Ok, what about "AIDS?"
It takes 10 microliters (equivalent to 10 drops) of blood and deep intramuscular puncture to transmit the HIV. Since tattoo needles are solid core (not hollow like a syringe) and the tattoo is applied just beneath the skin's surface, it is highly unlikely.
There has never been a documented case of AIDS transmission from tattooing.
The Alliance of Professional Tattooists Inc was established in 1992 as a nonprofit educational organization. Its primary concern is the continuing education of artists and their apprentices in the practice of infection control as well as the establishment and implementation of professional standards and practices with regard to health and safety within the tattoo industry.
Over 700 tattoo artists have successfully completed the "Preventing Disease Transmission in Tattooing" course taught by Dr. Kris Sperry, a forensic pathologist from Atlanta, Georgia. This course is an intense, in-depth study of infection control, the facts and cycles of disease transmission, and the practical application of proper standards of practice to eliminate risks.
In addition, the APT makes available educational information and materials to the general public, press, medical authorities, and government agencies to clarify issues relating to the prevention of disease transmission within the tattoo environment.
It's the goal of the APT to educate both artists and clients alike that when proper standards are learned and applied, tattooing is a safe expression of art.