Strategies for the Prevention and Control of Infectious Diseases (including Highly Pathogenic Avian Influenza) in Eastern Africa
http://www.fao.org/3/al838e/al838e.pdf
Biosecurity principles include simple procedures and practices which when applied prevent entry of disease agents into a farm or the exit of the disease agent from infected premises. This may involve protocols, practices, and manouvres to ensure that clean flocks remain free from entry of disease agents and that disease agents remain confined in infected flocks and do not spread to other premises. It includes controlling movement of stock, persons, equipment and products into the clean farm and out of infected premises; and finally it involves methods that enable farm to remain in a state of sustained cleanliness, referred to as sanitation.