Drinking water hygiene as an additional line of defence against avian influenza

When avian influenza (Highly Pathogenic Avian Influenza, HPAI), such as the H5N1 subtype, emerges, the focus in the poultry sector is usually on visible biosecurity measures. These include hygiene barriers, visitor registration, transport restrictions and preventing contact with wild birds.

These measures are important. At the same time, there is a less visible factor that flows through the entire barn every day: the drinking water system.

Water is often seen as a standard amenity, but in reality it can also play a role in the transport of microorganisms throughout a barn’s pipework network. That is why the drinking water system deserves attention as part of a well-thought-out hygiene strategy.

Water as a transport route for microorganisms

In a poultry house, a large volume of water flows through tanks, pipes and drinking nipples every day. If this system becomes contaminated with organic matter, the water can act as a carrier. It then transports not only water, but potentially also bacteria, fungi and viral particles throughout the entire drinking water system.

It is known that influenza A viruses, which include avian influenza, can remain infectious in aqueous environments under certain conditions. Factors such as temperature, pH and organic load play an important role in this (Brown et al., 2009).

This does not mean that drinking water is automatically a source of infection. However, it does underline that water hygiene can be a relevant factor in limiting microbial load within the livestock housing environment.

Biofilm: the hidden challenge in drinking water pipes

A common challenge in drinking water systems is biofilm formation.

Micro-organisms can attach themselves to the inner walls of pipes and form a protective structure there. This structure is known as a biofilm.

Biofilm can:

• Protect microorganisms from external influences
• Retain organic materialMake pipes more difficult to clean

As a result, biofilm can contribute to the persistence of microorganisms in water systems (Flemming & Wingender, 2010).

For poultry farms seeking to make structural improvements to their hygiene standards, controlling biofilm is therefore a key component of drinking water management.

Continuous disinfection of drinking water

The Watter system produces an HOCl-based disinfectant solution on site.

Hypochlorous acid (HOCl) is a powerful disinfectant. Unlike many traditional chlorine solutions, it can penetrate the protective outer layer of bacteria and viruses more easily. This enables it to rapidly inactivate microorganisms (Block, 2001).

By continuously and automatically adding this solution to the drinking water in low concentrations, existing biofilm can be gradually broken down and new growth can be limited.

The virucidal effect of Watter

In the context of avian influenza, it is important to note that disinfectants can inactivate not only bacteria but also viruses.

The solution produced by the Watter system has been tested in accordance with European standards for disinfection, including:

• EN 1276 – bactericidal efficacy
• EN 1650 – efficacy against yeasts and moulds
• EN 14476 – virucidal efficacy

The EN 14476 test is a standardised European method for demonstrating the virucidal activity of disinfectants (European Committee for Standardization, 2019).

This means that, under the test conditions of this standard, the solution is capable of inactivating viruses. In practice, this can help to reduce microbial load within the drinking water system as part of a broader hygiene strategy.

Producing in-house = not vulnerable to price rises

A key feature of the system is that the disinfectant solution is produced on-site.

The raw materials required consist solely of:

• Water
• Salt
• Electricity

This makes companies less reliant on external suppliers of conventional, bottled disinfectants.

Prices can rise, particularly during periods of heightened infection risk, when demand for hygiene products increases sharply. Producing these products in-house therefore provides greater certainty regarding availability and costs.

Drinking water disinfection as part of a biosecurity plan

No single measure can completely prevent avian influenza. Effective biosecurity always involves a combination of measures, including:

• Stable hygiene
• Visitor management
• Monitoring
• Infrastructure
• Water management

Drinking water hygiene is often underestimated as a risk in this context.

By raising hygiene standards, the Watter system can provide an additional layer of defence within a poultry farm’s overall biosecurity strategy.

References

• Block, S. S. (2001).
  Disinfection, Sterilization, and Preservation (5th ed.). Lippincott Williams & Wilkins.
• Brown, J. D., Goekjian, G., Poulson, R., Valeika, S., & Stallknecht, D. E. (2009).
  Avian influenza virus in water: Infectivity is dependent on pH, salinity and temperature.
• EN 14476: Chemical disinfectants and antiseptics – Quantitative suspension test for the evaluation of virucidal activity.
• Flemming, H.-C., & Wingender, J. (2010)
  The biofilm matrix. Nature Reviews Microbiology, 8, 623–633.