More than 500 health care workers have contracted Ebola since the outbreak began in December 2013, and 269 have died, according to WHO statistics through the end of October. Some of the deaths resulted from faulty or nonexistent personal protective equipment (PPE)—gloves, masks and other barriers used to block Ebola transmission. Yet more recent cases in well-equipped U.S. hospitals and in Spain have uncovered a broader PPE-related problem: the guidelines for how to use the gear were insufficient.
Two workers who tended to Liberian patient Thomas Eric Duncan in a Dallas hospital before his death last month tested positive for Ebola despite their use of protective gear. Meanwhile, the Spanish nurse’s aide who tested positive after treating patients in Madrid is thought to have become infected with the Ebola virus after touching her face with a glove while removing her protective gear. She was released from the hospital on Wednesday after a month-long battle with the disease and was the first person known to have contracted the Ebola virus outside Africa.
In the past few weeks both the World Health Organization and the U.S. Centers for Disease Control and Prevention have updated their PPE guidelines. In addition to encouraging health care workers to better cover their mucous membranes and skin when treating Ebola patients, the CDC in particular is advising greater caution and a strict adherence to the buddy system when removing coveralls and gloves potentially exposed to the virus.
Scientific American In-Depth Report, Ebola: What You Need to Know
The WHO has for the first time developed and released, on October 31, formal guidelines for choosing facial protection, gloves and other PPE when caring for Ebola patients and others infected with viruses in the same family (filoviruses). The WHO’s foremost recommendation is that all health workers completely cover the mucous membranes of their eyes, mouth and nose to guard against contaminated droplets and fluids. More specifically, the agency strongly recommends the use of either a face shield or goggles as well as a fluid-resistant medical mask with a structured design that does not collapse against the mouth. Health care workers should also wear a fluid-resistant, particulate-filtering respirator during procedures that generate aerosols of body fluids.
In addition, the WHO advises wearing two nitrile gloves—as opposed to less reliable latex—on each hand when working with Ebola patients. The agency discourages the use of three or more gloves per hand because this can interfere with a health care worker’s manual dexterity. The new guidelines also reiterate the WHO’s earlier recommendations that gowns, aprons and other coverings be disposable and disposed of properly—which means they should be incinerated or sterilized. Reusable equipment such as boots should be disinfected with a chlorine solution.
The revised WHO guidelines are the direct result of efforts to combat and contain what has become by far the biggest outbreak of hemorrhagic fever ever, says Edward Kelley, director of WHO Service Delivery and Safety.
The WHO’s updated guidelines follow the CDC’s efforts on October 20 to tighten previous guidance for health workers on controlling Ebola infection. The CDC issued a statement at the time saying its new guidelines were designed “to ensure there is no ambiguity” as to the specific PPE health care workers should wear and the proper use of that equipment.
The updated recommendations from the two agencies overlap in several places, but the CDC guidelines place greater emphasis on rigorous and repeated PPE training for medical staff, including practice putting on and removing equipment in a set order. The agency also warns health care professionals that no skin should be exposed when workers are fully suited and that all workers should be supervised by a trained monitor who watches them as they put on and remove PPE.
In terms of equipment, the CDC now advocates the use of coveralls and single-use, disposable hoods. The agency also recommends single-use, disposable full-face shields rather than goggles, which may not provide complete skin coverage. Goggles can also be problematic because they are not disposable, they may fog after extended use and health care workers may be tempted to manipulate them with contaminated gloved hands, according to the CDC.
Recommendations for more comprehensive PPE coverage should diminish the risk of transmission during patient care. The use of additional gear makes equipment removal more complicated, however, adding risk to health workers on the back end. Hence the need for additional training and mentoring while dressing and undressing, according to a team of researchers from the University of Iowa Carver College of Medicine. In an October 28 article in the Journal of the American Medical Association, the group noted that removing PPE without allowing the outer surfaces of gloves or gowns to touch skin or underclothing “is difficult and that extensive practice is required to achieve proficiency with currently available PPE technology.”
Unfortunately, some of the best available hood coverings and other protections against infection are also “nearly impossible to remove without self-contamination,” according to the University of Iowa researchers. They highlighted the need to redesign these products to shield the same body areas but “make removing them easier via having the products open and fall away from the worker to avoid touching skin.” Another option may be the use of disposable blunt scissors to cut the PPE in strategic locations to facilitate removal, the researchers wrote.
Given the ideal characteristics of equipment for health care workers and others caring for patients with Ebola, “reengineering of PPE with new materials and designs is required, both in U.S. hospitals but more critically for the outbreak zones in Africa,” the group concluded.