HPAI infection from contaminated aerosolized wild bird feces unlikely

By Tim Nelson

Infection of poultry housed indoors with highly pathogenic avian influenza virus (HPAIv) through aerosolized contaminated wild bird feces is highly unlikely. In fact, researchers conclude that it is likely to occur only once every 455 years.¹

This estimate was averaged across different farm types, virus strains and wild bird species and has a fairly high level of uncertainty. However, even in a worst-case situation, the probability that HPAIv will be introduced via this method is still very low and can be expected only once every 17 years.

A risk assessment model was developed to estimate the risk of infection to indoor housed poultry in the Netherlands during bird flu season. Based on their findings, the researchers concluded that the risk of contamination via aerosolization of the virus from contaminated wild bird feces is very low.

This means that HPAIv introduction is more often due to fomites such as people or equipment, underscoring how crucial biosecurity is to keep the virus out.

 

HPAIv introduction is more often due to fomites such as people or equipment, underscoring how crucial biosecurity is to keep the virus out.

 

Biosecurity practices like barn dedicated clothing and footwear on entry are a necessity. The British Egg Industry Council has even instituted a requirement for all poultry barns to have a change of footwear to ‘indoor’ colour coded footwear when entering the biosecure area of the barn.²

In addition, accurate, complete records of trucks or people visiting the farm are key to knowing exactly who and what has been on the farm and inside the barn. Having this information is critical in the event that disease is suspected and trace out activities need to be undertaken.

With fall migration season for wild birds underway, poultry farmers in the US are calling for a vaccine to help protect their flocks.³ The infection of dairy herds in 14 states and 13 dairy and poultry farm workers this year puts flocks in the $67 billion U.S. poultry industry at an even higher risk of infection.

USDA Agriculture Secretary Tom Vilsack says that a vaccine isn’t on the horizon at least in the near term. In part, this is because of potential export barriers that could result. Imports of vaccinated poultry are banned by many countries because of concerns that the vaccine can mask the virus.

The absence of a vaccine and research pointing to introduction of HPAIv by people and equipment are two strong arguments for the diligent implementation of biosecurity.

When it comes to improving biosecurity compliance, factoring in the influence of personality is an important consideration. Research has also shown that real-time feedback like biosecurity breach alerts can be very effective for improving compliance. Learn more at www.farmhealthguardian.com.