From the Department of Neuroimmunology, Blizard Institute, Queen Mary University of London, 4 Newark St, London E1 2AT, UK.
QJM. 2021 Apr 27;114(2):83-91. doi: 10.1093/qjmed/hcaa326.
During the COVID-19 pandemic, it became clear that smell and taste (chemosensory) disturbance is very common in the early stages of disease. This article addresses (i) why COVID-19 specifically targets the modalities of smell and possibly taste and what is the mechanism, (ii) what is the frequency of smell and taste loss and (iii) what is the overall prognosis. It is suggested that mouth-breathers may be at particular risk of COVID-19. Symptom-based questionnaires are likely to under-estimate the prevalence of chemosensory impairment by as much as 50%. The prevalence of smell loss is so high that a person who has normal olfaction on formal testing is unlikely to be infected significantly with Cov-2. Furthermore, someone without symptoms who has an abnormal smell test could still be infected and liable to spread the disease. Brief, low-cost, olfactory tests are available that would permit a high throughput in field stations and airports. A normal result might obviate the need for a nasopharyngeal swab for the Cov-2 virus.
在 COVID-19 大流行期间，很明显嗅觉和味觉（化学感觉）障碍在疾病的早期阶段非常常见。本文探讨了（i）为什么 COVID-19 专门针对嗅觉和味觉的模式，其机制是什么，（ii）嗅觉和味觉丧失的频率是多少，以及（iii）整体预后如何。有人认为口呼吸者可能特别容易感染 COVID-19。基于症状的问卷可能会低估化学感觉障碍的患病率，最多可达 50%。嗅觉丧失的患病率如此之高，以至于在正式测试中嗅觉正常的人不太可能被 Cov-2 严重感染。此外，无症状但嗅觉测试异常的人仍可能被感染并可能传播疾病。目前已经有简短、低成本的嗅觉测试，可在现场工作站和机场进行高通量检测。正常的结果可能可以避免对 Cov-2 病毒进行鼻咽拭子检测。
