Department of Physiology and Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV 89557-0352, USA.
School of Public Health, University of Nevada, Reno, NV 89557-0275, USA.
Cells. 2023 Jan 28;12(3):430. doi: 10.3390/cells12030430.
The omicron variant is thought to cause less olfactory dysfunction than previous variants of SARS-CoV-2, but the reported prevalence differs greatly between populations and studies. Our systematic review and meta-analysis provide information regarding regional differences in prevalence as well as an estimate of the global prevalence of olfactory dysfunction based on 62 studies reporting information on 626,035 patients infected with the omicron variant. Our estimate of the omicron-induced prevalence of olfactory dysfunction in populations of European ancestry is 11.7%, while it is significantly lower in all other populations, ranging between 1.9% and 4.9%. When ethnic differences and population sizes are considered, the global prevalence of omicron-induced olfactory dysfunction in adults is estimated to be 3.7%. Omicron's effect on olfaction is twofold to tenfold lower than that of the alpha or delta variants according to previous meta-analyses and our analysis of studies that directly compared the prevalence of olfactory dysfunction between omicron and previous variants. The profile of the prevalence differences between ethnicities mirrors the results of a recent genome-wide association study that connected a gene locus encoding an odorant-metabolizing enzyme, UDP glycosyltransferase, to the extent of COVID-19-related loss of smell. Our analysis is consistent with the hypothesis that this enzyme contributes to the observed population differences.
奥密克戎变异株被认为比以前的 SARS-CoV-2 变异株引起的嗅觉障碍少，但报告的流行率在不同人群和研究中差异很大。我们的系统评价和荟萃分析提供了关于流行率的区域差异的信息，以及根据 62 项报告有关感染奥密克戎变异株的 626,035 名患者信息的研究，估计全球嗅觉障碍流行率的信息。我们对欧洲血统人群中奥密克戎引起的嗅觉障碍流行率的估计为 11.7%，而在所有其他人群中，这一比例显著较低，在 1.9%至 4.9%之间。当考虑到种族差异和人口规模时，估计全球成年人中奥密克戎引起的嗅觉障碍的流行率为 3.7%。根据之前的荟萃分析和我们对直接比较奥密克戎和以前变异株引起的嗅觉障碍流行率的研究的分析，奥密克戎对嗅觉的影响比阿尔法或德尔塔变异株低两到十倍。种族间流行率差异的特征与最近一项全基因组关联研究的结果相吻合，该研究将编码一种气味代谢酶的基因座与 COVID-19 相关嗅觉丧失的程度联系起来。我们的分析与假设一致，即这种酶有助于解释观察到的人群差异。
