The effect of nail sticker use on hand surface bacterial counts after surgical scrubbing

We hypothesized that applying nail stickers to nails shorter than 2 mm would increase bacterial load and species abundance compared to nails of the same length without stickers. The aim of our study was to investigate aerobic bacterial load and species abundance on fingernails before and after nail sticker application over a 2-week period.

50 participants were enrolled, with 48 completing the entire study. Participants wore study-provided nail stickers (solid or patterned) for 7 days. All nails were trimmed to ≤ 2 mm. Standardized surgical scrubs with 4% chlorhexidine were performed, and swabs from fingernail surfaces and subungual spaces were collected at 3 time points: day 0 (before application), day 7 (immediately after application), and day 14 (1 week after application). We quantified bacterial load, and species were identified with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Median log10 bacterial loads were 1.48 at day 0, 1.00 at day 7, and 2.01 at day 14. Bacterial load increased from days 7 to 14 but did not differ between days 0 and 7 or days 0 and 14. Staphylococcus epidermidis abundance rose over time, while sticker design had no effect. Enterococcus faecalis was detected only once at day 14.

Wearing nail stickers for 1 week significantly increased bacterial load despite surgical scrubbing, likely due to adhesive surfaces promoting bacterial adhesion.

These findings suggest that nail stickers may compromise hand hygiene and increase infection risks in veterinary clinical settings. Avoiding nail stickers during procedures may reduce bacterial persistence and potential zoonotic transmission.