Physiologic, microbiologic, and seasonal effects of handwashing on the skin of health care personnel.

The handwashing practices of 22 personnel on an oncology unit in an urban medical center were studied for 2 months. During 891 person-hours of observation, 986 handwashes were observed. Subjects washed a mean of 1.1 times an hour for a mean of 13.2 seconds. Reported and observed handwashing behavior was only moderately correlated (p = 0.05 for frequency, 0.30 for duration of handwashing). Physicians washed significantly less often (p less than 0.001), but more thoroughly (p less than 0.001), than did nurses. Nurses washed more often after minimal or no patient contact than did physicians (p less than 0.001). Individuals were very consistent in their handwashing technique. A total of 558 isolates were recovered from 158 hand cultures. The mean log count was 4.88, with no significant difference between physicians and nurses. Coagulase-negative staphylococci isolated from hands of physicians and nurses were significantly more resistant to antimicrobial agents than those of personnel with minimal patient contact (p less than 0.01). Subjects had more skin damage in winter than in summer, as indicated by increased shedding of skin squames (p less than 0.05). We conclude that handwashing practices vary significantly by profession and that reporting of handwashing practices by personnel is inaccurate.