Extent and predictors of microbial hand contamination in a tertiary care ophthalmic outpatient practice

PURPOSE. To measure the extent of microbial hand contamination among ophthalmologists during routine clinic practice and examine its association with hand cleansing practices and beliefs, glove use, and patient load. METHODS. This was a single-masked analysis of resident and transient flora of ophthalmologists before and after patient examination and after handwashing by agar imprints of the dominant hand. Standardized questionnaires were used to collect information concerning subjects' hand cleansing practices and patient load. RESULTS. Of the 108 cultures, 107 (99.1%) were culture positive, yielding 15 separate organisms. Gram-negative bacilli were the most common transient flora, followed by Gram-positive cocci and fungi. Thirty-five (97.2%) ophthalmologists were culture positive for at least one resident and 8 (22.2%) ophthalmologists were culture positive for at least one transient organism, before patient contact. Regression models showed alcohol-based hand rub use, transient and resident floral load before patient contact, and patient load collectively accounted for 58.7% of the variance in resident floral load after patient contact. Use of alcohol-based hand rubs was associated with a mean resident floral reduction of 324.4 CFUs (95% confidence interval [CI] = 185.4 to 463.5; P < 0.01) and 31.6 CFUs ( 95% CI = 1.2 to 62.0; P < 0.05) after patient contact and handwashing, respectively. Handwashing with chlorhexidine was a significant predictor for transient floral load after handwashing ( unstandardized beta = - 17.2; 95% CI = - 10.2 to - 24.2; P < 0.01). CONCLUSIONS. The extent of contamination with pathogenic organisms after contact with eye outpatients, who have traditionally been perceived as relatively "clean," was of concern. Previously identified risk factors for hand contamination in inpatient settings, such as patient load, only explained a small proportion of variance in microbial load in the ophthalmic outpatient setting.