September 2013, Volume 34, Issue 8
Published by AEGIS Communications
Compendium has compiled Abstracts from key recently published articles in the
dental literature on infection control. These PubMed-indexed articles offer clinical relevance to the dental practitioner and can be applied to a range of situations.
Evaluation of in-office dental unit waterline testing
In-office dental unit waterline (DUWL) testing systems are commercially available for monitoring DUWL bacteria. The current study compared Aquasafe, Petrifilm, and Heterotrophic Plate Count Sampler (HPCS) with R2A plating methodology, considered the gold standard for enumerating heterotrophic bacteria in potable water. Samples were collected from 20 dental units. Heterotrophic bacterial counts of ≤500 CFUs/mL were used as the cutoff for assessing in-office testing compared to R2A laboratory plating. Validity was assessed using sensitivity and specificity, along with positive and negative predictive values. Results were also compared using concordance and kappa statistics. All in-office tests demonstrated 100% specificity and positive predictive values, while sensitivity and negative predictive values were low (Petrifilm, 57%/50%; HPCS, 50%/46%; Aquasafe, 21%/35%). Concordance and kappa values for agreement with R2A plating were as follows: Petrifilm 70% (κ = 0.44), HPCS 65% (κ = 0.38), and Aquasafe 45% (κ = 0.14). In-office DUWL testing with Aquasafe, Petrifilm, and HPCS agreed poorly with R2A plating methodology and is not valid or reliable as a means of accurately monitoring bacterial density in DUWL. These in-office test systems should not be used for assessing compliance with the ADA and CDC standard for acceptable heterotrophic bacterial counts in DUWLs (≤500 CFUs/mL).
The first step in infection control is hand hygiene
A dental healthcare worker (DHCW) has an obligation to prevent the spread of healthcare associated infections. Adhering to proper hand hygiene procedures, selecting appropriate hand hygiene products, and the use of gloves are all key elements of infection control. The CDC Guidelines for Hand Hygiene state that improved hand hygiene practices can reduce transmission of pathogenic microorganisms to patients and personnel in healthcare settings. DHCWs must also protect themselves by recognizing pitfalls such as irritants or allergies that may pose obstacles to proper hand hygiene. Occupational irritants and allergies can be caused by frequent hand washing, exposure to hand hygiene products, exposure to chemicals and shear forces associated with wearing or removing gloves. Since the primary defense against infection and transmission of pathogens is healthy, unbroken skin, DHCWs must take steps to ensure that their skin remains healthy and intact. These steps include evaluating different types of hand hygiene products, lotions, and gloves for the best, most effective compatibility. If the DHCW sees a breakdown of his or her skin barrier, remedies can include the use of alcohol-based hand sanitizers containing emollients and moisturizers and regular use of a medical grade hand lotion.
A randomized clinical trial of three options for N95 respirators and medical masks in health workers
Three policy options for the use of medical masks and N95 respirators in healthcare workers (HCWs) were compared via a cluster randomized clinical trial of 1,669 HCWs. Participants were randomized to medical masks, N95 respirators, or targeted use of N95 respirators while doing high-risk procedures. Outcomes included clinical respiratory illness (CRI) and laboratory-confirmed respiratory pathogens in symptomatic subjects. The rate of CRI was highest in the medical mask arm (98 of 572; 17%), followed by the targeted N95 arm (61 of 516; 11.8%), and the N95 arm (42 of 581; 7.2%) (P < 0.05). Bacterial respiratory tract colonization in subjects with CRI was highest in the medical mask arm (14.7%; 84 of 572), followed by the targeted N95 arm (10.1%; 52 of 516), and lowest in the N95 arm (6.2%; 36 of 581) (P = 0.02). After adjusting for confounders, only continuous use of N95 remained significant against CRI and bacterial colonization, and for just CRI compared with targeted N95 use. Targeted N95 use was not superior to medical masks. It was concluded that continuous use of N95 respirators was more efficacious against CRI than intermittent use of N95 or medical masks.