Blood borne pathogens
Diseases carried in the blood, such as HIV and Hepatitis C (both currently effectively fatal and incurable), can be passed via blood contact — the blood of a carrier is, in effect, an "infection potion." If tattoo machines, tattoo inks, tattoo needles, piercing needles, piercing jewelry, piercing tools, etc. are contaminated with the blood of either the artist or a previous customer, these diseases can be passed from person to person. Piercers and tattoo artists must educate themselves as to how these diseases are passed. Put simply, universal precautions must be followed, and anything involved in the penetration of the skin, even on a secondary level, needs to be either disposed of or adequately sterilized between customers. This includes counter tops and anything else that may have become contaminated.
Direct contact can occur if a piercer pierces you and then needlesticks him or herself accidentally (they'll be affected, but not you). It can also happen if a tattoo artist has been freshly tattooed on their hands and are tattooing you (the material of the glove can break down within ten minutes of tattooing). It can also happen if two people are play piercing and their blood comes in contact (for example, if a person with blood on their finger from their own wound pierces another person). To put it simply, don't put yourself in contact with the blood of anyone whom you wouldn't be 100% comfortable having unprotected sex with.
Also known as "cross contamination," indirect contact is when something bloody touches an object, which then touches another object, which then touches another person's blood. Each step along the chain is potentially contaminated, so every object touched could give you the diseases in the source blood. For example:
- Person One's Blood →
- Needle →
- Gloved hand →
- Tool drawer
- (Next client arrives)
- Tool drawer →
- Glove →
- Needle →
- Person Two's Blood
- Needle →
- Glove →
- Gloved hand →
- Needle →
That should illustrate why piercers change their gloves at certain steps during a procedure! It should also illustrate that if you go to a careless studio, getting one piercing could suddenly force you into what amounts to an unprotected orgy with thousands of people.