While the pigments are subject to FDA monitoring, "no specific FDA regulatory requirement explicitly provides that tattoo inks must be sterile," they said.
Local jurisdictions can further regulate the practice of tattooing, with Los Angeles County cited by the CDC as an area where only sterile water is allowed for use with tattoo ink. This is not, however, uniform around the country.
In a perspective article published Wednesday in the New England Journal, Pamela LeBlanc of the FDA comments on this.
"Even if a person receives a tattoo at a tattoo parlor that maintains the highest standards of hygienic practice, there remains a risk of infection from the use of contaminated ink," she writes.
Kennedy had found the source of infection in this patient's case. Now, he and his colleagues focused on both treatment as well as source control.
"To make sure we weren't missing any cases, we contacted all 60 tattoo parlors in the county," Kennedy said. Luckily, none of the other parlors had been in contact with the contaminated ink. Kennedy then instructed nearby pathology labs to notify the county health department of any reported cases of this same infection. Due to these combined efforts, 19 cases of this atypical and difficult-to-treat skin infection were identified and treated, all from the same tattoo parlor. Kennedy and his team then turned the case over to the FDA.
"This case really put it on the radar of the FDA," Kennedy said.
And it was not a day too soon. CDC testing revealed that 1 out of 3 unopened bottles of the gray ink from the original distributor in Arizona contained mycobacterium chelonae. The CDC then issued a national alert for local health officials to be on the lookout for tattoo-related infections caused by this bacteria.
According to the CDC, 21 percent of adults in the U.S. report having at least one tattoo -- an increase from 14 percent in 2008. But with this burden of ink comes increased need for monitoring of safe practices and tattoo-related complications -- especially skin infections.
The CDC urges consumers to be vigilant about ensuring hygienic practices at their tattoo parlor of choice, and to alert health care providers at any sign of infection or rash.
Doctors, meanwhile, are urged to report suspected or confirmed cases to FDA's MedWatch program.
"The local dermatologist was the person to put this on our radar," said John Ricci, Senior Public Health Educator at the Monroe County Department of Health. "Without this initial case report to us, it would never have been detected."