Failure of bland soap handwash to prevent hand transfer of patient bacteria to urethral catheters.

OBJECTIVE

The study was designed to compare the efficacies of bland soap handwash and isopropyl alcohol hand rinse in preventing transfer of aerobic gram-negative bacilli to urinary catheters via transient hand colonization acquired from direct patient contact. Glove juice recovery of gram-negative bacteria was considered transient colonization; catheter recovery was considered transfer colonization.

DESIGN

The contact source for gram-negative bacteria was a single "high burden" groin skin carrier (greater than or equal to 10(4)/ml cup scrub fluid). Using a two-period cross-over design, 6 healthcare workers had 2 15-second contacts for each hand followed by either soap handwash or alcohol hand rinse (12 experiments with each treatment). Between 4 to 5 minutes after contact, each hand manipulated a catheter; the catheter was then cultured and the hand was glove juice tested.

RESULTS

Soap handwash failed to prevent gram-negative bacteria transfer to the catheter in 11 of 12 (92%) experiments; alcohol hand rinse in 2 of 12 (17%) (p less than .001). Soap handwash failed to prevent transient colonization in 12 of 12 (100%) experiments; alcohol in 5 of 12 (42%) (risk ratio 2.4, 95% confidence interval 1.2-4.7). Single gram-negative bacteria species carried at source levels greater than or equal to 5.5 x 10(3)/ml (heavy contamination) established transient colonization in 23 of 30 (77%) exposures following soap handwash; single gram-negative bacteria species carried at levels less than or equal to 3.5 x 10(3)/ml established colonization in 1 of 22 (5%) similar exposures (p less than .001).

CONCLUSIONS

Bland soap handwash was generally ineffective in preventing hand transfer of gram-negative bacteria to catheters following brief contact with a heavy-contamination patient source; alcohol hand rinse was generally effective.