Loss of smell may persist years after SARS-CoV-2 infection

October 17, 2025

"Nearly 80% of adults with a previous SARS-CoV-2 infection demonstrated a loss of smell up to 2 years later, according to a study published in JAMA Network Open. Hyposmia has been well-documented as a symptom of COVID-19, affecting 80% of people with original wild-type virus and the alpha variant and one-third of omicron variant cases, according to Leora I. Horwitz, MD, MHS, professor in the departments of population health and medicine at NYU Grossman School of Medicine and director of the Center for Healthcare Innovation and Delivery Science at NYU Langone Health, and colleagues.

This loss of smell can create numerous complications, such as not being able to detect gas leaks and smoke, and it has been associated with neurodegenerative disease, which prompted Horwitz and colleagues to evaluate olfactory function in a prospective cohort study.

...

The researchers evaluated data from 3,525 participants (mean age, 47.6 years; 72.4% women or intersex; 59.3% non-Hispanic white) of the NIH’s Researching COVID to Enhance Recovery (RECOVER) Adult study who completed the 40-item University of Pennsylvania Smell Identification Test (UPSIT) to measure olfactory function a mean 1.8 years after the date of their first SARS-CoV-2 infection or negative test result.

Overall, among adults with prior SARS-CoV-2 infection, more than half demonstrated abnormal hyposmia whether or not they self-reported a change or loss in taste/smell (79.8% vs. 66%). The rate of severe microsmia or anosmia was 23% among those with self-reported changes vs. 8.2% without."

(more)

Healio

https://www.healio.com/news/infectious-disease/20251017/loss-of-smell-may-persist-years-after-sarscov2-infection

Self-reported loss of or change in the sense of smell is a cardinal manifestation of SARS-CoV-2 infection, seen in approximately 80% of people with acute infection in the original and Alpha waves of the pandemic and one-third of patients following infection with Omicron variants. [emphasis added]

...

Loss of or change in smell and taste can persist for months or years^6,7 and has important consequences, including weight loss,⁸ reduction in social interaction and quality of life,^9,10 and safety risks of being unable to identify spoiled food, gas leaks, smoke, and other dangers.^9,11 Additionally, epidemiological studies have linked impaired olfaction to neurodegenerative diseases, many of which involve pathophysiological changes in the brain’s olfactory regions.^12,13 Decades of research have found that verified olfactory dysfunction is a strong early factor associated with neurodegenerative disease, often preceding diagnosis by years....

In this cohort study of 3525 participants undergoing formal testing of 40 different smells after SARS-CoV-2 infection using the UPSIT tool a mean of 1.8 years after index date, we found that self-reported change in or loss of smell or taste in this population accurately reflected olfactory dysfunction: 79.8% with self-reported change or loss had hyposmia on UPSIT. On average, participants with prior SARS-CoV-2 infection and self-reported change or loss had UPSIT scores at the 15th percentile for their age and sex. However, 66.0% of infected participants without self-reported change or loss also had abnormal UPSIT scores (as did 60.0% without prior infection and no self-reported change or loss), suggesting unrecognized olfactory loss is both common in the general population and more prevalent among those with prior infection. Abnormal UPSIT scores coincided with self-reported cognitive deficits. [emphasis added]

(more)

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2839325