Newly Cleaned Physician Uniforms and Infrequently Washed White Coats Have Similar Rates of Bacterial Contamination After an 8-hour Workday

A Randomized Controlled Trial

Marisha Burden, MD; Lilia Cervantes, MD; Diane Weed, MA, MT (ASCP); Angela Keniston, MSPH; Connie S. Price; Richard K. Albert, MD


Journal of Hospital Medicine. 2011;6(4):177-182. 

In This Article


The important findings of this study are that, contrary to our hypotheses, at the end of an 8-hour workday, no significant differences were found between the extent of bacterial or MRSA contamination of infrequently washed white coats compared with those of newly laundered uniforms, no difference was observed with respect to the extent of bacterial or MRSA contamination of the wrists of physicians wearing either of the 2 garments, and no association was apparent between the extent of bacterial or MRSA contamination and the frequency with which white coats were washed or changed. In addition, we also found that bacterial contamination of newly laundered uniforms occurred within hours of putting them on.


Numerous studies have demonstrated that white coats and uniforms worn by health care providers are frequently contaminated with bacteria, including both methicillin-sensitive and -resistant Staphylococcus aureus and other pathogens[4–13] This contamination may come from nasal or perineal carriage of the health care provider, from the environment, and/or from patients who are colonized or infected.[11,15] Although many have suggested that patients can become contaminated from contact with health care providers' clothing and studies employing pulsed-field gel electrophoresis and other techniques have suggested that cross-infection can occur,[10,16–18] others have not confirmed this contention,[19,20] and Lessing and colleagues[16] concluded that transmission from staff to patients was a rare phenomenon. The systematic review reported to the Department of Health in England,[3] the British Medical Association guidelines regarding dress codes for doctors,[21] and the department's report on which the new clothing guidelines were based[1] concluded there was no conclusive evidence indicating that work clothes posed a risk of spreading infection to patients. Despite this, the Working Group and the British Medical Association recommended that white coats should not be worn when providing patient care and that shirts and blouses should be short-sleeved.[1] Recent evidence-based reviews concluded that there was insufficient evidence to justify this policy,[3,22] and our data indicate that the policy will not decrease bacterial or MRSA contamination of physicians' work clothes or skin.

The recommendation that long-sleeved clothing should be avoided comes from studies indicating that cuffs of these garments are more heavily contaminated than other areas[5,8] and are more likely to come in contact with patients.[1] Wong and colleagues[5] reported that cuffs and lower front pockets had greater contamination than did the backs of white coats, but no difference was seen in colony count from cuffs compared with pockets. Loh and colleagues[8] found greater bacterial contamination on the cuffs than on the backs of white coats, but their conclusion came from comparing the percentage of subjects with selected colony counts (ie, between 100 and 199 only), and the analysis did not adjust for repeated sampling of each participant. Apparently, colony counts from the cuffs were not different than those from the pockets. Callaghan[7] found that contamination of nursing uniforms was equal at all sites. We found that sleeve cuffs of white coats had slightly but significantly more contamination with bacteria than either the pocket or the midsleeve areas, but interestingly, we found no difference in colony count from cultures taken from the skin at the wrists of the subjects wearing either garment. We found no difference in the extent of bacterial contamination by site in the subjects wearing short-sleeved uniforms or in the percentage of subjects contaminated with MRSA by site of culture of either garment.

Contrary to our hypothesis, we found no association between the frequency with which white coats were changed or washed and the extent of bacterial contamination, despite the physicians having admitted to washing or changing their white coats infrequently (Table 4). Similar findings were reported by Loh and colleagues[8] and by Treakle and colleagues.[12]

Our finding that contamination of clean uniforms happens rapidly is consistent with published data. Speers and colleagues[4] found increasing contamination of nurses' aprons and dresses comparing samples obtained early in the day with those taken several hours later. Boyce and colleagues[6] found that 65% of nursing uniforms were contaminated with MRSA after performing morning patient-care activities on patients with MRSA wound or urine infections. Perry and colleagues[9] found that 39% of uniforms that were laundered at home were contaminated with MRSA, vancomycin-resistant enterococci, or Clostridium difficile at the beginning of the work shift, increasing to 54% by the end of a 24-hour shift, and Babb and colleagues[20] found that nearly 100% of nurses' gowns were contaminated within the first day of use (33% with Staphylococcus aureus). Dancer[22] recently suggested that "if staff were afforded clean coats every day, it is possible that concerns over potential contamination would be less of an issue." Our data suggest, however, that work clothes would have to be changed every few hours if the intent were to reduce bacterial contamination.


Our study has a number of potential limitations. The RODAC imprint method only sampled a small area of both the white coats and the uniforms, and accordingly, the culture data might not accurately reflect the total degree of contamination. However, we cultured 3 areas on the white coats and 2 on the uniforms, including areas thought to be more heavily contaminated (sleeve cuffs of white coats). Although this area had greater colony counts, the variation in bacterial and MRSA contamination from all areas was small.

We did not culture the anterior nares to determine if the participants were colonized with MRSA. Normal health care workers have varying degrees of nasal colonization with MRSA, and this could account for some of the 16%-20% MRSA contamination rate we observed. However, previous studies have shown that nasal colonization of healthcare workers only minimally contributes to uniform contamination.[4]

Although achieving good hand hygiene compliance has been a major focus at our hospital, we did not track the hand hygiene compliance of the physicians in either group. Accordingly, not finding reduced bacterial contamination in those wearing short-sleeved uniforms could be explained if physicians in this group had systematically worse hand-washing compliance than those randomized to wearing their own white coats. Our use of concurrent controls limits this possibility, as does that during the time of this study, hand hygiene compliance (assessed by monthly surreptitious observation) was approximately 90% throughout the hospital.

Despite the infrequent wash frequencies reported, the physicians' responses to the survey could have overestimated the true wash frequency as a result of the Hawthorne effect. The colony count and MRSA contamination rates observed, however, suggest that even if this occurred, it would not have altered our conclusion that bacterial contamination was not associated with wash frequency.


Because data were collected from a single, university-affiliated public teaching hospital from hospitalists and residents working on the internal medicine service, the results might not be generalizable to other types of institutions, other personnel, or other services.

In conclusion, bacterial contamination of work clothes occurs within the first few hours after donning them. By the end of an 8-hour work day, we found no data supporting the contention that long-sleeved white coats were more heavily contaminated than were short-sleeved uniforms. Our data do not support discarding white coats for uniforms that are changed on a daily basis or for requiring health care workers to avoid long-sleeved garments.


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