London, Dec 21 (IANS): Christmas can be a difficult time for those who have lost their sense of smell and taste owing to Covid as almost a third of long Covid patients suffer persistent smell loss, with almost a fifth experiencing loss of taste, a new study has found.

Smell loss is one of the most prevalent symptoms of long Covid, according to a new study by the University of East Anglia (UEA) in the UK.

"Long Covid is a complex condition that develops during or after having Covid, and it is classified as such when symptoms continue for more than 12 weeks," said lead researcher professor Carl Philpott from UEA's Norwich Medical School.

The research team investigated the prevalence of long Covid, and particularly ear, nose and throat-related symptoms such as smell loss and parosmia - where people experience strange and often unpleasant smell distortions.

The symptoms include headache, myalgia, fatigue and loss of taste and smell. Parosmia can persist for months after initial infection, alongside brain fog and memory loss.

"We wanted to find out more about the prevalence of long Covid, and particularly ear, nose and throat-related symptoms such as smell loss and parosmia," said Philpott.

The team looked at results from the UK Coronavirus Infection Survey and analysed information from over 360,000 people in March 2022.

A total of 10,431 participants were identified as suffering from long Covid, and were asked about the presence of 23 individual symptoms and the impact of the condition on their day-to-day activities.

Self-reported long Covid was defined as symptoms persisting for more than four weeks after the first suspected coronavirus infection but not explained by another condition.

"We found that almost 3 per cent of the participants self-identified as having long Covid, and if we scale this up to reflect the UK population, it would equate to around 1.8 million people," said Philpott.

Fatigue was the most common symptom, whilst ENT-related symptoms included loss of smell and taste, vertigo, shortness of breath, wheezing and sore throat.

"Almost a third of self-reported long Covid patients were suffering persistent smell loss, and almost a fifth were still experiencing loss of taste," the researchers noted.

The research, published in 'International Forum of Allergy & Rhinology', was led by the University of East Anglia in collaboration with the charity 'Fifth Sense', which represents those with smell and taste disorders.