An infection occurs when microorganisms, such as bacteria, viruses, fungi, or yeast, invade and grow in the body. The body's immune system usually fights off infections, but some cancer treatments can weaken the immune system and make infections more likely.

Washing hands with soap and water can prevent the spread of germs that cause respiratory infections like colds and influenza, as well as gastrointestinal infections like salmonellosis.

Personal hygiene is important because it helps protect you and others from illness. It can also help reduce infectious diseases and premature death.

Personal protective equipment (PPE) is clothing or equipment that protects the wearer from injury or illness. It can protect against physical, electrical, chemical, and other hazards.

Clinical waste should be disposed of based on the infection risk it carries. It's classed as orange or light blue if it's low-risk or “laboratory” waste, or yellow if it carries a high-risk of infection. Healthcare settings should also make use of sharp boxes to safely collect used sharps.