Balaji SwaminathanAnnamali University, India
Title: Prevalence of asymptomatic hearing loss in COVID-19 before and during the SARS COV 2 vaccination
This main objective of this study is to measure the thresholds of pure-tone audiometry in COVID-19 PCR-positive cases before vaccination era and during vaccination era.
Methodology: 35 confirmed COVID-19 positive cases formed the test group and 35 healthy age and sex matched individuals formed the control group. Of these 20 cases and 20 controls were assessed during 2020, during which there was no vaccine available for COVID and 15 cases and 15 controls were assessed during 2021, which was the era of vaccination. Their age ranged between 20 and 50 years to avoid any age-related hearing affection. Patients with diabetes, hypertension, previous history of ear disease, prolonged exposure to loud noise and family history of deafness were excluded from the study. PTA was done for both the groups on day 7 and day 30 .Air conduction and Bone conduction were measured. The audiometric thresholds were measured using the modified Hughson-Westlake method.
Result: In our study conducted before the vaccination era, 9 out of 20 patients had significant high frequency hearing impairment.7 out of the 9 affected patients showed improvement upon further testing done on day 30. In our study conducted during the vaccination era, Pure tone audiometry done on day 7 and 14 in all the patients revealed normal hearing.
Conclusion: Two years into this Covid journey we have learnt a lot, symptoms of this mysterious virus keeps changing. Loss of smell and taste which was predominantly present previously is reducing now. The difference between our previous and present study can be attributed to the massive vaccination coverage among people. Although Vaccine-breakthrough infections occurs, the severity of the illness is greatly less in vaccinated group when compared to the unvaccinated group and the virulence of the virus is decreased when it is transmitted from a vaccinated person. Thus, in this study we are highlighting the importance of vaccination and its protectives effects in the audiovestibular system.