[1] Zhao Y, Sun DL, Bouchard HC, et al. Coronavirus disease 2019 versus influenza a in children: an observational control study in China. Biomed Environ Sci, 2020; 33, 614−9.
[2] Ma Y, Zhu DS, Chen RB, et al. Association of overlapped and un-overlapped comorbidities with COVID-19 severity and treatment outcomes: a retrospective cohort study from nine provinces in China. Biomed Environ Sci, 2020; 33, 893−905.
[3] Ji YL, Wu Y, Qiu Z, et al. The pathogenesis and treatment of COVID-19: a system review. Biomed Environ Sci, 2021; 34, 50−60.
[4] Liu SH, Ma Y, Shi NN, et al. Qingfei Paidu decoction for COVID-19: a bibliometric analysis. Biomed Environ Sci, 2021; 34, 755−60.
[5] World Health Organization. Weekly operational update on COVID-19. World Health Organization. https://www.who.int/redirect-pages/page/novel-coronavirus-(covid-19)-situation-dashboard. [2021-11-19].
[6] Li ZJ, Chen QL, Feng LZ, et al. Active case finding with case management: the key to tackling the COVID-19 pandemic. Lancet, 2020; 396, 63−70. doi:  10.1016/S0140-6736(20)31278-2
[7] Huang CL, Wang YM, Li XW, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet, 2020; 395, 497−506. doi:  10.1016/S0140-6736(20)30183-5
[8] Eliezer M, Hautefort C, Hamel AL, et al. Sudden and complete olfactory loss of function as a possible symptom of COVID-19. JAMA Otolaryngol Head Neck Surg, 2020; 146, 674−5. doi:  10.1001/jamaoto.2020.0832
[9] Menni C, Valdes AM, Freidin MB, et al. Real-time tracking of self-reported symptoms to predict potential COVID-19. Nat Med, 2020; 26, 1037−40. doi:  10.1038/s41591-020-0916-2
[10] Centers for Disease Control and Prevention (CDC). Symptoms of coronavirus. CDC.https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html. [2021-05-18].
[11] World Health Organization (WHO). Coronavirus disease (COVID-19). WHO. https://www.who.int/health-topics/coronavirus#tab=tab_3. [2021-05-18].
[12] Yan CH, Faraji F, Prajapati DP, et al. Self-reported olfactory loss associates with outpatient clinical course in COVID-19. Int Forum Allergy Rhinol, 2020; 10, 821−31. doi:  10.1002/alr.22592
[13] Spinato G, Fabbris C, Polesel J, et al. Alterations in smell or taste in mildly symptomatic outpatients with SARS-CoV-2 Infection. JAMA, 2020; 323, 2089−90. doi:  10.1001/jama.2020.6771
[14] Lechien JR, Chiesa-Estomba CM, Hans S, et al. Loss of smell and taste in 2013 European patients with mild to moderate COVID-19. Ann Intern Med, 2020; 173, 672−5. doi:  10.7326/M20-2428
[15] Lechien JR, Chiesa-Estomba CM, De Siati DR, et al. Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): a multicenter European study. Eur Arch Otorhinolaryngol, 2020; 277, 2251−61. doi:  10.1007/s00405-020-05965-1
[16] Lee Y, Min P, Lee S, et al. Prevalence and duration of acute loss of smell or taste in COVID-19 patients. J Korean Med Sci, 2020; 35, e174. doi:  10.3346/jkms.2020.35.e174
[17] Mao L, Jin HJ, Wang MD, et al. Neurologic manifestations of hospitalized patients with coronavirus disease 2019 in Wuhan, China. JAMA Neurol, 2020; 77, 683−90. doi:  10.1001/jamaneurol.2020.1127
[18] Xydakis MS, Dehgani-Mobaraki P, Holbrook EH, et al. Smell and taste dysfunction in patients with COVID-19. Lancet Infect Dis, 2020; 20, 1015−6. doi:  10.1016/S1473-3099(20)30293-0
[19] Paderno A, Mattavelli D, Rampinelli V, et al. Olfactory and gustatory outcomes in COVID-19: a prospective evaluation in nonhospitalized subjects. Otolaryngol Head Neck Surg, 2020; 163, 1144−9. doi:  10.1177/0194599820939538
[20] Niklassen AS, Draf J, Huart C, et al. COVID-19: recovery from chemosensory dysfunction. a multicentre study on smell and taste. Laryngoscope, 2021; 131, 1095−100.
[21] Marshall M. COVID’s toll on smell and taste: what scientists do and don’t know. Nature, 2021; 589, 342−3. doi:  10.1038/d41586-021-00055-6
[22] Wan YM, Deng X, Tan EK. Olfactory dysfunction and COVID-19. Lancet Psychiat, 2020; 7, 663.
[23] China National Health Commission. Epidemic situation of China (up to January 17, 2021). http://www.nhc.gov.cn/xcs/yqfkdt/202101/8cb5929b31064955ba742815baf48f51.shtml. [2021-01-17].
[24] Shaanxi Provincial Health Commission. Health key news. http://sxwjw.shaanxi.gov.cn/sy/wjyw/index_8.html. [2021-01-17]. (In Chinese)
[25] China National Health Commission. Diagnosis and treatment guidelines for 2019 novel coronavirus pneumonia (Trial version 8). http://www.nhc.gov.cn/cms-search/downFiles/a449a3e2e2c94d9a856d5faea2ff0f94.pdf. (In Chinese)
[26] Coorperative Meta-Analysis Group of China Obesity Task Force. Predictive values of body mass index and waist circumference to risk factors of related diseases in Chinese adult population. Chin J Epidemiol, 2002; 23, 5−10. (In Chinese
[27] Lechien JR, Hsieh J, Barillari MR, et al. Patient-reported outcome questionnaires for the evaluation of olfactory and gustatory dysfunctions in COVID-19. Eur Arch Otorhinolaryngol, 2020; 277, 2393−4. doi:  10.1007/s00405-020-06083-8
[28] Lv H, Zhang W, Zhu ZY, et al. Prevalence and recovery time of olfactory and gustatory dysfunction in hospitalized patients with COVID-19 in Wuhan, China. Int J Infect Dis, 2020; 100, 507−12. doi:  10.1016/j.ijid.2020.09.039
[29] Carvalho-Schneider C, Laurent E, Lemaignen A, et al. Follow-up of adults with noncritical COVID-19 two months after symptom onset. Clin Microbiol Infect, 2021; 27, 258−63. doi:  10.1016/j.cmi.2020.09.052
[30] World Health Organization (WHO). Clinical Management of COVID-19. Geneva: WHO, 2020.
[31] Haehner A, Draf J, Dräger S, et al. Predictive value of sudden olfactory loss in the diagnosis of COVID-19. ORL J Otorhinolaryngol Relat Spec, 2020; 82, 175−80. doi:  10.1159/000509143
[32] Whitcroft KL, Hummel T. Olfactory dysfunction in COVID-19: diagnosis and management. JAMA, 2020; 323, 2512−4. doi:  10.1001/jama.2020.8391
[33] Sahoo PR, Sahu M, Surapaneni PS, et al. Evolution of olfactory and gustatory dysfunctions in COVID-19 patients in India. Eur Arch Otorhinolaryngol, 2021; 278, 2875−81. doi:  10.1007/s00405-020-06563-x
[34] Boscolo-Rizzo P, Borsetto D, Fabbris C, et al. Evolution of altered sense of smell or taste in patients with mildly symptomatic COVID-19. JAMA Otolaryngol Head Neck Surg, 2020; 146, 729−32. doi:  10.1001/jamaoto.2020.1379
[35] Nguyen NN, Hoang VT, Lagier JC, et al. Long-term persistence of olfactory and gustatory disorders in COVID-19 patients. Clin Microbiol Infect, 2021; 27, 931−2. doi:  10.1016/j.cmi.2020.12.021
[36] Oscolo-Rizzo P, Guida F, Polesel J, et al. Self-reported smell and taste recovery in coronavirus disease 2019 patients: a one-year prospective study. Eur Arch Otorhinolaryngol, 2021; 279, 515−20.
[37] Teaima AA, Salem OM, El Monem Teama MA, et al. Patterns and clinical outcomes of olfactory and gustatory disorders in six months: prospective study of 1031 COVID-19 patients. Am J Otolaryngol, 2022; 43, 103259. doi:  10.1016/j.amjoto.2021.103259
[38] Hopkins C, Surda P, Whitehead E, et al. Early recovery following new onset anosmia during the COVID-19 pandemic - an observational cohort study. J Otolaryngol Head Neck Surg, 2020; 49, 26. doi:  10.1186/s40463-020-00423-8
[39] Lechien JR, Journe F, Hans S, et al. Severity of anosmia as an early symptom of COVID-19 infection may predict lasting loss of smell. Front Med, 2020; 7, 582802. doi:  10.3389/fmed.2020.582802
[40] Petrocelli M, Cutrupi S, Salzano G, et al. Six-month smell and taste recovery rates in coronavirus disease 2019 patients: a prospective psychophysical study. J Laryngol Otol, 2021; 135, 436−41. doi:  10.1017/S002221512100116X
[41] Abdelalim AA, Mohamady AA, Elsayed RA, et al. Corticosteroid nasal spray for recovery of smell sensation in COVID-19 patients: a randomized controlled trial. Am J Otolaryngol, 2021; 42, 102884. doi:  10.1016/j.amjoto.2020.102884
[42] Brandão Neto D, Fornazieri MA, Dib C, et al. Chemosensory dysfunction in COVID-19: prevalences, recovery rates, and clinical associations on a large Brazilian sample. Otolaryngol Head Neck Surg, 2021; 164, 512−8. doi:  10.1177/0194599820954825
[43] Amer MA, Elsherif HS, Abdel-Hamid AS, et al. Early recovery patterns of olfactory disorders in COVID-19 patients; a clinical cohort study. Am J Otolaryngol, 2020; 41, 102725. doi:  10.1016/j.amjoto.2020.102725
[44] Bulğurcu S, Öztutgan T, Baz E, et al. Assessment of smell and taste disorders in COVID-19: a cross-sectional study. J Craniofac Surg, 2021; 32, e298−301. doi:  10.1097/SCS.0000000000007284
[45] Chary E, Carsuzaa F, Trijolet JP, et al. Prevalence and recovery from olfactory and gustatory dysfunctions in Covid-19 infection: a prospective multicenter study. Am J Rhinol Allergy, 2020; 34, 686−93. doi:  10.1177/1945892420930954
[46] Vaira LA, Hopkins C, Petrocelli M, et al. Efficacy of corticosteroid therapy in the treatment of long- lasting olfactory disorders in COVID-19 patients. Rhinology, 2021; 59(1), 21−5.
[47] Luers JC, Rokohl AC, Loreck N, et al. Olfactory and gustatory dysfunction in coronavirus disease 2019 (COVID-19). Clin Infect Dis, 2020; 71, 2262−4. doi:  10.1093/cid/ciaa525