Ebola May Spread Through Safety Clothing, Devices

Personal protective equipment like goggles, hoods, coveralls, boots, and respirators may not fully protect health care workers from exposure to Ebola virus, according to a recent study. Findings were presented by Steven S Theriault, PhD, on August 21, 2017, at the 3rd Annual Congress on Infectious Diseases in San Francisco, CA.

The Ebola virus outbreak in West Africa from 2013 to 2016 far exceeded the severity of previous outbreaks, with approximately 28,600 reported cases of Ebola and about 11,300 fatalities. The outbreak was also unique due to the large number of health care workers who were infected while working in the open-air Ebola treatment units (ETU). How health care workers became exposed to Ebola remains uncertain.
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To further explore health care workers’ exposure to Ebola, Theriault and colleagues attempted to define the risks of transmission associated with working in an ETU. They assessed possible fomite-driven transmission via personal protective equipment and examined whether saturation due to perspiration, condensation, or patients’ bodily fluids can compromise the integrity of personal protective equipment.

Results indicated that Ebola virus was able to survive at 27°C with 80% relative humidity from 1 to 24 hours on goggles, and for 24 to 72 hours on Kimberly-Clark 300 N95 respirators, Tyvek Micro-Clean hoods, Tychem QC coveralls, and HazMax boots.

These items retaining the largest amount of virus were further investigated for viral penetration. The researchers found that the virus could not pass through the Tychem QC coverall while dry or through the KC300 N95 respirator clippings while dry or wet. However, the virus was able to permeate the Tyvek MC hood while dry and wet, and through the Tychem QC coverall while wet.

Since various types of respirators are used in the field and contain several material layers that could complicate penetration studies, the researchers tested these items for viral penetration as well. A breathing mannequin-bust was fitted with 3 respirator types (KC300 N95, KC200 N95, and surgical-style). Wet and dry respirators of each type were challenged with Ebola virus for a typical ETU shift length of 30 minutes. Ultimately, the researchers found that only wet respirators allowed viral penetration.

“This study highlights the risks posed to [health care workers] with current [personal protective equipment] use in tropical conditions and calls for changes to [personal protective equipment] composition and updated protocols for its use,” the researchers concluded.

—Christina Vogt

Reference:

Theriault SS. Addressing healthcare workers’ safety during Ebola virus outbreaks. Paper presented at: 3rd Annual Congress on Infectious Diseases; August 21-23, 2017. San Francisco, CA. http://infection.conferenceseries.com/abstract/2017/addressing-healthcare-workers-safety-during-ebola-virus-outbreaks.