The impact of gel fingernail polish application on the reduction of bacterial viability following a surgical hand scrub.

OBJECTIVE To determine the effect of gel nail polish application on the reduction of bacterial viability immediately after a surgical hand scrub. STUDY DESIGN Randomized controlled trial. SAMPLE POPULATION Ten fingernails each from 40 female health care professionals and students. METHODS Participants' fingernails were randomized to receive no polish or gel nail polish during a manicure from a licensed manicurist. One day and 14 days after manicure, participants' fingernails were sampled before and after a surgical hand scrub with chlorhexidine gluconate. The samples for each fingernail were serially diluted, plated on a Trypsin sheep blood agar and MacConkey's agar plate, and incubated for 36 h. For each plate, bacterial colony forming units (CFU)/ml were determined. Mixed linear models were used to assess factors associated with the logarithmic reduction of viable bacterial counts from pre- to post-surgical scrub. RESULTS In the final model, no association was detected between gel nail polish and reduction of viable bacterial count (p = .09). On Day 14, among longer nail lengths (2 to <3-mm and ≥3-mm), surgical scrubs resulted in greater reduction in bacterial counts in left-handed than right-handed participants (p < .01). Increasing nail length was correlated with increased CFU/ml post-scrubbing (p < .001). CONCLUSION Application of gel nail polish did not seem to affect the ability of surgical scrub to reduce bacterial viability 1 and 14 days after a manicure. CLINICAL IMPACT This study does not provide evidence to prevent application of gel nail polish on short fingernails in surgeons prior to surgical hand scrub with chlorhexidine gluconate.