How the nose can predict Covid-19

The coronavirus disease is now a reality for most Kenyans. As cases rise and public figures come forward with their diagnoses, it is slowly downing on people that Covid-19 is neither a myth nor an infection that can just be wished away.

The disease is no longer foreign. Since it is already circulating within communities, health experts are urging people to exercise caution and take personal responsibility to protect themselves and others from infection.

The recommended prevention strategies include frequent hand washing with soap and water, maintaining physical distance with people and wearing masks while in public.

For those that test positive for the disease, isolation is required and appropriate care, based on the Ministry of Health's recommended guidelines for home care or hospitalisation.

But since not all people can be tested for the disease due to financial and logistical constraints, health experts have been urging Kenyans to be on the look out for any Covid-19 symptoms they might have and isolate themselves, even as they wait for testing.

Major symptoms of Covid-19 include fever, cough and shortness of breath.

Most infected individuals usually report symptoms between two and 14 days after exposure to the virus.

Medical assistance is needed if individuals have trouble breathing, persistent pressure or pain in the chest, as well as confusion and inability to rouse. But for most people, recovery usually comes without medical care.

Aside from the above common symptoms, new research findings published in the Journal of Otolaryngology - Head & Neck Surgery shows that the nose may also hold clues for identifying Covid-19.

The study, which was conducted by researchers from the US-based University of Cincinnati and the Cantonal Hospital (Kantonsspital) Aarau in Switzerland, reveals that one of the clues is the sudden loss of smell. This is medically known as anosmia.

This loss of smell is not unique to the coronavirus disease. Most people often experience it while suffering from common colds, the flu or certain allergies.

For these individuals, the loss of smell is usually accompanied by nasal obstruction or mucus production that blocks the nose.

But in the case of Covid-19, researchers have found that the loss of smell occurs without any blockage symptoms.

"The coronavirus disease is associated with a fairly unique combination of nasal symptoms. The occurrence of sudden onset loss of smell without nasal obstruction is highly predictive of Covid-19 and should trigger the affected individual to immediately self-quarantine with presumptive Covid-19," says Dr Ahmad Sedaghat, the principal investigator of the study who is an associate professor in the University of Cincinnati College of Medicine and a physician doctor specialising in diseases of the nose and sinuses.

According to him, the loss of smell can occur at any time, once someone has been infected, but when it happens as an initial symptom, this can be particularly instructive.

"A sudden loss of one's sense of smell wouldn't trigger most people to think they have Covid-19. These individuals could continue business as usual and unknowingly spread the disease as carriers, especially since the guidelines for when to formally test for Covid-19 remain fluid in the setting of limited tests,” says Dr Sedaghat.

“But if someone experiences loss of smell without nasal obstruction, aside from quarantining, it would not be unreasonable to reach out to one's primary care physician about getting tested."

During the study, the researchers examined characteristics and symptoms of 103 patients who were diagnosed with Covid-19 over a six-week period at the Cantonal Hospital (Kantonsspital) Aarau in Switzerland.

Through telephone calls, the patients were asked how many days they had suffered from Covid-19 symptoms. They were also asked to describe the timing and severity of loss or reduced sense of smell, along with other symptoms.

According to the results, at least 61 percent of the patients reported reduced or lost sense of smell.

The more severe it was, the worse the other symptoms of Covid-19 - such as shortness of breath or cough- became. Most of the patients also experienced a loss of the sense of taste.

The findings of this study were in line with a previous one done by Ear, Nose and Threat doctors in France (Dominique Salmon and Alain Corré).

They assessed 55 patients who were suffering from a lost sense of smell without nasal obstruction. Ninety-four (94) percent ended up testing positive for Covid-19.

Dr Sedaghat notes that health experts are increasingly recognising the importance of the nasal cavity in determining how the disease affects the body.

The nasal cavity is the inside of the nose. It is lined with a mucous membrane that helps keep the nose moist through the production of mucus. Without the mucus, people would suffer from dry noses leading to nose bleeds.

Threatening complications

The inside of the nose also has little hairs that help filter the air people breathe in, hence blocking dirt and dust from getting into the lungs, which can lead to life threatening complications.

According to Dr Sedaghat, the nasal cavity is likely the major site of entry and infection by coronavirus since at least 90 percent of inhaled air enters the body through the nose. "Nasal virus production is at very high levels and tends to occur early in the disease process while patients are still asymptomatic or having very mild symptoms," he notes.

As such, Dr Sedaghat states that the coronavirus disease can be spread when the virus, if present in the body, is produced in the lining of the nose and then released into mucus.

"When someone sneezes, this mucus, which contains the virus, is aerosolised (released as droplets) outwards.

“Similarly, if someone wipes their nose and then touches surfaces without washing their hands first, that could lead to the spread of Covid-19," he explains.

Maintaining a physical distance (of about two metres) between individuals and wearing masks helps prevent infection through aerosols or droplets in the air.

Frequent hand washing with soap and water, use of alcohol-based hand sanitisers and disinfecting commonly touched areas can help prevent infection through contaminated surfaces.