Becker's Clinical Quality & Infection Control

10 INFECTION CONTROL The seasonal-COVID-19 hypothesis: 6 things to know By Gabrielle Masson T here's some evidence indicating that COVID-19 is, or may become, a seasonal disease, which means un- derstanding the seasonal patterns could help scientists anticipate surges in advance, e Atlantic reported Nov. 20. With two years' worth of data to analyze and the knowledge that COVID-19 likely will not be eradicated, some researchers are explor- ing the seasonality of the virus. Six things to know about the possible seasonality of COVID-19, per The Atlantic: 1. e same disease can show different patterns in different areas. For example, the U.S. typically sees a winter flu season, but flu spikes in Bangladesh during the monsoon season — May to September — the warmest part of the year. 2. A group of researchers analyzed how COVID-19 fared in weather conditions worldwide and found temperature and humidity didn't play much of a role. Instead, their findings suggested case rates would rise in a particular area during times of lower UV exposure. Since then, others have found that the virus dies when exposed to UV rays with the same wavelength as sunlight. 3. A University of Pittsburgh study released in July projects a seasonal COVID-19 pat- tern in North America. e study has yet to be peer-reviewed. e researchers argue that COVID-19 in North America takes the form of three repeating waves like the ones of 2020: one starting in New England and east- ern Canada in the spring, the second travel- ing north from Mexico in the summer, and the third traveling in all directions from the Dakotas in the fall. e researchers predicted a summer 2021 wave in the South, and a fall 2021 wave in the north-central states, which is similar to what happened. 4. If COVID-19 is driven more by season- al changes than factors such as masking and vaccination rates, the disease would still behave like the flu at the local level, with each region experiencing one peak season per year — while the country overall had three. 5. is projected pattern may sharpen over the next few years, with patterning of past pandemics tending to follow a certain script, David Fisman, MD, epidemiologist at the University of Toronto, told e Atlantic. When a pandemic first hits, basically ev- eryone is vulnerable. en, as more people develop immunity, seasonal influences become more apparent. Finally, once the overwhelming majority of the population is immune, those same influences may become so subdued they're hardly visible. 6. Ben Zaitchik, PhD, a scientist at Bal- timore-based Johns Hopkins University who co-chairs the World Meteorological Organization's COVID-19 Research Task Team, previously said researchers didn't have enough data to find strong patterns. Now, with more data available, Dr. Zaitchik told e Atlantic that he feels confident saying weather influences COVID transmission in a statistically significant way, though he added, "COVID-19 has proven beyond a doubt that it can create hugely deadly outbreaks any- where in the world at any time of the year. And that's still true." n Infectious Disease Society of America issues guidelines for PPE use By Cailey Gleeson T he Infectious Disease Society of America issued eight guidelines for healthcare workers using personal protective equipment when working with COVID-19 patients. The guidelines, published Nov. 17 in Clinical Infectious Diseases, are evidence-based recommendations from a multidisciplinary panel on PPE usage in conventional, contingency and crisis settings. Recommendations are labeled as "strong" or "condi- tional," as indicated by the usage of "recommend" and "suggest," respectively. The panel acknowledged knowl- edge gaps and made no recommendation in instances of insufficient evidence. Eight guidelines: 1. The panel recommends healthcare personnel use either a medical/surgical mask or respirator compared with no mask. 2. The panel suggests healthcare personnel use eye pro- tection compared with no eye protection. 3. No recommendation was made for the use of double gloves versus single gloves. 4. No recommendation was made for the use of shoe covers versus no shoe covers. 5. The panel recommends healthcare personnel involved with aerosol-generating procedures use a respirator instead of a medical/surgical mask. 6. During contingency or crisis capacity settings, the panel suggests healthcare personnel involved with aerosol-gen- erating procedures use a reprocessed N95 respirator for reuse instead of medical/surgical masks. 7. During contingency or crisis settings, the panel rec- ommends healthcare personnel add a face shield or medical/surgical mask as a cover for the N95 respirator to allow for extended use. 8. During contingency or crisis settings, the panel suggests healthcare personnel add a face shield or medical/surgical mask as a cover for the N95 respirator to allow for reuse. n

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