The common cold, hepatitis, and measles are examples of what?

The common cold, hepatitis, and measles are classified as contagious diseases because they can be spread from one person to another through various means, such as direct contact, respiratory droplets, or contaminated surfaces. Understanding that these illnesses can easily be transmitted is crucial in nail technology, where hygiene and sanitation practices are imperative to prevent the spread of diseases.

While it is true that these illnesses are caused by specific pathogens—common cold and measles by viruses and hepatitis by a specific type of virus—they are primarily discussed within the context of their contagious nature in this question. The focus on their contagiousness emphasizes the need for practitioners to be aware of how these diseases spread and the importance of precautions in a salon environment to protect both clients and practitioners.