SARS-CoV-2 Lurking in the Middle Ear

From the common rhinovirus to infamous coronavirus, respiratory viruses can trigger a cascade of ear complications, including acute otitis media (AOM). This roster includes syncytial virus, rhinovirus, adenovirus, coronavirus, bocavirus, influenza virus, parainfluenza virus, enterovirus, human metapneumovirus and SARS-Cov2. Moreover, Otitis media can often manifest as the initial sign of COVID-19 and be associated with hearing loss. Otitis media secretory is one of the most common ear complications after infection with the Omicron strain of SARS-CoV-2 virus, and the significantly higher incidence is associated with middle ear viral infection. Middle ear effusion SARS-CoV-2 virus antigen test detected the virus, which survived longer in the middle ear effusion than in the nasal cavity. The middle ear effusion test can detect SARS-CoV-2 virus antigen and determine whether the organism contains virus residue. 

Recent findings have unveiled a potentially alarming revelation - individuals diagnosed with otitis media with effusion (OME) post-COVID-19 may harbor traces of the virus within their middle ear. In this study, a striking 12.0% of middle ear effusion samples tested positive for SARS-CoV-2, hinting at the possibility of viral persistence and recurrence.

The study examined 23 patients, ranging from 32 to 84 years of age, who presented with OME following Omicron infection. 91.3% of these patients showcased unilateral symptoms, with fluid accumulation observed in 88.0% of ears. The median duration from infection to middle ear effusion sampling was 21 days, showcasing the potential for prolonged viral presence in this concealed reservoir.

Adding to the intrigue is the elusive nature of OME itself. Characterized by fluid accumulation in the middle ear sans acute infection, OME has long puzzled experts in otolaryngology and audiology. While bacterial infections and immunological responses have been implicated, the precise mechanisms remain veiled in mystery.

REFERENCES

Chengzhou Han, Huifang Wang, Ying Wang, Chao Hang, Yangyang Wang, Xiangming Meng, The silent reservoir? SARS-CoV-2 detection in the middle ear effusion of patients with Otitis media with effusion after omicron infection, American Journal of Otolaryngology, 2024, 104229, ISSN 0196-0709, https://doi.org/10.1016/j.amjoto.2024.104229. 

Zhang Y, Liu J, Yang F, He Y, Yan S, Bai Y, Zhang Z, Luan F. COVID-19-related secretory otitis media in the omicron era: a case series. Eur Arch Otorhinolaryngol. 2023 Oct;280(10):4697-4700. doi: 10.1007/s00405-023-08075-w. Epub 2023 Jun 21. PMID: 37341758.

Fan Y, Gao R, Shang Y, Tian X, Zhao Y, Chen X. Presence of SARS-CoV-2 in middle ear fluid and characterization of otitis media with effusion in patients with COVID-19. International Journal of Infectious Diseases. 2023 Nov 1;136:44-8.

Karimi-Galougahi M, Raad N, Ghorbani J, Mikaniki N, Haseli S. Otitis Media in COVID-19: A Case Series. Authorea Preprints. 2020 Jul 7.

Gene Therapy Rescues Childhood Deafness

Gene therapy, a revolutionary medical technique first conceptualized in the 1980s, has steadily advanced, offering new hope in treating various genetic disorders. This approach involves altering a person’s genetic makeup to combat diseases, representing a significant shift from traditional methods like drugs or surgery. 

Gene therapy faces challenges, including immune reactions, targeting errors, and the risk of new mutations. But in many cases benefits outweigh the risks.

A recent milestone in gene therapy has been its application in treating inherited hearing loss. The focus is on DFNB9, a form of deafness caused by mutations in the OTOF gene, responsible for producing otoferlin, a crucial protein in sound signal transmission. This leads to nonsyndromic Hearing Loss - a hearing loss that occurs with no other symptoms. A collaborative clinical trial between Chinese researchers and Mass Eye and Ear investigators has yielded remarkable results.

The trial involved six children with autosomal recessive deafness (DFNB9), all between one and seven years old. The gene therapy entailed injecting a functional OTOF gene using viral carriers into the inner ear. This process enabled the cells to produce otoferlin, thereby restoring hearing capabilities.

Over 26 weeks, five of the six children showed significant hearing improvements, with abilities ranging from understanding speech to verbalizing words, even holding phone conversations. 

This success paves the way for addressing other genetic forms of deafness involving genes like GJB2, MYO15A, TMC1, or SLC26A4. These genes play various roles in the inner ear's development and function, and researchers are diligently working to develop targeted gene therapies for these conditions.

Gene therapy, once a concept, is now transforming lives. As research continues, it holds the promise of curing not just deafness but a spectrum of genetic disorders, marking a new era in medical science.

REFERENCE

Qi J, Tan F, Zhang L, Lu L, Zhang S, Zhai Y, Lu Y, Qian X, Dong W, Zhou Y, Zhang Z, Yang X, Jiang L, Yu C, Liu J, Chen T, Wu L, Tan C, Sun S, Song H, Shu Y, Xu L, Gao X, Li H, Chai R. AAV‐Mediated Gene Therapy Restores Hearing in Patients with DFNB9 Deafness. Adv Sci (Weinh). 2024 Jan 8:e2306788. doi: 10.1002/advs.202306788. Epub ahead of print. PMID: 38189623.