RT Journal Article SR Electronic T1 An outbreak of Pseudomonas aeruginosa infection linked to a “Black Friday” piercing event JF bioRxiv FD Cold Spring Harbor Laboratory SP 149914 DO 10.1101/149914 A1 Peter MacPherson A1 Katherine Valentine A1 Victoria Chadderton A1 Evdokia Dardamissis A1 Iain Doige A1 Andrew Fox A1 Sam Ghebrehewet A1 Tom Hampton A1 Ken Mutton A1 Claire Sherratt A1 Catherine M McCann YR 2017 UL http://biorxiv.org/content/early/2017/06/14/149914.abstract AB Background Outbreaks linked to cosmetic piercing are rare, but can cause significant illness. We report the investigation and management of a point-source outbreak that occurred during a “Black Friday” event in North West England.Methods Outbreak investigation was led by Public Health England, and included active case finding among individuals pierced at a piercing premises between 25/11/2016 (“Black Friday”) and 7/12/2016. Detailed epidemiological, environmental (including inspection and sampling), and microbiological investigation was undertaken.Results During the “Black Friday” event (25/11/2016), 45 people were pierced (13 by a newly-appointed practitioner). Eleven cases were identified (7 microbiologically-confirmed, 2 probable, and 2 possible). All cases had clinical signs of infection around piercing sites, and five required surgical intervention, with varying degrees of post-operative disfigurement. All confirmed and probable cases had a “scaffold piercing” placed with a guide bar by the newly-appointed practitioner. Pseudomonas aeruginosa, indistinguishable at nine-locus variable-number tandem repeat loci, was isolated from four of the confirmed cases, and from pre- and post-flush samples from five separate water taps (three sinks) in the premises. Water samples taken after remedial plumbing work confirmed elimination of Pseudomonas contamination.Conclusions Although high levels of Pseudomonas water contamination and some poor infection control procedures were identified, infection appeared to require additional exposure to an inexperienced practitioner, and the more invasive scaffold piercing. A proactive collaborative approach between piercers and health and environmental officials is required to reduce outbreak risk, particularly when unusually large events are planned.