Effects of handwashing agent, handwashing frequency, and clinical area on hand flora

Larson, E.

Six hundred twenty-two isolates from 554 samples taken from hands of 103 hospital personnel and 50 controls were obtained over a mean period of 35 days. Eighty-five were obtained immediately before and after handwashing (HW), the remainder after HW only. The relationship of HW agent used, clinical area and job, and frequency of HW to rates of bacterial colonization and numbers and types of organisms isolated, particularly gram-negative bacteria, were evaluated. The HW agent used ( nonantiseptic , hexachlorophene-based, chlorhexidine-based, or iodophor) was significantly correlated with the number of isolates obtained from each sample. Control subjects, all of whom used nonantiseptic soaps, had 1.42 mean isolates per sample; hospital personnel who used nonantiseptic soap had a mean of 1.00 isolates per sample. Other means were 1.25, hexachlorophene; 1.43, iodophor; 0.79, chlorhexidine; and 0.67 for those who used several different antiseptics, p less than 0.0001. The agent was also correlated with the type of organisms isolated (p = 0.002), but not with the counts of colony-forming units (CFU). Frequency of HW was significantly correlated with CFU counts before (p = 0.03) and after (p = 0.001) HW. In general, numbers decreased with increasing HW frequency, but at the higher HW frequencies there was a slight rise. There were significant differences in numbers of isolates per sample according to clinical area, with personnel working in obstetrics and nonpatient areas having the greatest number and those working on neonatal and medical-surgical units having the least (p less than 0.0001).