Health bosses say 651 people who used a piercing and tattoo studio in Newport have now attended clinic appointments for precautionary health checks.
Concerns were raised after five people with serious skin infections were treated as hospital in-patients.
The confirmed cases could also indicate a low risk of transmission of Hepatitis B and Hepatitis C and an extremely low risk of HIV transmission for all clients of these premises.
A blood test to check for Hepatitis B, Hepatitis C and HIV has been offered.
The local health board says clinic slots are still available and health staff are encouraging anyone that has had a procedure carried out at the premises to come forward for the test.
Tattoos might be becoming more fashionable - but it takes a lot of determination to decide that you're not going to offer up just an arm or a leg - but use your whole body.
That's exactly what Fran Atkinson from Rhyl went for. And now, eight years - and many inches of tattooists ink later, she's a living work of art. Whats more, she's hoping to make it into the Guinness book of records. Rob Shelley went to see for himself....
Tonight on ITV Cymru Wales news at 1800 Fran Atkinson from Rhyl tells us why she's gone through three years of pain for the tattoos she will never see.
The mum-of-one says her husband and the tattoo artist have acted as her eyes, describing the details of her intricate artwork from her neck down to her ankles.
Builder Lee Mayes was inspired by his church renovation project so much - he had the chapel's holy crosses tattooed on his arm.
The 43 year-old site manager was working at St Illtud’s Church in Llantwit Major where celtic crosses have been rehoused in a 13th century chapel.
“I’m not a religious person but as soon as I saw the Celtic designs I knew that I wanted to be involved in this project. I saw the designs on the stones and thought to myself, ‘I’m going to have that on my arm,’” said Lee.
The crosses which date back more than 1,000 years were relocated during a £850,000 refurbishment project which has seen the roofless ruin brought back to life a visitor centre.
The Galilee Chapel will be officially opened on Saturday, November 2, by the oldest member of the church 94 year-old Gladys Kilby.
A translation service in Swansea is warning people wanting tattoos to make sure spellings are correct before getting inked.
Sharon Stephens, managing director of Veritas Language Solutions, said: "There are some hilarious examples of translation errors out there.
"One man wanted the Chinese symbols for 'Live and let live' on his arm but ended up with the Mandarin for 'Sweet and Sour Chicken' [pictured].
"And a not-too-bright bad boy was left with "Jenius" branded on his forehead."
A translation service in Swansea is urging tattoo lovers to 'Think Before You Ink'. It's all part of a drive to ensure spellings are correct - before any mistakes are made permanent. It's after customers have been left branded with mis-spelled words and bizarre phrases in foreign languages.
Examples include one woman who used an internet translation tool to declare her love for her boyfriend in Hebrew but instead of "I love David" she got "Babylon is the world's leading dictionary and translation software" inked on her back.
DIY home tattooists using kit bought online for a few pounds are posing serious health risks to people looking for bargain body art in Wales.
You can now watch the full programme online here.
As tattoos become ever more popular, are new laws needed to clamp down on cut-price "scratchers" operating illegally from front rooms?
Wales This Week, Scratching The Surface is on at 8pm, Monday 25th February on ITV Cymru Wales.
Experts say that tattoo parlours in Wales should have to display hygiene ratings to customers. The Chartered Institute of Environmental Health is putting forward the idea, which it says would improve hygiene standards.