Growing interest has been given to the contamination of commonly used instruments in the physical exam (1,2). We are unaware of such scrutiny being given to the 10-g monofilament. The 10-g monofilament is a common screening test used to identify patients with loss of protective sensation and is part of recommended practice for the comprehensive foot exam for patients with diabetes (3). The instrument is typically used on feet with no open lesions or other breaks in the integument.
With the growing prevalence and concern associated with resistant organisms such as methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci, many preventative measures are now being used by clinics and hospitals around the country, including normal screening for these bacteria. This is of particular interest for patients with diabetes because infected foot ulcers remain one of the most common reasons for hospital admissions in patients with diabetes (4). While questions remain regarding the pathogenic nature of these resistant organisms in foot ulcers (5), improved hygiene remains of keen interest. Questions are often raised regarding the ability of these organisms to spread between patients, as well as the potential vehicle by which they may spread. This study aimed to determine the prevalence of contaminated monofilaments in a busy hospital clinic setting. Additionally, we explored the value of wiping the monofilament with an alcohol pad and the subsequent reduction of the bacterial load.
This study was conducted at the Veterans Affairs Medical Center in North Chicago, Illinois. Twenty-seven multiuse 10-g monofilaments were collected from the pockets and treatment drawers of health care professionals, inoculated on a standard blood agar plate, wiped with an alcohol pad, and then inoculated on another blood agar plate. Each inoculated plate was then streaked using a standard loop in the four-quadrant streaking technique and incubated at 37°C. Plates were read at 24 and 48 h to assess growth of pathogens in addition to quantitative analysis evaluating the number of bacterial colonies present.
We found 70% (19/27) of monofilaments cultured out isolates. This was reduced to 7% (2/27) after being wiped with an alcohol pad (P < 0.0001, using a two sample Student t test of equal variances). The mean number of isolates found on contaminated monofilaments was 1.5 with the vast majority of these being gram-positive cocci in chains, clusters (4), pairs (4), or rods (2). Five monofilaments were determined to be heavily contaminated, and alcohol pad wiping eliminated all isolates on four of five monofilaments.
The prevalence of contamination in this study (70%) was similar to that of contaminated stethoscopes (80%) (2). Overall, this study allows for a better understanding among health care professionals of the kinds of organisms that may exist on multiuse monofilaments. Alcohol wiping appears to be an effective strategy to decrease the bacterial load. Recognizing this information as well as the potential ability and risks of spreading pathogens among patients, health care professionals can take the appropriate steps to prevent the spread of potential pathogens between patients in the clinical setting.
The opinions and views contained herein are the private views of the authors and are not to be construed as representing the views of the Health Care Financing Administration, the Department of Veterans Affairs, or the U.S. Government.
Acknowledgments
No potential conflicts of interest relevant to this article were reported.
A.M.S., A.G., R.Y., W.C., and J.S.W. researched data, contributed to the discussion, wrote the manuscript, and reviewed/edited the manuscript.
