Since 2005, 74 countries have reported cases of African swine fever. With the highly contagious and deadly viral disease affecting both domestic and feral swine around the globe, efforts to prevent and control transmission of the emerging disease through biosecurity and good farming practices is critical, says Elien Claeys, product manager for CID Lines, an Ecolab company.

During her presentation, "How to control and prevent African swine fever?" at EuroTier last week in Hannover, Germany, Claeys detailed the three highest risk routes for transmission on farm and why proper hygiene is crucial for entrances, tools and equipment, and transportation.

"In general, the cleaning step is the most important step in the whole process. If you have an efficient cleaning, then we remove more than 90% of all the microorganisms present in our environment," says Claeys. "After the efficient cleaning step, we can go to an optimal disinfection step where we can reduce 99.9% of all the microorganisms."

To address specific disease challenges, Claeys says it is important to choose a product that works on all types of surfaces, with broad spectrum activity to kill bacteria, virus, spores and fungi. It should also be easy to use for the end user.

"It's good if you have different types of applications with only one product so that you can foam the product, spray the product, thermal fogging, cold fogging, for example," Claeys says. "The safety is very important as well, because when we talk about chemicals, so detergent and biocides are chemical substances, and there we need to take care of the environment."

Proper storage conditions are critical to guarantee the shelf life of the product. For accurate application, producers should always follow the correct concentration, contact time, temperature and pH levels.  

The final factor when choosing a cleaning or disinfection product is efficacy, Claeys says, and only authorized biocides should be used and applied. 

To properly clean and disinfect barns, Claeys advises starting with a dry cleaning to remove organic matter that is inside the barn. A pre-soaking step can also be an optional step, however not always needed. "It depends on the dirt load in the environment, but it can make the cleaning, and this disinfection process more efficient," Claeys says.

For the main cleaning of the premise, she recommends foam application as foam is visual.

"You see what you do, so you see that you cover all the different parts in the environment, and it gives a longer contact time," Claeys says. "If you have a nice foam quality, then it stays where you apply it, so it can work longer on that place, for sure on vertical walls, for example, and it can have a better working action."

After the contact time, a rinse with high pressure and clean water is crucial, otherwise the environment can become re-contaminated. The next step is to let it dry.

"That's quite an important one and sometimes forgotten in the field, but that's very important if you want to use the correct dilution for your disinfectant afterwards," Claeys says. "So, make sure that everything is dry before you disinfect and after the drying step, we go to the disinfection step where we apply foam, again, because of the visual aspect, you see what you disinfect and the better contact time and attachment on all kinds of surfaces."

In addition to practicing an all-in/all-out system, Claeys advises cleaning and disinfecting all areas of the building including the ceiling, walls, floor, pipelines, feeding troughs and drinking nipples.

A similar cleaning and disinfection process should be conducted for transport as well.

"First of all, when a truck comes on a farm site or the site of a slaughterhouse, you should have disinfection or a disinfection for wheels for sure, if there is a specific challenge. Then for the vehicle itself, you should do a dry cleaning before you start using water and detergent. Then the main cleaning with foam application," Claeys says "After the contact time, we do a rinsing with clean water and high pressure. We let it dry, and I know in practice, this is a difficult one, because most of the time truck drivers, don't have time to wait to let it dry, but that's the most optimal protocol."

After the drying time, disinfect again, including everything inside of the truck and outside of the truck, for best possible results.

"The cabin hygiene is important as well … for sure the contact points like pedals, steering wheel, the stairs to enter the cabin," Claeys says. "We should take care of that as well if we want to reduce the risk of transmission as much as possible."

Personal hygiene is an also important factor in transport hygiene as truck drivers are coming from one farm to another, from slaughterhouses, etc.

"If they carry the pathogen, they can spread it everywhere as well, so hand hygiene, boot hygiene, changing shoes or boots if they come on a premise is quite important as well," she says. "Changing clothes when they have to load animals, for example, are some critical points. I'm not saying that this is an easy one to practice, it's a very difficult one, but we should try to do our best."

When it comes to good cleaning and disinfection practices for transport, Claeys stresses the word "all."

"Because we need to make sure that we clean and disinfect all vehicles on the farm. It's not only the truck that is coming on your farm, but even the vehicles that are used on the farm itself, like a tractor," Claeys says.

In addition to cleaning and disinfecting all vehicles, all parts of the vehicle, such as the wheels, need to be attended to and washed. It's also essential that producers clean and disinfect their vehicles in all types of conditions, including increment weather conditions.

Producers should also limit movement on farm as much as possible, and that includes people.

"The fewer people coming on your farm, the lower the risk will be. Make sure that you have clean and dirty zones, clear instructions at the hygiene, and that they know what they have to do to reduce the transmission risk as much as possible," Claeys says.

A limited movement of animals and supplies will also lower the risk of introducing disease on farm.

When it comes to cleaning and disinfecting equipment, Claeys says procedures need to be specific for that farm, each barn and for the different kinds of equipment on farm.

"If a technician or a supplier is coming and they have their own materials, it can be a risk, so we need to make sure if we have the materials on the farm itself. Then it's always better to use the farm specific materials," Claeys says. "If you have more barns on one location, then it's important to have barn specific materials as well to make sure that you don't spread the disease on your own."

Claeys acknowledges equipment is not easy to clean and disinfect.

"If there is an African swine fever outbreak or another disease outbreak, then it can be important to dismantle equipment and to clean manually as well," she says. "We need to think about everything that can transmit pathogens."

While one might consider personal hygiene, such as hand or boot hygiene, the easiest protocol to enforce on farm, Claeys says it is often more difficult than one might think. She cites a recent study that was done on entrance hygiene in the poultry sector, where almost 80% of the people entering farms made mistakes with hand hygiene. With a red line on the floor to mark separation between clean and dirty lines, the study found almost 74% of the people not following protocol and crossing the red line without taking any measures. Even with a bench entry, 24% of people in the study went over the bench and did not follow standard operating procedures.

"You as a farmer can take the correct measures and can do everything to make sure that they follow the rules, but if you don't check it, then mistakes can still happen and it can be quite the high risk of having introduction of pathogens in your farm environment," Claeys says.

Limiting people coming on farm and practicing good entrance procedures are key, but it is also important to make sure there are clear instructions and photos so everyone entering the farm knows what to do, even if they don't speak the language.

"On entrance hygiene, make sure you have clear instructions that everyone knows what to do. On material, I think specific is the most important, so farm and barn specific materials to reduce the risk of introduction and spread as much as possible," Claeys says. "And on transport and also entrance hygiene, keep the movement on the farm as limited as possible if you want to prevent having introduction or spread of diseases on your farm."