"An ounce of prevention is worth a pound of cure"
. . . . . . Benjamin Franklin
Biosecurity refers to management practices put in place on your farm to prevent the introduction to and/or spread of disease in your poultry flock. Biosecurity is the cheapest, most effective means of disease control.
It is important to be able to identify signs of a health problem in your flock, and take immediate action. It is important to keep your poultry house and equipment clean. If you borrow equipment from others it is very important that you clean and disinfect the equipment before using them with your flock. The other flock may look healthy but could be carriers of a disease, which can occur if they have been sick and recovered.
Keep poultry diseases away (USDA/APHIS)
The role of humans in poultry disease outbreaks (University of Florida)