What is the primary benefit of limiting access by non-staff visitors in animal colonies?

• A. Reducing disease introduction
• B. Reducing noise
• C. Increasing productivity
• D. Saving water

Answer: (A)

Limiting access by non-staff visitors primarily reduces disease introduction into animal colonies. People can carry pathogens on clothing, shoes, or equipment, and visitors may bring in contaminants from outside environments or other facilities. In a colony setting, even a single pathogenic introduction can spread through cages and surfaces, harming animal welfare and compromising experimental results. By restricting entry to trained personnel and enforcing proper biosafety practices—such as clean PPE, facility attire changes, and hand hygiene—the opportunity for pathogens to reach the colonies is greatly diminished. While other benefits like reduced noise or productivity might occur in different contexts, they do not directly address the risk of pathogen introduction through visitors.