A study in the New England Journal of Medicine that investigates the recent outbreak of M. chelonae infections among newly tattooed individuals has linked the source of the infection to the ink used.
A group of researchers from several institutions in Rochester, NY, in conjunction with the CDC and the FDA, began investigating the cases — 19 infections in all — in January 2012. The first M. chelonae infection occurred in an otherwise healthy 20-year-old man who had a history of receiving tattoos without any complications who had developed a persistent granulomatous rash after getting his latest tattoo. According to the NEJM article, investigators from the Department of Public Health found that similar reactions had developed in other people who had recently been tattooed by the same artist in the same parlor. When investigators interviewed the artist, they discovered he had been using a new, hand-blended, diluted black ink (gray wash) that contained pigment, distilled water, witch hazel and glycerin. The artist told investigators that the manufacturer had diluted the black ink with distilled water before it was packaged and shipped, and had been prepackaged in three dilution strengths per set: a 30%, or light, wash (ie, greatest dilution); a 60%, or medium, wash (ie, intermediate dilution); and a 90%, or dark, wash (ie, least dilution). The product labeling had no lot number or other unique manufacturing identification and the artist had stopped using the mixture.
The investigation determined that the tattoo artist had followed the proper protocols to avoid infection, including sterile instruments, clean, disposable gloves, single-use ink containers and appropriate aftercare instructions. Importantly, no dilution or mixing of inks at the parlor occurred, according to the NEJM article, and the artist avoided contamination of ink from tap water.
After evaluation, the researchers determined that the pre-mixed gray ink was responsible for the M. chelonae infections. The CDC issued a nationwide alert about the ink and the manufacturer voluntarily recalled the ink.
According to the researchers, previous studies have shown that unopened stock bottles of tattoo ink may contain bacteria that are pathogenic in humans despite claims of sterility, although not testing specifically for mycobacteria.
They conclude: “In the current study, mycobacteria were detected in both opened and unopened bottles of ink. These findings suggest that mycobacteria may be another potential contaminant, especially if the ink is diluted with non-sterile water before distribution.”
