The popularity of tattooing varies across different societies and at different time periods and at the time of writing, tattooing is at a relatively high level of popularity, not just in terms of the numbers of people seeking to have their skin adorned with permanent body art but also in terms of the sharing of images on social media and a bunch of reality television programs revealing the exploits within tattoo parlors. The proportion of the adult population with a tattoo in industrialized countries is between 10 and 20 percent.
Despite the popularity, tattooing introduces risks. The more established risks relate to skin damage (either in the form of skin damage or an allergic reaction); and less well-known risks relate to the reactions of red colored pigments with ultraviolet light, which can lead to the formation of melanomas.
An important risk relates to microbial contamination of the ink or with the practices involved in injecting ink into the skin.
How common are infections?
Infections from bacteria, fungi or viruses can theoretically be transmitted by the use of or contaminated ink, leading to surface infections of the skin. Based on published surveys, between 0.5 and 6 percent of the people with a tattoo experienced infectious complications after being tattooed.
Microbiological surveys indicate that tattoo inks vary in their quality by manufacturer and region. One review of a range of inks assessed the contamination rate at 10 percent of bottles (plus a typical contamination rate of 17 percent of previously used stock bottles).
Types of contaminants
In terms of the types of contamination, the bacterial species represented bacteria considered pathogenic in humans together with non‐pathogenic environmental bacteria. One area of concern is with the recovery of mycobacteria, a genus within which there are several pathogens (such as Mycobacterium chelonae), and where the species that form the genus are well-equipped to survive environments that other organisms would find inhospitable. The recovery of fungi was less common than bacteria. As well as the actual inks, another source of contamination has been shown to be the water used to dilute down inks.
Recent data (from 2020) showed that 52 percent of sampled inks were contaminated with microorganisms, up to 10 million cells per gram. This was consistent with previous survey results undertaken by the researchers (from the U.S. FDA’s National Center for Toxicological Research).
The recent review isolated and identified 25 bacterial strains. This included species of Bacillus (the majority of the organisms isolated). In addition, clinically relevant strains were also isolated. By clinically relevant, this means bacteria that are capable of causing human skin infections. What is also of interest is that the recovery of the organisms was very similar to previous inquiries by the same research team.
In most countries, there are no regulations requiring that tattoo inks be sterile. For the typical consumer the individual seeking to have a tattoo adorned to their skin only has a company’s or an artist’s assurance to go on. A related concern is with the control and labeling of inks. Around one-third of inks appear to be identifiable by brand name. Associated information indicating the content, sterility, risks or expiry date is often missing from the label.
As well as directly contaminated inks, microorganisms can also find their way into the body during the healing phase of a tattoo. Bacterial infections may include not only infections with Staphylococcus, Streptococcus, Pseudomonas, and Clostridium species (with the latter, tetanus is a risk factor) , but also infections with atypical bacteria and fungi.
Other infection risks
Further infection risks emerge from inappropriate hygiene measures in tattoo parlors and non-medical wound care.
Another cause of infection arises from tattoo needle penetration of the skin barrier. This may introduce a range of microorganisms into a person, particularly if the needle is not sterile or is shared among persons, resulting in a range of infections. In relation to instruments. Hence, all equipment should be sterilized in a certified autoclave before and after every use.
Tattoo inks can also play a role in decreasing the ability of the body to fight infections. For example, on some occasions it has been reported that tattoo ink can travel in the bloodstream and accumulate in the lymph nodes, obstructing their ability to fight infections.
Research paper
The recent study has been published in the Letters in Applied Microbiology, and it is titled “Microbial contamination of tattoo and permanent makeup inks marketed in the US: a follow‐up study.”
Essential Science
This article forms part of Digital Journal’s regular Essential Science column, where we present science stories of interest.
Last week, we looked at how well do face masks work in terms of minimizing coronavirus spread? The evidence is compelling if a person is infected and the right type of mask is worn (and worn correctly). Scientific data challenges the opinions of some leading politicians.
The week before we considered whether big data analytics can assist with environmental problems and by applying the correct algorithms. The answer was a yes’, and the article demonstrated the potential power of big data when harnessed for the social good.
