What is Avian Influenza?

Avian influenza (AI) is a highly contagious, notifiable disease. It can be easily spread between flocks through contact with infected birds or contaminated surfaces. AI viruses can be classified as either low pathogenic avian influenza (LPAI) or highly pathogenic avian influenza (HPAI). Poultry species infected with LPAI demonstrate no symptoms or mild clinical signs, which means it often goes undetected. Infection with HPAI however can result in severe disease and mortality rates which can reach 90% to 100% within just 48 hours. Both LPAI and HPAI viruses can spread rapidly through poultry flocks and can result in huge economic losses due to culling if disease is detected.

 Minimising the Spread of AI

Regular cleaning and a high level of biosecurity are the main ways to ensure AI does not infect an entire farm or production unit. Biosecurity is the first line of defence against viral challenges and an integrated approach is needed to ensure a high level of biosecurity. This includes boot, wheel and lorry washing, as well as effective drying of equipment following disinfection to ensure that no live virus is transported onto the site. Staff and visitors can also pose a threat in introducing a virus to the farm. Cleaning poultry housing thoroughly and ensuring optimum feed and water hygiene are also fundamental control measures in preventing the spread of AI between poultry species, within the flock and in the environment. 


Credence consists of troclosene (sodium dichloroisocyanurate, known as NaDCC), which is a stabilised form of chlorine and is quick to act on contaminants. It is highly effective against bacteria, viruses, fungi and protozoa, providing a broad spectrum, fast acting sanitiser and water steriliser.

Credence has long persistency in water and is highly cost effective, making it ideal for use in biosecurity programmes. It is also less toxic and corrosive when compared to other available disinfectants. The form of chlorine within Credence is highly stable and therefore very different to other disinfectants commonly used on farm, at home and in veterinary surgeries. As a result of this, it has a low volatility when in solution and therefore emits minimal odour.

Ideal for use as a surface disinfectant in preventing the spread of bacteria and viruses, the efficacy of Credence against Avian Influenza has been recognised. It has been determined, following the undertaking of a quantitative suspension test to evaluate the virucidal activity of chemical disinfectants, that when used at a concentration of 333 ppm available chlorine*, Credence is effective for infection prevention measures against Avian Influenza (MAFF, UK).

*Equivalent to 1 tablet/15L water