The Incidence of Sudden Sensorineural Hearing Loss (SSNHL) in COVID-19 Patients in Tertiary Care Referral Units

COVID-19 is a new pandemic infectious disease that emerged in Wuhan, China, at the end of 2019. We aimed to evaluate the sudden sensorineural hearing loss (SSNHL) prevalence after COVID-19 infection or even vaccination. This is a two-center retrospective, observational cross-sectional study performed at tertiary care referral Audiovestibular Medicine Units at the period between August 1, 2020, and October 31, 2021. All SSNHL patients diagnosed in a period of a month with COVID-19 or vaccinated with a COVID-19 vaccine were included in this study. Fifty-three cases with confirmed COVID-19 and one patient vaccinated with a COVID-19 vaccine 1 week before, who reported sudden sensory neural hearing loss, were included in this study. Forty-eight patients had unilateral hearing loss and 6 patients had bilateral hearing loss. Forty-nine patients had typical COVID-19 symptoms; one patient discovered them after complaining of anosmia and ageusia and one patient after COVID-19 vaccination; and three patients were complaining only from hearing loss and had a PCR test for nasopharyngeal swabs to prove infection. Different degrees of SSNHL ranged from mild to severe and most of the patients had severe hearing loss. With more patients, COVID-19 may be a potential factor in sudden sensorineural hearing loss. It should be kept in mind that SSNHL may be the only indicator used to identify COVID-19 cases.

Predictive factors for recovery in idiopathic sudden sensory neural hearing loss

Background

Idiopathic sudden sensorineural hearing loss (ISSNHL) is considered a clinical symptom of various conditions. Circulatory disorders, viral infection, labyrinthine membrane rupture, and autoimmune reactions are considered as the common causes, but the exact cause remains unestablished. Various drugs and methods have been used empirically for the treatment of ISSHL. The current study aimed at evaluation factors contributing to the success of standardized medical therapy in cases of ISSNHL.

Methods

In period between 2019 and 2021, a total 40 patients with ISSNHL were enrolled. All patients were subjected to history taking, physical and ENT evaluation. Patients were managed according to the recent guidelines for managing ISSNHL included systemic steroid and salvage therapy.

Results

Mean age of studied patients was 42.55 ± 13.14 years with range between 19 and 70 years. Out of the studied patients; 26 (65%) patients were males and 14 (35%) patients were females. Majority (80%) of patients had no comorbidities. Based on the current study, we found that only 12 (30%) patients were improved while 28 (70%) patients were not improved. It was found that majority (58.3%) of improved patients was females. Frequency of vertigo was significantly higher among patients who were not improved. Three (10.7%) patients of not-improved group and 5 (41.7%) patients of improved group had low lymphocyte:monocytes ratio.

Conclusion

Patients with ISSNHL, the presence of vertigo and late onset of presentation may carry a risk for poor prognosis. Multiple centers studies with large number of patients are warranted to confirm such findings.

Effect of thymus extract on immunologic reactivity of chicken vaccinated with infectious bursal disease virus

The effects of crude thymus extract on the immune response and protection against challenge with virulent infectious bursal disease virus (IBDV) were studied in one-day-old chick. Oral administration of thymus extract (1 ml/kg) markedly and significantly increased the total protein, albumin, globulin, Tri-iodothyronine (T3), Thyroxine (T4) and the body weight gain in one-day-old chick. In addition, it increased the total lymphocytic count over four weeks after administration. Although vaccination also increased total protein, globulin, T4 and the total lymphocytic count but it significantly decreased the body weight gain of the chick and administration of thymus extract, before, during or after vaccination markedly improved the vaccination effectiveness with significant elevation of the globulin level and body weight gain of the chick. It also prevented the decrease in the relative weights of bursa, spleen and thyroid gland which commonly prevailed during vaccination. Chicken administered thymus extract and vaccinated with infectious bursal disease (IBD) vaccine showed 100% protection against challenge with IBDV. Meanwhile the vaccinated non-thymus treated group exhibited 80% protection against IBDV challenge. These results indicate a potentiating effect of thymus extract on the immune system in baby chick. These findings are supported by ELISA results that showed a marked increase in antibody titers in thymus treated groups. Additionally, microscopical examination of the bursa and the existent lymphoid hyperplasia in thymus treated groups but not vaccinated group support our findings.