Survey of studies on microbial contamination of marketed tattoo inks.

Tattooing became a popular phenomenon during the late twentieth century. Because the act of tattooing involves repeated injection of ink through the skin, a risk of contracting infections from contaminated tattooing equipment and ink and the surrounding environment exists. Progress has been made in infection control strategies; however, contraction of bacterial and viral infections from tattooing continues to occur. The risk of acquiring a tattoo-related infection largely depends on the hygiene conditions under which the tattoo is applied. Nevertheless, even when adequate hygiene and sanitation measures are taken, the inks themselves may contain infectious microorganisms that are able to survive under hostile conditions, such as in inks. The results of the few studies on the microbiological quality of unopened and opened tattoo inks are reported. Some authors' conclusions demonstrated that the current ink sterilisation systems show a low capability to inactivate microbial contamination in tattoo inks. At the moment, European Resolution ResAP2008-1 recommends that the ink be sterile and supplied in containers that maintain the sterility of the product until application. In light of the outcomes of published studies, at the moment, preservation of the microbial quality and safety of ink seems challenging and still difficult to reach.