determining its resilience.

This research underlines why it’s so important to take every possible step to prevent an outbreak of listeria and why it’s so important to ensure drainage – a key area in which bacteria can grow - is hygienically engineered to the highest possible standards.

Death toll in South Africa listeria outbreak jumps to 61
Death toll in South Africa listeria outbreak jumps to 61

JOHANNESBURG (Reuters) - The death toll from an outbreak of listeria in South Africa has jumped beyond 60 in the past month, health authorities said on Monday, adding they had closed a poultry abattoir where the bug that causes the disease had been detected.
Since monitoring of the outbreak began last January, 720 laboratory-confirmed cases of food poisoning due to the disease, also known as listeriosis, have been reported, the National Institute of Communicable Diseases (NICD) said. That was up from 557 in December, since when recorded deaths had risen to 61 from 36.

https://www.reuters.com/…/death-toll-in-south-africa-lister…

As one of the world’s leading commercial drainage specialists, ACO Group understands the critical role
that drainage plays in a successful commercial food preparation business. We appreciate that food safety, hygiene and cost control are all vital factors yet we also understand that for many, drainage is out of sight and therefore out of mind.
Food safety can be severely affected due to poor drainage and grease separation systems. ACO solutions are designed to effectively and safely drain away and handle process water. We design our products specifically to reduce the risk of food contamination.

Find out more about HygieneFirst at www.hygienefirst.com. ACO Systems SA are available to assist you with any further information you may require. We can be contacted on 011 8243525.