NEW RESEARCH HAS suggested that the virus responsible for Covid-19 could be entering the body by targeting a specific part of the nose which allows people to smell.

The study, published today in the European Respiratory Journal, may also offer clues as to why Covid-19 is so infectious and suggests that targeting this part of the body could offer more effective treatments for the coronavirus.

Its findings may also show why so many people who contract Covid-19 lose their sense of smell, but show no other symptoms of the virus.

The team used tissue samples from the back of the nose of 23 patients, removed during surgical procedures for other conditions, as well as biopsies from windpipe of seven patients. None of the patients had been diagnosed with the coronavirus.

In the lab, the researchers detected the presence of angiotensin converting enzyme II (ACE2) on the samples.

This enzyme is thought to be the ‘entry point’ that allows Covid-19 to get into the cells of the body and cause an infection.

They found levels of ACE2 between 200 and 700 times more on the olfactory epithelium, the area at the back of the nose where the body detects smells, than on other tissue in the nose and windpipe.

Dr Mengfei Chen, a research associate at Johns Hopkins University School of Medicinein the US, explained that the study allowed researchers to see that the levels of ACE2 were highest in the part of the nose that enables people to smell.

“These results suggest that this area of the nose could be where the coronavirus is gaining entry to the body,” he said.

“The olfactory epithelium is quite an easy part of the body for a virus to reach. It’s not buried away deep in our body, and the very high levels of ACE2 that we found there might explain why it’s so easy to catch Covid-19.”

Common respiratory infections, such as coughs and colds, can make people temporarily lose our sense of smell alongside a blocked nose or a sore throat.

However, other research has shown that Covid-19 is unusual in that being unable to smell can be the only symptom.

This latest study could suggest why so many people with Covid-19 lose their sense of smell, even when they have no other symptoms.

The study’s director Professor Andrew Lane, also of Johns Hopkins University School of Medicine, explained that it suggests that the part of the nose responsible for smelling could also be the place where the coronavirus gains a foothold in the body. 

“This finding will need to be confirmed, but it offers possible new avenues for treating the infection,” he said.

Lane added that the research still needed to be confirmed, but that the team will carry out more experiments to see whether the virus is using these cells to access and infect the body.

“If that’s the case, we may be able to tackle the infection with antiviral therapies delivered directly though the nose,” he said.