London, Jan 20 : It is due to Covid-19 that a majority of patients with respiratory infections lose their sense of smell, claims a new study. According to a study, published in the journal Chemical Senses, the disease also often results in both the loss of taste and other senses in the mouth. "This emphasises how important it is to be aware of this symptom, as it may be the only symptom of the disease," said Alexander Wieck Fjaeldstad, Associate Professor at Aarhus University, who also stresses only around half of patients with a loss of smell have gotten their sense of smell back after 40 days. For the study, a total of 23 nationalities and over 4,500 Covid patients from all over the world have responded to the researchers' questionnaire. The findings showed that the average loss of the sense of smell was 79.7 on a scale from 0-100 -- which indicates a large to complete sensory loss, said the researcher. The loss of the sense of smell, the sense of taste was also significantly reduced, to 69.0 on a scale from 0-100, just as the remaining sense of feeling in the mouth was also reduced, this time to 37.3 on a scale from 0-100. "It shows that the loss of smell is specific to Covid-19, which is both relevant in relation to recognising the infection, and because it indicates that the sense of smell is closely linked to how SARS-CoV-2 infects the body," the researcher said. /IANS