Biosecurity Guide for Avian Flu

• Avian Influenza – The Bottom Line
• How Does Avian Flu spread?
• 7 Steps of Cleaning and Disinfection
• Disinfectant Application -Tips and Tricks
• Disinfecting Against the Avian Influenza Virus Using Prevail® Concentrate
• How to Disinfect Livestock Trailers Using Prevail®

Avian Influenza – The Bottom Line

Avian influenza (AI), also known as “bird flu”, presents a significant threat to poultry producers worldwide. AI can be caused by multiple different strains of Avian Influenza A virus, which may be classified as highly pathogenic (HPAI) or low pathogenic (LPAI) based on the severity of disease that the virus causes[1,2].

While LPAI often causes few or no symptoms, HPAI outbreaks can be devastating to poultry producers, causing widespread destruction to flocks and major business impacts as a result[1,2]. As such, rigorous biosecurity is critical to protect poultry and people from the health and economic consequences that an AI outbreak would bring.

Preventing the Spread of Avian Flu

North America specifically has suffered a considerable number of positive cases in both commercial and non-commercial poultry flocks. The resulting economic loss has been devastating to producers and the industry at large. Poultry producers must stay vigilant at all times due to the fact that there may or may not be any clinical signs of infection. Therefore it is in the best interest of all poultry producers that the risks of AI are well known and procedures are implemented that limit the chances of the disease developing or spreading.

As there is no treatment currently available for birds infected with HPAI, prevention is the only protective measure in place. If a facility were to report a case of the disease, the only option would involve depopulating all the birds exposed to the virus. In addition, a reported case would trigger severe limitations on the movement and export of poultry and poultry products, creating a ripple effect throughout the industry with lasting economic consequences. For these reasons, good biosecurity is vital to prevent the entry and spread of HPAI. Preventing the spread of HPAI requires an understanding of how the virus is transmitted to commercial poultry flocks.

How does Avian Flu Spread?

4 key modes of transmission:

Wild Birds and Waterfowl
Direct contact (touching) between an infected bird and a healthy bird can introduce the virus to a new host. Wild birds and waterfowl have been identified as a possible vector for the transmission of AI to domestic flocks.

Fomite Transmission
‘Fomites’ are surfaces that can harbour infectious pathogens, which could be picked up by an uninfected individual. On a farm setting, this can include contaminated equipment, housing surfaces, transport vehicles or even clothing or footwear worn by workers.

Contaminated Feed
AIV has been demonstrated to be able to survive in poultry feed for extended periods of time, which can be consumed by healthy birds.

Airborne Transmission
While there has been some limited evidence of AI being spread via airborne transmission for short distances, the general consensus is that the risk of airborne transmission over long distances is negligible. [3]

Most of these modes of viral transmission can be prevented to a great extent by good biosecurity practices. Biosecurity encompasses many different types of strategies, but in the context of AI includes:

• Ensuring that wild birds are prevented from entering poultry houses
• Feed is sourced from reputable suppliers
• Ensuring that surfaces are thoroughly cleaned and disinfected between flocks.

In addition, ensuring that farm staff or visitors are not bringing any contaminated materials, whether through food, clothing, or equipment, is essential. This means:

• Thoroughly cleaning and disinfecting contaminated items (including clothing and footwear) before they are introduced into a poultry facility
• Making use of a Danish entry system for visitors such as a Biosecurity Boot Bench
• Persons entering the production area of a poultry facility should either change, cover or disinfect their footwear prior to entry.

When implemented correctly, a rigorous biosecurity protocol acts as the first line of defense in preventing the entry and spread of this virus throughout poultry operations.

7 Steps of Cleaning and Disinfection

1. Dry Cleaning and Removal of Gross Soils
   • The first step is to remove any major dirt and debris to prepare for cleaning and disinfection. This means removing any items from the area that can be removed, and using a scraper, shovel, or brush to remove feces, dirt, feedstuffs, and bedding. This step must occur in order for cleaning and disinfection to be successful.
2. Soaking of Surfaces
   • This step involves soaking the surface with water and a detergent. This will help suspend soil residues in the wash solution, and dislodge tough, hydrophobic soils such as feces and biological fluids. Ideally, the detergent should be applied from the bottom to the top of the surface, to avoid runoff and to be able to clearly see where the detergent has been applied.
   • Some disinfectants, such as Prevail®, contain detergents built into their formulation. In this case, the disinfectant may be used at a higher dilution to perform the pre-soak step.
3. High Pressure Cleaning
   • Once the detergent has been allowed to soak on the surface and dislodge soil residues, the next step is to remove these soils by rinsing with water at a high pressure (750 – 1800 psi).
   • This should ideally be done with hot water to aid the cleaning process, and should be applied in the opposite direction as the detergent (from top to bottom).
4. Drying Prior to Disinfection
   • Once the surface has been rinsed, it should ideally be allowed to dry prior to the disinfection step. There are two reasons for this:
     • Water left behind on the surface can dilute the disinfectant, resulting in a weaker solution than what may be required to successfully kill pathogens.
     • If there is any detergent left after the rinse step, this could potentially interact with the disinfectant and interfere with its efficacy.
   • If a full drying step is not possible, this can be addressed by selecting a detergent with some biocidal activity, or in using a disinfectant that is highly effective against a broad spectrum of organisms in a rapid contact time, as this product would unlikely be inactivated by low levels of residual water on a surface. If the same product is used for the pre-soak and disinfection step, this can also prevent any interactions between different chemicals.
5. Disinfection
   • This is the process of applying a Health Canada registered disinfectant to kill pathogens of concern. This is done by evenly applying the chemical to the surface, and letting the solution remain wet for the required contact time, which is specified on the product label.
   • There are a few factors to consider when selecting a disinfectant. The ideal disinfectant is non-toxic and non-irritating to people and animals, and is also non-corrosive to equipment. In addition, it is ideally environmentally friendly, as runoff will ultimately end up in the environment or in wastewater treatment systems that depend on microflora. However, the disinfectant should have strong efficacy against a wide range of pathogens, and do so in a realistic contact time. It should also be able to be applied as a foam, to improve surface coverage.
6. Drying Prior to Restocking
   • The purpose of this step is to protect the animals from exposure to harmful chemical residue. If a non-toxic and non-irritating disinfectant is used, as recommended in the previous step, then this drying step is not required.
7. Surface Sampling
   • Surface sampling can be performed to validate the efficacy of the cleaning and disinfection process, by detecting the presence of dirt or pathogens remaining in the surface. There are several methods available:
   • ATP bioluminescence measures the efficiency of cleanliness by assessing the bioburden (organic matter) on a surface.
   • Agar contact plates or swab sampling provide a more in-depth analysis of the types of organisms, but are more time consuming.
   • PCR testing provides a snapshot of the amount of viral material on a surface, but does not distinguish between infective and “dead” inactivated virus.

Disinfectant Application – Tips and Tricks

Perhaps even more important than choosing the right disinfectant product is pairing it with the appropriate method of application.

• For disinfecting large areas, a power washing system with a foaming gun will help cover surfaces rapidly. If using a concentrated disinfectant product, an automated dilution system can help eliminate human error from the process.
• Selecting a disinfectant that will produce foam when applied at pressure will allow for easy validation that the surface is covered evenly. It will also allow for increased surface coverage with less product, resulting in cost and resource savings.
• Ensure that footwear is either changed, covered or are disinfected with Prevail® before entering the Restricted Access Zone or Production Area. The use of a Biosecurity Boot Bench as part of a Danish Entry System is recommended.

• For smaller surfaces throughout production facilities or even in the cab of transport vehicles, pre-moistened wipes can be used to easily apply the right volume of disinfectant, and physically remove dirt and debris in the process.
• Ensure all equipment and materials are disinfected prior to entry into the poultry facility. This includes tools, brooms, shovels, and loader tractors.
• Implement an effective pest control program. Ensure all cracks or openings in the building are sealed so that pests and wild birds can not enter facility.
• Make sure all staff and visitors are informed and trained on your facility’s biosecurity protocols.

For information on preventing the entry and spread of AI contact Ethoguard 226-523-5969.