Study finds how long Covid causes smell loss for months, even years
Washington (PTI): Scientists have uncovered details about the reason behind loss of smell continuing as part of long Covid symptoms, according to a new study.
The reason some people fail to recover their sense of smell after COVID-19 is linked to an ongoing immune assault on olfactory nerve cells and an associated decline in the number of those cells, a team of scientists from Duke University, US, report.
Olfactory nerve cells are associated with our ability to distinguish scents and smells.
The findings, published in the journal Science Translational Medicine, provide an important insight into a vexing problem that has plagued millions who have not fully recovered their sense of smell after COVID-19, the study said.
While focusing on the loss smell, the findings also shed light on the possible underlying causes of other long COVID-19 symptoms - including generalized fatigue, shortness of breath, and brain fog - that might be triggered by similar biological mechanisms.
"One of the first symptoms that has typically been associated with COVID-19 infection is loss of smell," said senior author Bradley Goldstein, Duke University.
"Fortunately, many people who have an altered sense of smell during the acute phase of viral infection will recover smell within the next one to two weeks, but some do not," said Goldstein.
"We need to better understand why this subset of people will go on to have persistent smell loss for months to years after being infected with SARS-CoV-2," said Goldstein.
In the study, Goldstein and colleagues at Duke, Harvard and the University of California-San Diego analyzed olfactory epithelial samples collected from 24 biopsies, including nine patients suffering from long-term smell loss following COVID-19.
This biopsy-based approach revealed widespread infiltration of T-cells engaged in an inflammatory response in the olfactory epithelium, the tissue in the nose where smell nerve cells are located. This unique inflammation process persisted despite the absence of detectable SARS-CoV-2 levels, the study said.
Additionally, the number of olfactory sensory neurons were diminished, possibly due to damage of the delicate tissue from the ongoing inflammation, the study said.
"The findings are striking," said Goldstein. "It's almost resembling a sort of autoimmune-like process in the nose."
Goldstein said learning what sites are damaged and what cell types are involved is a key step toward beginning to design treatments. He said the researchers were encouraged that neurons appeared to maintain some ability to repair even after the long-term immune onslaught.
"We are hopeful that modulating the abnormal immune response or repair processes within the nose of these patients could help to at least partially restore a sense of smell," said Goldstein, noting that this work was currently underway in his lab.
He said the findings from this study could also inform additional research into other long-COVID-19 symptoms that might be undergoing similar inflammatory processes.
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Notice sent to SAU PhD student over Noam Chomsky's critique of PM; Sri Lankan scholar resigns
New Delhi: According to The Indian Express, a doctoral research proposal on the ethnography and politics of Kashmir, which referenced American linguist Noam Chomsky's criticism of the NDA government, has resulted in a show-cause notice for a PhD scholar and a disciplinary inquiry for his supervisor at South Asian University (SAU).
Days after the disciplinary inquiry was initiated, Sasanka Perera, a founding member of the Sociology department at SAU and a sociology professor, resigned from the varsity. The PhD scholar has since apologized to the university administration for any offense caused.
Perera, a cultural anthropologist with a Master's and a PhD from the University of California, Santa Barbara, held several positions at SAU, including Chairman of the Department of Sociology, Dean of the Faculty of Social Sciences, and Vice President. Prior to joining SAU, he spent 20 years at the University of Colombo, Sri Lanka, and was the Founding Chairman of the Colombo Institute for Advanced Study of Society and Culture.
SAU has denied that the PhD proposal triggered Perera's resignation but did not clarify what was objectionable in the proposal. According to university rules, a PhD student must seek approval from the supervisor, the Dean, and/or the Department Board of Studies before commencing fieldwork. The proposal in question was forwarded to the Dean after being approved by the supervisor, but only after a show-cause notice dated May 9 was issued to the student.
The letter pointed out that the cited video was a private YouTube video from 2021, uploaded in 2022 by the scholar. In the video, Chomsky spoke critically about the Modi government. Explanations were requested from the student and the supervisor for selecting that particular topic. The student responded with an apology and took down the video on May 15. An inquiry committee was subsequently formed to investigate the role of the supervisor and the motive behind the proposal.
Amidst all this, Perera submitted his resignation from the university. SAU, which is sponsored by eight SAARC countries and under the Ministry of External Affairs, recently appointed K K Aggarwal as its president after the post had remained vacant for four years.
Responding to questions from The Indian Express, SAU stated that disciplinary action was taken based on the SAARC Intergovernmental Agreement, Rules, Regulations, and Bye-Laws. The inquiry is still pending.
