Our skin and immune system protect us from infectious diseases. Infectious diseases are transmitted primarily in two main ways: through contact and breathing
When touching a carrier of infection, microorganisms can enter the body of a healthy person through a gap or cut in the skin, through the eyes, mouth, or sexually. The most serious risk is direct contact with the blood or secretions of an infected person, especially if you have open wounds on your skin. The infection can also be transmitted through objects contaminated with the blood or secretions of an infected person (indirect contact). Although the skin protects us from diseases transmitted through contact, a sharp object can damage the skin and thus introduce infection into the body. Great care should always be taken when handling items that may be contaminated. You should also avoid contact of unprotected hands with blood unless absolutely necessary.
The infection can also be acquired by inhaling microorganisms released into the air by the sneezing of a person with the flu. But the risk of getting an infection in this way when providing first aid is no greater than during normal communication with family members, friends or while in a public place.