Becker's Clinical Quality & Infection Control

6 INFECTION CONTROL The value of wearing a mask when others don't By Mackenzie Bean and Erica Carbajal A federal judge's rejection of the na- tion's mask mandate for travelers taking public transportation set off a flurry of responses. Some Americans cheered midflight and took their masks off when they found out Judge Kathryn Kimball Mizelle's April 18 ruling meant they were no longer required to wear them, e New York Times reported. But some people who travel with young children not yet eligible for COVID-19 vaccination and those at high risk for severe illness met the announcement with worry and fear. Many health experts also expressed concern about the timing of the loosened restric- tions, which came as COVID-19 cases and hospitalizations were rising nationwide. e new recommendations put the onus on individuals to determine how to best protect themselves. Many are asking if wearing a mask works if no one else around you is wearing one. e CDC still recommends wearing a mask. "It is CDC's continuing assessment that at this time an order requiring masking in the indoor transportation corridor remains nec- essary for the public health," the agency said April 20, adding that "wearing masks is most beneficial in crowded or poorly ventilated locations, such as the transportation corridor." Many infectious disease experts and other health experts have said they will continue to wear a mask, regardless of whether passen- gers around them are masked or not. "You can quote me on this: I'm going to continue to wear an N95 mask," said David Freeman, MD, professor emeritus of infectious diseases at the University of Alabama at Birmingham. "No question. You have no idea who's on a plane," he told e Washington Post. Plenty of factors play into the level of protec- tion provided from wearing a mask — the type of mask, duration of exposure to an infected person and the mode of transporta- tion the mask-wearer is using to name a few. While some environments may pose higher risks than others, a number of studies have indicated masks offer at least some degree of protection to the wearer. One study published Dec. 2 in the peer-re- viewed journal PNAS found someone wearing a surgical mask had up to a 90 percent chance of contracting COVID-19 aer speaking with an unmasked, infected person for half an hour. is risk dropped to 20 percent aer a full hour if the person was wearing a respirator and just 0.4 percent if both people were wearing respirators. Universal masking is the gold standard in infection control, as it both contains the wearer's germs and filters out other people's. at said, "one-way masking is definitely better than nothing," Emily Sickbert-Ben- nett, PhD, director of infection prevention at UNC Medical Center in Chapel Hill, N.C., told Time. Wearing a good-fitting, high-quality mask correctly offers the wearer a high degree of protection, even if other people in proximity aren't masked, according to Scott Gottlieb, MD, former FDA commissioner and current Pfizer board member. "One-way masking does work," he said during an interview on CNBC's Squawk Box. "So people who feel vulnerable, if they continue to do that, are going to be able to protect themselves in that setting even if other people aren't wearing masks." n Aerosolized hydrogen peroxide cuts C. diff infection risk By Erica Carbajal A dding aerosolized hydrogen peroxide to infection prevention protocols reduces the risk of Clostrid- ioides difficile infections in healthcare settings, according to a study published March 17 in the American Journal of Infection Control. Researchers evaluated the effectiveness of a system that generates an aerosolized dry-mist fog containing a certain percentage of hydrogen peroxide. The fog covers all exposed surfaces and is meant to kill any C. diff spores that remain after surface cleaning. The team conducted a retrospective study analyzing C. diff infection rates at a large, acute-care hospital in Philadelphia over a 10-year period to evaluate the effectiveness of an aerosol system at reducing infections by comparing incidence rates prior to and after implementation of the system. They found consistent use of the disinfection system in addition to standard room-cleaning procedures helped reduce infection rates. Before implementing the system, the Philadelphia hospital had 120 healthcare-associated C. diff infections over a 27-month period. There were 72 cases over a 33-month period after implementing the system, reflecting a 41 percent decrease in the facility's infection rate from 4.6 per 10,000 patient days to 2.7 per 10,000 days. In the second half of the study, the rate was further reduced to 1.4 per 10,000 patient days. "Our study showed that persistence in utilizing an aerosol- ized hydrogen peroxide system had a significant impact on reducing C. difficile infections hospital-wide," said Christopher Truitt, PhD, lead study author and associate professor of chemistry at Wayland Baptist University in Plainview, Texas. n

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