protection of hcp from ebola 1231
precautions, which includes different room placement (ie, private room or airborne isolation room) and HCP use of PPE (gloves, gowns, mask, N95 respirator, and/or face shield) based on the mechanism of transmission of the infectious agent (ie, contact, droplet, airborne).17 Given the acquisition of Ebola by HCP in Dallas and the large number of HCP in West Africa, 2 key questions have arisen. First, what is the evidence that PPE protects HCP from acquiring a contact transmitted disease? Second, what steps can we take to mini- mize the risk to HCP of acquiring EVD while caring for an infected patient? The gloves and gowns of HCP frequently become con-
taminated with pathogens while providing care to patients on contact precautions. Recently, Williams et al18 reported that HCP frequently contaminated their clothing despite wearing gloves and gowns for patient care. Casanova et al19,20 assessed the ability of standard PPE (ie, gloves, gowns, respirator, and goggles) to protect against contamination of skin and clothes by dotting the outside of the PPE with bacteriophage MS2, a nonenveloped, nonpathogenic RNA virus. PPE was removed using the CDC-recommended doffing procedure. Initial experiments revealed that underlying clothing (scrub shirt, pants) and skin (dominant and nondominant hand) were contaminated>70% of the time.19 Further, the mean viral titer recovered was 1.8–2.4-log10 (inoculating dose = 104 on several PPE sites). Despite double gloving, skin contamination (6%–23%) and clothing contamination (56%–94%) remained common.20 The failure of standard PPE to protect HCP against skin and clothing contamination and the lack of validation of the level of protection afforded by PPE recom- mended for Ebola care have raised concerns.21 At the present time, it is recommended that HCP providing
care to a patient with EVD use enhanced PPE.22 Although there is no consensus on each of the specific components of PPE among the major organizations providing care to EVD patients, all agree that it should uniformly protect the major portals of entry including mucous membranes and nonintact skin. CDC guidelines, which are directed toward the use of
HCP is that during the doffing procedure contamination of underlying clothes or skin may occur. This raises the question of whether additional methods may be used to further protect the HCP such as decontamination of the PPE prior to removal by either ultraviolet light (UV) or use of a germicide (eg, hypochlorite). In this issue, Tomas et al23 report that a portable booth using UV-C radiation can be used to disinfect
PPE in US hospitals, recommend double gloves, a single-use fluid-resistant gown or coverall, an impervious apron, and either a powered air-purifying respirator (PAPR) or an N95 respirator. If the latter is used, then it must be accompanied by a single-use surgical hood extending to the shoulders and a full face shield. Critical to maximizing PPE protection are detailed donning and doffing procedures, comprehensive training on proper donning and doffing, and use of a monitor to ensure proper donning and doffing.22 As demonstrated by Casanova et al, the major risk to the
full-body PPE. They demonstrated that the delivered UV-C radiation resulted in ≥3-log10 reduction in MS2 virus and methicillin-resistant Staphylococcus aureus (MRSA) within 3 minutes. Additionally, UV-C radiation has been demon- strated to inactivate the Ebola virus.24 Although the UV-C booth may reduce the risk of skin/clothing contamination during the doffing procedure, it may be impractical for use in lesser-developed countries. Another strategy to mitigate the risk of skin/clothing contamination during doffingwould be to decontaminate the outside of the PPE using a germicide applied by spray or wipe such as hypochlorite (diluted bleach).25 However, although this procedure has often been used in the field, there is considerable debate about the use of sprays because of concern for aerosolizing laden body fluids that may contaminate the PPE. To protect our HCP against acquisition of highly virulent pathogens such Ebola, we must assess all the potential risks for transmission (eg, inadequate detection of possible cases, inappropriate use of PPE) and implement strategies to mini- mize this risk (Table 1). The public health community needs to reduce the risks to our HCP by validating the currently recommended PPE, improving PPE as necessary, improve training of our HCP, and expand the number of facilities with healthcare units specifically designed to care for highly communicable diseases. We need to continue to develop innovative approaches such as that assessed by Dr. Tomas. Finally, HCP at all US hospitals need to remember that
more than 1 million travelers arrive in the United States each week.26 As demonstrated by the recent case of Lassa fever in New Jersey,27 the outbreak of MERS-CoV in Korea,28 and the Ebola cases resulting from travelers from West Africa,29 we are all only a plane ride away from potentially highly communic- able and virulent infectious diseases.
acknowledgments
Financial support. No financial support was provided relevant to this article. Potential conflicts of interest. All authors report no conflicts of interest
relevant to this article. Address correspondence to David J. Weber, MD, MPH, 2163 Bioinfor-
matics, CB #7030, Chapel Hill, NC 27599-7030 (
dweber@unch.unc.edu).
references 1. Ebola (Ebola virus disease). Centers for Disease Control and Prevention Web site.
http://www.cdc.gov/vhf/ebola/outbreaks/ 2014-west-africa/
case-counts.html. Published 2015. Accessed July 13, 2015.
2. Centers for Disease Control and Prevention. Estimating the future number of cases in the Ebola epidemic—Liberia and Sierra Leone, 2014–2015. MMWR 2014;63:1–14.
3. World Health Organization. Ebola situation report, July 8, 2015. World Health Organization Web site.
http://apps.who.int/ebola/ current-situation/ebola-situation-report-8-july-2015. Published 2015. Accessed July 13, 2015.
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