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

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.

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.

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.

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.

Health care workers should remove finger rings and watches at work. Fingernails should be shorter than 2 mm, nail polish may be used.