Becker's Clinical Quality & Infection Control

20 PATIENT SAFETY & OUTCOMES Why do some people lose smell, taste from COVID-19? 1 explanation By Gabrielle Masson A mechanism has been identified that may explain why some people with COVID-19 lose their sense of smell, according to research published Feb. 1 in Cell. Researchers from NYU Grossman School of Medicine and Columbia University, both based in New York City, explored the molecular con- sequences of SARS-CoV-2 infection in golden hamsters and olfactory tissue taken from 23 human autopsies. ey found that the virus indirectly decreases action of olfactory recep- tors, which detect the molecules associated with odors. According to the study authors, COVID-19 appears to cause longer-lasting disruption in chromosomal regulation of gene expression that could prevent the resto- ration of olfactory receptor transcription even aer the virus is cleared. e study may also shed light on other neurological lingering effects of COVID-19, such as "brain fog," headaches and depression. "Our findings provide the first mechanistic explanation of smell loss in COVID-19 and how this may underlie long COVID-19 biology," said co-corresponding author Benjamin tenOever, PhD, professor at NYU Langone Health. "e work, in addition to another study from the tenOever group, also suggests how the pandemic virus, which infects less than 1 percent of cells in the human body, can cause such severe damage in so many organs." In most cases, loss of smell lasts only a few weeks, but for more than 12 percent of people with COVID-19, olfactory dysfunction persists in the form of ongoing reduction in the ability to smell or changes in how smells are perceived. "e realization that the sense of smell relies on 'fragile' genomic interactions between chromosomes has important implications," Dr. tenOever said. "If olfactory gene expression ceases every time the immune system responds in certain ways that disrupts inter-chro- mosomal contacts, then the lost sense of smell may act as the 'canary in the coal mine,' providing early signals that the COVID-19 virus is damaging brain tissue before other symptoms present, and suggesting new ways to treat it." n COVID-19 ups risk of developing mental health issues, study suggests By Erica Carbajal P eople who had COVID-19 were 39 percent more likely to be diagnosed with depression in the months after their infection compared to those without COVID-19, according to a study of nearly 154,000 COVID-19 patients at the Veterans Health Administration. To conduct the study, published Feb. 15 in The BMJ, researchers looked at medical records from 153,848 VA COVID-19 patients who tested positive between March 2020 and January 2021 and who survived at least 30 days. The patients were followed through Nov. 30, 2021, and compared to a contemporary control group of more than 5.6 million VA patients who didn't test positive, as well as a cohort of 5.8 million pre-pandemic patients. Findings showed in the months following infection, COVID-19 patients were 39 percent more likely to be diagnosed with depression and 35 percent more likely to be diagnosed with anxiety compared to patients without COVID-19. The COVID-19 cohort was also more likely to be diagnosed with stress and adjustment disorders (38 percent) and sleep disorders (41 percent). Overall, those who were hospitalized for COVID-19 were more likely to be diagnosed with mental health issues relative to those with less severe illness, though those with mild cases were still more likely to receive such a diagno- sis compared to uninfected people. "There appears to be a clear excess of mental health diag- noses in the months after COVID," Dr. Paul Harrison, psychi- atry professor at the University of Oxford in the U.K., who was not involved in the study, told The New York Times. "It's not an epidemic of anxiety and depression, fortunately," he said. "But it's not trivial." The study findings did not indicate most COVID-19 patients develop mental health problems, as only 4.4 percent of the COVID-19 cohort developed de- pression, and 5.5 received anxiety or stress and adjustment disorder diagnoses. Ziyad Al-Aly, MD, a senior author on the study, told the Times his team is planning to evaluate whether subse- quent vaccination alters people's mental health symptoms and other post COVID-19 symptoms, as many of the patients were infected before vaccinations were widely available. Dr. Al-Aly is chief of research and development at the VA St. Louis Health Care System and a clinical epi- demiologist at Washington University in St. Louis. n COVID-19 patients were 39 percent more likely to be diagnosed with depression and 35 percent more likely to be diagnosed with anxiety compared to patients without COVID-19.

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