新冠后遗症？还能恢复吗？

When will the sense of taste and smell lost due to the SARS-CoV-2 be restored？

因新冠而失去的味觉和嗅觉何时能恢复？

1

Part1 According to the survey

调查数据显示

According to the results of several questionnaires, fever, cough, and body aches were themost common symptoms in most patients after contracting SARS-CoV-2, and nearly 30% ofrespondents had a brief loss of taste and smell. Afterwards, most of those who recoveredfrom SARS-CoV-2 found that their sense of smell returned within a few weeks (18-21 days),and about 5% had not regained their sense of smell at least up to 6 months after their firstinfection.

根据多项调查问卷结果显示，大部分患者在感染新冠病毒之后，发烧、咳嗽、浑身酸痛等症状最常见，近三成受访者的味觉与嗅觉短暂消失。之后，大多数从新冠肺炎中康复的人发现他们的嗅觉在几周内（18-21天）就会恢复，约5％在首次感染至少长达6个月后还没有恢复嗅觉。

In addition, about 96% reported no aftereffects were found, and of the six individuals whogave feedback on the presence of aftereffects, four reported that their sense of taste wasaffected, such as loss of taste and sensitivity, and others reported weakness, sore throat, dryeyes, forgetfulness, or decreased motor skills.

此外，约96％的人表示没有发现后遗症，在反馈存在后遗症的6个人中，有4人表示味觉受影响，比如味觉减退、敏感度下降，还有人表示出现乏力、咽痛、眼干、健忘或运动能力下降的现象。

Deeper survey data suggests that 12% of people over the age of 40 will have an olfactorydeficit by 2020. This means that diminished or lost sense of smell will be more likely tooccur in older age groups.

更深层次的调查数据表明，在2020年之前，在40岁以上的人群中有12％的人存在嗅觉缺陷。这意味着嗅觉减退或丧失会更容易出现在年龄更大的人群中。

International survey data show that about 41% of patients with SARS-CoV-2 have alteredsense of smell or taste, with the prevalence of olfactory or taste impairment in Chinese, German and French patients at 32%,69% and 49%, respectively.

国际调查数据显示，有嗅觉或味觉改变的新冠患者约占41％，其中中国、德国和法国患者嗅觉或味觉障碍的发病率分别为32％、69％和49％。

Among those who already suffer from SARS-CoV-2-induced olfactory loss, perhaps 1 in 20 will never regain their sense of smell. This shows that we must take this problem of olfactoryloss seriously.

在那些已经患有新冠肺炎诱导的嗅觉丧失的人中，每20人中或许就有1人永远不会恢复嗅觉。这表明，我们必须对嗅觉丧失的这一问题提起重视。

2

Part2 How SARS-CoV-2 stole

our sense of smell?

嗅觉丧失的可能原因

As far as the current study is concerned, the altered olfactory and gustatory functions ofpatients are due to neurological invasion by the SARS-CoV-2.

就目前的研究来看，患者嗅觉和味觉功能改变是由于新冠病毒入侵了神经系统。

Scientists have confirmed that Angiotensin-Converting Enzyme 2 (ACE2 receptor) may bethe key factor. For neurons in the nose, which do not have the type of receptor used bySARS-CoV-2 to infect cells - ACE2 receptors - and therefore are not normally infected. Incontrast, ACE2 receptors are present in taste bud cells, where people taste food, as well as insalivary glands, and when the virus invades the taste bud cells, it may cause a loss of tastesensation. Or when the virus spreads from the pharyngeal region to the middle ear and affectsthe tympanic cord nerve, it can also lead to taste disorders. The diastolic cells surroundingolfactory sensory neurons in the olfactory epithelium are also filled with ACE2 receptors.These diastolic cells are also called support cells, and the new coronavirus can directly attackthe support cells surrounding olfactory sensory neurons thus causing infection, damage oreven death of these cells.

科学家证实，血管紧张素转换酶2（ACE2受体）或许是关键因素。对于鼻子中的神经元来说，其中没有SARS-CoV-2用于感染细胞的受体类型-ACE2受体，因此通常不会被感染。而人品尝食物味道的味蕾细胞以及唾液腺中都有ACE2受体，当病毒入侵味蕾细胞后，就有可能导致味觉失灵。或者当病毒从咽喉区域扩散到中耳，影响到鼓膜索神经时，也会导致味觉障碍。而围绕嗅觉上皮嗅觉传感神经元的舒张细胞也充满了ACE2新冠后遗症？还能恢复吗？

How do these support cells affect olfactory sensory neurons and cause loss of smell? Wheninfected with SARS-CoV-2, they are in the acute phase of infection, which producesmolecules that activate the inflammatory response against the virus, and these molecules alsoenter the olfactory receptor neurons, thus altering the distribution of genes in them. Thisalteration results in the inability to synthesize proteins in many olfactory sensory neurons. Inthe short term, the protein deficiency prevents neurons from detecting odors and affectsneuronal transmission of odors.

而这些支持细胞是如何影响嗅觉感受神经元从而导致嗅觉丧失的呢？当感染新冠后，此时它们正处于急性感染期，由此产生分子激活炎症反应来对抗病毒，而这些分子也会进入到嗅觉感受神经元，从而改变其中的基因分布形式。这种改变导致许多嗅觉感受神经元的蛋白质无法合成。在短期内，蛋白质缺乏会阻止神经元检测气味，并影响神经元传递气味。

Additional studies suggest that olfactory failure may also be associated with TransmembraneSerine Protease 2 (TMPRSS2). ACE2 primarily expresses the host cell receptor for SARS-CoV-2, and TMPRSS2 expresses surface proteases that mediate the entry of SARS-CoV-2into cells. They are highly expressed in a variety of olfactory epithelial cell types, facilitatingviral entry into the cells and attacking the olfactory system, and leading to inflammation,resulting in impaired olfaction in humans.

更多研究指出，嗅觉失灵或许也与跨膜丝氨酸蛋白酶2（TMPRSS2）有关。ACE2主要表达新冠病毒的宿主细胞受体，TMPRSS2表达介导新冠病毒进入细胞的表面蛋白酶。它们在多种嗅觉上皮细胞类型中高度表达，促进病毒进入细胞而对嗅觉系统进行攻击，并引起炎症，从而导致人体嗅觉出现障碍。

It has also been speculated that patients with a genetic variant on chromosome 4 are 11%more likely to lose their sense of smell or taste. People who are highly sensitive to smell ortaste and those with Alzheimer's disease are also more likely to suffer from loss of smell. Inaddition, genetic changes acquired during the evolution of viruses can affect the impact onolfactory tissue. Tiny genes produce mutations thereby increasing the risk of peopledeveloping post-SARS-CoV-2 myxoma, perhaps because it makes the virus more adept atinfecting the supporting cells in the nasal cavity.

也有研究猜测，其患者4号染色体上发生基因变异使人失去嗅觉或味觉的可能性要高出11％。对于嗅觉或味觉高度敏感的人和阿尔茨海默病患者也更易遭受嗅觉丧失。此外，病毒进化过程中获得的遗传变化，也会影响对嗅觉组织的影响。其微小的基因产生突变从而增加了人们患新冠肺炎后肌瘤的风险，也许是因为它使病毒更擅长感染鼻腔中的支持细胞。

(EXPANSION: In addition, a variety offactors including the common cold orinfluenza virus, viral, bacterial orfungal infections of the upperrespiratory tract, head trauma, nasalpolyps, and neurodegenerative diseasessuch as Alzheimer's can reducepeople's ability to smell or even causepermanent loss of the sense of smell.Olfactory failure may also be caused byexposure to toxic chemicals, certaindrugs, or injury to the nose or to areasof the brain that process and interpretodor information. (People with specificvariants in genes associated with odormetabolism are particularly susceptibleto loss of smell due to SARS-CoV-2.)

（扩展：此外，多种因素包括普通感冒或流感病毒、上呼吸道感染的病毒、细菌或真菌感染、头部创伤、鼻息肉、神经退行性疾病（例如阿尔兹海默症），都会降低人们的嗅觉能力甚至造成嗅觉永久丧失。也可能由接触有毒化学品、某些药物或鼻子或处理和解释气味信息的大脑区域受伤而引起嗅觉失灵。（另外，与气味代谢相关的基因特殊变异的人特别容易因新冠病毒而失去嗅觉。）

As the SARS-CoV-2 epidemic develops further, scientists are conducting further in-depthresearch into the causes of the loss of smell due to SARS-CoV-2.

随着新冠疫情进一步发展，科学家们对新冠病毒而导致的嗅觉丧失的原因正在进行进一步的深层研究。

3

Part3 Current status

现阶段状况

From the original strain at the beginning to the currently circulating Omicron variant, the rateof developing olfactory and gustatory disturbances has decreased from about 70% to 17%.The Omicron mutant strain is highly infectious and has multiple new mutations on itsstinging proteins that may make it less likely to enter the nasal mucosal barrier and thusthreaten the supporting cells in the nose, thus easily breaking through at the first respiratorytissues it encounters, such as the human throat, making sore throat the first noticeablesymptom of the new crown infection today.

从起初的原始毒株，至当下流传的奥密克戎变异株，出现嗅觉和味觉障碍的比例从70％左右降至了17％。奥密克戎变异株具有高传染性，其刺突蛋白上的多种新突变，可能会让其更不容易进入鼻腔黏膜屏障进而威胁鼻子中的支持细胞，因此很容易在其遇到的第一个呼吸道组织处攻破防线，例如人的咽喉，因此咽喉痛成为当下感染新冠后最先出现的明显症状。

4

Part4 Can the sense of smell

be restored?

嗅觉还能恢复吗？

The slow recovery of smell, and the loss of smell associated with SARS-CoV-2 may last forseveral months, is due to the time needed for olfactory neurons to regenerate from the stemcell supply in the nasal lining.

嗅觉恢复缓慢，与新冠病毒相关的嗅觉丧失可能会持续数月，是因为嗅觉神经元需要时间从鼻腔内壁的干细胞供应中再生。

According to research studies, most patients will regain their sense of smell or taste, and onlya very small percentage of patients will experience long-term loss of smell or taste. In thissmall percentage of patients, the study indicates that recovery is lower in women than in menand that the presence of nasal congestion or more severe symptoms can lead to a slowrecovery.Abnormal function of some classes of immune cells such as Centrosome and Tcells may also affect the recovery of smell. These T cells produce inflammation and thusprevent full recovery in people with long-term olfactory problems after post-SARS-CoV-2pneumonia.

根据研究调查显示，大部分患者会恢复嗅觉或味觉，只有极少部分的患者会经历长期的嗅觉或味觉丧失。在这极少部分患者中，研究表示女性的恢复比例比男性低，且出现鼻塞或更严重症状也会导致恢复缓慢。一些免疫细胞例如中心粒细胞、T细胞中一些类群的功能异常，也可能会影响嗅觉恢复。这些T细胞产生炎症从而阻止新冠肺炎后长期嗅觉问题的人完全康复。

5

Part5

How to bring back the sense of smell?

嗅觉恢复的治疗方案

Currently, researchers say many of the treatments being investigated are aimed at promotingneuronal regeneration and calming inflammation. Scientists are investigating a number oftherapies that promote cell regeneration, and some studies are testing whether injections ofplatelet-rich plasma, vitamin A, can help restore olfactory neurons. In addition, someelectrical stimulation of the sense of smell, or training, show that this is helpful in post-viralolfactory loss, in post-traumatic olfactory loss, and possibly also in ageing.

目前，研究人员表示，目前正在调查的许多治疗方法旨在促进神经元的再生和镇定炎症。科学家们正在研究一些能促进细胞再生的疗法，还有一些研究正在测试注射富血小板的血浆、维生素A是否能帮助恢复嗅觉神经元。此外，对嗅觉进行一些电刺激，或者训练，这些行为会对病毒后嗅觉丧失、创伤后嗅觉丧失的恢复有帮助，可能也有助于缓解衰老。

Scientists have also found that omega-3 fatty acids can help restore the sense of smell inthose who have lost it after undergoing surgery with instruments through the nose. An anti-nodular inflammatory drug known as a JAKinhibitor - an enzyme that targets the Janusfamily of kinases to prevent communication through pro-inflammatory signaling molecules -could help calm the immune response to the nose and is now considered to have considerablepotential.

科学家们还发现，omega-3脂肪酸可以帮助那些在接受仪器通过鼻子的手术后失去嗅觉的人恢复。一种被称为JAK抑制剂的抗节炎药物-针对Janus激酶家族的酶，以防止通过促炎信号分子进行沟通-可以帮助平息鼻子的免疫反应，目前被认为有相当的潜力

6

Part6 Beware

提醒和注意

For some patients after the infection blindly take drugs, experts have made recommendations.Do not take a variety of cold medicines together, it is best to read the instructions carefullywhen taking the medicine to check whether the active ingredients, especially acetaminophen,are repeated; also do not eat cold medicines containing acetaminophen ingredients, but alsotake antipyretics; the same effect such as antipyretics only take one kind of medicine, it is notrecommended to alternate acetaminophen and ibuprofen.

对于部分患者感染后盲目乱服药的现象，专家们进行了建议。不要多种感冒药一起吃，吃药时最好认真阅读说明书，查看有效成分尤其是对乙酰氨基酚是否重复；也不要吃了含对乙酰氨基酚成分的感冒药后，还吃退烧药；同一功效比如退烧的药只吃一种，不建议交替吃对乙酰氨基酚和布洛芬。

For some specific susceptible people who suffer from new crown sequelae such as loss ofsense of smell, early intervention and treatment are required. Some active olfactory trainingcan be done in the early stage, do not wait until after full recovery, which makes the recoveryof smell more likely.

对于一些特定的易感人群，若遭受嗅觉丧失等新冠后遗症，要尽早进行干预和治疗。在早期可积极进行一些嗅觉训练，不要等到完全康复之后，这使嗅觉恢复的可能性更大。

Because diminished or lost sense of smell will be more likely to appear in older people,therefore for some middle-aged and elderly people, they should actively pay attention to theirhealth status, seek help from their neighbors, and get appropriate treatment at an early stage.

因为嗅觉减退或丧失会更容易出现在年龄更大的人群中，故此对于一些中老年人要积极关注自身健康状况，积极向周边人寻求帮助，在早期进行相应的治疗。

If some people have underlying diseases and other related diseases, they should try to avoidinfection or secondary infection. People should be fully aware of the seriousness of thesequelae of the new crown and avoid taking it lightly, which may pose a threat to their health.

若部分人群存在基础病等相关疾病，则尽量避免感染或二次感染。人民要充分认识到新冠后遗症的严重性，避免存在轻视的态度而对自身健康产生威胁。

Wish you a speedy recovery

and good health!

祝“小阳人们”早日康复，健健康康！

7

Reference

Persistent post–COVID-19 smell loss is associated with immune cell infiltration andaltered gene expression in olfactory epitheliumhttps://www.science.org/doi/10.1126/scitranslmed.add0484

How to bring back the sense of smell

https://www.nature.com/articles/d41586-022-01628-9

The science behind COVID’s assault on smell

https://www.nature.com/articles/d41586-022-01627-w

How COVID-19 stole our sense of smell

https://cen.acs.org/articles/100/i34/COVID-19-stole-sense-smell.html

打赏