Factors interfering with the microflora on hands: a regression analysis of samples from 465 healthcare workers.

AIMS: This paper is a report of a study of the impact of finger rings, wrist watches, nail polish, length of fingernails, hand lotion, gender and occupation on hand microbiology of healthcare workers. BACKGROUND: The impact of the above mentioned variables on hand microbiology of healthcare workers is not well defined. Large scale studies suitable for multivariate analysis are needed to elucidate their role. METHODS: Both hands of 465 Norwegian healthcare workers were sampled by the glove juice method during two study periods (2004 and 2007), and examined for total number of bacteria and presence of Staphylococcus aureus, Enterobacteriacea and non-fermentative Gram-negative rods. Multiple regression analysis was performed. RESULTS: The use of a wrist watch was associated with an enhanced total bacterial count on hands compared to hands without a watch [(B) 3·25 (95% CI: 1·73-6·07), P <0·001], while the use of one plain finger ring increased the carriage rate of Enterobacteriaceae [odds ratio 2·71 (95% CI: 1·42-5·20), P = 0·003]. The carriage rate of Staphylococcus aureus was enhanced with fingernails longer than 2 mm [odds ratio 2·17 (95% CI: 1·29-3·66), P = 0·004] and after recent use of hand lotion [odds ratio 22·52 (95% CI: 4·05-125·30), P < 0·001]. No effect of nail polish was observed. We found an association between occupation and carriage rate of S. aureus and Enterobacteriaceae. CONCLUSIONS: Health care workers should remove finger rings and watches at work. Fingernails should be shorter than 2 mm, nail polish may be used.

Impact of finger rings on transmission of bacteria during hand contact.

OBJECTIVE: To investigate the impact of finger rings on the transmission of bacteria from the hands of healthcare workers and the impact on the microflora on the hands of healthcare workers in clinical practice. DESIGN: Our study had a nonequivalent control group posttest-only design (pre-experimental). Healthcare workers who wore finger ring(s) on 1 hand and no ring on the other hand (n = 100) and a control group of healthcare workers who did not wear any rings (n = 100) exchanged standardized hand shakes with an investigator wearing sterile gloves. Samples from the gloved hands of the investigators and the bare hands of the healthcare workers were thereafter obtained by the glove juice technique. SETTING: Two Norwegian acute care hospitals. PARTICIPANTS: Healthcare workers (n = 200) during ordinary clinical work. RESULTS: A significantly higher bacterial load (odds ratio, 2.63 [95% confidence interval, 1.28-5.43]; P = .009) and a significantly higher number of bacteria transmitted (parameter estimates, [corrected] 2.43 [95% confidence interval, 1.44-4.13]; P = .001) were associated with ringed hands, compared with control hands. However, a multiple analysis of covariance revealed no statistically significant effect of rings alone. The prevalence of nonfermentative gram-negative bacteria (42% vs 26%) and Enterobacteriaceae (26% vs 13%) was also significantly higher among persons who wore rings than among persons who did not wear rings. However, no statistically significant differences in the incidence of transmission of these pathogens were detected after hand contact. The prevalence of Staphylococcus aureus and incidence of transmission of S. aureus were the same in both groups. CONCLUSIONS: Wearing finger rings increases the carriage rate of nonfermentative gram-negative bacteria and Enterobacteriaceae on the hands of healthcare workers. However, no statistically significant differences in the incidence of transmission of nonfermentative gram-negative bacteria or Enterobacteriaceae were detected between the healthcare workers who wore rings and those who did not.

Impact of a single plain finger ring on the bacterial load on the hands of healthcare workers.

OBJECTIVE: To investigate the impact of a single plain finger ring on the number and types of bacteria on the hands of healthcare workers (HCWs). DESIGN: Nonequivalent control groups, posttest only (preexperimental). METHODS: A total of 121 HCWs wearing 1 plain ring and 113 HCWs wearing no rings had both hands sampled by the "glove juice" technique. Quantitative culture of the samples was performed and microorganisms were identified. SETTING: Two Norwegian acute care hospitals. PARTICIPANTS: A total of 234 HCWs who had physical contact with patients. RESULTS: Total bacterial counts did not differ when hands with rings and hands without rings were compared, both according to nonpaired analysis (which compared the ring-bearing hands of ring-wearing HCWs to the hands of HCWs who did not wear rings [P=.661]) and according to paired analysis (which compared the ring-bearing and ring-free hands of ring-wearing HCWs [P=.071]). Staphylococcus aureus was recovered from 18.6% of the hands sampled, belonging to 26.9% of the HCWs, but neither paired nor nonpaired analysis showed any association with ring wearing. Gram-negative bacteria were recovered from 20.3% of the hands sampled, belonging to 28.6% of the HCWs. Ring-wearing HCWs were significantly more likely to be carriers of Enterobacteriaceae (P=.006), but paired comparison of the ring-bearing and ring-free hands of these HCWs did not show significant differences (P=.180). Carriage of nonfermentative gram-negative rods did not differ between the 2 groups, by either paired or nonpaired analysis. CONCLUSIONS: Wearing a single plain finger ring did not increase the total bacterial load on the hands, nor was it associated with an increased rate of carriage of S. aureus or nonfermentative gram-negative rods. However, plain rings were associated with an increased rate of Enterobacteriaceae carriage.