The emergence of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), the agent of novel coronavirus 2019 (COVID‐19), has kept the globe in disquiets due to its severe life‐threatening conditions. The most common symptoms of COVID‐19 are fever, sore throat, and shortness of breath. According to the anecdotal reports from the health care workers, it has been suggested that the virus could reach the brain and can cause anosmia, hyposmia, hypogeusia, and hypopsia. Once the SARS‐CoV‐2 has entered the central nervous system (CNS), it can either exit in an inactive form in the tissues or may lead to neuroinflammation. Here, we aim to discuss the chronic infection of the olfactory bulb region of the brain by SARS‐CoV‐2 and how this could affect the nearby residing neurons in the host. We further review the probable cellular mechanism and activation of the microglia 1 phenotype possibly leading to various neurodegenerative disorders. In conclusion, SARS‐CoV‐2 might probably infect the olfactory bulb neuron enervating the nasal epithelium accessing the CNS and might cause neurodegenerative diseases in the future.

中文翻译：

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COVID-19 和嗅觉功能障碍：一种可能与神经退行性疾病相关的方法。

严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 是 2019 年新型冠状病毒 (COVID-19) 的病原体，由于其严重威胁生命的情况，全球一直处于不安之中。COVID-19 最常见的症状是发烧、喉咙痛和呼吸急促。根据医护人员的轶事报道，有人认为该病毒可以到达大脑并导致嗅觉丧失、嗅觉减退、味觉减退和视力减退。一旦 SARS-CoV-2 进入中枢神经系统 (CNS)，它可以在组织中以非活性形式退出，或者可能导致神经炎症。在这里，我们旨在讨论 SARS-CoV-2 对大脑嗅球区域的慢性感染，以及这如何影响宿主体内附近的神经元。我们进一步回顾了可能导致各种神经退行性疾病的小胶质细胞 1 表型的可能细胞机制和激活。总之，SARS-CoV-2 可能会感染嗅球神经元，这些神经元会削弱进入中枢神经系统的鼻上皮细胞，并可能在未来引起神经退行性疾病。