Bio-security: practical tips to minimize the human risk of contamination

Bio-security: practical tips to minimize the human risk of contamination

All poultry operations are under a constant threat from the ever-present enemy of disease and infection. It is imperative in all operations that we teach our staff how to reduce potential risks as far as possible. In this article, I explain how diseases are transmitted and how you can reduce the risk of human transmission.

By Jason Cormick, Petersime Hatchery Development Specialist

How are diseases transmitted?

One of the greatest risks to any poultry operation is the risk of contamination of disease. This not only depletes production, but can also damage the reputation of the company. The transmission of disease can be spread in two ways. 

1. Firstly, disease can be spread vertically when bacteria such as salmonella and mycoplasma, or viruses like avian influenza etc., are spread already in the oviduct of the hen laying the egg. This means that the developing embryo will already be infected during development.


2. The second type of infection is through horizontal transmission which can be from bacteria spread by a vector, which could be anything from airborne dust particles, animals frequenting livestock (beetles, rats, birds etc.), equipment that moves from infected stock to clean stock or the action of people transmitting disease to your stock. It is this ‘human risk’ we will cover in this article.


The three main sources of infections: mycoplasma, salmonella and avian influenza


Mycoplasma is one of the main culprits of infections. It is a bacteria that can be transmitted both vertically and horizontally and which is able to survive for up to four days off its natural host. Therefore it has huge potential to jump from one location to another. A thorough ‘showering in’ regime (staff that enters should take a shower) and change of clothing should greatly reduce the risk from mycoplasma being brought in by personnel.


Salmonella is another prime issue in poultry. This can also be spread both vertically and horizontally, but can also easily infect people. Breeding stock operations should have routine testing of staff and visitors.

Avian influenza 

One of the biggest threats today to our operations comes from avian influenza, which has managed to spread across the world. There are many strains of avian influenza, but these are generally split into two main categories: 

1. low pathogenic

2. high pathogenic

Low pathogenic strains can result in low impact on stock. However, strains of H5 and H7 have the potential to mutate from low pathogenic to high pathogenic which can wipe houses and can also infect other species including humans coming into contact with it. Avian influenza can also be transmitted both vertically and horizontally.
These are just three potential risks but there are many others too numerous to go into during this discussion.

Practical tips to minimize the human risk of contamination

Don’ts for poultry workers

There are some basic rules that all poultry workers should adhere to: poultry workers should…

1. not own or keep any Avian species

2. not come into contact with backyard chickens

3. avoid live/wet markets

4. not have second jobs that involve avian species

5. be discouraged from wild bird hunting.

All employees of a poultry operation should have an understanding of bio-security, as it is not only production workers that could be vectors for disease entering an operation. 

Dos and don’ts for visitors

Likewise, any visitors are potential risks to the operation. When it comes to external visitors, the golden rule is: ‘if they do not...

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