Professional tattooing in sterile environment not associated with risk of hepatitis C

Tattooing or body piercing in professional parlours is not associated with an increased risk of infection with hepatitis C virus, a literature review published in the online edition of Clinical Infectious Diseases shows. However, the authors did find evidence that tattooing in non-sterile environments, such as prisons, was associated with the infection. They also found isolated case reports of possible hepatitis C infections due to the use of inadequately sterilised equipment in professional settings.

“The findings emphasize the need to prevent hepatitis C transmission from use of unsterile tattooing and piercing equipment, especially in prisons,” write the authors. “Awareness campaigns should highlight the dangers of such procedures in unregulated and potentially unsterile environments, such as homes and prisons.”

Hepatitis C is a blood-borne infection and affects approximately three million individuals in the US. In 2009, approximately 16,000 new cases of the infection were diagnosed in the country. Injecting drug use is the principal mode of hepatitis C transmission. However, a fifth of people with incident infections deny traditional risk factors.

Research conducted in 1994 and 2006 found that approximately 6% of patients with acute hepatitis C reported recent tattooing. However, it also showed that two-thirds of these individuals also reported other risk factors for hepatitis C, including injecting drug use.

Because multiple risk factors are often present, the importance of tattooing or piercing as a mode of hepatitis C transmission is far from certain.

Therefore, investigators from the US Centers for Disease Control and Prevention (CDC) conducted a literature review to clarify this issue. They were partly motivated to undertake the research because of the increasing prevalence of tattooing in the general population, especially younger individuals.

“The review is intended to inform recommendations to prevent or reduce the risk of hepatitis C virus transmission,” write the authors.

A total of 62 studies conducted between 1994 and 2011 met the criteria for inclusion.

Some 19 involved individuals in the general population, and ten were case-controlled studies. After taking into account other risk factors, six of these studies reported no increased risk of tattooing and hepatitis C virus. However, two studies found that tattooing in non-sterile environments was associated with 2-3-fold increase in the risk of the infection.

A study conducted in a gastroenterology clinic found a possible association between tattooing and hepatitis C. However, 29% of individuals who originally denied injecting drug use admitted to this behaviour when re-examined about risk factors. Moreover, tattooing was frequently performed by friends or family member using non-sterile equiment.

There was no association between tattooing in a professional parlour and hepatitis C in a large cross-sectional study involving 5000 US college students. However, tattooing in a non-sterile setting was associated with a three-fold increase in the risk of the infection.

This association between hepatitis C and tattooing in non-sterile environments was also suggested in a Brazilian study. It found that individuals with tattoos were more likely to have hepatitis C, but more than half of individuals received their tattoos in non-professional settings using non-sterile implements. In addition, 20% of those with a tattoo reported injecting drug use, compared to 0% of those who did not have a tattoo.

One case report suggested possible hepatitis C transmission by tattooing in a commercial parlour. This was due to the reuse of non-disposable needles which were not adequately sterilised.

In many countries, individuals who have had a recent tattoo or piercing are temporarily excluded from donating blood. A number of studies examined hepatitis C risk factors in potential blood donors. After controlling for other risk factors – especially injecting drug use – there was no substantial evidence that tattooing was a major risk factor for the infection. The studies that did find an association did not enquire about the venue of tattooing. 

Several studies examined the risk of tattooing and hepatitis C in high-risk population, such as drug users, prisoners and the homeless.

Their results were inconsistent. However, tattooing in prison using non-sterile equipment did appear to be a risk factor. Some 90% of tattooed prisoners received their tattoos in non-professional settings and case reports of acute hepatitis C infection among prisoners suggest that tattooing in prison could have been the source.

Research involving US military veterans found that prevalence of hepatitis C was three times higher in tattooed individuals. But the investigators did not enquire about the venue of tattooing.

The association between piercing and hepatitis C infection was examined in 23 studies. However, the majority were limited because they did not enquire about piercing venue. Although some studies did find an increased prevalence of the infection among pierced individuals, several studies involving high-risk individuals found no such association. Nor was an association identified in the study of 5000 US college students.

“There is no definitive evidence that [hepatitis C] infections occur when sterile equipment is used,” comment the investigators. “Of note, no outbreaks of hepatitis C infection have been detected in the United States that originate from professional tattooing or piercing parlours.”

However, they emphasise that tattooing in non-sterile environments was associated with an increased hepatitis C risk.