Clinical Characteristics and Treatment of Anosmia and Ageusia Due to SARS-CoV2 Variants

Summary

The SARS-CoV-2 pandemic has consisted of multiple surges of infection because of continuous viral mutations. The WHO and CDC have defined the main SARS-CoV-2 variants based on international and national data for the circulation of SARS-CoV-2 into at least 4 waves. Studies from different parts of the world have demonstrated significant variations in the clinical manifestations of viral infection in relation to different SARS-CoV-2 variants. They also indicated that the current high levels of population immunity, due to prior infection and/or vaccination, have been associated with a vastly decreased overall risk of severe disease. Anosmia (with or without ageusia) was identified as a hallmark of COVID-19 early in the pandemic (ancestral Wuhan strain, alpha and delta variants), with a prevalence of \~60%. Prolonged olfactory disorders, lasting ≥6 months to years, has been reported in \~35-40% of infected individuals. However, studies reported that olfactory and gustatory disorders were less frequent with Omicron variants compared to pre-omicron variants. It has been indicated that SARS-CoV-2 can cause destruction, disorganization and molecular changes in the nasal olfactory neuroepithelium resulting in loss and distortion of the sense of smell. There are several trials to treat these persistent disorders but none has shown significant positive results except ours (Hamed et al., Expert Review of Clinical Pharmacology 2023;16(12):1261-1276 DOI: 10.1080/17512433.2023.2282715). Hamed et al. reported that cerebrolycin, a commercially available multimodal neurotropic factor, has the ability to cure at least 60% (100% complete and persistent recovery) of post-covid-19 persistent olfactory and gustatory dysfunctions. This drug is available in the market of at least 75 countries since 1996 and easily dispensed from local pharmacies after doctors prescriptions. It is used for treatment of many disorders of the central and peripheral nervous systems. This could be due to its ability to promote neurogenesis and remodeling of olfactory and gustatory neurons.

Timeline

Start

2021-08-30

Primary completion

2024-04-30

Completion

2024-05-30

Publications

• Results Hamed SA, Ahmed MAA. The effectiveness of cerebrolysin, a multi-modal neurotrophic factor, for treatment of post-covid-19 persistent olfactory, gustatory and trigeminal chemosensory dysfunctions: a randomized clinical trial. Expert Rev Clin Pharmacol. 2023 Jul-Dec;16(12):1261-1276. doi: 10.1080/17512433.2023.2282715. Epub 2023 Dec 9.
• Results Hamed SA. Post-COVID-19 persistent olfactory, gustatory, and trigeminal chemosensory disorders: definitions, mechanisms, and potential treatments. World J Otorhinolaryngol. 2023;10(2):4-22. doi: 10.5319/wjo.v10.i2.448
• Results Taquet M, Sillett R, Zhu L, Mendel J, Camplisson I, Dercon Q, Harrison PJ. Neurological and psychiatric risk trajectories after SARS-CoV-2 infection: an analysis of 2-year retrospective cohort studies including 1 284 437 patients. Lancet Psychiatry. 2022 Oct;9(10):815-827. doi: 10.1016/S2215-0366(22)00260-7. Epub 2022 Aug 17.
• Results Yau JWK, Lee MYK, Lim EQY, Tan JYJ, Tan KBJC, Chua RSB. Genesis, evolution and effectiveness of Singapore's national sorting logic and home recovery policies in handling the COVID-19 Delta and Omicron waves. Lancet Reg Health West Pac. 2023 Jun;35:100719. doi: 10.1016/j.lanwpc.2023.100719. Epub 2023 Mar 2.
• Results Micheletti C, Medori MC, Dhuli K, Maltese PE, Cecchin S, Bonetti G, Fioretti F, Assoni L, Calzoni A, Praderio A, De Angelis MG, Donato K, Arabia G, Lorusso L, Manganotti P, Capelli E, Marceddu G, Bertelli M, Nodari S. Linking pathogenic and likely pathogenic gene variants to long-COVID symptoms. Eur Rev Med Pharmacol Sci. 2023 Dec;27(6 Suppl):20-32. doi: 10.26355/eurrev_202312_34686.
• Results Velavan TP, Ntoumi F, Kremsner PG, Lee SS, Meyer CG. Emergence and geographic dominance of Omicron subvariants XBB/XBB.1.5 and BF.7 - the public health challenges. Int J Infect Dis. 2023 Mar;128:307-309. doi: 10.1016/j.ijid.2023.01.024. Epub 2023 Jan 19. No abstract available.
• Results Hamed SA, Kamal-Eldeen EB, Ahmed MAA. Evaluation of children and adults with post-COVID-19 persistent smell, taste and trigeminal chemosensory disorders: A hospital based study. World J Clin Pediatr. 2023 Jun 9;12(3):133-150. doi: 10.5409/wjcp.v12.i3.133. eCollection 2023 Jun 9.

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