New research has revealed the extent of sensory loss among people suffering from long Covid, with around 30% reporting a decreased sense of smell, and a similar number finding their sense of taste continuing to be affected 12 weeks or more after the initial infection. The research has been published in the journal Frontiers in Medicine.

Researchers from Anglia Ruskin University (ARU) analysed data from 14 separate studies exploring the prevalence of persistent anosmia (full loss of smell), hyposmia (decreased sense of smell), ageusia (loss of sense of taste), and hypogeusia (reduced sense of taste), as well as vision and hearing-related long Covid symptoms.

Among the 4,702 people with long Covid included within the study, 31.2% reported suffering from reduced sense of taste and 29.9% reported decreased sense of smell at least 12 weeks after first being infected. In addition, 12.2% reported full loss of smell and 11.7% encountered full loss of taste.

Several people reported other symptoms affecting the eyes or ears, such as tinnitus, blurred vision or dry eyes.

Long Covid affects somewhere between 13% and 15% of people who test positive for Covid-19, and is defined as symptoms lasting for longer than 12 weeks post-infection. At the time of the last estimate by the Office of National Statistics, around two million people in the UK were believed to have long Covid.

Senior author Professor Shahina Pardhan, Director of the Vision and Eye Research Institute (VERI) at ARU, said: "Persistent changes in taste and smell have manifested as symptoms of long Covid. These are generally associated with decreases in quality of life, so it is vital that we understand these changes in patients' smell and taste to help medical professionals advise or manage patients appropriately.

"Our results also show an elevated prevalence of persistent blurred vision and hearing-related symptoms after three months. Future research is required to understand why this is the case and so that healthcare providers can provide the right kind of care for people suffering from various sensory losses due to Covid-19."

Lead author Dr Mike Trott, Visiting Fellow at ARU, said: ''Knowing the prevalence of changes in sensory symptoms post-Covid is essential to aiding our understanding of the pathophysiology of the disease, especially as our understanding of long Covid is in its infancy."