Doctors Still Are Not Sure Why COVID-19 Is Causing Hearing Loss

COVID-19 is the deadliest virus humanity has ever seen. It started in Wuhan and has spread to over 200 countries around the world. It has killed around 80,000 people all over. There is no permanent cure or vaccine for corona infection. The scientists say that the virus will remain over 2years before its strength gradually decreases. The studies also show that the virus is evolving, which makes it more powerful and difficult to control.

Hearing loss

The Symptoms during a Coronavirus Infection

Many symptoms like runny nose, headache, sore throat, which changes to fever, breathing problems, which can later turn to pneumonia and can also cause death. Even though the patient gets free from the virus, the COVID-19 viruses can be there in the body for a long time. It can also cause some long term effects in the body of the patient. Researchers say that COVID-19 can cause adverse effects on both mental and physical problems on people.

The Post Cure Effects of Coronavirus Infection

Short term

The after-effects of coronavirus can be numerous.  The patients recovered from the COVID-19 viruses can have health issues like lingering hair loss, hearing problems, memory loss, pains, aches, stress, depression, heart problems, etc. In old age people, it can also cause Alzheimer’s, dementia, etc.

Scientists all over the world are still trying to figure out how the virus acts, how it spreads and causes these long term effects. COVID-19 is not just a cold or flu, but it can cause great damage to the body, mainly for the respiratory system. It can cause problems for people of all ages in different degrees. It will affect some more strongly than the other.

Long term

One of the most commonly reported long term effects of COVID-19 is fatigue. It causes a problem called myalgic encephalomyelitis chronic fatigue syndrome. This can last for over six months and include problems like extreme tiredness, joint or muscle weakness, and pain, fever, etc.

This fatigue worsens with more activities and will not decrease with rest. These long term effects can last for weeks, and even months, even after the patient tested negative for the viral infection. Some can even experience loss of smell and confusion since the virus affects the neural system, which affects the brain functions. These can also permanently damage the body.

Can COVID-19 cause hearing loss?

The first case of hearing loss due to COVID-19 was reported by the American Journal of Otolaryngology. And another case was reported in Thailand. When they tested 82 cases, an old female showed hearing loss due to the infection. Even though her respiratory problems were treated completely, the loss of hearing persisted.

Discovery of hearing loss

The doctors’ stats that it may be due to the neuro – auditory problem developed by the virus in the patient. It can happen since the COVID-19 can affect the neurological system. But hearing loss due to COVID-19 is not yet confirmed and has never been reported in the literature till now. The scientists are continuously working on it. And as per this article, the virus can travel through the blood. Our brain contains a lot of receptors called ACE2 receptors; the SARS-CoV-2 can use the cell surface protein to enter healthy cells. The part of the brain which controls hearing also contains these receptors, so the virus can attack this and can cause hearing impairment.

The study

In other tests conducted among 20 people, the people who did not even have the symptoms of COVID – 19 found their hearing ability worsened based on results in multiple auditory tests. In these people, the age was around 20 to 50 years old and did not have any hearing problems before.

The current study results show that the COVID-19 infection has some adverse effects on the hair cells in the cochlea. The cochlea is a spiral-shaped bone present in the inner ear. It helps in hearing. Even though there will not be any major symptoms, the good functioning of the cochlea is not guaranteed.

In another study done in Iran, COVID-19 patients age 22 to 45 are examined. They had only mild symptoms of fever, cold, cough, etc. did not have any hearing problems. After confirming the infection of COVID -19, they showed some problems with hearing. They showed problems like tinnitus, which cause noise in the ears; some had vertigo, which is the loss of balance. And all had mild hearing loss.

The scientists say that there is a high chance that these otologic symptoms are directly related to COVID-19. According to the research, the doctors say that there are patients who did not have any hearing problems, but after the infection showed some of the symptoms.

An autopsy study published by JAMA Otolaryngology-Head and Neck Surgery has seen the genetic material of SARS – CoV – 2 in the middle ear and mastoid of the deceased patient. The study by the European Archives of Oto – Rhino – Laryngology also states that some of the infected persons showed tinnitus and other ear problems.

The coronaviruses like SARS – CoV – 1 and MERS – CoV does not have any reported case of hearing loss. But whenever there is a virus infection, the loss of balance or hearing loss can happen. It is a familiar phenomenon. The virus can get into the inner ear and can cause damage-causing sudden hearing loss, or balance problems. Based on the studies, the condition of hearing loss can happen in mild or symptomless COVID-19 cases.

The scientists suggest that the SARS – CoV – 2 VIRUS neuro invasiveness can also target the auditory centers of the brain, such as the temporal lobe (based on brain imaging studies) or brain stem. The autopsy study showed the presence of SARS – CoV -2 virus in the brain stem. This hearing loss appears in younger people who do not have any issues. This hearing impairment is generally mild and often does not lead to deafness. How long this hearing impairment can last are not yet understood. And if the virus continues to persist, this hearing loss can also become permanent.

Conclusion

Most of this hearing loss is viral, and patients are treated with steroids. And the studies show that patients with a mild degree of hearing loss usually recover. There is also the effect of drugs used in the treatment of COVID-19 that can contribute to these hearing problems. Some of the drugs can have Ototoxicity as a side effect, which means that it is toxic to the ear.

Some of these drugs are AZITHROMYCIN, FAVIPIRAVIR, and LOPINAVIR, etc., cause tinnitus. The Ototoxicity of these drugs depends on the dose and duration of the drug used. The problems surface post weeks or months of drug usage.

There are other suggestions like virus invasion, or virus-induced hypoxia, which causes not enough oxygen in the blood can also be a cause for the hearing problem because of COVID-19. It is to be considered that like other viruses like HSV and VZV, SARS – CoV – 2 can also target the inner ear.

And the cochlear hair is highly metabolic active and is vulnerable to hypoxic and ischemic damage. Viruses like measles, mumps, meningitis, etc. can cause hear loss. And the COVID-19 viruses can damage the nerves that carry information from and to the brain.